[gtk/matthiasc/for-master] gsk: Handle 2D transforms better

[Matthias Clasen <matthiasc src gnome org>]

commit 6a60214e8c7f6d49f970e0a3293befe6a6a2870c
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Sep 17 09:42:20 2021 -0400

    gsk: Handle 2D transforms better
    
    For 2D transforms, we can read the scale
    factors more directly off the matrix.
    
    This should eventually be moved out into a
    function to decompose a 2D transform into
    scale + rotation + skew + translation.

 gsk/ngl/gsknglrenderjob.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)
---
diff --git a/gsk/ngl/gsknglrenderjob.c b/gsk/ngl/gsknglrenderjob.c
index 4cccd89ba5..baf87f6461 100644
--- a/gsk/ngl/gsknglrenderjob.c
+++ b/gsk/ngl/gsknglrenderjob.c
@@ -453,10 +453,21 @@ extract_matrix_metadata (GskNglRenderModelview *modelview)
                                &modelview->dx, &modelview->dy);
       break;
 
+    case GSK_TRANSFORM_CATEGORY_2D:
+      {
+        float xx, xy, yx, yy, dx, dy;
+
+        gsk_transform_to_2d (modelview->transform,
+                             &xx, &xy, &yx, &yy, &dx, &dy);
+
+        modelview->scale_x = sqrtf (xx * xx + xy * xy);
+        modelview->scale_y = sqrtf (yx * yx + yy * yy);
+      }
+      break;
+
     case GSK_TRANSFORM_CATEGORY_UNKNOWN:
     case GSK_TRANSFORM_CATEGORY_ANY:
     case GSK_TRANSFORM_CATEGORY_3D:
-    case GSK_TRANSFORM_CATEGORY_2D:
       {
         graphene_vec3_t col1;
         graphene_vec3_t col2;