comment regarding bug [#27175] UV faces show incorrect image in object mode (VBO's)

1 files changed, 13 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/cdderivedmesh.c b/source/blender/blenkernel/intern/cdderivedmesh.c
index 24b677cc240..8bd650b1a42 100644
--- a/source/blender/blenkernel/intern/cdderivedmesh.c
+++ b/source/blender/blenkernel/intern/cdderivedmesh.c
@@ -770,6 +770,19 @@ static void cdDM_drawFacesTex_common(DerivedMesh *dm,
 		}
 
 		if( !GPU_buffer_legacy(dm) ) {
+			/* warning!, this logic is incorrect, see bug [#27175]
+			 * firstly, there are no checks for changes in context, such as texface image.
+			 * secondly, drawParams() sets the GL context, so checking if there is a change
+			 * from lastFlag is too late once glDrawArrays() runs, since drawing the arrays
+			 * will use the modified, OpenGL settings.
+			 * 
+			 * However its tricky to fix this without duplicating the internal logic
+			 * of drawParams(), perhaps we need an argument like...
+			 * drawParams(..., keep_gl_state_but_return_when_changed) ?.
+			 *
+			 * We could also just disable VBO's here, since texface may be deprecated - campbell.
+			 */
+			
 			glShadeModel( GL_SMOOTH );
 			lastFlag = 0;
 			for(i = 0; i < dm->drawObject->nelements/3; i++) {