From edabdd157e9216fc5c1262324e886d51cf9fe880 Mon Sep 17 00:00:00 2001
From: Garux <garux@mail.ru>
Date: Thu, 25 Mar 2021 18:03:46 +0300
Subject: [PATCH] shorten BernsteinPolynomial

---
 libs/math/curve.h | 106 ++++++++--------------------------------------
 radiant/patch.cpp |   6 +--
 2 files changed, 20 insertions(+), 92 deletions(-)

diff --git a/libs/math/curve.h b/libs/math/curve.h
index ac21c743..6d76a90e 100644
--- a/libs/math/curve.h
+++ b/libs/math/curve.h
@@ -31,92 +31,20 @@
 
 
 template<int I, int Degree>
-struct BernsteinPolynomial
-{
-	static double apply( double t ){
-		return 1; // general case not implemented
-	}
-};
+double BernsteinPolynomial( double t ){
+	     if constexpr( I == 0 && Degree == 0 ) return 1;
+	else if constexpr( I == 0 && Degree == 1 ) return 1 - t;
+	else if constexpr( I == 1 && Degree == 1 ) return t;
+	else if constexpr( I == 0 && Degree == 2 ) return ( 1 - t ) * ( 1 - t );
+	else if constexpr( I == 1 && Degree == 2 ) return 2 * ( 1 - t ) * t;
+	else if constexpr( I == 2 && Degree == 2 ) return t * t;
+	else if constexpr( I == 0 && Degree == 3 ) return ( 1 - t ) * ( 1 - t ) * ( 1 - t );
+	else if constexpr( I == 1 && Degree == 3 ) return 3 * ( 1 - t ) * ( 1 - t ) * t;
+	else if constexpr( I == 2 && Degree == 3 ) return 3 * ( 1 - t ) * t * t;
+	else if constexpr( I == 3 && Degree == 3 ) return t * t * t;
+	else 0 = 1; // general case not implemented
+}
 
-template<>
-struct BernsteinPolynomial<0, 0>
-{
-	static double apply( double t ){
-		return 1;
-	}
-};
-
-template<>
-struct BernsteinPolynomial<0, 1>
-{
-	static double apply( double t ){
-		return 1 - t;
-	}
-};
-
-template<>
-struct BernsteinPolynomial<1, 1>
-{
-	static double apply( double t ){
-		return t;
-	}
-};
-
-template<>
-struct BernsteinPolynomial<0, 2>
-{
-	static double apply( double t ){
-		return ( 1 - t ) * ( 1 - t );
-	}
-};
-
-template<>
-struct BernsteinPolynomial<1, 2>
-{
-	static double apply( double t ){
-		return 2 * ( 1 - t ) * t;
-	}
-};
-
-template<>
-struct BernsteinPolynomial<2, 2>
-{
-	static double apply( double t ){
-		return t * t;
-	}
-};
-
-template<>
-struct BernsteinPolynomial<0, 3>
-{
-	static double apply( double t ){
-		return ( 1 - t ) * ( 1 - t ) * ( 1 - t );
-	}
-};
-
-template<>
-struct BernsteinPolynomial<1, 3>
-{
-	static double apply( double t ){
-		return 3 * ( 1 - t ) * ( 1 - t ) * t;
-	}
-};
-
-template<>
-struct BernsteinPolynomial<2, 3>
-{
-	static double apply( double t ){
-		return 3 * ( 1 - t ) * t * t;
-	}
-};
-
-template<>
-struct BernsteinPolynomial<3, 3>
-{
-	static double apply( double t ){
-		return t * t * t;
-	}
-};
 
 typedef Array<Vector3> ControlPoints;
 
@@ -125,22 +53,22 @@ inline Vector3 CubicBezier_evaluate( const Vector3* firstPoint, double t ){
 	double denominator = 0;
 
 	{
-		double weight = BernsteinPolynomial<0, 3>::apply( t );
+		double weight = BernsteinPolynomial<0, 3>( t );
 		result += vector3_scaled( *firstPoint++, weight );
 		denominator += weight;
 	}
 	{
-		double weight = BernsteinPolynomial<1, 3>::apply( t );
+		double weight = BernsteinPolynomial<1, 3>( t );
 		result += vector3_scaled( *firstPoint++, weight );
 		denominator += weight;
 	}
 	{
-		double weight = BernsteinPolynomial<2, 3>::apply( t );
+		double weight = BernsteinPolynomial<2, 3>( t );
 		result += vector3_scaled( *firstPoint++, weight );
 		denominator += weight;
 	}
 	{
-		double weight = BernsteinPolynomial<3, 3>::apply( t );
+		double weight = BernsteinPolynomial<3, 3>( t );
 		result += vector3_scaled( *firstPoint++, weight );
 		denominator += weight;
 	}
diff --git a/radiant/patch.cpp b/radiant/patch.cpp
index e9b347bc..9fb2d337 100644
--- a/radiant/patch.cpp
+++ b/radiant/patch.cpp
@@ -1789,19 +1789,19 @@ inline PatchControl QuadraticBezier_evaluate( const PatchControl* firstPoint, do
 	double denominator = 0;
 
 	{
-		double weight = BernsteinPolynomial<0, 2>::apply( t );
+		double weight = BernsteinPolynomial<0, 2>( t );
 		vector3_add( result.m_vertex, vector3_scaled( firstPoint[0].m_vertex, weight ) );
 		vector2_add( result.m_texcoord, vector2_scaled( firstPoint[0].m_texcoord, weight ) );
 		denominator += weight;
 	}
 	{
-		double weight = BernsteinPolynomial<1, 2>::apply( t );
+		double weight = BernsteinPolynomial<1, 2>( t );
 		vector3_add( result.m_vertex, vector3_scaled( firstPoint[1].m_vertex, weight ) );
 		vector2_add( result.m_texcoord, vector2_scaled( firstPoint[1].m_texcoord, weight ) );
 		denominator += weight;
 	}
 	{
-		double weight = BernsteinPolynomial<2, 2>::apply( t );
+		double weight = BernsteinPolynomial<2, 2>( t );
 		vector3_add( result.m_vertex, vector3_scaled( firstPoint[2].m_vertex, weight ) );
 		vector2_add( result.m_texcoord, vector2_scaled( firstPoint[2].m_texcoord, weight ) );
 		denominator += weight;