/*
   Copyright (C) 1999-2006 Id Software, Inc. and contributors.
   For a list of contributors, see the accompanying CONTRIBUTORS file.

   This file is part of GtkRadiant.

   GtkRadiant is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   GtkRadiant is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with GtkRadiant; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#pragma once

/// \file
/// \brief The brush primitive.
///
/// A collection of planes that define a convex polyhedron.
/// The Boundary-Representation of this primitive is a manifold polygonal mesh.
/// Each face polygon is represented by a list of vertices in a \c Winding.
/// Each vertex is associated with another face that is adjacent to the edge
/// formed by itself and the next vertex in the winding. This information can
/// be used to find edge-pairs and vertex-rings.


#include "debugging/debugging.h"

#include "itexdef.h"
#include "iundo.h"
#include "iselection.h"
#include "irender.h"
#include "imap.h"
#include "ibrush.h"
#include "igl.h"
#include "ifilter.h"
#include "nameable.h"
#include "moduleobserver.h"

#include <set>

#include "cullable.h"
#include "renderable.h"
#include "selectable.h"
#include "editable.h"
#include "mapfile.h"

#include "math/frustum.h"
#include "selectionlib.h"
#include "render.h"
#include "texturelib.h"
#include "container/container.h"
#include "generic/bitfield.h"
#include "signal/signalfwd.h"

#include "winding.h"
#include "brush_primit.h"

const unsigned int BRUSH_DETAIL_FLAG = 27;
const unsigned int BRUSH_DETAIL_MASK = ( 1 << BRUSH_DETAIL_FLAG );


#define BRUSH_CONNECTIVITY_DEBUG 0
#define BRUSH_DEGENERATE_DEBUG 0

#define Update_move_planepts_vertex 0

inline bool texdef_sane( const texdef_t& texdef ){
	return fabs( texdef.shift[0] ) < ( 1 << 16 )
	    && fabs( texdef.shift[1] ) < ( 1 << 16 );
}

inline void Winding_DrawWireframe( const Winding& winding ){
	gl().glVertexPointer( 3, GL_DOUBLE, sizeof( WindingVertex ), &winding.points.data()->vertex );
	gl().glDrawArrays( GL_LINE_LOOP, 0, GLsizei( winding.numpoints ) );
}

inline void Winding_Draw( const Winding& winding, const Vector3& normal, RenderStateFlags state ){
	gl().glVertexPointer( 3, GL_DOUBLE, sizeof( WindingVertex ), &winding.points.data()->vertex );

	Vector3 normals[c_brush_maxFaces];

	if ( ( state & RENDER_BUMP ) != 0 ) {
		typedef Vector3* Vector3Iter;
		for ( Vector3Iter i = normals, end = normals + winding.numpoints; i != end; ++i )
		{
			*i = normal;
		}
		gl().glNormalPointer( GL_FLOAT, sizeof( Vector3 ), normals );
		gl().glVertexAttribPointer( c_attr_TexCoord0, 2, GL_FLOAT, 0, sizeof( WindingVertex ), &winding.points.data()->texcoord );
		gl().glVertexAttribPointer( c_attr_Tangent, 3, GL_FLOAT, 0, sizeof( WindingVertex ), &winding.points.data()->tangent );
		gl().glVertexAttribPointer( c_attr_Binormal, 3, GL_FLOAT, 0, sizeof( WindingVertex ), &winding.points.data()->bitangent );
	}
	else
	{
		if ( state & RENDER_LIGHTING ) {
			typedef Vector3* Vector3Iter;
			for ( Vector3Iter i = normals, last = normals + winding.numpoints; i != last; ++i )
			{
				*i = normal;
			}
			gl().glNormalPointer( GL_FLOAT, sizeof( Vector3 ), normals );
		}

		if ( state & RENDER_TEXTURE ) {
			gl().glTexCoordPointer( 2, GL_FLOAT, sizeof( WindingVertex ), &winding.points.data()->texcoord );
		}
	}
#if 0
	if ( state & RENDER_FILL ) {
		gl().glDrawArrays( GL_TRIANGLE_FAN, 0, GLsizei( winding.numpoints ) );
	}
	else
	{
		gl().glDrawArrays( GL_LINE_LOOP, 0, GLsizei( winding.numpoints ) );
	}
#else
	gl().glDrawArrays( GL_POLYGON, 0, GLsizei( winding.numpoints ) );
#endif

#if 0
	const Winding& winding = winding;

	if ( state & RENDER_FILL ) {
		gl().glBegin( GL_POLYGON );
	}
	else
	{
		gl().glBegin( GL_LINE_LOOP );
	}

	if ( state & RENDER_LIGHTING ) {
		gl().glNormal3fv( normal );
	}

	for ( int i = 0; i < winding.numpoints; ++i )
	{
		if ( state & RENDER_TEXTURE ) {
			gl().glTexCoord2fv( &winding.points[i][3] );
		}
		gl().glVertex3fv( winding.points[i] );
	}
	gl().glEnd();
#endif
}


#include "shaderlib.h"

typedef DoubleVector3 PlanePoints[3];

inline bool planepts_equal( const PlanePoints planepts, const PlanePoints other ){
	return planepts[0] == other[0] && planepts[1] == other[1] && planepts[2] == other[2];
}

inline void planepts_assign( PlanePoints planepts, const PlanePoints other ){
	planepts[0] = other[0];
	planepts[1] = other[1];
	planepts[2] = other[2];
}

inline void planepts_quantise( PlanePoints planepts, double snap ){
	vector3_snap( planepts[0], snap );
	vector3_snap( planepts[1], snap );
	vector3_snap( planepts[2], snap );
}

inline float vector3_max_component( const Vector3& vec3 ){
	return std::max( fabsf( vec3[0] ), std::max( fabsf( vec3[1] ), fabsf( vec3[2] ) ) );
}

inline void edge_snap( Vector3& edge, double snap ){
	float scale = static_cast<float>( ceil( fabs( snap / vector3_max_component( edge ) ) ) );
	if ( scale > 0.0f ) {
		vector3_scale( edge, scale );
	}
	vector3_snap( edge, snap );
}

inline void planepts_snap( PlanePoints planepts, double snap ){
	Vector3 edge01( vector3_subtracted( planepts[1], planepts[0] ) );
	Vector3 edge12( vector3_subtracted( planepts[2], planepts[1] ) );
	Vector3 edge20( vector3_subtracted( planepts[0], planepts[2] ) );

	double length_squared_01 = vector3_dot( edge01, edge01 );
	double length_squared_12 = vector3_dot( edge12, edge12 );
	double length_squared_20 = vector3_dot( edge20, edge20 );

	vector3_snap( planepts[0], snap );

	if ( length_squared_01 < length_squared_12 ) {
		if ( length_squared_12 < length_squared_20 ) {
			edge_snap( edge01, snap );
			edge_snap( edge12, snap );
			planepts[1] = vector3_added( planepts[0], edge01 );
			planepts[2] = vector3_added( planepts[1], edge12 );
		}
		else
		{
			edge_snap( edge20, snap );
			edge_snap( edge01, snap );
			planepts[1] = vector3_added( planepts[0], edge20 );
			planepts[2] = vector3_added( planepts[1], edge01 );
		}
	}
	else
	{
		if ( length_squared_01 < length_squared_20 ) {
			edge_snap( edge01, snap );
			edge_snap( edge12, snap );
			planepts[1] = vector3_added( planepts[0], edge01 );
			planepts[2] = vector3_added( planepts[1], edge12 );
		}
		else
		{
			edge_snap( edge12, snap );
			edge_snap( edge20, snap );
			planepts[1] = vector3_added( planepts[0], edge12 );
			planepts[2] = vector3_added( planepts[1], edge20 );
		}
	}
}

inline PointVertex pointvertex_for_planept( const DoubleVector3& point, const Colour4b& colour ){
	return PointVertex(
	           Vertex3f(
	               static_cast<float>( point.x() ),
	               static_cast<float>( point.y() ),
	               static_cast<float>( point.z() )
	           ),
	           colour
	       );
}

inline PointVertex pointvertex_for_windingpoint( const Vector3& point, const Colour4b& colour ){
	return PointVertex(
	           vertex3f_for_vector3( point ),
	           colour
	       );
}

inline DepthTestedPointVertex depthtested_pointvertex_for_windingpoint( const Vector3& point, const Colour4b& colour ){
	return DepthTestedPointVertex(
	           vertex3f_for_vector3( point ),
	           colour
	       );
}

inline bool check_plane_is_integer( const PlanePoints& planePoints ){
	return !float_is_integer( planePoints[0][0] )
	    || !float_is_integer( planePoints[0][1] )
	    || !float_is_integer( planePoints[0][2] )
	    || !float_is_integer( planePoints[1][0] )
	    || !float_is_integer( planePoints[1][1] )
	    || !float_is_integer( planePoints[1][2] )
	    || !float_is_integer( planePoints[2][0] )
	    || !float_is_integer( planePoints[2][1] )
	    || !float_is_integer( planePoints[2][2] );
}

inline void brush_check_shader( const char* name ){
	if ( !texdef_name_valid( name ) ) {
		globalErrorStream() << "brush face has invalid texture name: '" << name << "'\n";
	}
}

class FaceShaderObserver
{
public:
	virtual void realiseShader() = 0;
	virtual void unrealiseShader() = 0;
};

typedef ReferencePair<FaceShaderObserver> FaceShaderObserverPair;


class ContentsFlagsValue
{
public:
	ContentsFlagsValue(){
	}
	ContentsFlagsValue( int surfaceFlags, int contentFlags, int value, bool specified ) :
		m_surfaceFlags( surfaceFlags ),
		m_contentFlags( contentFlags ),
		m_value( value ),
		m_specified( specified ){
	}
	int m_surfaceFlags;
	int m_contentFlags;
	int m_value;
	bool m_specified;
};

inline void ContentsFlagsValue_assignMasked( ContentsFlagsValue& flags, const ContentsFlagsValue& other ){
	bool detail = bitfield_enabled( flags.m_contentFlags, BRUSH_DETAIL_MASK );
	flags = other;
	if ( detail ) {
		flags.m_contentFlags = bitfield_enable( flags.m_contentFlags, BRUSH_DETAIL_MASK );
	}
	else
	{
		flags.m_contentFlags = bitfield_disable( flags.m_contentFlags, BRUSH_DETAIL_MASK );
	}
}


class FaceShader : public ModuleObserver
{
public:
	class SavedState
	{
	public:
		CopiedString m_shader;
		ContentsFlagsValue m_flags;

		SavedState( const FaceShader& faceShader ){
			m_shader = faceShader.getShader();
			m_flags = faceShader.m_flags;
		}

		void exportState( FaceShader& faceShader ) const {
			faceShader.setShader( m_shader.c_str() );
			//faceShader.setFlags( m_flags ); //detail, structural flags aren't undoable with this
			faceShader.m_flags = m_flags;
		}
	};

	CopiedString m_shader;
	Shader* m_state;
	ContentsFlagsValue m_flags;
	FaceShaderObserverPair m_observers;
	bool m_instanced;
	bool m_realised;

	FaceShader( const char* shader, const ContentsFlagsValue& flags = ContentsFlagsValue( 0, 0, 0, false ) ) :
		m_shader( shader ),
		m_state( 0 ),
		m_flags( flags ),
		m_instanced( false ),
		m_realised( false ){
		captureShader();
	}
	~FaceShader(){
		releaseShader();
	}
// copy-construction not supported
	FaceShader( const FaceShader& other ) = delete;

	void instanceAttach(){
		m_instanced = true;
		m_state->incrementUsed();
	}
	void instanceDetach(){
		m_state->decrementUsed();
		m_instanced = false;
	}

	void captureShader(){
		ASSERT_MESSAGE( m_state == 0, "shader cannot be captured" );
		brush_check_shader( m_shader.c_str() );
		m_state = GlobalShaderCache().capture( m_shader.c_str() );
		m_state->attach( *this );
	}
	void releaseShader(){
		ASSERT_MESSAGE( m_state != 0, "shader cannot be released" );
		m_state->detach( *this );
		GlobalShaderCache().release( m_shader.c_str() );
		m_state = 0;
	}

	void realise(){
		ASSERT_MESSAGE( !m_realised, "FaceTexdef::realise: already realised" );
		m_realised = true;
		m_observers.forEach( []( FaceShaderObserver& observer ){ observer.realiseShader(); } );
	}
	void unrealise(){
		ASSERT_MESSAGE( m_realised, "FaceTexdef::unrealise: already unrealised" );
		m_observers.forEach( []( FaceShaderObserver& observer ){ observer.unrealiseShader(); } );
		m_realised = false;
	}

	void attach( FaceShaderObserver& observer ){
		m_observers.attach( observer );
		if ( m_realised ) {
			observer.realiseShader();
		}
	}

	void detach( FaceShaderObserver& observer ){
		if ( m_realised ) {
			observer.unrealiseShader();
		}
		m_observers.detach( observer );
	}

	const char* getShader() const {
		return m_shader.c_str();
	}
	void setShader( const char* name ){
		if ( m_instanced ) {
			m_state->decrementUsed();
		}
		releaseShader();
		m_shader = name;
		captureShader();
		if ( m_instanced ) {
			m_state->incrementUsed();
		}
	}
	ContentsFlagsValue getFlags() const {
		ASSERT_MESSAGE( m_realised, "FaceShader::getFlags: flags not valid when unrealised" );
		if ( !m_flags.m_specified ) {
			return ContentsFlagsValue(
			           m_state->getTexture().surfaceFlags,
			           m_state->getTexture().contentFlags,
			           m_state->getTexture().value,
			           true
			       );
		}
		return m_flags;
	}
	void setFlags( const ContentsFlagsValue& flags ){
		ASSERT_MESSAGE( m_realised, "FaceShader::setFlags: flags not valid when unrealised" );
		ContentsFlagsValue_assignMasked( m_flags, flags );
	}

	Shader* state() const {
		return m_state;
	}

	std::size_t width() const {
		if ( m_realised ) {
			return m_state->getTexture().width;
		}
		return 1;
	}
	std::size_t height() const {
		if ( m_realised ) {
			return m_state->getTexture().height;
		}
		return 1;
	}
	unsigned int shaderFlags() const {
		if ( m_realised ) {
			return m_state->getFlags();
		}
		return 0;
	}
};




class FaceTexdef : public FaceShaderObserver
{
public:
	class SavedState
	{
	public:
		TextureProjection m_projection;

		SavedState( const FaceTexdef& faceTexdef ){
			m_projection = faceTexdef.m_projection;
		}

		void exportState( FaceTexdef& faceTexdef ) const {
			Texdef_Assign( faceTexdef.m_projection, m_projection );
		}
	};

	FaceShader& m_shader;
	TextureProjection m_projection;
	bool m_projectionInitialised;
	bool m_scaleApplied;

// not copyable
	FaceTexdef( const FaceTexdef& other ) = delete;
// not assignable
	FaceTexdef& operator=( const FaceTexdef& other ) = delete;

	FaceTexdef(
	    FaceShader& shader,
	    const TextureProjection& projection,
	    bool projectionInitialised = true
	) :
		m_shader( shader ),
		m_projection( projection ),
		m_projectionInitialised( projectionInitialised ),
		m_scaleApplied( false ){
		m_shader.attach( *this );
	}
	~FaceTexdef(){
		m_shader.detach( *this );
	}

	void addScale(){
		ASSERT_MESSAGE( !m_scaleApplied, "texture scale already added" );
		m_scaleApplied = true;
		m_projection.m_brushprimit_texdef.addScale( m_shader.width(), m_shader.height() );
	}
	void removeScale(){
		ASSERT_MESSAGE( m_scaleApplied, "texture scale already removed" );
		m_scaleApplied = false;
		m_projection.m_brushprimit_texdef.removeScale( m_shader.width(), m_shader.height() );
	}

	void realiseShader(){
		if ( m_projectionInitialised && !m_scaleApplied ) {
			addScale();
		}
	}
	void unrealiseShader(){
		if ( m_projectionInitialised && m_scaleApplied ) {
			removeScale();
		}
	}

	void setTexdef( const TextureProjection& projection, bool setBasis ){
		removeScale();
		Texdef_Assign( m_projection, projection, setBasis );
		addScale();
	}

	void setTexdef( const float* hShift, const float* vShift, const float* hScale, const float* vScale, const float* rotation ){
		removeScale();
		Texdef_Assign( m_projection, hShift, vShift, hScale, vScale, rotation );
//		if( hShift || vShift ){
//			Texdef_normalise( m_projection, m_shader.width(), m_shader.height() );
//		}
		addScale();
	}

	void shift( float s, float t ){
		ASSERT_MESSAGE( texdef_sane( m_projection.m_texdef ), "FaceTexdef::shift: bad texdef" );
		removeScale();
		Texdef_Shift( m_projection, s, t );
//		Texdef_normalise( m_projection, m_shader.width(), m_shader.height() );
		addScale();
	}

	void scale( float s, float t ){
		removeScale();
		Texdef_Scale( m_projection, s, t );
		addScale();
	}

	void rotate( float angle ){
		removeScale();
		Texdef_Rotate( m_projection, angle );
		addScale();
	}
///ProjectTexture along 'direction' with parameters, defined by texdef_t
	void ProjectTexture( const Plane3& plane, const texdef_t& texdef, const Vector3* direction ){
		Texdef_ProjectTexture( m_projection, m_shader.width(), m_shader.height(), plane, texdef, direction );
	}
///ProjectTexture along 'normal' with parameters, defined by TextureProjection
	void ProjectTexture( const Plane3& plane, const TextureProjection& projection, const Vector3& normal ){
		Texdef_ProjectTexture( m_projection, m_shader.width(), m_shader.height(), plane, projection, normal );
	}

	void Convert( TexdefTypeId in, TexdefTypeId out, const Plane3& plane ){
		Texdef_Convert( in, out, plane, m_projection, m_shader.width(), m_shader.height() );
		m_scaleApplied = true;
	}

	void fit( const Vector3& normal, const Winding& winding, float s_repeat, float t_repeat, bool only_dimension ){
		Texdef_FitTexture( m_projection, m_shader.width(), m_shader.height(), normal, winding, s_repeat, t_repeat, only_dimension );
	}

	void emitTextureCoordinates( Winding& winding, const Vector3& normal, const Matrix4& localToWorld ){
		Texdef_EmitTextureCoordinates( m_projection, m_shader.width(), m_shader.height(), winding, normal, localToWorld );
	}

	void transform( const Plane3& plane, const Matrix4& matrix ){
		removeScale();
		Texdef_transformLocked( m_projection, m_shader.width(), m_shader.height(), plane, matrix );
		addScale();
	}

