From bafb339c09b132422c0e0a9d4013102b34cbc922 Mon Sep 17 00:00:00 2001
From: Garux <garux@mail.ru>
Date: Fri, 3 Sep 2021 06:23:40 +0300
Subject: [PATCH] MergeMetaTriangles: epsilon compare st, improves merging
 imprecise sts, e.g. for nonplanar surfaces after q3map_tcgen or just brush
 face texture projection

---
 libs/math/vector.h                   | 19 +++++++++++++++++++
 tools/quake3/q3map2/surface_meta.cpp |  2 +-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/libs/math/vector.h b/libs/math/vector.h
index b7f5a410..91cadb0d 100644
--- a/libs/math/vector.h
+++ b/libs/math/vector.h
@@ -123,6 +123,25 @@ inline Element float_mod( const Element& self, const ModulusElement& modulus ){
 }
 
 
+template<typename Element, typename OtherElement>
+inline bool vector2_equal( const BasicVector2<Element>& self, const BasicVector2<OtherElement>& other ){
+	return self.x() == other.x() && self.y() == other.y();
+}
+template<typename Element, typename OtherElement>
+inline bool operator==( const BasicVector2<Element>& self, const BasicVector2<OtherElement>& other ){
+	return vector2_equal( self, other );
+}
+template<typename Element, typename OtherElement>
+inline bool operator!=( const BasicVector2<Element>& self, const BasicVector2<OtherElement>& other ){
+	return !vector2_equal( self, other );
+}
+
+template<typename Element, typename OtherElement, typename Epsilon>
+inline bool vector2_equal_epsilon( const BasicVector2<Element>& self, const BasicVector2<OtherElement>& other, Epsilon epsilon ){
+	return float_equal_epsilon( self.x(), other.x(), epsilon )
+	    && float_equal_epsilon( self.y(), other.y(), epsilon );
+}
+
 template<typename Element, typename OtherElement>
 inline BasicVector2<Element> vector2_added( const BasicVector2<Element>& self, const BasicVector2<OtherElement>& other ){
 	return BasicVector2<Element>(
diff --git a/tools/quake3/q3map2/surface_meta.cpp b/tools/quake3/q3map2/surface_meta.cpp
index a023121e..527e5c66 100644
--- a/tools/quake3/q3map2/surface_meta.cpp
+++ b/tools/quake3/q3map2/surface_meta.cpp
@@ -1297,7 +1297,7 @@ int AddMetaVertToSurface( mapDrawSurface_t *ds, const bspDrawVert_t& dv1, const
 		( *coincident )++;
 
 		/* compare texture coordinates and color */
-		if ( dv1.st[ 0 ] != dv2.st[ 0 ] || dv1.st[ 1 ] != dv2.st[ 1 ] ) {
+		if ( !vector2_equal_epsilon( dv1.st, dv2.st, 1e-4f ) ) {
 			continue;
 		}
 		if ( dv1.color[ 0 ].alpha() != dv2.color[ 0 ].alpha() ) {