OpenGL: matrix fixes & compatibility

Was multiplying matrices backward, so concatenation was broken. Fixed!

Also a way to mix legacy matrix stacks with the new library. Just during the transition! Anything within SUPPORT_LEGACY_MATRIX will go away after we switch to core profile.

Part of T49450

1 files changed, 13 insertions, 0 deletions

diff --git a/source/blender/gpu/GPU_matrix.h b/source/blender/gpu/GPU_matrix.h
index 73566292799..3c3acc08f58 100644
--- a/source/blender/gpu/GPU_matrix.h
+++ b/source/blender/gpu/GPU_matrix.h
@@ -39,6 +39,12 @@
 extern "C" {
 #endif
 
+/* For now we support the legacy matrix stack in gpuGetMatrix functions.
+ * Will remove this after switching to core profile, which can happen after
+ * we convert all code to use the API in this file. */
+#define SUPPORT_LEGACY_MATRIX 1
+
+
 void gpuMatrixInit(void); /* called by system -- make private? */
 
 
@@ -120,6 +126,13 @@ const float *gpuGetModelViewMatrix3D(float m[4][4]);
 const float *gpuGetProjectionMatrix3D(float m[4][4]);
 const float *gpuGetModelViewProjectionMatrix3D(float m[4][4]);
 
+
+#if SUPPORT_LEGACY_MATRIX
+/* copy top matrix from each legacy stack into new fresh stack */
+void gpuMatrixBegin3D_legacy(void);
+#endif
+
+
 /* set uniform values for currently bound shader */
 void gpuBindMatrices(GLuint program);