	TextureProjection normalised() const {
		brushprimit_texdef_t tmp( m_projection.m_brushprimit_texdef );
		tmp.removeScale( m_shader.width(), m_shader.height() );
		return TextureProjection( m_projection.m_texdef, tmp, m_projection.m_basis_s, m_projection.m_basis_t );
	}
#if 0 /* axial projection */
	void setBasis( const Vector3& normal ){
		Matrix4 basis;
		Normal_GetTransform( normal, basis );
		m_projection.m_basis_s = Vector3( basis.xx(), basis.yx(), basis.zx() );
		m_projection.m_basis_t = Vector3( -basis.xy(), -basis.yy(), -basis.zy() );
	}
#else /* face projection */
	void setBasis( const Vector3& normal ){
		ComputeAxisBase( normal, m_projection.m_basis_s, m_projection.m_basis_t );
	}
#endif
};

inline void planepts_print( const PlanePoints& planePoints, TextOutputStream& ostream ){
	ostream << "( " << planePoints[0][0] << ' ' << planePoints[0][1] << ' ' << planePoints[0][2] << " ) "
	        << "( " << planePoints[1][0] << ' ' << planePoints[1][1] << ' ' << planePoints[1][2] << " ) "
	        << "( " << planePoints[2][0] << ' ' << planePoints[2][1] << ' ' << planePoints[2][2] << " )";
}


inline Plane3 Plane3_applyTranslation( const Plane3& plane, const Vector3& translation ){
	Plane3 tmp( plane3_translated( Plane3( plane.normal(), -plane.dist() ), translation ) );
	return Plane3( tmp.normal(), -tmp.dist() );
}

inline Plane3 Plane3_applyTransform( const Plane3& plane, const Matrix4& matrix ){
	/* fails for scaling */
	//Plane3 tmp( plane3_transformed( Plane3( plane.normal(), -plane.dist() ), matrix ) );
	//return Plane3( tmp.normal(), -tmp.dist() );
	/* ok */
	return plane3_transformed_affine_full( plane, matrix );
}

class FacePlane
{
	PlanePoints m_planepts;
	Plane3 m_planeCached;
	Plane3 m_plane;
public:
	Vector3 m_funcStaticOrigin;

	static EBrushType m_type;

	static bool isDoom3Plane(){
		return FacePlane::m_type == eBrushTypeDoom3 || FacePlane::m_type == eBrushTypeQuake4;
	}

	class SavedState
	{
	public:
		PlanePoints m_planepts;
		Plane3 m_plane;

		SavedState( const FacePlane& facePlane ){
			if ( facePlane.isDoom3Plane() ) {
				m_plane = facePlane.m_plane;
			}
			else
			{
				planepts_assign( m_planepts, facePlane.planePoints() );
			}
		}

		void exportState( FacePlane& facePlane ) const {
			if ( facePlane.isDoom3Plane() ) {
				facePlane.m_plane = m_plane;
				facePlane.updateTranslated();
			}
			else
			{
				planepts_assign( facePlane.planePoints(), m_planepts );
				facePlane.MakePlane();
			}
		}
	};

	FacePlane() : m_funcStaticOrigin( 0, 0, 0 ){
	}
	FacePlane( const FacePlane& other ) : m_funcStaticOrigin( 0, 0, 0 ){
		if ( !isDoom3Plane() ) {
			planepts_assign( m_planepts, other.m_planepts );
			MakePlane();
		}
		else
		{
			m_plane = other.m_plane;
			updateTranslated();
		}
	}
	FacePlane& operator=( const FacePlane& ) = default;

	void MakePlane(){
		if ( !isDoom3Plane() ) {
#if 0
			if ( check_plane_is_integer( m_planepts ) ) {
				globalErrorStream() << "non-integer planepts: ";
				planepts_print( m_planepts, globalErrorStream() );
				globalErrorStream() << '\n';
			}
#endif
			m_planeCached = plane3_for_points( m_planepts );
		}
	}

	void reverse(){
		if ( !isDoom3Plane() ) {
			vector3_swap( m_planepts[0], m_planepts[2] );
			MakePlane();
		}
		else
		{
			m_planeCached = plane3_flipped( m_plane );
			updateSource();
		}
	}
	void transform( const Matrix4& matrix, bool mirror ){
		if ( !isDoom3Plane() ) {

#if 0
			bool off = check_plane_is_integer( planePoints() );
#endif

			matrix4_transform_point( matrix, m_planepts[0] );
			matrix4_transform_point( matrix, m_planepts[1] );
			matrix4_transform_point( matrix, m_planepts[2] );

			if ( mirror ) {
				reverse();
			}

#if 0
			if ( check_plane_is_integer( planePoints() ) ) {
				if ( !off ) {
					globalErrorStream() << "caused by transform\n";
				}
			}
#endif
			MakePlane();
		}
		else
		{
			m_planeCached = Plane3_applyTransform( m_planeCached, matrix );
			updateSource();
		}
	}
	void offset( float offset ){
		if ( !isDoom3Plane() ) {
			Vector3 move( vector3_scaled( m_planeCached.normal(), -offset ) );

			vector3_subtract( m_planepts[0], move );
			vector3_subtract( m_planepts[1], move );
			vector3_subtract( m_planepts[2], move );

			MakePlane();
		}
		else
		{
			m_planeCached.d += offset;
			updateSource();
		}
	}

	void updateTranslated(){
		m_planeCached = Plane3_applyTranslation( m_plane, m_funcStaticOrigin );
	}
	void updateSource(){
		m_plane = Plane3_applyTranslation( m_planeCached, vector3_negated( m_funcStaticOrigin ) );
	}


	PlanePoints& planePoints(){
		return m_planepts;
	}
	const PlanePoints& planePoints() const {
		return m_planepts;
	}
	const PlanePoints& getPlanePoints(){
		if( isDoom3Plane() ){
			m_planepts[0] = m_planeCached.normal() * m_planeCached.dist();
			ComputeAxisBase( m_planeCached.normal(), m_planepts[1], m_planepts[2] );
			m_planepts[1] = m_planepts[1] + m_planepts[0];
			m_planepts[2] = m_planepts[2] + m_planepts[0];
		}
		return m_planepts;
	}
	const Plane3& plane3() const {
		return m_planeCached;
	}
	void setDoom3Plane( const Plane3& plane ){
		m_plane = plane;
		updateTranslated();
	}
	const Plane3& getDoom3Plane() const {
		return m_plane;
	}

	void copy( const FacePlane& other ){
		if ( !isDoom3Plane() ) {
			planepts_assign( m_planepts, other.m_planepts );
			MakePlane();
		}
		else
		{
			m_planeCached = other.m_plane;
			updateSource();
		}
	}
	void copy( const DoubleVector3& p0, const DoubleVector3& p1, const DoubleVector3& p2 ){
		if ( !isDoom3Plane() ) {
			m_planepts[0] = p0;
			m_planepts[1] = p1;
			m_planepts[2] = p2;
			MakePlane();
		}
		else
		{
			m_planeCached = plane3_for_points( p0, p1, p2 );
			updateSource();
		}
	}
	void copy( const PlanePoints planepoints ){
		if ( !isDoom3Plane() ) {
			planepts_assign( m_planepts, planepoints );
			MakePlane();
		}
		else
		{
			m_planeCached = plane3_for_points( planepoints );
			updateSource();
		}
	}
};

inline void Winding_testSelect( Winding& winding, SelectionTest& test, SelectionIntersection& best, const DoubleVector3 planepoints[3] ){
	test.TestPolygon( VertexPointer( reinterpret_cast<VertexPointer::pointer>( &winding.points.data()->vertex ), sizeof( WindingVertex ) ), winding.numpoints, best, planepoints );
}

const double GRID_MIN = 0.125;

inline double quantiseInteger( double f ){
	return float_to_integer( f );
}

inline double quantiseFloating( double f ){
#if 0
	return float_snapped( f, 1.f / ( 1 << 16 ) );
#else
	return f;
#endif
}

typedef double ( *QuantiseFunc )( double f );

class Face;

class FaceFilter
{
public:
	virtual bool filter( const Face& face ) const = 0;
};

bool face_filtered( Face& face );
void add_face_filter( FaceFilter& filter, int mask, bool invert = false );

void Brush_addTextureChangedCallback( const SignalHandler& callback );
void Brush_textureChanged();


extern bool g_brush_texturelock_enabled;
extern bool g_brush_textureVertexlock_enabled;

inline TexdefTypeId BrushType_getTexdefType( EBrushType type ){
	switch ( type )
	{
	case eBrushTypeQuake3BP:
	case eBrushTypeQuake2BP:
	case eBrushTypeDoom3:
	case eBrushTypeQuake4:
		return TEXDEFTYPEID_BRUSHPRIMITIVES;
	case eBrushTypeValve220:
	case eBrushTypeQuake2Valve220:
	case eBrushTypeQuake3Valve220:
		return TEXDEFTYPEID_VALVE;
	default:
		return TEXDEFTYPEID_QUAKE;
	}
}

class FaceObserver
{
public:
	virtual void planeChanged() = 0;
	virtual void connectivityChanged() = 0;
	virtual void shaderChanged() = 0;
	virtual void evaluateTransform() = 0;
};

class Face :
	public OpenGLRenderable,
	public Filterable,
	public Undoable,
	public FaceShaderObserver
{
	std::size_t m_refcount;

	class SavedState : public UndoMemento
	{
	public:
		FacePlane::SavedState m_planeState;
		FaceTexdef::SavedState m_texdefState;
		FaceShader::SavedState m_shaderState;

		SavedState( const Face& face ) : m_planeState( face.getPlane() ), m_texdefState( face.getTexdef() ), m_shaderState( face.getShader() ){
		}

		void exportState( Face& face ) const {
			m_planeState.exportState( face.getPlane() );
			m_shaderState.exportState( face.getShader() );
			m_texdefState.exportState( face.getTexdef() );
		}

		void release(){
			delete this;
		}
	};

public:
	static QuantiseFunc m_quantise;
	static EBrushType m_type;

	PlanePoints m_move_planepts;
	PlanePoints m_move_planeptsTransformed;
private:
	FacePlane m_plane;
	FacePlane m_planeTransformed;
	FaceShader m_shader;
	FaceTexdef m_texdef;
	TextureProjection m_texdefTransformed;

	Winding m_winding;
	Vector3 m_centroid;
	Vector3 m_centroid_cached; //this is far not pretty hack! (invariant point for texlock in AP)
	bool m_filtered;

	FaceObserver* m_observer;
	UndoObserver* m_undoable_observer;
	MapFile* m_map;

public:

// assignment not supported
	Face& operator=( const Face& other ) = delete;
// copy-construction not supported
	Face( const Face& other ) = delete;

	Face( FaceObserver* observer ) :
		m_refcount( 0 ),
		m_shader( texdef_name_default() ),
		m_texdef( m_shader, TextureProjection(), false ),
		m_filtered( false ),
		m_observer( observer ),
		m_undoable_observer( 0 ),
		m_map( 0 ){
		m_shader.attach( *this );
		m_plane.copy( DoubleVector3( 0, 0, 0 ), DoubleVector3( 64, 0, 0 ), DoubleVector3( 0, 64, 0 ) );
		m_texdef.setBasis( m_plane.plane3().normal() );
		planeChanged();
	}
	Face(
	    const DoubleVector3& p0,
	    const DoubleVector3& p1,
	    const DoubleVector3& p2,
	    const char* shader,
	    const TextureProjection& projection,
	    FaceObserver* observer
	) :
		m_refcount( 0 ),
		m_shader( shader ),
		m_texdef( m_shader, projection ),
		m_observer( observer ),
		m_undoable_observer( 0 ),
		m_map( 0 ){
		m_shader.attach( *this );
		m_plane.copy( p0, p1, p2 );
		m_texdef.setBasis( m_plane.plane3().normal() );
		planeChanged();
		updateFiltered();
	}
	Face( const Face& other, FaceObserver* observer ) :
		m_refcount( 0 ),
		m_shader( other.m_shader.getShader(), other.m_shader.m_flags ),
		m_texdef( m_shader, other.getTexdef().normalised() ),
		m_observer( observer ),
		m_undoable_observer( 0 ),
		m_map( 0 ){
		m_shader.attach( *this );
		m_plane.copy( other.m_plane );
		planepts_assign( m_move_planepts, other.m_move_planepts );
//		m_texdef.setBasis( m_plane.plane3().normal() ); //don't reset basis on face clone
		planeChanged();
		updateFiltered();
	}
	~Face(){
		m_shader.detach( *this );
	}

	void planeChanged(){
		revertTransform();
		m_observer->planeChanged();
	}

	void realiseShader(){
		m_observer->shaderChanged();
	}
	void unrealiseShader(){
	}

	void instanceAttach( MapFile* map ){
		m_shader.instanceAttach();
		m_map = map;
		m_undoable_observer = GlobalUndoSystem().observer( this );
		GlobalFilterSystem().registerFilterable( *this );
	}
	void instanceDetach( MapFile* map ){
		GlobalFilterSystem().unregisterFilterable( *this );
		m_undoable_observer = 0;
		GlobalUndoSystem().release( this );
		m_map = 0;
		m_shader.instanceDetach();
	}

	void render( RenderStateFlags state ) const {
		Winding_Draw( m_winding, m_planeTransformed.plane3().normal(), state );
	}

	void updateFiltered(){
		m_filtered = face_filtered( *this );
	}
	bool isFiltered() const {
		return m_filtered;
	}

	void undoSave(){
		if ( m_map != 0 ) {
			m_map->changed();
		}
		if ( m_undoable_observer != 0 ) {
			m_undoable_observer->save( this );
		}
	}

// undoable
	UndoMemento* exportState() const {
		return new SavedState( *this );
	}
	void importState( const UndoMemento* data ){
		undoSave();

		static_cast<const SavedState*>( data )->exportState( *this );

		planeChanged();
		m_observer->connectivityChanged();
		texdefChanged();
		m_observer->shaderChanged();
		updateFiltered();
	}

	void IncRef(){
		++m_refcount;
	}
	void DecRef(){
		if ( --m_refcount == 0 ) {
			delete this;
		}
	}

	void flipWinding(){
		m_plane.reverse();
		planeChanged();
	}

	bool intersectVolume( const VolumeTest& volume, const Matrix4& localToWorld ) const {
		return volume.TestPlane( Plane3( plane3().normal(), -plane3().dist() ), localToWorld );
	}

	void render( Renderer& renderer, const Matrix4& localToWorld ) const {
		renderer.SetState( m_shader.state(), Renderer::eFullMaterials );
		renderer.addRenderable( *this, localToWorld );
	}

	void texdef_from_points(){
		Matrix4 local2tex;
		Texdef_Construct_local2tex( m_texdef.m_projection, m_shader.width(), m_shader.height(), m_plane.plane3().normal(), local2tex );
		DoubleVector3 st[3];
		for ( std::size_t i = 0; i < 3; ++i )
			st[i] = matrix4_transformed_point( local2tex, m_move_planepts[i] );
		Texdef_from_ST( m_texdefTransformed, m_move_planeptsTransformed, st, m_shader.width(), m_shader.height() );

		Brush_textureChanged();
	}

	void transform_texdef( const Matrix4& matrix, const Vector3& invariant = g_vector3_identity ){
		revertTexdef();
//	Texdef_transformLocked( m_texdefTransformed, m_shader.width(), m_shader.height(), m_plane.plane3(), matrix, static_cast<Vector3>( m_plane.plane3().normal() * m_plane.plane3().dist() ) );
		Texdef_transform( m_texdefTransformed, m_shader.width(), m_shader.height(), m_plane.plane3(), matrix, invariant );
		EmitTextureCoordinates();
		Brush_textureChanged();
	}

	void transform( const Matrix4& matrix, bool mirror ){
		if ( g_brush_texturelock_enabled ) {
			Texdef_transformLocked( m_texdefTransformed, m_shader.width(), m_shader.height(), m_plane.plane3(), matrix,
			                        contributes() ? m_centroid_cached
			                        : static_cast<Vector3>( m_plane.plane3().normal() * m_plane.plane3().dist() ) );
			Brush_textureChanged();
		}
		else if( g_bp_globals.m_texdefTypeId == TEXDEFTYPEID_VALVE ){
			const DoubleVector3 from = vector3_normalised( vector3_cross( m_texdefTransformed.m_basis_s, m_texdefTransformed.m_basis_t ) );
			const DoubleVector3 to = matrix4_transformed_normal( matrix, from );
			Quaternion quat = quaternion_for_unit_vectors( from, to );
			if( quat.w() != quat.w() ){ //handle 180` cases
				if( vector3_max_abs_component_index( from ) == 2 )
					quat = Quaternion( g_vector3_axis_y, 0 );
				else
					quat = Quaternion( g_vector3_axis_z, 0 );
			}
			const Matrix4 mat = matrix4_rotation_for_quaternion( quat );
			m_texdefTransformed.m_basis_s = vector3_normalised( matrix4_transformed_direction( mat, m_texdefTransformed.m_basis_s ) );
			m_texdefTransformed.m_basis_t = vector3_normalised( matrix4_transformed_direction( mat, m_texdefTransformed.m_basis_t ) );
		}

		m_planeTransformed.transform( matrix, mirror );

#if 0
		ASSERT_MESSAGE( projectionaxis_for_normal( normal ) == projectionaxis_for_normal( plane3().normal() ), "bleh" );
#endif
		m_observer->planeChanged();
	}

	void assign_planepts( const PlanePoints planepts ){
		m_planeTransformed.copy( planepts );
		m_observer->planeChanged();
	}

