From d4ffaf291ffb805b2c1d0389b284a57ba3471383 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonas=20=C3=85dahl?= <jadahl@gmail.com>
Date: Tue, 8 Feb 2022 17:14:06 +0100
Subject: [PATCH] shaped-texture: Pass along the snippet to the texture tower

The snippet is used make sure the right source is sampled in the shader.
This wasn't done in the texture tower, meaning the textures from the
tower were not correct.

Related: https://gitlab.gnome.org/GNOME/mutter/-/issues/528
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2278>
---
 src/compositor/meta-shaped-texture.c |  2 ++
 src/compositor/meta-texture-tower.c  | 27 +++++++++++++++++++++++++++
 src/compositor/meta-texture-tower.h  |  3 +++
 3 files changed, 32 insertions(+)

diff --git a/src/compositor/meta-shaped-texture.c b/src/compositor/meta-shaped-texture.c
index fd3dc73fc..b45b1732c 100644
--- a/src/compositor/meta-shaped-texture.c
+++ b/src/compositor/meta-shaped-texture.c
@@ -1144,6 +1144,8 @@ meta_shaped_texture_set_snippet (MetaShapedTexture *stex,
   g_clear_pointer (&stex->snippet, cogl_object_unref);
   if (snippet)
     stex->snippet = cogl_object_ref (snippet);
+
+  meta_texture_tower_set_snippet (stex->paint_tower, snippet);
 }
 
 /**
diff --git a/src/compositor/meta-texture-tower.c b/src/compositor/meta-texture-tower.c
index c491e4d12..510e85f79 100644
--- a/src/compositor/meta-texture-tower.c
+++ b/src/compositor/meta-texture-tower.c
@@ -62,6 +62,7 @@ struct _MetaTextureTower
   CoglOffscreen *fbos[MAX_TEXTURE_LEVELS];
   Box invalid[MAX_TEXTURE_LEVELS];
   CoglPipeline *pipeline_template;
+  CoglSnippet *snippet;
 };
 
 /**
@@ -97,6 +98,7 @@ meta_texture_tower_free (MetaTextureTower *tower)
     cogl_object_unref (tower->pipeline_template);
 
   meta_texture_tower_set_base_texture (tower, NULL);
+  cogl_clear_object (&tower->snippet);
 
   g_free (tower);
 }
@@ -216,6 +218,28 @@ meta_texture_tower_update_area (MetaTextureTower *tower,
     }
 }
 
+void
+meta_texture_tower_set_snippet (MetaTextureTower *tower,
+                                CoglSnippet      *snippet)
+{
+  int i;
+
+  if (tower->snippet == snippet)
+    return;
+
+  g_clear_pointer (&tower->snippet, cogl_object_unref);
+
+  if (snippet)
+    tower->snippet = cogl_object_ref (snippet);
+
+  for (i = 1; i < tower->n_levels; i++)
+    {
+      cogl_clear_object (&tower->textures[i]);
+      g_clear_object (&tower->fbos[i]);
+    }
+  cogl_clear_object (&tower->pipeline_template);
+}
+
 /* It generally looks worse if we scale up a window texture by even a
  * small amount than if we scale it down using bilinear filtering, so
  * we always pick the *larger* adjacent level. */
@@ -410,6 +434,9 @@ texture_tower_revalidate (MetaTextureTower *tower,
   pipeline = cogl_pipeline_copy (tower->pipeline_template);
   cogl_pipeline_set_layer_texture (pipeline, 0, tower->textures[level - 1]);
 
+  if (tower->snippet && level == 1)
+    cogl_pipeline_add_layer_snippet (pipeline, 0, tower->snippet);
+
   cogl_framebuffer_draw_textured_rectangle (fb, pipeline,
                                             invalid->x1, invalid->y1,
                                             invalid->x2, invalid->y2,
diff --git a/src/compositor/meta-texture-tower.h b/src/compositor/meta-texture-tower.h
index 1f5b37146..5522dfbb1 100644
--- a/src/compositor/meta-texture-tower.h
+++ b/src/compositor/meta-texture-tower.h
@@ -63,6 +63,9 @@ void              meta_texture_tower_update_area       (MetaTextureTower *tower,
 CoglTexture      *meta_texture_tower_get_paint_texture (MetaTextureTower    *tower,
                                                         ClutterPaintContext *paint_context);
 
+void meta_texture_tower_set_snippet (MetaTextureTower *tower,
+                                     CoglSnippet      *snippet);
+
 G_END_DECLS
 
 #endif /* __META_TEXTURE_TOWER_H__ */