[gtk/wip/baedert/for-master: 7/23] gl renderer: Avoid setting modelview to identical values

[Timm Bäder <baedert src gnome org>]

commit a8213d7f4529483abe84c96f0c010edf1eacf6f8
Author: Timm Bäder <mail baedert org>
Date:   Thu Dec 17 17:24:31 2020 +0100

    gl renderer: Avoid setting modelview to identical values
    
    The previous comment here was incorrect. We can save the op itself, we
    just can't save us the entry in the modelview stack.

 gsk/gl/gskglrenderops.c | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)
---
diff --git a/gsk/gl/gskglrenderops.c b/gsk/gl/gskglrenderops.c
index a6e071f657..20bd178a3f 100644
--- a/gsk/gl/gskglrenderops.c
+++ b/gsk/gl/gskglrenderops.c
@@ -357,19 +357,18 @@ ops_set_modelview_internal (RenderOpBuilder *builder,
                             GskTransform    *transform)
 {
   ProgramState *current_program_state = get_current_program_state (builder);
-  OpMatrix *op;
-
-#if 0
-  XXX This is not possible if we want pop() to work.
-  if (builder->current_program &&
-      gsk_transform_equal (builder->current_program_state->modelview, transform))
-    return;
-#endif
 
-  if (!(op = op_buffer_peek_tail_checked (&builder->render_ops, OP_CHANGE_MODELVIEW)))
-    op = op_buffer_add (&builder->render_ops, OP_CHANGE_MODELVIEW);
+  if (current_program_state &&
+      gsk_transform_equal (current_program_state->modelview, transform))
+    {
+      /* We can save us this op entirely... */
+    }
+  else
+    {
+      OpMatrix *op = op_buffer_add (&builder->render_ops, OP_CHANGE_MODELVIEW);
 
-  gsk_transform_to_matrix (transform, &op->matrix);
+      gsk_transform_to_matrix (transform, &op->matrix);
+    }
 
   if (builder->current_program != NULL)
     {