/// \brief Reverts the transformable state of the brush to identity.
	void revertTransform(){
		m_planeTransformed = m_plane;
		planepts_assign( m_move_planeptsTransformed, m_move_planepts );
		m_texdefTransformed = m_texdef.m_projection;
	}
	void freezeTransform(){
		undoSave();
		m_plane = m_planeTransformed;
		planepts_assign( m_move_planepts, m_move_planeptsTransformed );
		m_texdef.m_projection = m_texdefTransformed;
	}

	void update_move_planepts_vertex( std::size_t index, PlanePoints planePoints ){
		if( contributes() ){
			std::size_t numpoints = getWinding().numpoints;
			ASSERT_MESSAGE( index < numpoints, "update_move_planepts_vertex: invalid index" );

			std::size_t opposite = Winding_Opposite( getWinding(), index );
			std::size_t adjacent = Winding_wrap( getWinding(), opposite + numpoints - 1 );
			planePoints[0] = getWinding()[opposite].vertex;
			planePoints[1] = getWinding()[index].vertex;
			planePoints[2] = getWinding()[adjacent].vertex;
			// winding points are very inaccurate, so they must be quantised before using them to generate the face-plane
//			planepts_quantise( planePoints, GRID_MIN );
		}
	}

	void snapto( float snap ){
		if ( contributes() ) {
#if 0
			ASSERT_MESSAGE( plane3_valid( m_plane.plane3() ), "invalid plane before snap to grid" );
			planepts_snap( m_plane.planePoints(), snap );
			ASSERT_MESSAGE( plane3_valid( m_plane.plane3() ), "invalid plane after snap to grid" );
#else
			PlanePoints planePoints;
			update_move_planepts_vertex( 0, planePoints );
			vector3_snap( planePoints[0], snap );
			vector3_snap( planePoints[1], snap );
			vector3_snap( planePoints[2], snap );
			assign_planepts( planePoints );
			freezeTransform();
#endif
			SceneChangeNotify();
			if ( !plane3_valid( m_plane.plane3() ) ) {
				globalWarningStream() << "WARNING: invalid plane after snap to grid\n";
			}
		}
	}

	void testSelect( SelectionTest& test, SelectionIntersection& best ){
		Winding_testSelect( m_winding, test, best, m_plane.getPlanePoints() );
	}

	void testSelect_centroid( SelectionTest& test, SelectionIntersection& best ) const {
		test.TestPoint( m_centroid, best );
	}

	void shaderChanged(){
		EmitTextureCoordinates();
		Brush_textureChanged();
		m_observer->shaderChanged();
		updateFiltered();
		planeChanged();
		SceneChangeNotify();
	}

	const char* GetShader() const {
		return m_shader.getShader();
	}
	void SetShader( const char* name ){
		undoSave();
		m_shader.setShader( name );
		shaderChanged();
	}

	void revertTexdef(){
		m_texdefTransformed = m_texdef.m_projection;
	}
	void texdefChanged(){
		revertTexdef();
		EmitTextureCoordinates();
		Brush_textureChanged();
	}

	void GetTexdef( TextureProjection& projection ) const {
		projection = m_texdef.normalised();
	}
	void SetTexdef( const TextureProjection& projection, bool setBasis = true, bool resetBasis = false ){
		undoSave();
		m_texdef.setTexdef( projection, setBasis );
		if( resetBasis ){
			m_texdef.setBasis( m_plane.plane3().normal() );
		}
		texdefChanged();
	}

	void SetTexdef( const float* hShift, const float* vShift, const float* hScale, const float* vScale, const float* rotation ){
		undoSave();
		m_texdef.setTexdef( hShift, vShift, hScale, vScale, rotation );
		texdefChanged();
	}

	void GetFlags( ContentsFlagsValue& flags ) const {
		flags = m_shader.getFlags();
	}
	void SetFlags( const ContentsFlagsValue& flags ){
		undoSave();
		m_shader.setFlags( flags );
		m_observer->shaderChanged();
		Brush_textureChanged();
		updateFiltered();
	}

	void ShiftTexdef( float s, float t ){
		undoSave();
		m_texdef.shift( s, t );
		texdefChanged();
	}

	void ScaleTexdef( float s, float t ){
		undoSave();
		m_texdef.scale( s, t );
		texdefChanged();
	}

	void RotateTexdef( float angle ){
		undoSave();
		m_texdef.rotate( angle );
		texdefChanged();
	}

	void ProjectTexture( const texdef_t& texdef, const Vector3* direction ){
		undoSave();
		m_texdef.ProjectTexture( m_plane.plane3(), texdef, direction );
		texdefChanged();
	}

	void ProjectTexture( const TextureProjection& projection, const Vector3& normal ){
		undoSave();
		m_texdef.ProjectTexture( m_plane.plane3(), projection, normal );
		texdefChanged();
	}

	void Convert( TexdefTypeId in, TexdefTypeId out ){
		m_texdef.Convert( in, out, m_plane.plane3() );
		texdefChanged();
	}

	void FitTexture( float s_repeat, float t_repeat, bool only_dimension ){
		undoSave();
		m_texdef.fit( m_plane.plane3().normal(), m_winding, s_repeat, t_repeat, only_dimension );
		texdefChanged();
	}

	void EmitTextureCoordinates(){
		Texdef_EmitTextureCoordinates( m_texdefTransformed, m_shader.width(), m_shader.height(), m_winding, plane3().normal(), g_matrix4_identity );
	}


	const Vector3& centroid() const {
		return m_centroid;
	}

	void construct_centroid(){
		Winding_Centroid( m_winding, plane3(), m_centroid );
	}

	const Winding& getWinding() const {
		return m_winding;
	}
	Winding& getWinding(){
		return m_winding;
	}

	void cacheCentroid() {
		m_centroid_cached = m_centroid;
	}

	const Plane3& plane3() const {
		m_observer->evaluateTransform();
		return m_planeTransformed.plane3();
	}
	const Plane3& plane3_() const {
		return m_planeTransformed.plane3();
	}
	FacePlane& getPlane(){
		return m_plane;
	}
	const FacePlane& getPlane() const {
		return m_plane;
	}
	FaceTexdef& getTexdef(){
		return m_texdef;
	}
	const FaceTexdef& getTexdef() const {
		return m_texdef;
	}
	FaceShader& getShader(){
		return m_shader;
	}
	const FaceShader& getShader() const {
		return m_shader;
	}

	bool isDetail() const {
		return ( m_shader.m_flags.m_contentFlags & BRUSH_DETAIL_MASK ) != 0;
	}
	void setDetail( bool detail ){
		undoSave();
		if ( detail && !isDetail() ) {
			m_shader.m_flags.m_contentFlags |= BRUSH_DETAIL_MASK;
		}
		else if ( !detail && isDetail() ) {
			m_shader.m_flags.m_contentFlags &= ~BRUSH_DETAIL_MASK;
		}
		m_observer->shaderChanged();
	}

	bool contributes() const {
		return m_winding.numpoints > 2;
	}
	bool is_bounded() const {
		for ( Winding::const_iterator i = m_winding.begin(); i != m_winding.end(); ++i )
		{
			if ( ( *i ).adjacent == c_brush_maxFaces ) {
				return false;
			}
		}
		return true;
	}
};


class FaceVertexId
{
	std::size_t m_face;
	std::size_t m_vertex;

public:
	FaceVertexId( std::size_t face, std::size_t vertex )
		: m_face( face ), m_vertex( vertex ){
	}

	std::size_t getFace() const {
		return m_face;
	}
	std::size_t getVertex() const {
		return m_vertex;
	}
};

typedef std::size_t faceIndex_t;

struct EdgeRenderIndices
{
	RenderIndex first;
	RenderIndex second;

	EdgeRenderIndices()
		: first( 0 ), second( 0 ){
	}
	EdgeRenderIndices( const RenderIndex _first, const RenderIndex _second )
		: first( _first ), second( _second ){
	}
};

struct EdgeFaces
{
	faceIndex_t first;
	faceIndex_t second;

	EdgeFaces()
		: first( c_brush_maxFaces ), second( c_brush_maxFaces ){
	}
	EdgeFaces( const faceIndex_t _first, const faceIndex_t _second )
		: first( _first ), second( _second ){
	}
};

class RenderableWireframe : public OpenGLRenderable
{
public:
	void render( RenderStateFlags state ) const {
#if 1
		gl().glVertexPointer( 3, GL_FLOAT, sizeof( DepthTestedPointVertex ), &m_vertices->vertex );
		gl().glDrawElements( GL_LINES, GLsizei( m_size << 1 ), RenderIndexTypeID, m_faceVertex.data() );
#else
		gl().glBegin( GL_LINES );
		for ( std::size_t i = 0; i < m_size; ++i )
		{
			gl().glVertex3fv( &m_vertices[m_faceVertex[i].first].vertex.x );
			gl().glVertex3fv( &m_vertices[m_faceVertex[i].second].vertex.x );
		}
		gl().glEnd();
#endif
	}

	Array<EdgeRenderIndices> m_faceVertex;
	std::size_t m_size;
	const DepthTestedPointVertex* m_vertices;
};

class Brush;
typedef std::vector<Brush*> brush_vector_t;

class BrushFilter
{
public:
	virtual bool filter( const Brush& brush ) const = 0;
};

bool brush_filtered( Brush& brush );
void add_brush_filter( BrushFilter& filter, int mask, bool invert = false );


/// \brief Returns true if 'self' takes priority when building brush b-rep.
inline bool plane3_inside( const Plane3& self, const Plane3& other, bool selfIsLater ){
	if ( vector3_equal_epsilon( self.normal(), other.normal(), 0.001 ) ) {
		// same plane? prefer the one with smaller index
		if ( self.dist() == other.dist() ) {
			return selfIsLater;
		}
		return self.dist() < other.dist();
	}
	return true;
}

typedef SmartPointer<Face> FaceSmartPointer;
typedef std::vector<FaceSmartPointer> Faces;

/// \brief Returns the unique-id of the edge adjacent to \p faceVertex in the edge-pair for the set of \p faces.
inline FaceVertexId next_edge( const Faces& faces, FaceVertexId faceVertex ){
	std::size_t adjacent_face = faces[faceVertex.getFace()]->getWinding()[faceVertex.getVertex()].adjacent;
	std::size_t adjacent_vertex = Winding_FindAdjacent( faces[adjacent_face]->getWinding(), faceVertex.getFace() );

	ASSERT_MESSAGE( adjacent_vertex != c_brush_maxFaces, "connectivity data invalid" );
	if ( adjacent_vertex == c_brush_maxFaces ) {
		return faceVertex;
	}

	return FaceVertexId( adjacent_face, adjacent_vertex );
}

/// \brief Returns the unique-id of the vertex adjacent to \p faceVertex in the vertex-ring for the set of \p faces.
inline FaceVertexId next_vertex( const Faces& faces, FaceVertexId faceVertex ){
	FaceVertexId nextEdge = next_edge( faces, faceVertex );
	return FaceVertexId( nextEdge.getFace(), Winding_next( faces[nextEdge.getFace()]->getWinding(), nextEdge.getVertex() ) );
}

class SelectableEdge
{
public:
	Vector3 getEdge() const {
		const Winding& winding = getFace().getWinding();
		return vector3_mid( winding[m_faceVertex.getVertex()].vertex, winding[Winding_next( winding, m_faceVertex.getVertex() )].vertex );
	}

	Faces& m_faces;
	FaceVertexId m_faceVertex;

	SelectableEdge( Faces& faces, FaceVertexId faceVertex )
		: m_faces( faces ), m_faceVertex( faceVertex ){
	}
	SelectableEdge& operator=( const SelectableEdge& other ){
		m_faceVertex = other.m_faceVertex;
		return *this;
	}

	Face& getFace() const {
		return *m_faces[m_faceVertex.getFace()];
	}

	void testSelect( SelectionTest& test, SelectionIntersection& best ){
		test.TestPoint( getEdge(), best );
	}
};

class SelectableVertex
{
public:
	DoubleVector3 getVertex() const {
		return getFace().getWinding()[m_faceVertex.getVertex()].vertex;
	}

	Faces& m_faces;
	FaceVertexId m_faceVertex;

	SelectableVertex( Faces& faces, FaceVertexId faceVertex )
		: m_faces( faces ), m_faceVertex( faceVertex ){
	}
	SelectableVertex& operator=( const SelectableVertex& other ){
		m_faceVertex = other.m_faceVertex;
		return *this;
	}

	Face& getFace() const {
		return *m_faces[m_faceVertex.getFace()];
	}

	void testSelect( SelectionTest& test, SelectionIntersection& best ){
		test.TestPoint( getVertex(), best );
	}
};

class BrushObserver
{
public:
	virtual void reserve( std::size_t size ) = 0;
	virtual void clear() = 0;
	virtual void push_back( Face& face ) = 0;
	virtual void pop_back() = 0;
	virtual void erase( std::size_t index ) = 0;
	virtual void connectivityChanged() = 0;

	virtual void edge_clear() = 0;
	virtual void edge_push_back( SelectableEdge& edge ) = 0;

	virtual void vertex_clear() = 0;
	virtual void vertex_push_back( SelectableVertex& vertex ) = 0;

	virtual void vertex_select() = 0;
	virtual void vertex_snap( const float snap ) = 0;

	virtual void DEBUG_verify() const = 0;
};

class BrushVisitor
{
public:
	virtual void visit( Face& face ) const = 0;
};

class Brush :
	public TransformNode,
	public Bounded,
	public Cullable,
	public Snappable,
	public Undoable,
	public FaceObserver,
	public Filterable,
	public Nameable,
	public BrushDoom3
{
private:
	scene::Node* m_node;
	typedef UniqueSet<BrushObserver*> Observers;
	Observers m_observers;
	UndoObserver* m_undoable_observer;
	MapFile* m_map;

// state
	Faces m_faces;
// ----

// cached data compiled from state
	Array<PointVertex> m_faceCentroidPoints;
	RenderablePointArray<PointVertex> m_render_faces;

	mutable Array<DepthTestedPointVertex> m_uniqueVertexPoints;
	typedef std::vector<SelectableVertex> SelectableVertices;
	SelectableVertices m_select_vertices;
	RenderablePointArray<DepthTestedPointVertex> m_render_vertices;
	RenderableDepthTestedPointArray m_render_deepvertices;

	Array<PointVertex> m_uniqueEdgePoints;
	typedef std::vector<SelectableEdge> SelectableEdges;
	SelectableEdges m_select_edges;
	RenderablePointArray<PointVertex> m_render_edges;

	Array<EdgeRenderIndices> m_edge_indices;
	Array<EdgeFaces> m_edge_faces;

	AABB m_aabb_local;
// ----

	Callback m_evaluateTransform;
	Callback m_boundsChanged;

	mutable bool m_planeChanged;   // b-rep evaluation required
	mutable bool m_transformChanged;   // transform evaluation required
	bool m_BRep_evaluation = false; //mutex for invalidation
// ----

public:
	STRING_CONSTANT( Name, "Brush" );

	Callback m_lightsChanged;

// static data
	static Shader* m_state_point;
	static Shader* m_state_deeppoint;
// ----

	static EBrushType m_type;
	static double m_maxWorldCoord;

	Brush( scene::Node& node, const Callback& evaluateTransform, const Callback& boundsChanged ) :
		m_node( &node ),
		m_undoable_observer( 0 ),
		m_map( 0 ),
		m_render_faces( m_faceCentroidPoints, GL_POINTS ),
		m_render_vertices( m_uniqueVertexPoints, GL_POINTS ),
		m_render_deepvertices( m_uniqueVertexPoints, GL_POINTS ),
		m_render_edges( m_uniqueEdgePoints, GL_POINTS ),
		m_evaluateTransform( evaluateTransform ),
		m_boundsChanged( boundsChanged ),
		m_planeChanged( false ),
		m_transformChanged( false ){
		planeChanged();
	}
	Brush( const Brush& other, scene::Node& node, const Callback& evaluateTransform, const Callback& boundsChanged ) :
		m_node( &node ),
		m_undoable_observer( 0 ),
		m_map( 0 ),
		m_render_faces( m_faceCentroidPoints, GL_POINTS ),
		m_render_vertices( m_uniqueVertexPoints, GL_POINTS ),
		m_render_deepvertices( m_uniqueVertexPoints, GL_POINTS ),
		m_render_edges( m_uniqueEdgePoints, GL_POINTS ),
		m_evaluateTransform( evaluateTransform ),
		m_boundsChanged( boundsChanged ),
		m_planeChanged( false ),
		m_transformChanged( false ){
		copy( other );
	}
	Brush( const Brush& other ) :
		TransformNode( other ),
		Bounded( other ),
		Cullable( other ),
		Snappable(),
		Undoable( other ),
		FaceObserver( other ),
		Filterable( other ),
		Nameable( other ),
		BrushDoom3( other ),
		m_node( 0 ),
		m_undoable_observer( 0 ),
		m_map( 0 ),
		m_render_faces( m_faceCentroidPoints, GL_POINTS ),
		m_render_vertices( m_uniqueVertexPoints, GL_POINTS ),
		m_render_deepvertices( m_uniqueVertexPoints, GL_POINTS ),
		m_render_edges( m_uniqueEdgePoints, GL_POINTS ),
		m_planeChanged( false ),
		m_transformChanged( false ){
		copy( other );
	}
	~Brush(){
		ASSERT_MESSAGE( m_observers.empty(), "Brush::~Brush: observers still attached" );
	}

