Added a new function+struct to glutil that takes care of reading in the OpenGL data needed for gluProject/gluUnProject. This allows retopo and sculptmode to share some of the same code, and is probably useful elsewhere as well.

1 files changed, 23 insertions, 0 deletions

diff --git a/source/blender/src/glutil.c b/source/blender/src/glutil.c
index 9a4a67c7f35..eef5e41dee2 100644
--- a/source/blender/src/glutil.c
+++ b/source/blender/src/glutil.c
@@ -596,6 +596,29 @@ void bglEnd(void)
 	
 }
 
+/* Uses current OpenGL state to get view matrices for gluProject/gluUnProject */
+void bgl_get_mats(bglMats *mats)
+{
+	const double badvalue= 1.0e-6;
+
+	glGetDoublev(GL_MODELVIEW_MATRIX, mats->modelview);
+	glGetDoublev(GL_PROJECTION_MATRIX, mats->projection);
+	glGetIntegerv(GL_VIEWPORT, (GLint *)mats->viewport);
+	
+	/* Very strange code here - it seems that certain bad values in the
+	   modelview matrix can cause gluUnProject to give bad results. */
+	if(mats->modelview[0] < badvalue &&
+	   mats->modelview[0] > -badvalue)
+		mats->modelview[0]= 0;
+	if(mats->modelview[5] < badvalue &&
+	   mats->modelview[5] > -badvalue)
+		mats->modelview[5]= 0;
+	
+	/* Set up viewport so that gluUnProject will give correct values */
+	mats->viewport[0] = 0;
+	mats->viewport[1] = 0;
+}
+
 /* *************** glPolygonOffset hack ************* */
 
 // both temporal, so here for now (ton)