2D matrix transforms; add shear function, add tests for all 2D transforms

glm/gtx/matrix_transform_2d.hpp

@@ -14,6 +14,7 @@
 #pragma once
 
 // Dependency:
+#include "../trigonometric.hpp"
 #include "../mat3x3.hpp"
 #include "../vec2.hpp"
 
@@ -33,7 +34,7 @@ namespace glm
 	/// @param m Input matrix multiplied by this translation matrix.
 	/// @param v Coordinates of a translation vector.
 	template<typename T, qualifier Q>
-	GLM_FUNC_QUALIFIER mat<3, 3, T, Q> translate(
+	GLM_FUNC_DECL GLM_CONSTEXPR mat<3, 3, T, Q> translate(
 		mat<3, 3, T, Q> const& m,
 		vec<2, T, Q> const& v);
 
@@ -42,7 +43,7 @@ namespace glm
 	/// @param m Input matrix multiplied by this translation matrix.
 	/// @param angle Rotation angle expressed in radians.
 	template<typename T, qualifier Q>
-	GLM_FUNC_QUALIFIER mat<3, 3, T, Q> rotate(
+	GLM_FUNC_DECL mat<3, 3, T, Q> rotate(
 		mat<3, 3, T, Q> const& m,
 		T angle);
 
@@ -51,7 +52,7 @@ namespace glm
 	/// @param m Input matrix multiplied by this translation matrix.
 	/// @param v Coordinates of a scale vector.
 	template<typename T, qualifier Q>
-	GLM_FUNC_QUALIFIER mat<3, 3, T, Q> scale(
+	GLM_FUNC_DECL GLM_CONSTEXPR mat<3, 3, T, Q> scale(
 		mat<3, 3, T, Q> const& m,
 		vec<2, T, Q> const& v);
 
@@ -60,7 +61,7 @@ namespace glm
 	/// @param m Input matrix multiplied by this translation matrix.
 	/// @param y Shear factor.
 	template<typename T, qualifier Q>
-	GLM_FUNC_QUALIFIER mat<3, 3, T, Q> shearX(
+	GLM_FUNC_DECL GLM_CONSTEXPR mat<3, 3, T, Q> shearX(
 		mat<3, 3, T, Q> const& m,
 		T y);
 
@@ -69,10 +70,19 @@ namespace glm
 	/// @param m Input matrix multiplied by this translation matrix.
 	/// @param x Shear factor.
 	template<typename T, qualifier Q>
-	GLM_FUNC_QUALIFIER mat<3, 3, T, Q> shearY(
+	GLM_FUNC_DECL GLM_CONSTEXPR mat<3, 3, T, Q> shearY(
 		mat<3, 3, T, Q> const& m,
 		T x);
 
+	/// Builds a shear 3 * 3 matrix.
+	///
+	/// @param m Input matrix multiplied by this translation matrix.
+	/// @param s Shear vector.
+	template <typename T, qualifier Q>
+	GLM_FUNC_DECL GLM_CONSTEXPR mat<3, 3, T, Q> shear(
+		mat<3, 3, T, Q> const& m,
+		vec<2, T, Q> const& s);
+
 	/// @}
 }//namespace glm
 

glm/gtx/matrix_transform_2d.inl

@@ -1,13 +1,10 @@
 /// @ref gtx_matrix_transform_2d
 /// @author Miguel Ángel Pérez Martínez
 
-#include "../trigonometric.hpp"
-
 namespace glm
 {
-
 	template<typename T, qualifier Q>
-	GLM_FUNC_QUALIFIER mat<3, 3, T, Q> translate(
+	GLM_FUNC_QUALIFIER GLM_CONSTEXPR mat<3, 3, T, Q> translate(
 		mat<3, 3, T, Q> const& m,
 		vec<2, T, Q> const& v)
 	{
@@ -16,7 +13,6 @@ namespace glm
 		return Result;
 	}
 
-
 	template<typename T, qualifier Q>
 	GLM_FUNC_QUALIFIER mat<3, 3, T, Q> rotate(
 		mat<3, 3, T, Q> const& m,
@@ -34,7 +30,7 @@ namespace glm
 	}
 
 	template<typename T, qualifier Q>
-	GLM_FUNC_QUALIFIER mat<3, 3, T, Q> scale(
+	GLM_FUNC_QUALIFIER GLM_CONSTEXPR mat<3, 3, T, Q> scale(
 		mat<3, 3, T, Q> const& m,
 		vec<2, T, Q> const& v)
 	{
@@ -46,7 +42,7 @@ namespace glm
 	}
 
 	template<typename T, qualifier Q>
-	GLM_FUNC_QUALIFIER mat<3, 3, T, Q> shearX(
+	GLM_FUNC_QUALIFIER GLM_CONSTEXPR mat<3, 3, T, Q> shearX(
 		mat<3, 3, T, Q> const& m,
 		T y)
 	{
@@ -56,7 +52,7 @@ namespace glm
 	}
 
 	template<typename T, qualifier Q>
-	GLM_FUNC_QUALIFIER mat<3, 3, T, Q> shearY(
+	GLM_FUNC_QUALIFIER GLM_CONSTEXPR mat<3, 3, T, Q> shearY(
 		mat<3, 3, T, Q> const& m,
 		T x)
 	{
@@ -65,4 +61,18 @@ namespace glm
 		return m * Result;
 	}
 