// assignment not supported
	Brush& operator=( const Brush& other ) = delete;

	void setDoom3GroupOrigin( const Vector3& origin ){
		//globalOutputStream() << "func_static origin before: " << m_funcStaticOrigin << " after: " << origin << '\n';
		for ( Faces::iterator i = m_faces.begin(); i != m_faces.end(); ++i )
		{
			( *i )->getPlane().m_funcStaticOrigin = origin;
			( *i )->getPlane().updateTranslated();
			( *i )->planeChanged();
		}
		planeChanged();
	}

	void attach( BrushObserver& observer ){
		for ( Faces::iterator i = m_faces.begin(); i != m_faces.end(); ++i )
		{
			observer.push_back( *( *i ) );
		}

		for ( SelectableEdges::iterator i = m_select_edges.begin(); i != m_select_edges.end(); ++i )
		{
			observer.edge_push_back( *i );
		}

		for ( SelectableVertices::iterator i = m_select_vertices.begin(); i != m_select_vertices.end(); ++i )
		{
			observer.vertex_push_back( *i );
		}

		m_observers.insert( &observer );
	}
	void detach( BrushObserver& observer ){
		m_observers.erase( &observer );
	}

	void forEachFace( const BrushVisitor& visitor ) const {
		for ( Faces::const_iterator i = m_faces.begin(); i != m_faces.end(); ++i )
		{
			visitor.visit( *( *i ) );
		}
	}

	void forEachFace_instanceAttach( MapFile* map ) const {
		for ( Faces::const_iterator i = m_faces.begin(); i != m_faces.end(); ++i )
		{
			( *i )->instanceAttach( map );
		}
	}
	void forEachFace_instanceDetach( MapFile* map ) const {
		for ( Faces::const_iterator i = m_faces.begin(); i != m_faces.end(); ++i )
		{
			( *i )->instanceDetach( map );
		}
	}

	InstanceCounter m_instanceCounter;
	void instanceAttach( const scene::Path& path ){
		if ( ++m_instanceCounter.m_count == 1 ) {
			m_map = path_find_mapfile( path.begin(), path.end() );
			m_undoable_observer = GlobalUndoSystem().observer( this );
			GlobalFilterSystem().registerFilterable( *this );
			forEachFace_instanceAttach( m_map );
		}
		else
		{
			ASSERT_MESSAGE( path_find_mapfile( path.begin(), path.end() ) == m_map, "node is instanced across more than one file" );
		}
	}
	void instanceDetach( const scene::Path& path ){
		if ( --m_instanceCounter.m_count == 0 ) {
			forEachFace_instanceDetach( m_map );
			GlobalFilterSystem().unregisterFilterable( *this );
			m_map = 0;
			m_undoable_observer = 0;
			GlobalUndoSystem().release( this );
		}
	}

// nameable
	const char* name() const {
		return "brush";
	}
	void attach( const NameCallback& callback ){
	}
	void detach( const NameCallback& callback ){
	}

// filterable
	void updateFiltered(){
		if ( m_node != 0 ) {
			if ( brush_filtered( *this ) ) {
				m_node->enable( scene::Node::eFiltered );
			}
			else
			{
				m_node->disable( scene::Node::eFiltered );
			}
		}
	}

// observer
	void planeChanged(){
		/* m_BRep_evaluation mutex prevents cyclic dependency:
		transformModifier.set ; transformChanged() ; planeChanged() ; pivotChanged() ; sceneChangeNotify() ;
		sceneRender() ; localAABB ; evaluateBRep ; buildBRep() ; evaluateTransform ; !!!problem starts here!!!! planeChanged() ; pivotChanged() ; sceneChangeNotify() ;
		sceneRender() ; localAABB ; evaluateBRep ; buildBRep() ; */
		if( !m_BRep_evaluation ){
			m_planeChanged = true;
			aabbChanged();
			m_lightsChanged();
		}
	}
	void shaderChanged(){
		updateFiltered();
		planeChanged(); ///isn't too much for shader changed only?
	}

	void evaluateBRep() const {
		if ( m_planeChanged ) {
			m_planeChanged = false;
			const_cast<Brush*>( this )->buildBRep();
		}
	}

	void transformChanged(){
		planeChanged();
		m_transformChanged = true;
	}
	typedef MemberCaller<Brush, &Brush::transformChanged> TransformChangedCaller;

	void evaluateTransform(){
		if ( m_transformChanged ) {
			revertTransform();
			m_evaluateTransform();
			m_transformChanged = false;
		}
	}
	const Matrix4& localToParent() const {
		return g_matrix4_identity;
	}
	void aabbChanged(){
		m_boundsChanged();
	}
	const AABB& localAABB() const {
		evaluateBRep();
		return m_aabb_local;
	}

	VolumeIntersectionValue intersectVolume( const VolumeTest& test, const Matrix4& localToWorld ) const {
		return test.TestAABB( m_aabb_local, localToWorld );
	}

	void renderComponents( SelectionSystem::EComponentMode mode, Renderer& renderer, const VolumeTest& volume, const Matrix4& localToWorld ) const {
		switch ( mode )
		{
		case SelectionSystem::eVertex:
			{
				if( volume.fill() ){
					renderer.SetState( m_state_deeppoint, Renderer::eFullMaterials );
					renderer.addRenderable( m_render_deepvertices, localToWorld );
				}
				else{
					for( auto& p : m_uniqueVertexPoints )
						p.colour = colour_vertex;
					renderer.addRenderable( m_render_vertices, localToWorld );
				}
			}
			break;
		case SelectionSystem::eEdge:
			renderer.addRenderable( m_render_edges, localToWorld );
			break;
		case SelectionSystem::eFace:
			renderer.addRenderable( m_render_faces, localToWorld );
			break;
		default:
			break;
		}
	}

	void transform( const Matrix4& matrix ){
		bool mirror = matrix4_handedness( matrix ) == MATRIX4_LEFTHANDED;

		for ( Faces::iterator i = m_faces.begin(); i != m_faces.end(); ++i )
		{
			( *i )->transform( matrix, mirror );
		}
	}
	void snapto( float snap ){
		for ( Observers::iterator i = m_observers.begin(); i != m_observers.end(); ++i )
		{
			( *i )->vertex_snap( snap );
		}
//		for ( Faces::iterator i = m_faces.begin(); i != m_faces.end(); ++i )
//		{
//			( *i )->snapto( snap );
//		}
	}
	void revertTransform(){
		for ( Faces::iterator i = m_faces.begin(); i != m_faces.end(); ++i )
		{
			( *i )->revertTransform();
		}
	}
	void freezeTransform(){
		for ( Faces::iterator i = m_faces.begin(); i != m_faces.end(); ++i )
		{
			( *i )->freezeTransform();
		}
		m_transformChanged = false;
	}

	class VertexModeVertex
	{
	public:
		const DoubleVector3 m_vertex;
		DoubleVector3 m_vertexTransformed;
		const bool m_selected;
		std::vector<const Face*> m_faces;
		VertexModeVertex( const DoubleVector3& vertex, const bool selected ) : m_vertex( vertex ), m_vertexTransformed( vertex ), m_selected( selected ) {
		}
	};
	typedef std::vector<VertexModeVertex> VertexModeVertices;


	VertexModeVertices m_vertexModeVertices;
	bool m_vertexModeOn{false};

	void vertexModeInit(){
		m_vertexModeOn = true;
		m_vertexModeVertices.clear();
		undoSave();
	}

	void vertexModeFree(){
		m_vertexModeOn = false;
//		m_vertexModeVertices.clear(); //keep, as it may be required by buildBRep() after this call
	}

	void vertexModeTransform( const Matrix4& matrix );
	void vertexModeBuildHull( bool allTransformed = false );
	void vertexModeSnap( const float snap, bool all );

/// \brief Returns the absolute index of the \p faceVertex.
	std::size_t absoluteIndex( FaceVertexId faceVertex ){
		std::size_t index = 0;
		for ( std::size_t i = 0; i < faceVertex.getFace(); ++i )
		{
			index += m_faces[i]->getWinding().numpoints;
		}
		return index + faceVertex.getVertex();
	}

	void appendFaces( const Faces& other ){
		clear();
		for ( Faces::const_iterator i = other.begin(); i != other.end(); ++i )
		{
			push_back( *i );
		}
	}

/// \brief The undo memento for a brush stores only the list of face references - the faces are not copied.
	class BrushUndoMemento : public UndoMemento
	{
	public:
		BrushUndoMemento( const Faces& faces ) : m_faces( faces ){
		}
		void release(){
			delete this;
		}

		Faces m_faces;
	};

	void undoSave(){
		if ( m_map != 0 ) {
			m_map->changed();
		}
		if ( m_undoable_observer != 0 ) {
			m_undoable_observer->save( this );
		}
	}

	UndoMemento* exportState() const {
		return new BrushUndoMemento( m_faces );
	}

	void importState( const UndoMemento* state ){
		undoSave();
		appendFaces( static_cast<const BrushUndoMemento*>( state )->m_faces );
		planeChanged();

		for ( Observers::iterator i = m_observers.begin(); i != m_observers.end(); ++i )
		{
			( *i )->DEBUG_verify();
		}
	}

	bool isDetail(){
		return !m_faces.empty() && m_faces.front()->isDetail();
	}

/// \brief Appends a copy of \p face to the end of the face list.
	Face* addFace( const Face& face ){
		if ( m_faces.size() == c_brush_maxFaces ) {
			return 0;
		}
		undoSave();
		push_back( FaceSmartPointer( new Face( face, this ) ) );
		m_faces.back()->setDetail( isDetail() );
		planeChanged();
		return m_faces.back();
	}

/// \brief Appends a new face constructed from the parameters to the end of the face list.
	Face* addPlane( const DoubleVector3& p0, const DoubleVector3& p1, const DoubleVector3& p2, const char* shader, const TextureProjection& projection ){
		if ( m_faces.size() == c_brush_maxFaces ) {
			return 0;
		}
		undoSave();
		push_back( FaceSmartPointer( new Face( p0, p1, p2, shader, projection, this ) ) );
		m_faces.back()->setDetail( isDetail() );
		planeChanged();
		return m_faces.back();
	}

	static void constructStatic( EBrushType type ){
		m_type = type;
		Face::m_type = type;
		FacePlane::m_type = type;

		g_bp_globals.m_texdefTypeId = BrushType_getTexdefType( type );

		m_state_point = GlobalShaderCache().capture( "$POINT" );
		m_state_deeppoint = GlobalShaderCache().capture( "$DEEPPOINT" );
	}
	static void destroyStatic(){
		GlobalShaderCache().release( "$POINT" );
		GlobalShaderCache().release( "$DEEPPOINT" );
	}

	std::size_t DEBUG_size(){
		return m_faces.size();
	}

	typedef Faces::const_iterator const_iterator;

	const_iterator begin() const {
		return m_faces.begin();
	}
	const_iterator end() const {
		return m_faces.end();
	}

	Face* back(){
		return m_faces.back();
	}
	const Face* back() const {
		return m_faces.back();
	}
	void reserve( std::size_t count ){
		m_faces.reserve( count );
		for ( Observers::iterator i = m_observers.begin(); i != m_observers.end(); ++i )
		{
			( *i )->reserve( count );
		}
	}
	void push_back( Faces::value_type face ){
		m_faces.push_back( face );
		if ( m_instanceCounter.m_count != 0 ) {
			m_faces.back()->instanceAttach( m_map );
		}
		for ( Observers::iterator i = m_observers.begin(); i != m_observers.end(); ++i )
		{
			( *i )->push_back( *face );
			( *i )->DEBUG_verify();
		}
	}
	void pop_back(){
		if ( m_instanceCounter.m_count != 0 ) {
			m_faces.back()->instanceDetach( m_map );
		}
		m_faces.pop_back();
		for ( Observers::iterator i = m_observers.begin(); i != m_observers.end(); ++i )
		{
			( *i )->pop_back();
			( *i )->DEBUG_verify();
		}
	}
	void erase( std::size_t index ){
		if ( m_instanceCounter.m_count != 0 ) {
			m_faces[index]->instanceDetach( m_map );
		}
		m_faces.erase( m_faces.begin() + index );
		for ( Observers::iterator i = m_observers.begin(); i != m_observers.end(); ++i )
		{
			( *i )->erase( index );
			( *i )->DEBUG_verify();
		}
	}
	void connectivityChanged(){
		for ( Observers::iterator i = m_observers.begin(); i != m_observers.end(); ++i )
		{
			( *i )->connectivityChanged();
		}
	}


	void clear(){
		undoSave();
		if ( m_instanceCounter.m_count != 0 ) {
			forEachFace_instanceDetach( m_map );
		}
		m_faces.clear();
		for ( Observers::iterator i = m_observers.begin(); i != m_observers.end(); ++i )
		{
			( *i )->clear();
			( *i )->DEBUG_verify();
		}
	}
	std::size_t size() const {
		return m_faces.size();
	}
	bool empty() const {
		return m_faces.empty();
	}

/// \brief Returns true if any face of the brush contributes to the final B-Rep.
	bool hasContributingFaces() const {
		for ( const_iterator i = begin(); i != end(); ++i )
		{
			if ( ( *i )->contributes() ) {
				return true;
			}
		}
		return false;
	}

/// \brief Removes faces that do not contribute to the brush. This is useful for cleaning up after CSG operations on the brush.
/// Note: removal of empty faces is not performed during direct brush manipulations, because it would make a manipulation irreversible if it created an empty face.
	void removeEmptyFaces(){
		evaluateBRep();

		{
			std::size_t i = 0;
			while ( i < m_faces.size() )
			{
				if ( !m_faces[i]->contributes() ) {
					erase( i );
					planeChanged();
				}
				else
				{
					++i;
				}
			}
		}
	}

/// \brief Constructs \p winding from the intersection of \p plane with the other planes of the brush.
	void windingForClipPlane( Winding& winding, const Plane3& plane ) const {
		FixedWinding buffer[2];
		bool swap = false;

		// get a poly that covers an effectively infinite area
		Winding_createInfinite( buffer[swap], plane, m_maxWorldCoord );

		// chop the poly by all of the other faces
		{
			for ( std::size_t i = 0; i < m_faces.size(); ++i )
			{
				const Face& clip = *m_faces[i];

				if ( plane3_equal( clip.plane3(), plane )
				  || !plane3_valid( clip.plane3() ) || !plane_unique( i )
				  || plane3_opposing( plane, clip.plane3() ) ) {
					continue;
				}

				if( buffer[swap].points.empty() ){
					//globalErrorStream() << "windingForClipPlane: about to feed empty winding to Winding_Clip\n";
					break;
				}

				buffer[!swap].clear();

#if BRUSH_CONNECTIVITY_DEBUG
				globalOutputStream() << "clip vs face: " << i << '\n';
#endif

				{
					// flip the plane, because we want to keep the back side
					Plane3 clipPlane( vector3_negated( clip.plane3().normal() ), -clip.plane3().dist() );
					Winding_Clip( buffer[swap], plane, clipPlane, i, buffer[!swap] );
				}

#if BRUSH_CONNECTIVITY_DEBUG
				for ( FixedWinding::Points::iterator k = buffer[!swap].points.begin(), j = buffer[!swap].points.end() - 1; k != buffer[!swap].points.end(); j = k, ++k )
				{
					if ( vector3_length_squared( vector3_subtracted( ( *k ).vertex, ( *j ).vertex ) ) < 1 ) {
						globalOutputStream() << "v: " << std::distance( buffer[!swap].points.begin(), j ) << " tiny edge adjacent to face " << ( *j ).adjacent << '\n';
					}
				}
#endif

				//ASSERT_MESSAGE(buffer[!swap].numpoints != 1, "created single-point winding");

				swap = !swap;
			}
		}

		Winding_forFixedWinding( winding, buffer[swap] );

#if BRUSH_CONNECTIVITY_DEBUG
		Winding_printConnectivity( winding );

		for ( Winding::iterator i = winding.begin(), j = winding.end() - 1; i != winding.end(); j = i, ++i )
		{
			if ( vector3_length_squared( vector3_subtracted( ( *i ).vertex, ( *j ).vertex ) ) < 1 ) {
				globalOutputStream() << "v: " << std::distance( winding.begin(), j ) << " tiny edge adjacent to face " << ( *j ).adjacent << '\n';
			}
		}
#endif
	}

	void update_wireframe( RenderableWireframe& wire, const bool* faces_visible ) const {
		wire.m_faceVertex.resize( m_edge_indices.size() );
		wire.m_vertices = m_uniqueVertexPoints.data();
		wire.m_size = 0;
		for ( std::size_t i = 0; i < m_edge_faces.size(); ++i )
		{
			if ( faces_visible[m_edge_faces[i].first]
			  || faces_visible[m_edge_faces[i].second] ) {
				wire.m_faceVertex[wire.m_size++] = m_edge_indices[i];
			}
		}
	}


	void update_faces_wireframe( Array<PointVertex>& wire, const bool* faces_visible ) const {
		std::size_t count = 0;
		for ( std::size_t i = 0; i < m_faceCentroidPoints.size(); ++i )
		{
			if ( faces_visible[i] ) {
				++count;
			}
		}

		wire.resize( count );
		Array<PointVertex>::iterator p = wire.begin();
		for ( std::size_t i = 0; i < m_faceCentroidPoints.size(); ++i )
		{
			if ( faces_visible[i] ) {
				*p++ = m_faceCentroidPoints[i];
			}
		}
	}

/// \brief Makes this brush a deep-copy of the \p other.
	void copy( const Brush& other ){
		for ( Faces::const_iterator i = other.m_faces.begin(); i != other.m_faces.end(); ++i )
		{
			addFace( *( *i ) );
		}
		planeChanged();
	}

/// for the only use to quickly check, if about to be transformed brush makes sense
	bool contributes() const {
		/* plane_unique() ripoff, calling no evaluation */
		auto plane_unique_ = [this]( std::size_t index ) -> bool {
			// duplicate plane
			for ( std::size_t i = 0; i < m_faces.size(); ++i )
			{
				if ( index != i && !plane3_inside( m_faces[index]->plane3_(), m_faces[i]->plane3_(), index < i ) ) {
					return false;
				}
			}
			return true;
		};

		/* windingForClipPlane() ripoff, calling no evaluation */
		auto windingForClipPlane_ = [this, &plane_unique_]( const Plane3& plane ) -> bool {
			FixedWinding buffer[2];
			bool swap = false;

			// get a poly that covers an effectively infinite area
			Winding_createInfinite( buffer[swap], plane, m_maxWorldCoord );

