[gtk/wip/chergert/glproto] inline most common transform, 2d-affine

[Christian Hergert <chergert src gnome org>]

commit 20430380d3d66b02185bb77d8981c6d6a62b7574
Author: Christian Hergert <chergert redhat com>
Date:   Tue Feb 9 12:25:44 2021 -0800

    inline most common transform, 2d-affine

 gsk/next/gskglrenderjob.c | 53 +++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 47 insertions(+), 6 deletions(-)
---
diff --git a/gsk/next/gskglrenderjob.c b/gsk/next/gskglrenderjob.c
index b2eca55b10..969a74c0ed 100644
--- a/gsk/next/gskglrenderjob.c
+++ b/gsk/next/gskglrenderjob.c
@@ -691,19 +691,60 @@ gsk_gl_render_job_transform_bounds (GskGLRenderJob        *job,
                                     const graphene_rect_t *rect,
                                     graphene_rect_t       *out_rect)
 {
-  graphene_rect_t r;
+  GskTransform *transform;
+  GskTransformCategory category;
 
   g_assert (job != NULL);
   g_assert (job->modelview->len > 0);
   g_assert (rect != NULL);
   g_assert (out_rect != NULL);
 
-  r.origin.x = rect->origin.x + job->offset_x;
-  r.origin.y = rect->origin.y + job->offset_y;
-  r.size.width = rect->size.width;
-  r.size.height = rect->size.height;
+  transform = job->current_modelview->transform;
+  category = gsk_transform_get_category (transform);
+
+  /* Our most common transform is 2d-affine, so inline it.
+   * Both identity and 2d-translate are virtually unseen here.
+   */
+  if G_LIKELY (category == GSK_TRANSFORM_CATEGORY_2D_AFFINE)
+    {
+      float dx, dy, scale_x, scale_y;
+
+      gsk_transform_to_affine (transform, &scale_x, &scale_y, &dx, &dy);
+
+      /* Init directly into out rect */
+      out_rect->origin.x = ((rect->origin.x + job->offset_x) * scale_x) + dx;
+      out_rect->origin.y = ((rect->origin.y + job->offset_y) * scale_y) + dy;
+      out_rect->size.width = rect->size.width * scale_x;
+      out_rect->size.height = rect->size.height * scale_y;
+
+      /* Normaize in place */
+      if (out_rect->size.width < 0.f)
+        {
+          float size = fabsf (out_rect->size.width);
+
+          out_rect->origin.x -= size;
+          out_rect->size.width = size;
+        }
 
-  gsk_transform_transform_bounds (job->current_modelview->transform, &r, out_rect);
+      if (out_rect->size.height < 0.f)
+        {
+          float size = fabsf (out_rect->size.height);
+
+          out_rect->origin.y -= size;
+          out_rect->size.height = size;
+        }
+    }
+  else
+    {
+      graphene_rect_t r;
+
+      r.origin.x = rect->origin.x + job->offset_x;
+      r.origin.y = rect->origin.y + job->offset_y;
+      r.size.width = rect->size.width;
+      r.size.height = rect->size.height;
+
+      gsk_transform_transform_bounds (transform, &r, out_rect);
+    }
 }
 
 static inline void