+	template <typename T, qualifier Q>
+	GLM_FUNC_QUALIFIER GLM_CONSTEXPR mat<3, 3, T, Q> shear(
+		mat<3, 3, T, Q> const& m,
+		vec<2, T, Q> const& s)
+	{
+		mat<3, 3, T, Q> Result{};
+
+		Result[0] = m[0] * (s.x * s.y + 1.0f) + m[1] * s.y;
+		Result[1] = m[0] * s.x + m[1];
+		Result[2] = m[2];
+
+		return Result;
+	}
+
 }//namespace glm

test/ext/ext_matrix_transform.cpp

@@ -44,7 +44,7 @@ static int test_rotate()
 
 	glm::mat4 const R = glm::rotate(glm::mat4(1.0f), glm::radians(90.f), glm::vec3(0, 0, 1));
 	glm::vec4 const B = R * A;
-	Error += glm::all(glm::equal(B, glm::vec4(0.0f, 1.0f, 0.0f, 1.0f), 0.0001f)) ? 0 : 1;
+	Error += glm::all(glm::equal(B, glm::vec4(0.0f, 1.0f, 0.0f, 1.0f), glm::epsilon<float>())) ? 0 : 1;
 
 	return Error;
 }

test/gtx/gtx_matrix_transform_2d.cpp

@@ -1,9 +1,108 @@
 #define GLM_ENABLE_EXPERIMENTAL
 #include <glm/gtx/matrix_transform_2d.hpp>
+#include <glm/gtc/constants.hpp>
+#include <glm/ext/matrix_relational.hpp>
+#include <glm/ext/matrix_float3x3.hpp>
+#include <glm/ext/vector_relational.hpp>
+#include <glm/ext/vector_float3.hpp>
+#include <glm/ext/vector_float2.hpp>
+
+static int test_translate()
+{
+	int Error = 0;
+
+	glm::mat3 const M(1.0f);
+	glm::vec2 const V(1.0f);
+
+	glm::mat3 const T = glm::translate(M, V);
+	Error += glm::all(glm::equal(T[2], glm::vec3(1.0f), glm::epsilon<float>())) ? 0 : 1;
+
+	return Error;
+}
+
+static int test_rotate()
+{
+	int Error = 0;
+
+	glm::vec3 const A(1.0f, 0.0f, 1.0f);
+	float constexpr a = glm::radians(90.f);
+
+	glm::mat3 const R = glm::rotate(glm::mat3(1.0f), a);
+	glm::vec3 const B = R * A;
+	Error += glm::all(glm::equal(B, glm::vec3(0.0f, 1.0f, 1.0f), glm::epsilon<float>())) ? 0 : 1;
+
+	return Error;
+}
+
+static int test_scale()
+{
+	int Error = 0;
+
+	glm::mat3 const M(1.0f);
+	glm::vec2 const V(2.0f);
+
+	glm::mat3 const S = glm::scale(M, V);
+	glm::mat3 const R = glm::mat3(
+		glm::vec3(2, 0, 0),
+		glm::vec3(0, 2, 0),
+		glm::vec3(0, 0, 1));
+	Error += glm::all(glm::equal(S, R, glm::epsilon<float>())) ? 0 : 1;
+
+	return Error;
+}
+
+static int test_shearX()
+{
+	int Error = 0;
+
+	glm::mat3 const M(1.0f);
+	float constexpr y = 1.0f;
+
+	glm::mat3 const S = glm::shearX(M, y);
+	glm::vec3 const V = S * glm::vec3(1.0f);
+	Error += glm::all(glm::equal(V, glm::vec3(1.0f, 2.0f, 1.0f), glm::epsilon<float>())) ? 0 : 1;
+
+	return Error;
+}
+
+static int test_shearY()
+{
+	int Error = 0;
+
+	glm::mat3 const M(1.0f);
+	float constexpr x = 1.0f;
+
+	glm::mat3 const S = glm::shearY(M, x);
+	glm::vec3 const V = S * glm::vec3(1.0f);
+	Error += glm::all(glm::equal(V, glm::vec3(2.0f, 1.0f, 1.0f), glm::epsilon<float>())) ? 0 : 1;
+
+	return Error;
+}
+
+static int test_shear()
+{
+	int Error = 0;
+
+	glm::mat3 const M(1.0f);
+	glm::vec2 const s(1.0f);
+
+	glm::mat3 const S = glm::shear(M, s);
+	glm::vec3 const V = S * glm::vec3(1.0f);
+	Error += glm::all(glm::equal(V, glm::vec3(3.0f, 2.0f, 1.0f), glm::epsilon<float>())) ? 0 : 1;
+
+	return Error;
+}
 
 int main()
 {
 	int Error(0);
 
+	Error += test_translate();
+	Error += test_rotate();
+	Error += test_scale();
+	Error += test_shearX();
+	Error += test_shearY();
+	Error += test_shear();
+
 	return Error;
 }