			// chop the poly by all of the other faces
			for ( std::size_t i = 0; i < m_faces.size(); ++i )
			{
				const Face& clip = *m_faces[i];

				if ( plane3_equal( clip.plane3_(), plane )
				  || !plane3_valid( clip.plane3_() ) || !plane_unique_( i )
				  || plane3_opposing( plane, clip.plane3_() ) ) {
					continue;
				}

				if( buffer[swap].points.empty() ){
					break;
				}

				buffer[!swap].clear();

				{
					// flip the plane, because we want to keep the back side
					Plane3 clipPlane( vector3_negated( clip.plane3_().normal() ), -clip.plane3_().dist() );
					Winding_Clip( buffer[swap], plane, clipPlane, i, buffer[!swap] );
				}
				swap = !swap;
			}

			return buffer[swap].size() > 2;
		};


		std::size_t contributing = 0;

		for ( std::size_t i = 0; i < m_faces.size(); ++i )
		{
			Face& f = *m_faces[i];

			if ( plane3_valid( f.plane3_() ) && plane_unique_( i ) ) {
				if( windingForClipPlane_( f.plane3_() ) ){
					++contributing;
					if( contributing > 3 )
						return true;
				}
			}
		}
		return false;
	}

private:
	void edge_push_back( FaceVertexId faceVertex ){
		m_select_edges.push_back( SelectableEdge( m_faces, faceVertex ) );
		for ( Observers::iterator i = m_observers.begin(); i != m_observers.end(); ++i )
		{
			( *i )->edge_push_back( m_select_edges.back() );
		}
	}
	void edge_clear(){
		m_select_edges.clear();
		for ( Observers::iterator i = m_observers.begin(); i != m_observers.end(); ++i )
		{
			( *i )->edge_clear();
		}
	}
	void vertex_push_back( FaceVertexId faceVertex ){
		m_select_vertices.push_back( SelectableVertex( m_faces, faceVertex ) );
		for ( Observers::iterator i = m_observers.begin(); i != m_observers.end(); ++i )
		{
			( *i )->vertex_push_back( m_select_vertices.back() );
		}
	}
	void vertex_clear(){
		m_select_vertices.clear();
		for ( Observers::iterator i = m_observers.begin(); i != m_observers.end(); ++i )
		{
			( *i )->vertex_clear();
		}
	}

/// \brief Returns true if the face identified by \p index is preceded by another plane that takes priority over it.
	bool plane_unique( std::size_t index ) const {
		// duplicate plane
		for ( std::size_t i = 0; i < m_faces.size(); ++i )
		{
			if ( index != i && !plane3_inside( m_faces[index]->plane3(), m_faces[i]->plane3(), index < i ) ) {
				return false;
			}
		}
		return true;
	}

/// \brief Removes edges that are smaller than the tolerance used when generating brush windings.
	void removeDegenerateEdges(){
		for ( std::size_t i = 0; i < m_faces.size(); ++i )
		{
			Winding& winding = m_faces[i]->getWinding();
			for ( Winding::iterator j = winding.begin(); j != winding.end(); )
			{
				std::size_t index = std::distance( winding.begin(), j );
				std::size_t next = Winding_next( winding, index );
				if ( Edge_isDegenerate( winding[index].vertex, winding[next].vertex ) ) {
#if BRUSH_DEGENERATE_DEBUG
					globalOutputStream() << "Brush::buildWindings: face " << i << ": degenerate edge adjacent to " << winding[index].adjacent << '\n';
#endif
					Winding& other = m_faces[winding[index].adjacent]->getWinding();
					std::size_t adjacent = Winding_FindAdjacent( other, i );
					if ( adjacent != c_brush_maxFaces ) {
						other.erase( other.begin() + adjacent );
					}
					winding.erase( j );
				}
				else
				{
					++j;
				}
			}
		}
	}

/// \brief Invalidates faces that have only two vertices in their winding, while preserving edge-connectivity information.
	void removeDegenerateFaces(){
		// save adjacency info for degenerate faces
		for ( std::size_t i = 0; i < m_faces.size(); ++i )
		{
			Winding& degen = m_faces[i]->getWinding();

			if ( degen.numpoints == 2 ) {
#if BRUSH_DEGENERATE_DEBUG
				globalOutputStream() << "Brush::buildWindings: face " << i << ": degenerate winding adjacent to " << degen[0].adjacent << ", " << degen[1].adjacent << '\n';
#endif
				// this is an "edge" face, where the plane touches the edge of the brush
				{
					Winding& winding = m_faces[degen[0].adjacent]->getWinding();
					std::size_t index = Winding_FindAdjacent( winding, i );
					if ( index != c_brush_maxFaces ) {
#if BRUSH_DEGENERATE_DEBUG
						globalOutputStream() << "Brush::buildWindings: face " << degen[0].adjacent << ": remapping adjacent " << winding[index].adjacent << " to " << degen[1].adjacent << '\n';
#endif
						winding[index].adjacent = degen[1].adjacent;
					}
				}

				{
					Winding& winding = m_faces[degen[1].adjacent]->getWinding();
					std::size_t index = Winding_FindAdjacent( winding, i );
					if ( index != c_brush_maxFaces ) {
#if BRUSH_DEGENERATE_DEBUG
						globalOutputStream() << "Brush::buildWindings: face " << degen[1].adjacent << ": remapping adjacent " << winding[index].adjacent << " to " << degen[0].adjacent << '\n';
#endif
						winding[index].adjacent = degen[0].adjacent;
					}
				}

				degen.resize( 0 );
			}
		}
	}

/// \brief Removes edges that have the same adjacent-face as their immediate neighbour.
	void removeDuplicateEdges(){
		// verify face connectivity graph
		for ( std::size_t i = 0; i < m_faces.size(); ++i )
		{
			//if(m_faces[i]->contributes())
			{
				Winding& winding = m_faces[i]->getWinding();
				for ( std::size_t j = 0; j != winding.numpoints; )
				{
					std::size_t next = Winding_next( winding, j );
					if ( winding[j].adjacent == winding[next].adjacent ) {
#if BRUSH_DEGENERATE_DEBUG
						globalOutputStream() << "Brush::buildWindings: face " << i << ": removed duplicate edge adjacent to face " << winding[j].adjacent << '\n';
#endif
						winding.erase( winding.begin() + next );
					}
					else
					{
						++j;
					}
				}
			}
		}
	}

/// \brief Removes edges that do not have a matching pair in their adjacent-face.
	void verifyConnectivityGraph(){
		// verify face connectivity graph
		for ( std::size_t i = 0; i < m_faces.size(); ++i )
		{
			//if(m_faces[i]->contributes())
			{
				Winding& winding = m_faces[i]->getWinding();
				for ( Winding::iterator j = winding.begin(); j != winding.end(); )
				{
#if BRUSH_CONNECTIVITY_DEBUG
					globalOutputStream() << "Brush::buildWindings: face " << i << ": adjacent to face " << ( *j ).adjacent << '\n';
#endif
					// remove unidirectional graph edges
					if ( ( *j ).adjacent == c_brush_maxFaces
					  || Winding_FindAdjacent( m_faces[( *j ).adjacent]->getWinding(), i ) == c_brush_maxFaces ) {
#if BRUSH_CONNECTIVITY_DEBUG
						globalOutputStream() << "Brush::buildWindings: face " << i << ": removing unidirectional connectivity graph edge adjacent to face " << ( *j ).adjacent << '\n';
#endif
						winding.erase( j );
					}
					else
					{
						++j;
					}
				}
			}
		}
	}

/// \brief Returns true if the brush is a finite volume. A brush without a finite volume extends past the maximum world bounds and is not valid.
	bool isBounded(){
		for ( const_iterator i = begin(); i != end(); ++i )
		{
			if ( !( *i )->is_bounded() ) {
				return false;
			}
		}
		return true;
	}

/// \brief Constructs the polygon windings for each face of the brush. Also updates the brush bounding-box and face texture-coordinates.
	bool buildWindings(){

		{
			m_aabb_local = AABB();

			if( m_faces.size() )
				m_faces[0]->plane3(); //force evaluateTransform() first, as m_faces is changed during vertexModeTransform

			for ( std::size_t i = 0; i < m_faces.size(); ++i )
			{
				Face& f = *m_faces[i];

				if ( !plane3_valid( f.plane3() ) || !plane_unique( i ) ) {
					f.getWinding().resize( 0 );
				}
				else
				{
#if BRUSH_CONNECTIVITY_DEBUG
					globalOutputStream() << "face: " << i << '\n';
#endif
					windingForClipPlane( f.getWinding(), f.plane3() );

					// update brush bounds
					const Winding& winding = f.getWinding();
					for ( Winding::const_iterator i = winding.begin(); i != winding.end(); ++i )
					{
						aabb_extend_by_point_safe( m_aabb_local, ( *i ).vertex );
					}

					// update texture coordinates
					f.EmitTextureCoordinates();
				}
			}
		}

		bool degenerate = !isBounded();

		if ( !degenerate ) {
			// clean up connectivity information.
			// these cleanups must be applied in a specific order.
			removeDegenerateEdges();
			removeDegenerateFaces();
			removeDuplicateEdges();
			verifyConnectivityGraph();
		}

		return degenerate;
	}

/// \brief Constructs the face windings and updates anything that depends on them.
	void buildBRep();
};



class FaceInstance;

class FaceInstanceSet
{
	typedef SelectionList<FaceInstance> FaceInstances;
	FaceInstances m_faceInstances;
public:
	void insert( FaceInstance& faceInstance ){
		m_faceInstances.append( faceInstance );
	}
	void erase( FaceInstance& faceInstance ){
		m_faceInstances.erase( faceInstance );
	}

	template<typename Functor>
	void foreach( Functor functor ){
		for ( FaceInstances::iterator i = m_faceInstances.begin(); i != m_faceInstances.end(); ++i )
		{
			functor( *( *i ) );
		}
	}

	bool empty() const {
		return m_faceInstances.empty();
	}
	FaceInstance& last() const {
		return m_faceInstances.back();
	}
};

extern FaceInstanceSet g_SelectedFaceInstances;

typedef std::list<std::size_t> VertexSelection;

inline VertexSelection::iterator VertexSelection_find( VertexSelection& self, std::size_t value ){
	return std::find( self.begin(), self.end(), value );
}

inline VertexSelection::const_iterator VertexSelection_find( const VertexSelection& self, std::size_t value ){
	return std::find( self.begin(), self.end(), value );
}

inline VertexSelection::iterator VertexSelection_insert( VertexSelection& self, std::size_t value ){
	VertexSelection::iterator i = VertexSelection_find( self, value );
	if ( i == self.end() ) {
		self.push_back( value );
		return --self.end();
	}
	return i;
}
inline void VertexSelection_erase( VertexSelection& self, std::size_t value ){
	VertexSelection::iterator i = VertexSelection_find( self, value );
	if ( i != self.end() ) {
		self.erase( i );
	}
}

inline bool triangle_reversed( std::size_t x, std::size_t y, std::size_t z ){
	return !( ( x < y && y < z ) || ( z < x && x < y ) || ( y < z && z < x ) );
}
template<typename Element>
inline Vector3 triangle_cross( const BasicVector3<Element>& x, const BasicVector3<Element> y, const BasicVector3<Element>& z ){
	return vector3_cross( y - x, z - x );
}
template<typename Element>
inline bool triangles_same_winding( const BasicVector3<Element>& x1, const BasicVector3<Element> y1, const BasicVector3<Element>& z1, const BasicVector3<Element>& x2, const BasicVector3<Element> y2, const BasicVector3<Element>& z2 ){
	return vector3_dot( triangle_cross( x1, y1, z1 ), triangle_cross( x2, y2, z2 ) ) > 0;
}


class VectorLightList : public LightList
{
	typedef std::vector<const RendererLight*> Lights;
	Lights m_lights;
public:
	void addLight( const RendererLight& light ){
		m_lights.push_back( &light );
	}
	void clear(){
		m_lights.clear();
	}
	void evaluateLights() const {
	}
	void lightsChanged() const {
	}
	void forEachLight( const RendererLightCallback& callback ) const {
		for ( Lights::const_iterator i = m_lights.begin(); i != m_lights.end(); ++i )
		{
			callback( *( *i ) );
		}
	}
};


class FaceInstance
{
	Face* m_face;
	ObservedSelectable m_selectable;
	ObservedSelectable m_selectableVertices;
	ObservedSelectable m_selectableEdges;
	SelectionChangeCallback m_selectionChanged;

	VertexSelection m_vertexSelection;
	VertexSelection m_edgeSelection;

public:
	mutable VectorLightList m_lights;

	FaceInstance( Face& face, const SelectionChangeCallback& observer ) :
		m_face( &face ),
		m_selectable( SelectedChangedCaller( *this ) ),
		m_selectableVertices( observer ),
		m_selectableEdges( observer ),
		m_selectionChanged( observer ){
	}
	FaceInstance( const FaceInstance& other ) :
		m_face( other.m_face ),
		m_selectable( SelectedChangedCaller( *this ) ),
		m_selectableVertices( other.m_selectableVertices ),
		m_selectableEdges( other.m_selectableEdges ),
		m_selectionChanged( other.m_selectionChanged ){
	}
	FaceInstance& operator=( const FaceInstance& other ){
		m_face = other.m_face;
		return *this;
	}

	Face& getFace(){
		return *m_face;
	}
	const Face& getFace() const {
		return *m_face;
	}

	void selectedChanged( const Selectable& selectable ){
		if ( selectable.isSelected() ) {
			g_SelectedFaceInstances.insert( *this );
		}
		else
		{
			g_SelectedFaceInstances.erase( *this );
		}
		m_selectionChanged( selectable );
	}
	typedef MemberCaller1<FaceInstance, const Selectable&, &FaceInstance::selectedChanged> SelectedChangedCaller;

	bool selectedVertices() const {
		return !m_vertexSelection.empty();
	}
	bool selectedEdges() const {
		return !m_edgeSelection.empty();
	}
	bool isSelected() const {
		return m_selectable.isSelected();
	}

	bool selectedComponents() const {
		return selectedVertices() || selectedEdges() || isSelected();
	}
	bool selectedComponents( SelectionSystem::EComponentMode mode ) const {
		switch ( mode )
		{
		case SelectionSystem::eVertex:
			return selectedVertices();
		case SelectionSystem::eEdge:
			return selectedEdges();
		case SelectionSystem::eFace:
			return isSelected();
		default:
			return false;
		}
	}
	void setSelected( SelectionSystem::EComponentMode mode, bool select ){
		switch ( mode )
		{
		case SelectionSystem::eFace:
			m_selectable.setSelected( select );
			break;
		case SelectionSystem::eVertex:
			ASSERT_MESSAGE( !select, "select-all not supported" );

			m_vertexSelection.clear();
			m_selectableVertices.setSelected( false );
			break;
		case SelectionSystem::eEdge:
			ASSERT_MESSAGE( !select, "select-all not supported" );

			m_edgeSelection.clear();
			m_selectableEdges.setSelected( false );
			break;
		default:
			break;
		}
	}

	template<typename Functor>
	void SelectedVertices_foreach( Functor functor ) const {
		for ( VertexSelection::const_iterator i = m_vertexSelection.begin(); i != m_vertexSelection.end(); ++i )
		{
			std::size_t index = Winding_FindAdjacent( getFace().getWinding(), *i );
			if ( index != c_brush_maxFaces ) {
				functor( getFace().getWinding()[index].vertex );
			}
		}
	}
	template<typename Functor>
	void SelectedEdges_foreach( Functor functor ) const {
		for ( VertexSelection::const_iterator i = m_edgeSelection.begin(); i != m_edgeSelection.end(); ++i )
		{
			std::size_t index = Winding_FindAdjacent( getFace().getWinding(), *i );
			if ( index != c_brush_maxFaces ) {
				const Winding& winding = getFace().getWinding();
				std::size_t adjacent = Winding_next( winding, index );
				functor( vector3_mid( winding[index].vertex, winding[adjacent].vertex ) );
			}
		}
	}
	template<typename Functor>
	void SelectedFaces_foreach( Functor functor ) const {
		if ( isSelected() ) {
			functor( centroid() );
		}
	}

	template<typename Functor>
	void SelectedComponents_foreach( Functor functor ) const {
		SelectedVertices_foreach( functor );
		SelectedEdges_foreach( functor );
		SelectedFaces_foreach( functor );
	}

	void iterate_selected( AABB& aabb ) const {
		SelectedComponents_foreach( AABBExtendByPoint( aabb ) );
	}

	void gatherSelectedComponents( const Vector3Callback& callback ) const {
		const Winding& winding = getFace().getWinding();
		if( isSelected() )
			for ( std::size_t i = 0; i != winding.numpoints; ++i )
				callback( winding[i].vertex );
		for ( VertexSelection::const_iterator i = m_vertexSelection.begin(); i != m_vertexSelection.end(); ++i ){
			std::size_t index = Winding_FindAdjacent( winding, *i );
			if ( index != c_brush_maxFaces ) {
				callback( winding[index].vertex );
			}
		}
		for ( VertexSelection::const_iterator i = m_edgeSelection.begin(); i != m_edgeSelection.end(); ++i ){
			std::size_t index = Winding_FindAdjacent( winding, *i );
			if ( index != c_brush_maxFaces ) {
				std::size_t adjacent = Winding_next( winding, index );
				callback( winding[index].vertex );
				callback( winding[adjacent].vertex );
			}
		}
	}

	class RenderablePointVectorPushBack
	{
		RenderablePointVector& m_points;
	public:
		RenderablePointVectorPushBack( RenderablePointVector& points ) : m_points( points ){
		}
		void operator()( const Vector3& point ) const {
			m_points.push_back( pointvertex_for_windingpoint( point, colour_selected ) );
		}
	};

	void iterate_selected( RenderablePointVector& points ) const {
		SelectedComponents_foreach( RenderablePointVectorPushBack( points ) );
	}

	bool intersectVolume( const VolumeTest& volume, const Matrix4& localToWorld ) const {
		return m_face->intersectVolume( volume, localToWorld );
	}

