add matrix multiply for projection that outputs 2d values.

2 files changed, 20 insertions, 0 deletions

diff --git a/source/blender/blenlib/BLI_math_matrix.h b/source/blender/blenlib/BLI_math_matrix.h
index ada2d43b81f..e408b223923 100644
--- a/source/blender/blenlib/BLI_math_matrix.h
+++ b/source/blender/blenlib/BLI_math_matrix.h
@@ -88,11 +88,13 @@ void mul_serie_m4(float R[4][4],
 
 void mul_m4_v3(float M[4][4], float r[3]);
 void mul_v3_m4v3(float r[3], float M[4][4], const float v[3]);
+void mul_v2_m4v3(float r[2], float M[4][4], const float v[3]);
 void mul_v2_m2v2(float r[2], float M[2][2], const float v[2]);
 void mul_mat3_m4_v3(float M[4][4], float r[3]);
 void mul_m4_v4(float M[4][4], float r[4]);
 void mul_v4_m4v4(float r[4], float M[4][4], const float v[4]);
 void mul_project_m4_v3(float M[4][4], float vec[3]);
+void mul_v2_project_m4_v3(float r[2], float M[4][4], const float vec[3]);
 
 void mul_m3_v3(float M[3][3], float r[3]);
 void mul_v3_m3v3(float r[3], float M[3][3], const float a[3]);
diff --git a/source/blender/blenlib/intern/math_matrix.c b/source/blender/blenlib/intern/math_matrix.c
index d9063b80f13..fa85e015ee8 100644
--- a/source/blender/blenlib/intern/math_matrix.c
+++ b/source/blender/blenlib/intern/math_matrix.c
@@ -344,6 +344,15 @@ void mul_v3_m4v3(float r[3], float mat[4][4], const float vec[3])
 	r[2] = x * mat[0][2] + y * mat[1][2] + mat[2][2] * vec[2] + mat[3][2];
 }
 
+void mul_v2_m4v3(float r[2], float mat[4][4], const float vec[3])
+{
+	float x;
+
+	x = vec[0];
+	r[0] = x * mat[0][0] + vec[1] * mat[1][0] + mat[2][0] * vec[2] + mat[3][0];
+	r[1] = x * mat[0][1] + vec[1] * mat[1][1] + mat[2][1] * vec[2] + mat[3][1];
+}
+
 void mul_v2_m2v2(float r[2], float mat[2][2], const float vec[2])
 {
 	float x;
@@ -375,6 +384,15 @@ void mul_project_m4_v3(float mat[4][4], float vec[3])
 	vec[2] /= w;
 }
 
+void mul_v2_project_m4_v3(float r[2], float mat[4][4], const float vec[3])
+{
+	const float w = mul_project_m4_v3_zfac(mat, vec);
+	mul_v2_m4v3(r, mat, vec);
+
+	r[0] /= w;
+	r[1] /= w;
+}
+
 void mul_v4_m4v4(float r[4], float mat[4][4], const float v[4])
 {
 	float x, y, z;