	void render( Renderer& renderer, const VolumeTest& volume, const Matrix4& localToWorld ) const {
		if ( !m_face->isFiltered() && m_face->contributes() && intersectVolume( volume, localToWorld ) ) {
			renderer.PushState();
			renderer.Highlight( Renderer::ePrimitiveWire );
			if ( selectedComponents() ) {
				renderer.Highlight( Renderer::EHighlightMode( Renderer::eFace | Renderer::eFaceWire ) );
			}
			m_face->render( renderer, localToWorld );
			renderer.PopState();
		}
	}

	void testSelect( SelectionTest& test, SelectionIntersection& best ) const {
		if ( !m_face->isFiltered() ) {
			m_face->testSelect( test, best );
		}
	}
	void testSelect( Selector& selector, SelectionTest& test ){
		SelectionIntersection best;
		testSelect( test, best );
		if ( best.valid() ) {
			Selector_add( selector, m_selectable, best );
		}
	}
	void testSelect_centroid( Selector& selector, SelectionTest& test ){
		if ( m_face->contributes() && !m_face->isFiltered() ) {
			SelectionIntersection best;
			m_face->testSelect_centroid( test, best );
			if ( best.valid() ) {
				Selector_add( selector, m_selectable, best );
			}
		}
	}

	void addSelectable( Selector& selector ){
		Selector_add( selector, m_selectable );
	}

	void selectReversedPlane( Selector& selector, const SelectedPlanes& selectedPlanes ){
		if ( selectedPlanes.contains( plane3_flipped( getFace().plane3() ) ) ) {
			Selector_add( selector, m_selectable );
		}
	}

	bool trySelectPlane( const SelectionTest& test ){
		const Vector3 projected = vector4_projected( matrix4_transformed_vector4( test.getVolume().GetViewMatrix(), Vector4( getFace().centroid(), 1 ) ) );
		const Vector3 closest_point = vector4_projected( matrix4_transformed_vector4( test.getScreen2world(), Vector4( 0, 0, projected[2], 1 ) ) );
		for ( Winding::const_iterator i = getFace().getWinding().begin(); i != getFace().getWinding().end(); ++i ){
			if ( vector3_dot( getFace().plane3().normal(), closest_point - ( *i ).vertex ) < 0.005 ) /* epsilon to prevent almost perpendicular faces pickup */
				return false;
		}
		return true;
	}

	void transformComponents( const Matrix4& matrix ){
		if ( isSelected() ) {
			m_face->transform( matrix, false );
		}
		if ( selectedVertices() ) {
			if ( m_vertexSelection.size() == 1 ) {
				matrix4_transform_point( matrix, m_face->m_move_planeptsTransformed[1] );
				m_face->assign_planepts( m_face->m_move_planeptsTransformed );
			}
			else if ( m_vertexSelection.size() == 2 ) {
				matrix4_transform_point( matrix, m_face->m_move_planeptsTransformed[1] );
				matrix4_transform_point( matrix, m_face->m_move_planeptsTransformed[2] );
				m_face->assign_planepts( m_face->m_move_planeptsTransformed );
			}
			else if ( m_vertexSelection.size() >= 3 ) {
				matrix4_transform_point( matrix, m_face->m_move_planeptsTransformed[0] );
				matrix4_transform_point( matrix, m_face->m_move_planeptsTransformed[1] );
				matrix4_transform_point( matrix, m_face->m_move_planeptsTransformed[2] );
				m_face->assign_planepts( m_face->m_move_planeptsTransformed );
			}
		}
		if ( selectedEdges() ) {
			if ( m_edgeSelection.size() == 1 ) {
				matrix4_transform_point( matrix, m_face->m_move_planeptsTransformed[0] );
				matrix4_transform_point( matrix, m_face->m_move_planeptsTransformed[1] );
				m_face->assign_planepts( m_face->m_move_planeptsTransformed );
			}
			else if ( m_edgeSelection.size() >= 2 ) {
				matrix4_transform_point( matrix, m_face->m_move_planeptsTransformed[0] );
				matrix4_transform_point( matrix, m_face->m_move_planeptsTransformed[1] );
				matrix4_transform_point( matrix, m_face->m_move_planeptsTransformed[2] );
				m_face->assign_planepts( m_face->m_move_planeptsTransformed );
			}
		}
		if ( g_brush_textureVertexlock_enabled && ( selectedVertices() || selectedEdges() ) ) {
			m_face->texdef_from_points();
		}
	}

	void snapto( float snap ){
		m_face->snapto( snap );
	}

	void snapComponents( float snap ){
		if ( isSelected() ) {
			snapto( snap );
		}
		if ( selectedVertices() ) {
			vector3_snap( m_face->m_move_planepts[0], snap );
			vector3_snap( m_face->m_move_planepts[1], snap );
			vector3_snap( m_face->m_move_planepts[2], snap );
			m_face->assign_planepts( m_face->m_move_planepts );
			planepts_assign( m_face->m_move_planeptsTransformed, m_face->m_move_planepts );
			m_face->freezeTransform();
		}
		if ( selectedEdges() ) {
			vector3_snap( m_face->m_move_planepts[0], snap );
			vector3_snap( m_face->m_move_planepts[1], snap );
			vector3_snap( m_face->m_move_planepts[2], snap );
			m_face->assign_planepts( m_face->m_move_planepts );
			planepts_assign( m_face->m_move_planeptsTransformed, m_face->m_move_planepts );
			m_face->freezeTransform();
		}
	}
#if Update_move_planepts_vertex
	void update_move_planepts_vertex( std::size_t index ){
		m_face->update_move_planepts_vertex( index, m_face->m_move_planepts );
	}
	void update_move_planepts_vertex2( std::size_t index, std::size_t other ){
		if( m_face->contributes() ){
			const std::size_t numpoints = m_face->getWinding().numpoints;
			ASSERT_MESSAGE( index < numpoints, "select_vertex: invalid index" );

			const std::size_t opposite = Winding_Opposite( m_face->getWinding(), index, other );

			if ( triangle_reversed( index, other, opposite ) ) {
				std::swap( index, other );
			}

			///! this actually happens with ON_EPSILON 1.0 / ( 1 << 8 )
			ASSERT_MESSAGE(
			    triangles_same_winding(
			        m_face->getWinding()[opposite].vertex,
			        m_face->getWinding()[index].vertex,
			        m_face->getWinding()[other].vertex,
			        m_face->getWinding()[0].vertex,
			        m_face->getWinding()[1].vertex,
			        m_face->getWinding()[2].vertex
			    ),
			    "update_move_planepts_vertex2: error"
			);

			m_face->m_move_planepts[0] = m_face->getWinding()[opposite].vertex;
			m_face->m_move_planepts[1] = m_face->getWinding()[index].vertex;
			m_face->m_move_planepts[2] = m_face->getWinding()[other].vertex;
			planepts_quantise( m_face->m_move_planepts, GRID_MIN ); // winding points are very inaccurate
		}
	}
#endif
	void update_selection_vertex(){
		if ( m_vertexSelection.size() == 0 ) {
			m_selectableVertices.setSelected( false );
		}
		else
		{
			m_selectableVertices.setSelected( true );
#if Update_move_planepts_vertex
			if ( m_vertexSelection.size() == 1 ) {
				std::size_t index = Winding_FindAdjacent( getFace().getWinding(), *m_vertexSelection.begin() );

				if ( index != c_brush_maxFaces ) {
					update_move_planepts_vertex( index );
				}
			}
			else if ( m_vertexSelection.size() == 2 ) {
				std::size_t index = Winding_FindAdjacent( getFace().getWinding(), *m_vertexSelection.begin() );
				std::size_t other = Winding_FindAdjacent( getFace().getWinding(), *( ++m_vertexSelection.begin() ) );

				if ( index != c_brush_maxFaces
				  && other != c_brush_maxFaces ) {
					update_move_planepts_vertex2( index, other );
				}
			}
#endif
		}
	}
	void select_vertex( std::size_t index, bool select ){
		if ( select ) {
			VertexSelection_insert( m_vertexSelection, getFace().getWinding()[index].adjacent );
		}
		else
		{
			VertexSelection_erase( m_vertexSelection, getFace().getWinding()[index].adjacent );
		}

		SceneChangeNotify();
		update_selection_vertex();
	}

	bool selected_vertex( std::size_t index ) const {
		return VertexSelection_find( m_vertexSelection, getFace().getWinding()[index].adjacent ) != m_vertexSelection.end();
	}

	void update_move_planepts_edge( std::size_t index ){
		if( m_face->contributes() ){
			std::size_t numpoints = m_face->getWinding().numpoints;
			ASSERT_MESSAGE( index < numpoints, "select_edge: invalid index" );

			std::size_t adjacent = Winding_next( m_face->getWinding(), index );
			std::size_t opposite = Winding_Opposite( m_face->getWinding(), index );
			m_face->m_move_planepts[0] = m_face->getWinding()[index].vertex;
			m_face->m_move_planepts[1] = m_face->getWinding()[adjacent].vertex;
			m_face->m_move_planepts[2] = m_face->getWinding()[opposite].vertex;
//			planepts_quantise( m_face->m_move_planepts, GRID_MIN ); // winding points are very inaccurate
		}
	}
	void update_selection_edge(){
		if ( m_edgeSelection.size() == 0 ) {
			m_selectableEdges.setSelected( false );
		}
		else
		{
			m_selectableEdges.setSelected( true );

			if ( m_edgeSelection.size() == 1 ) {
				std::size_t index = Winding_FindAdjacent( getFace().getWinding(), *m_edgeSelection.begin() );

				if ( index != c_brush_maxFaces ) {
					update_move_planepts_edge( index );
				}
			}
		}
	}
	void select_edge( std::size_t index, bool select ){
		if ( select ) {
			VertexSelection_insert( m_edgeSelection, getFace().getWinding()[index].adjacent );
		}
		else
		{
			VertexSelection_erase( m_edgeSelection, getFace().getWinding()[index].adjacent );
		}

		SceneChangeNotify();
		update_selection_edge();
	}

	bool selected_edge( std::size_t index ) const {
		return VertexSelection_find( m_edgeSelection, getFace().getWinding()[index].adjacent ) != m_edgeSelection.end();
	}

	const Vector3& centroid() const {
		return m_face->centroid();
	}

	void connectivityChanged(){
		// This occurs when a face is added or removed.
		// The current vertex and edge selections no longer valid and must be cleared.
		m_vertexSelection.clear();
		m_selectableVertices.setSelected( false );
		m_edgeSelection.clear();
		m_selectableEdges.setSelected( false );
	}
};

class BrushClipPlane : public OpenGLRenderable
{
	Plane3 m_plane;
	Winding m_winding;
	static Shader* m_state;
public:
	static void constructStatic(){
		m_state = GlobalShaderCache().capture( "$CLIPPER_OVERLAY" );
	}
	static void destroyStatic(){
		GlobalShaderCache().release( "$CLIPPER_OVERLAY" );
	}

	void setPlane( const Brush& brush, const Plane3& plane ){
		m_plane = plane;
		if ( plane3_valid( m_plane ) ) {
			brush.windingForClipPlane( m_winding, m_plane );
		}
		else
		{
			m_winding.resize( 0 );
		}
	}

	void render( RenderStateFlags state ) const {
		if ( ( state & RENDER_FILL ) != 0 ) {
			Winding_Draw( m_winding, m_plane.normal(), state );
		}
		else
		{
			Winding_DrawWireframe( m_winding );

			// also draw a line indicating the direction of the cut
			Vector3 lineverts[2];
			Winding_Centroid( m_winding, m_plane, lineverts[0] );
			lineverts[1] = vector3_added( lineverts[0], vector3_scaled( m_plane.normal(), Brush::m_maxWorldCoord * 4 ) );

			gl().glVertexPointer( 3, GL_FLOAT, sizeof( Vector3 ), &lineverts[0] );
			gl().glDrawArrays( GL_LINES, 0, GLsizei( 2 ) );
		}
	}

	void render( Renderer& renderer, const VolumeTest& volume, const Matrix4& localToWorld ) const {
		renderer.SetState( m_state, Renderer::eWireframeOnly );
		renderer.SetState( m_state, Renderer::eFullMaterials );
		renderer.addRenderable( *this, localToWorld );
	}
};

inline void Face_addLight( const FaceInstance& face, const Matrix4& localToWorld, const RendererLight& light ){
	const Plane3& facePlane = face.getFace().plane3();
	const Vector3& origin = light.aabb().origin;
	Plane3 tmp( plane3_transformed( Plane3( facePlane.normal(), -facePlane.dist() ), localToWorld ) );
	if ( !plane3_test_point( tmp, origin )
	  || !plane3_test_point( tmp, vector3_added( origin, light.offset() ) ) ) {
		face.m_lights.addLight( light );
	}
}



typedef std::vector<FaceInstance> FaceInstances;
typedef std::vector<FaceInstance*> FaceInstances_ptrs;

class EdgeInstance : public Selectable
{
	FaceInstances& m_faceInstances;
	SelectableEdge* m_edge;

	void select_edge( bool select ){
		FaceVertexId faceVertex = m_edge->m_faceVertex;
		m_faceInstances[faceVertex.getFace()].select_edge( faceVertex.getVertex(), select );
		faceVertex = next_edge( m_edge->m_faces, faceVertex );
		m_faceInstances[faceVertex.getFace()].select_edge( faceVertex.getVertex(), select );
	}
	bool selected_edge() const {
		FaceVertexId faceVertex = m_edge->m_faceVertex;
		if ( !m_faceInstances[faceVertex.getFace()].selected_edge( faceVertex.getVertex() ) ) {
			return false;
		}
		faceVertex = next_edge( m_edge->m_faces, faceVertex );
		if ( !m_faceInstances[faceVertex.getFace()].selected_edge( faceVertex.getVertex() ) ) {
			return false;
		}

		return true;
	}

public:
	EdgeInstance( FaceInstances& faceInstances, SelectableEdge& edge )
		: m_faceInstances( faceInstances ), m_edge( &edge ){
	}
	EdgeInstance& operator=( const EdgeInstance& other ){
		m_edge = other.m_edge;
		return *this;
	}

	void setSelected( bool select ){
		select_edge( select );
	}
	bool isSelected() const {
		return selected_edge();
	}


	void testSelect( Selector& selector, SelectionTest& test ){
		SelectionIntersection best;
		m_edge->testSelect( test, best );
		if ( best.valid() ) {
			Selector_add( selector, *this, best );
		}
	}
	void gatherComponentsHighlight( std::vector<std::vector<Vector3>>& polygons, SelectionIntersection& intersection, SelectionTest& test ) const {
		SelectionIntersection best;
		m_edge->testSelect( test, best );
		if ( SelectionIntersection_closer( best, intersection ) ) {
			intersection = best;
			polygons.clear();
			polygons.emplace_back( std::initializer_list<Vector3>( { m_edge->getEdge() } ) );
		}
	}

	void bestPlaneIndirect( const SelectionTest& test, Plane3& plane, Vector3& intersection, float& dist, float& dot ) const {
		const Winding& winding = m_edge->getFace().getWinding();
		FaceVertexId faceVertex = m_edge->m_faceVertex;
		Line line( winding[faceVertex.getVertex()].vertex, winding[Winding_next( winding, faceVertex.getVertex() )].vertex );
		if( matrix4_clip_line_by_nearplane( test.getVolume().GetViewMatrix(), line ) == 2 ){
			const Vector3 intersection_new = line_closest_point( line, g_vector3_identity );
			const float dist_new = vector3_length_squared( intersection_new );
			const float dot_new = fabs( vector3_dot( vector3_normalised( intersection_new ), vector3_normalised( line.end - line.start ) ) );
			if( dist - dist_new > 1e-6f // new dist noticeably smaller
			 || ( float_equal_epsilon( dist_new, dist, 1e-6f ) && dot_new < dot ) ){ // or ambiguous case. Resolve it by dot comparison
				const Plane3& plane1 = m_faceInstances[faceVertex.getFace()].getFace().plane3();
				faceVertex = next_edge( m_edge->m_faces, faceVertex );
				const Plane3& plane2 = m_faceInstances[faceVertex.getFace()].getFace().plane3();

				auto assign_plane = [&plane, &intersection, intersection_new, &dist, dist_new, &dot, dot_new]( const Plane3& plane_new ){
					plane = plane_new;
					intersection = intersection_new;
					dist = dist_new;
					dot = dot_new;
				};

				if( test.getVolume().fill() ){
					if( plane3_distance_to_point( plane1, test.getVolume().getViewer() ) <= 0 )
						assign_plane( plane1 );
					else if( plane3_distance_to_point( plane2, test.getVolume().getViewer() ) <= 0 )
						assign_plane( plane2 );
				}
				else if( fabs( vector3_length_squared( line.end - line.start ) ) > 1e-3 ){
					if( fabs( vector3_dot( plane1.normal(), test.getVolume().getViewDir() ) ) < fabs( vector3_dot( plane2.normal(), test.getVolume().getViewDir() ) ) )
						assign_plane( plane1 );
					else
						assign_plane( plane2 );
				}
			}
		}
	}
};

class VertexInstance : public Selectable
{
	FaceInstances& m_faceInstances;
	SelectableVertex* m_vertex;

	void select_vertex( bool select ){
		FaceVertexId faceVertex = m_vertex->m_faceVertex;
		do
		{
			m_faceInstances[faceVertex.getFace()].select_vertex( faceVertex.getVertex(), select );
			faceVertex = next_vertex( m_vertex->m_faces, faceVertex );
		}
		while ( faceVertex.getFace() != m_vertex->m_faceVertex.getFace() );
	}
	bool selected_vertex() const {
		FaceVertexId faceVertex = m_vertex->m_faceVertex;
		do
		{
			if ( !m_faceInstances[faceVertex.getFace()].selected_vertex( faceVertex.getVertex() ) ) {
				return false;
			}
			faceVertex = next_vertex( m_vertex->m_faces, faceVertex );
		}
		while ( faceVertex.getFace() != m_vertex->m_faceVertex.getFace() );
		return true;
	}

public:
	VertexInstance( FaceInstances& faceInstances, SelectableVertex& vertex )
		: m_faceInstances( faceInstances ), m_vertex( &vertex ){
	}
	VertexInstance& operator=( const VertexInstance& other ){
		m_vertex = other.m_vertex;
		return *this;
	}

	void setSelected( bool select ){
		select_vertex( select );
	}
	bool isSelected() const {
		return selected_vertex();
	}

	void testSelect( Selector& selector, SelectionTest& test ){
		SelectionIntersection best;
		m_vertex->testSelect( test, best );
		if ( best.valid() ) {
			Selector_add( selector, *this, best );
		}
	}
	void gatherComponentsHighlight( std::vector<std::vector<Vector3>>& polygons, SelectionIntersection& intersection, SelectionTest& test ) const {
		SelectionIntersection best;
		m_vertex->testSelect( test, best );
		if ( SelectionIntersection_closer( best, intersection ) ) {
			intersection = best;
			polygons.clear();
			polygons.emplace_back( std::initializer_list<Vector3>( { m_vertex->getVertex() } ) );
		}
	}

	void selectVerticesOfFace( const FaceInstance& faceinstance ){
		FaceVertexId faceVertex = m_vertex->m_faceVertex;
		do
		{
			if( &faceinstance == &m_faceInstances[faceVertex.getFace()] ){
				setSelected( true );
				return;
			}
			faceVertex = next_vertex( m_vertex->m_faces, faceVertex );
		}
		while ( faceVertex.getFace() != m_vertex->m_faceVertex.getFace() );
	}
	void gather( Brush::VertexModeVertices& vertexModeVertices ) const {
		vertexModeVertices.emplace_back( m_vertex->getVertex(), isSelected() );
		FaceVertexId faceVertex = m_vertex->m_faceVertex;
		do
		{
			vertexModeVertices.back().m_faces.push_back( &m_faceInstances[faceVertex.getFace()].getFace() );
			faceVertex = next_vertex( m_vertex->m_faces, faceVertex );
		}
		while ( faceVertex.getFace() != m_vertex->m_faceVertex.getFace() );
	}
	bool vertex_select( const DoubleVector3& vertex ){
		if( vector3_length_squared( vertex - m_vertex->getVertex() ) < ( 0.1 * 0.1 ) ){
			setSelected( true );
			return true;
		}
		return false;
	}
};

class BrushInstanceVisitor
{
public:
	virtual void visit( FaceInstance& face ) const = 0;
};

class BrushInstance :
	public BrushObserver,
	public scene::Instance,
	public Selectable,
	public Renderable,
	public SelectionTestable,
	public ComponentSelectionTestable,
	public ComponentEditable,
	public ComponentSnappable,
	public PlaneSelectable,
	public LightCullable
{
	class TypeCasts
	{
		InstanceTypeCastTable m_casts;
	public:
		TypeCasts(){
			InstanceStaticCast<BrushInstance, Selectable>::install( m_casts );
			InstanceContainedCast<BrushInstance, Bounded>::install( m_casts );
			InstanceContainedCast<BrushInstance, Cullable>::install( m_casts );
			InstanceStaticCast<BrushInstance, Renderable>::install( m_casts );
			InstanceStaticCast<BrushInstance, SelectionTestable>::install( m_casts );
			InstanceStaticCast<BrushInstance, ComponentSelectionTestable>::install( m_casts );
			InstanceStaticCast<BrushInstance, ComponentEditable>::install( m_casts );
			InstanceStaticCast<BrushInstance, ComponentSnappable>::install( m_casts );
			InstanceStaticCast<BrushInstance, PlaneSelectable>::install( m_casts );
			InstanceIdentityCast<BrushInstance>::install( m_casts );
			InstanceContainedCast<BrushInstance, Transformable>::install( m_casts );
		}
		InstanceTypeCastTable& get(){
			return m_casts;
		}
	};


	Brush& m_brush;

	FaceInstances m_faceInstances;

	typedef std::vector<EdgeInstance> EdgeInstances;
	EdgeInstances m_edgeInstances;
	typedef std::vector<VertexInstance> VertexInstances;
	VertexInstances m_vertexInstances;

	ObservedSelectable m_selectable;

	mutable RenderableWireframe m_render_wireframe;
	mutable RenderablePointVector m_render_selected;
	mutable AABB m_aabb_component;
	mutable Array<PointVertex> m_faceCentroidPointsCulled;
	RenderablePointArray<PointVertex> m_render_faces_wireframe;
	mutable bool m_viewChanged;   // requires re-evaluation of view-dependent cached data

	BrushClipPlane m_clipPlane;

	static Shader* m_state_selpoint;

	const LightList* m_lightList;

	BrushTransformModifier m_transform;
public:
	static Counter* m_counter;

	typedef LazyStatic<TypeCasts> StaticTypeCasts;

	void lightsChanged(){
		m_lightList->lightsChanged();
	}
	typedef MemberCaller<BrushInstance, &BrushInstance::lightsChanged> LightsChangedCaller;

	STRING_CONSTANT( Name, "BrushInstance" );

	BrushInstance( const BrushInstance& other ) = delete; // NOT COPYABLE
	BrushInstance& operator=( const BrushInstance& other ) = delete; // NOT ASSIGNABLE

	BrushInstance( const scene::Path& path, scene::Instance* parent, Brush& brush ) :
		Instance( path, parent, this, StaticTypeCasts::instance().get() ),
		m_brush( brush ),
		m_selectable( SelectedChangedCaller( *this ) ),
		m_render_selected( GL_POINTS ),
		m_render_faces_wireframe( m_faceCentroidPointsCulled, GL_POINTS ),
		m_viewChanged( false ),
		m_transform( Brush::TransformChangedCaller( m_brush ), ApplyTransformCaller( *this ) ){
		m_brush.instanceAttach( Instance::path() );
		m_brush.attach( *this );
		m_counter->increment();

		m_lightList = &GlobalShaderCache().attach( *this );
		m_brush.m_lightsChanged = LightsChangedCaller( *this ); ///\todo Make this work with instancing.

		Instance::setTransformChangedCallback( LightsChangedCaller( *this ) );
	}
	~BrushInstance(){
		Instance::setTransformChangedCallback( Callback() );

		m_brush.m_lightsChanged = Callback();
		GlobalShaderCache().detach( *this );

		m_counter->decrement();
		m_brush.detach( *this );
		m_brush.instanceDetach( Instance::path() );
	}

	Brush& getBrush(){
		return m_brush;
	}
	const Brush& getBrush() const {
		return m_brush;
	}

	Bounded& get( NullType<Bounded>){
		return m_brush;
	}
	Cullable& get( NullType<Cullable>){
		return m_brush;
	}
	Transformable& get( NullType<Transformable>){
		return m_transform;
	}

	void selectedChanged( const Selectable& selectable ){
		GlobalSelectionSystem().getObserver ( SelectionSystem::ePrimitive )( selectable );
		GlobalSelectionSystem().onSelectedChanged( *this, selectable );

		Instance::selectedChanged();
	}
	typedef MemberCaller1<BrushInstance, const Selectable&, &BrushInstance::selectedChanged> SelectedChangedCaller;

	void selectedChangedComponent( const Selectable& selectable ){
		GlobalSelectionSystem().getObserver ( SelectionSystem::eComponent )( selectable );
		GlobalSelectionSystem().onComponentSelection( *this, selectable );
	}
	typedef MemberCaller1<BrushInstance, const Selectable&, &BrushInstance::selectedChangedComponent> SelectedChangedComponentCaller;

	const BrushInstanceVisitor& forEachFaceInstance( const BrushInstanceVisitor& visitor ){
		for ( FaceInstances::iterator i = m_faceInstances.begin(); i != m_faceInstances.end(); ++i )
		{
			visitor.visit( *i );
		}
		return visitor;
	}

	static void constructStatic(){
		m_state_selpoint = GlobalShaderCache().capture( "$SELPOINT" );
	}
	static void destroyStatic(){
		GlobalShaderCache().release( "$SELPOINT" );
	}

	void clear(){
		m_faceInstances.clear();
	}
	void reserve( std::size_t size ){
		m_faceInstances.reserve( size );
	}

	void push_back( Face& face ){
		m_faceInstances.push_back( FaceInstance( face, SelectedChangedComponentCaller( *this ) ) );
	}
	void pop_back(){
		ASSERT_MESSAGE( !m_faceInstances.empty(), "erasing invalid element" );
		m_faceInstances.pop_back();
	}
	void erase( std::size_t index ){
		ASSERT_MESSAGE( index < m_faceInstances.size(), "erasing invalid element" );
		m_faceInstances.erase( m_faceInstances.begin() + index );
	}
	void connectivityChanged(){
		for ( FaceInstances::iterator i = m_faceInstances.begin(); i != m_faceInstances.end(); ++i )
		{
			( *i ).connectivityChanged();
		}
	}

	void edge_clear(){
		m_edgeInstances.clear();
	}
	void edge_push_back( SelectableEdge& edge ){
		m_edgeInstances.push_back( EdgeInstance( m_faceInstances, edge ) );
	}

	void vertex_clear(){
		m_vertexInstances.clear();
	}
	void vertex_push_back( SelectableVertex& vertex ){
		m_vertexInstances.push_back( VertexInstance( m_faceInstances, vertex ) );
	}

	void vertex_select(){
		bool src_selected = false;
		bool dst_selected = false;
		for( const auto& v : m_brush.m_vertexModeVertices )
			if( v.m_selected ){
				src_selected = true;
				for( auto& i : m_vertexInstances )
					dst_selected |= i.vertex_select( v.m_vertexTransformed );
			}
		if( src_selected && !dst_selected && !m_vertexInstances.empty() )
			m_vertexInstances[0].setSelected( true ); //select at least something to prevent transform interruption after removing all selected vertices during vertexModeTransform
	}

	void vertex_snap( const float snap, bool all ){
		m_brush.vertexModeInit();
		m_brush.m_vertexModeVertices.reserve( m_vertexInstances.size() );
		for ( const auto& i : m_vertexInstances ){
			i.gather( m_brush.m_vertexModeVertices );
		}
		m_brush.vertexModeSnap( snap, all );
		m_brush.evaluateBRep();
		m_brush.vertexModeFree();
		m_brush.freezeTransform();
	}

	void vertex_snap( const float snap ){
		vertex_snap( snap, true );
	}

	void DEBUG_verify() const {
		ASSERT_MESSAGE( m_faceInstances.size() == m_brush.DEBUG_size(), "FATAL: mismatch" );
	}

	bool isSelected() const {
		return m_selectable.isSelected();
	}
	void setSelected( bool select ){
		m_selectable.setSelected( select );
		if ( !select && parent() ){
			Selectable* sel_parent = Instance_getSelectable( *parent() );
			if ( sel_parent && sel_parent->isSelected() )
				sel_parent->setSelected( false );
		}
	}

	void update_selected() const {
		m_render_selected.clear();
		for ( FaceInstances::const_iterator i = m_faceInstances.begin(); i != m_faceInstances.end(); ++i )
		{
			if ( ( *i ).getFace().contributes() ) {
				( *i ).iterate_selected( m_render_selected );
			}
		}
	}

	void evaluateViewDependent( const VolumeTest& volume, const Matrix4& localToWorld ) const {
		if ( m_viewChanged ) {
			m_viewChanged = false;

			bool faces_visible[c_brush_maxFaces];
			{
				bool* j = faces_visible;
				for ( FaceInstances::const_iterator i = m_faceInstances.begin(); i != m_faceInstances.end(); ++i, ++j )
				{
					*j = ( *i ).intersectVolume( volume, localToWorld );
				}
			}

			m_brush.update_wireframe( m_render_wireframe, faces_visible );
			m_brush.update_faces_wireframe( m_faceCentroidPointsCulled, faces_visible );
		}
	}

	void renderComponentsSelected( Renderer& renderer, const VolumeTest& volume, const Matrix4& localToWorld ) const {
		m_brush.evaluateBRep();

		update_selected();
		if ( !m_render_selected.empty() ) {
			renderer.Highlight( Renderer::ePrimitive, false );
			renderer.SetState( m_state_selpoint, Renderer::eWireframeOnly );
			renderer.SetState( m_state_selpoint, Renderer::eFullMaterials );
			renderer.addRenderable( m_render_selected, localToWorld );
		}
	}

	void renderComponents( Renderer& renderer, const VolumeTest& volume ) const {
		m_brush.evaluateBRep();

		const Matrix4& localToWorld = Instance::localToWorld();

		renderer.SetState( m_brush.m_state_point, Renderer::eWireframeOnly );
		renderer.SetState( m_brush.m_state_point, Renderer::eFullMaterials );

		if ( volume.fill() && GlobalSelectionSystem().ComponentMode() == SelectionSystem::eFace ) {
			evaluateViewDependent( volume, localToWorld );
			renderer.addRenderable( m_render_faces_wireframe, localToWorld );
		}
		else
		{
			m_brush.renderComponents( GlobalSelectionSystem().ComponentMode(), renderer, volume, localToWorld );
		}
	}

	void renderClipPlane( Renderer& renderer, const VolumeTest& volume ) const {
		if ( GlobalSelectionSystem().ManipulatorMode() == SelectionSystem::eClip && isSelected() ) {
			m_clipPlane.render( renderer, volume, localToWorld() );
		}
	}

	void renderCommon( Renderer& renderer, const VolumeTest& volume ) const {
		bool componentMode = GlobalSelectionSystem().Mode() == SelectionSystem::eComponent;

		if ( componentMode && isSelected() ) {
			renderComponents( renderer, volume );
		}

		if ( parentSelected() ) {
			if ( !componentMode ) {
				renderer.Highlight( Renderer::eFace );
			}
			renderer.Highlight( Renderer::ePrimitive );
		}
	}

	void renderSolid( Renderer& renderer, const VolumeTest& volume, const Matrix4& localToWorld ) const {
		//renderCommon(renderer, volume);

		m_lightList->evaluateLights();

		for ( FaceInstances::const_iterator i = m_faceInstances.begin(); i != m_faceInstances.end(); ++i )
		{
			renderer.setLights( ( *i ).m_lights );
			( *i ).render( renderer, volume, localToWorld );
		}

		renderComponentsSelected( renderer, volume, localToWorld );
	}

	void renderWireframe( Renderer& renderer, const VolumeTest& volume, const Matrix4& localToWorld ) const {
		//renderCommon(renderer, volume);

		evaluateViewDependent( volume, localToWorld );

		if ( m_render_wireframe.m_size != 0 ) {
			renderer.addRenderable( m_render_wireframe, localToWorld );
		}

		renderComponentsSelected( renderer, volume, localToWorld );
	}

	void renderSolid( Renderer& renderer, const VolumeTest& volume ) const {
		m_brush.evaluateBRep();

		renderClipPlane( renderer, volume );

		renderSolid( renderer, volume, localToWorld() );
	}

	void renderWireframe( Renderer& renderer, const VolumeTest& volume ) const {
		m_brush.evaluateBRep();

		renderClipPlane( renderer, volume );

		renderWireframe( renderer, volume, localToWorld() );
	}

	void viewChanged() const {
		m_viewChanged = true;
	}

	void testSelect( Selector& selector, SelectionTest& test ){
		test.BeginMesh( localToWorld() );

		SelectionIntersection best;
		for ( FaceInstances::iterator i = m_faceInstances.begin(); i != m_faceInstances.end(); ++i )
		{
			( *i ).testSelect( test, best );
		}
		if ( best.valid() ) {
			selector.addIntersection( best );
		}
	}

	bool isSelectedComponents() const {
		for ( FaceInstances::const_iterator i = m_faceInstances.begin(); i != m_faceInstances.end(); ++i )
		{
			if ( ( *i ).selectedComponents() ) {
				return true;
			}
		}
		return false;
	}
	void setSelectedComponents( bool select, SelectionSystem::EComponentMode mode ){
		for ( FaceInstances::iterator i = m_faceInstances.begin(); i != m_faceInstances.end(); ++i )
		{
			( *i ).setSelected( mode, select );
		}
	}
	void testSelectComponents( Selector& selector, SelectionTest& test, SelectionSystem::EComponentMode mode ){
		test.BeginMesh( localToWorld() );

		switch ( mode )
		{
		case SelectionSystem::eVertex:
			{
				for ( VertexInstances::iterator i = m_vertexInstances.begin(); i != m_vertexInstances.end(); ++i )
				{
					( *i ).testSelect( selector, test );
				}
			}
			break;
		case SelectionSystem::eEdge:
			{
				for ( EdgeInstances::iterator i = m_edgeInstances.begin(); i != m_edgeInstances.end(); ++i )
				{
					( *i ).testSelect( selector, test );
				}
			}
			break;
		case SelectionSystem::eFace:
			{
				if ( test.getVolume().fill() ) {
					for ( FaceInstances::iterator i = m_faceInstances.begin(); i != m_faceInstances.end(); ++i )
					{
						( *i ).testSelect( selector, test );
					}
				}
				else
				{
					for ( FaceInstances::iterator i = m_faceInstances.begin(); i != m_faceInstances.end(); ++i )
					{
						( *i ).testSelect_centroid( selector, test );
					}
				}
			}
			break;
		default:
			break;
		}
	}
	void gatherComponentsHighlight( std::vector<std::vector<Vector3>>& polygons, SelectionIntersection& intersection, SelectionTest& test, SelectionSystem::EComponentMode mode ) const {
		test.BeginMesh( localToWorld() );

		switch ( mode )
		{
		case SelectionSystem::eVertex:
			{
				for ( const VertexInstance& i : m_vertexInstances )
				{
					i.gatherComponentsHighlight( polygons, intersection, test );
				}
			}
			break;
		case SelectionSystem::eEdge:
			{
				for ( const EdgeInstance& i : m_edgeInstances )
				{
					i.gatherComponentsHighlight( polygons, intersection, test );
				}
			}
			break;
		case SelectionSystem::eFace:
			{
				if ( test.getVolume().fill() ) {
					const Plane3* plane = nullptr;
					bool newint = false;
					for ( const FaceInstance& i : m_faceInstances )
					{
						SelectionIntersection best;
						i.testSelect( test, best );
						if( best.valid() && intersection.equalEpsilon( best, 0.25f, 2e-6f ) ){
							plane = &i.getFace().plane3();
						}
						else if ( SelectionIntersection_closer( best, intersection ) ) {
							intersection = best;
							newint = true;
							plane = &i.getFace().plane3();
						}
					}
					if( plane ){
						if( newint || ( !polygons.empty() && polygons.back().size() >= 3 && !plane3_equal( *plane, plane3_for_points( polygons.back().data() ) ) ) ){
							polygons.clear();
						}
						gatherPolygonsByPlane( *plane, polygons, false );
					}
				}
				else
				{
					for ( const FaceInstance& i : m_faceInstances )
					{
						SelectionIntersection best;
						i.getFace().testSelect_centroid( test, best );
						if ( SelectionIntersection_closer( best, intersection ) ) {
							intersection = best;
							polygons.clear();
							polygons.emplace_back( std::initializer_list<Vector3>( { i.getFace().centroid() } ) );
						}
					}
				}
			}
			break;
		default:
			break;
		}
	}

	void invertComponentSelection( SelectionSystem::EComponentMode mode ){
		switch ( mode )
		{
		case SelectionSystem::eVertex:
			{
				for ( VertexInstances::iterator i = m_vertexInstances.begin(); i != m_vertexInstances.end(); ++i )
				{
					( *i ).setSelected( !( *i ).isSelected() );
				}
			}
			break;
		case SelectionSystem::eEdge:
			{
				for ( EdgeInstances::iterator i = m_edgeInstances.begin(); i != m_edgeInstances.end(); ++i )
				{
					( *i ).setSelected( !( *i ).isSelected() );
				}
			}
			break;
		case SelectionSystem::eFace:
			{
				for ( FaceInstances::iterator i = m_faceInstances.begin(); i != m_faceInstances.end(); ++i )
				{
					if( !( *i ).getFace().isFiltered() )
						( *i ).setSelected( mode, !( *i ).isSelected() );
				}
			}
			break;
		default:
			break;
		}
	}

	void selectPlanes( SelectionTest& test, FaceInstances_ptrs& bestInstances ){
		test.BeginMesh( localToWorld() );

		const Vector3 viewdir( test.getVolume().getViewDir() );
		double bestDot = 1;

		for ( FaceInstances::iterator i = m_faceInstances.begin(); i != m_faceInstances.end(); ++i )
		{
			if( !( *i ).trySelectPlane( test ) ){
				continue;
			}
			const double dot = fabs( vector3_dot( ( *i ).getFace().plane3().normal(), viewdir ) );
			const double diff = bestDot - dot;
			if( diff > 0.03 ){
				bestDot = dot;
				bestInstances.clear();
				bestInstances.push_back( &( *i ) );
			}
			else if( fabs( diff ) <= 0.03 ){
				bestInstances.push_back( &( *i ) );
			}
		}
	}
	void selectPlanes( Selector& selector, SelectionTest& test, const PlaneCallback& selectedPlaneCallback ){
		FaceInstances_ptrs bestInstances;
		selectPlanes( test, bestInstances );

		for ( FaceInstances_ptrs::iterator i = bestInstances.begin(); i != bestInstances.end(); ++i ){
			( *i )->addSelectable( selector );
			selectedPlaneCallback( ( *i )->getFace().plane3() );
			if( test.getVolume().fill() )
				return; // select only plane in camera
		}
	}
	void selectReversedPlanes( Selector& selector, const SelectedPlanes& selectedPlanes ){
		for ( FaceInstances::iterator i = m_faceInstances.begin(); i != m_faceInstances.end(); ++i )
		{
			( *i ).selectReversedPlane( selector, selectedPlanes );
		}
	}

	void bestPlaneDirect( SelectionTest& test, Plane3& plane, SelectionIntersection& intersection ) const {
		test.BeginMesh( localToWorld() );
		for ( const FaceInstance& fi : m_faceInstances )
		{
			SelectionIntersection intersection_new;
			fi.testSelect( test, intersection_new );
			if( SelectionIntersection_closer( intersection_new, intersection ) ){
				intersection = intersection_new;
				plane = fi.getFace().plane3();
			}
		}
	}
	void bestPlaneIndirect( SelectionTest& test, Plane3& plane, Vector3& intersection, float& dist ) const {
		test.BeginMesh( localToWorld() );
		float dot = 1;
		for ( const EdgeInstance& ei : m_edgeInstances )
		{
			ei.bestPlaneIndirect( test, plane, intersection, dist, dot );
		}
	}
	void selectByPlane( const Plane3& plane ){
		for ( FaceInstance& fi : m_faceInstances )
			if( plane3_equal( plane, fi.getFace().plane3() ) || plane3_equal( plane, plane3_flipped( fi.getFace().plane3() ) ) )
				fi.setSelected( SelectionSystem::eFace, true );
	}
	void gatherPolygonsByPlane( const Plane3& plane, std::vector<std::vector<Vector3>>& polygons ) const {
		gatherPolygonsByPlane( plane, polygons, true );
	}
	void gatherPolygonsByPlane( const Plane3& plane, std::vector<std::vector<Vector3>>& polygons, const bool reversed_plane_also ) const {
		for ( const FaceInstance& fi : m_faceInstances )
			if( plane3_equal( plane, fi.getFace().plane3() ) || ( reversed_plane_also && plane3_equal( plane, plane3_flipped( fi.getFace().plane3() ) ) ) )
				if( fi.getFace().contributes() ){
					const Winding& winding = fi.getFace().getWinding();
					polygons.emplace_back( winding.numpoints );
					for( std::size_t i = 0; i < winding.numpoints; ++i ){
						polygons.back()[i] = winding[i].vertex;
					}
				}
	}

	void selectVerticesOnPlane( const Plane3& plane ){
		for ( FaceInstance& fi : m_faceInstances )
			if( plane3_equal( plane, fi.getFace().plane3() ) || plane3_equal( plane, plane3_flipped( fi.getFace().plane3() ) ) )
				for ( VertexInstance& vi : m_vertexInstances )
					vi.selectVerticesOfFace( fi );
	}

	void transformComponents( const Matrix4& matrix );

	const AABB& getSelectedComponentsBounds() const {
		m_aabb_component = AABB();

		for ( FaceInstances::const_iterator i = m_faceInstances.begin(); i != m_faceInstances.end(); ++i )
		{
			( *i ).iterate_selected( m_aabb_component );
		}

		return m_aabb_component;
	}
	void gatherSelectedComponents( const Vector3Callback& callback ) const {
		for ( FaceInstances::const_iterator i = m_faceInstances.begin(); i != m_faceInstances.end(); ++i )
		{
			( *i ).gatherSelectedComponents( callback );
		}
	}

	void insert_vertices( const Brush::VertexModeVertices& vertexModeVertices ){
		if( !m_vertexInstances.empty() ){
			m_brush.vertexModeInit();
			m_brush.m_vertexModeVertices.reserve( m_vertexInstances.size() + 2 );
			for ( const auto& i : m_vertexInstances ){
				i.gather( m_brush.m_vertexModeVertices );
			}
			for ( const auto& i : vertexModeVertices ){
				m_brush.m_vertexModeVertices.push_back( i );
				if( i.m_faces.empty() )
					m_brush.m_vertexModeVertices.back().m_faces.push_back( m_brush.m_vertexModeVertices[0].m_faces[0] );
			}
			m_transform.m_transformFrozen = false;
			m_transform.setType( TRANSFORM_COMPONENT );
			m_brush.transformChanged();
			m_brush.evaluateBRep();
		}
	}

	void remove_vertices(){
		if( !m_vertexInstances.empty() ){
			m_brush.vertexModeInit();
			Brush::VertexModeVertices v;
			v.reserve( m_vertexInstances.size() );
			for ( const auto& i : m_vertexInstances ){
				i.gather( v );
				if( v.back().m_selected )
					v.pop_back();
			}
			std::vector<bool> ok( v.size(), true );
			gatherSelectedComponents( [&]( const DoubleVector3 & value ) {
				for( std::size_t i = 0; i < v.size(); ++i )
					if( vector3_length_squared( v[i].m_vertex - value ) < 0.05 * 0.05 )
						ok[i] = false;
			} );

			m_brush.m_vertexModeVertices.reserve( v.size() );
			for( std::size_t i = 0; i < v.size(); ++i ){
				if( ok[i] )
					m_brush.m_vertexModeVertices.push_back( v[i] );
			}
			m_brush.vertexModeBuildHull();
			m_brush.evaluateBRep();
			m_brush.vertexModeFree();
			m_brush.freezeTransform();
		}
	}

	void snapComponents( float snap ){
		for ( const auto& fi : m_faceInstances ){
			if( fi.selectedComponents( SelectionSystem::eVertex ) ){
				vertex_snap( snap, false );
				return;
			}
		}

		for ( auto& fi : m_faceInstances )
			fi.snapComponents( snap );
	}
	void evaluateTransform(){
		if( m_transform.m_transformFrozen && m_transform.isIdentity() )
			return;
		if( m_transform.m_transformFrozen && !m_transform.isIdentity() ){ /* new transform */
			m_transform.m_transformFrozen = false;
			for( auto& i : m_faceInstances )
				i.getFace().cacheCentroid();

			if( m_transform.getType() == TRANSFORM_COMPONENT ){
				for ( const auto& i : m_faceInstances ){
					if( i.selectedComponents( SelectionSystem::eVertex ) ){
						m_brush.vertexModeInit();
						m_brush.m_vertexModeVertices.reserve( m_vertexInstances.size() );
						for ( const auto& i : m_vertexInstances ){
							i.gather( m_brush.m_vertexModeVertices );
						}
						break;
					}
				}
			}
		}

		const Matrix4 matrix( m_transform.calculateTransform() );

		if ( m_transform.getType() == TRANSFORM_PRIMITIVE ) {
			m_brush.transform( matrix );
		}
		else
		{
			if( m_brush.m_vertexModeOn ){
				m_brush.vertexModeTransform( matrix );
			}
			else{
				const bool tmp = g_brush_texturelock_enabled;
				/* do not want texture projection transformation while resizing brush */
				if( GlobalSelectionSystem().ManipulatorMode() == SelectionSystem::eDrag && GlobalSelectionSystem().Mode() == SelectionSystem::ePrimitive )
					g_brush_texturelock_enabled = false;
				transformComponents( matrix );
				g_brush_texturelock_enabled = tmp;
			}
		}
	}
	void applyTransform(){
		if( !m_transform.isIdentity() ){
			if( m_transform.m_transformFrozen ){ //not yet unfrozen by evaluateTransform(), so evaluate
//				m_brush.revertTransform();
//				evaluateTransform();
				m_brush.evaluateBRep();
			}
			m_brush.freezeTransform();
			m_transform.setIdentity();
		}
		m_brush.vertexModeFree();
	}
	typedef MemberCaller<BrushInstance, &BrushInstance::applyTransform> ApplyTransformCaller;

	void setClipPlane( const Plane3& plane ){
		m_clipPlane.setPlane( m_brush, plane );
	}

	bool testLight( const RendererLight& light ) const {
		return light.testAABB( worldAABB() );
	}
	void insertLight( const RendererLight& light ){
		const Matrix4& localToWorld = Instance::localToWorld();
		for ( FaceInstances::const_iterator i = m_faceInstances.begin(); i != m_faceInstances.end(); ++i )
		{
			Face_addLight( *i, localToWorld, light );
		}
	}
	void clearLights(){
		for ( FaceInstances::const_iterator i = m_faceInstances.begin(); i != m_faceInstances.end(); ++i )
		{
			( *i ).m_lights.clear();
		}
	}
};

inline BrushInstance* Instance_getBrush( scene::Instance& instance ){
	return InstanceTypeCast<BrushInstance>::cast( instance );
}


template<typename Functor>
class BrushSelectedVisitor : public SelectionSystem::Visitor
{
	const Functor& m_functor;
public:
	BrushSelectedVisitor( const Functor& functor ) : m_functor( functor ){
	}
	void visit( scene::Instance& instance ) const {
		BrushInstance* brush = Instance_getBrush( instance );
		if ( brush != 0 ) {
			m_functor( *brush );
		}
	}
};

template<typename Functor>
inline const Functor& Scene_forEachSelectedBrush( const Functor& functor ){
	GlobalSelectionSystem().foreachSelected( BrushSelectedVisitor<Functor>( functor ) );
	return functor;
}

template<typename Functor>
class BrushVisibleSelectedVisitor : public SelectionSystem::Visitor
{
	const Functor& m_functor;
public:
	BrushVisibleSelectedVisitor( const Functor& functor ) : m_functor( functor ){
	}
	void visit( scene::Instance& instance ) const {
		BrushInstance* brush = Instance_getBrush( instance );
		if ( brush != 0
		  && instance.path().top().get().visible() ) {
			m_functor( *brush );
		}
	}
};

template<typename Functor>
inline const Functor& Scene_forEachVisibleSelectedBrush( const Functor& functor ){
	GlobalSelectionSystem().foreachSelected( BrushVisibleSelectedVisitor<Functor>( functor ) );
	return functor;
}

class BrushForEachFace
{
	const BrushInstanceVisitor& m_visitor;
public:
	BrushForEachFace( const BrushInstanceVisitor& visitor ) : m_visitor( visitor ){
	}
	void operator()( BrushInstance& brush ) const {
		brush.forEachFaceInstance( m_visitor );
	}
};

template<class Functor>
class FaceInstanceVisitFace : public BrushInstanceVisitor
{
	const Functor& functor;
public:
	FaceInstanceVisitFace( const Functor& functor )
		: functor( functor ){
	}
	void visit( FaceInstance& face ) const {
		functor( face.getFace() );
	}
};

template<typename Functor>
inline const Functor& Brush_forEachFace( BrushInstance& brush, const Functor& functor ){
	brush.forEachFaceInstance( FaceInstanceVisitFace<Functor>( functor ) );
	return functor;
}

template<class Functor>
class FaceVisitAll : public BrushVisitor
{
	const Functor& functor;
public:
	FaceVisitAll( const Functor& functor )
		: functor( functor ){
	}
	void visit( Face& face ) const {
		functor( face );
	}
};

template<typename Functor>
inline const Functor& Brush_forEachFace( const Brush& brush, const Functor& functor ){
	brush.forEachFace( FaceVisitAll<Functor>( functor ) );
	return functor;
}

template<typename Functor>
inline const Functor& Brush_forEachFace( Brush& brush, const Functor& functor ){
	brush.forEachFace( FaceVisitAll<Functor>( functor ) );
	return functor;
}

template<class Functor>
class FaceInstanceVisitAll : public BrushInstanceVisitor
{
	const Functor& functor;
public:
	FaceInstanceVisitAll( const Functor& functor )
		: functor( functor ){
	}
	void visit( FaceInstance& face ) const {
		functor( face );
	}
};

template<typename Functor>
inline const Functor& Brush_ForEachFaceInstance( BrushInstance& brush, const Functor& functor ){
	brush.forEachFaceInstance( FaceInstanceVisitAll<Functor>( functor ) );
	return functor;
}

template<typename Functor>
inline const Functor& Scene_forEachBrush( scene::Graph& graph, const Functor& functor ){
	graph.traverse( InstanceWalker< InstanceApply<BrushInstance, Functor> >( functor ) );
	return functor;
}

template<typename Type, typename Functor>
class InstanceIfVisible : public Functor
{
public:
	InstanceIfVisible( const Functor& functor ) : Functor( functor ){
	}
	void operator()( scene::Instance& instance ){
		if ( instance.path().top().get().visible() ) {
			Functor::operator()( instance );
		}
	}
};

template<typename Functor>
class BrushVisibleWalker : public scene::Graph::Walker
{
	const Functor& m_functor;
public:
	BrushVisibleWalker( const Functor& functor ) : m_functor( functor ){
	}
	bool pre( const scene::Path& path, scene::Instance& instance ) const {
		if ( path.top().get().visible() ) {
			BrushInstance* brush = Instance_getBrush( instance );
			if ( brush != 0 ) {
				m_functor( *brush );
			}
			return true;
		}
		return false;
	}
};

template<typename Functor>
inline const Functor& Scene_forEachVisibleBrush( scene::Graph& graph, const Functor& functor ){
	graph.traverse( BrushVisibleWalker<Functor>( functor ) );
	return functor;
}

template<typename Functor>
inline const Functor& Scene_ForEachBrush_ForEachFace( scene::Graph& graph, const Functor& functor ){
	Scene_forEachBrush( graph, BrushForEachFace( FaceInstanceVisitFace<Functor>( functor ) ) );
	return functor;
}

// d1223m
template<typename Functor>
inline const Functor& Scene_ForEachBrush_ForEachFaceInstance( scene::Graph& graph, const Functor& functor ){
	Scene_forEachBrush( graph, BrushForEachFace( FaceInstanceVisitAll<Functor>( functor ) ) );
	return functor;
}

template<typename Functor>
inline const Functor& Scene_ForEachSelectedBrush_ForEachFace( scene::Graph& graph, const Functor& functor ){
	Scene_forEachSelectedBrush( BrushForEachFace( FaceInstanceVisitFace<Functor>( functor ) ) );
	return functor;
}

template<typename Functor>
inline const Functor& Scene_ForEachSelectedBrush_ForEachFaceInstance( scene::Graph& graph, const Functor& functor ){
	Scene_forEachSelectedBrush( BrushForEachFace( FaceInstanceVisitAll<Functor>( functor ) ) );
	return functor;
}

template<typename Functor>
class FaceVisitorWrapper
{
	const Functor& functor;
public:
	FaceVisitorWrapper( const Functor& functor ) : functor( functor ){
	}

	void operator()( FaceInstance& faceInstance ) const {
		functor( faceInstance.getFace() );
	}
};

template<typename Functor>
inline const Functor& Scene_ForEachSelectedBrushFace( scene::Graph& graph, const Functor& functor ){
	g_SelectedFaceInstances.foreach( FaceVisitorWrapper<Functor>( functor ) );
	return functor;
}