[gtk/fix-gl-texture-cache] gsk: Fix the gl texture cache

[Matthias Clasen <matthiasc src gnome org>]

commit 1057588a8ff55e8c43938fe528e46776ca5a1fb3
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Sep 9 13:55:09 2020 -0400

    gsk: Fix the gl texture cache
    
    We need to include both the scale and the filtering
    in the key for the texture cache, since those affect
    the texture.
    
    This fixes misrendering in the recorder in the inspector
    whenever transforms are involved. An example where this
    was showing up is testrevealer's swing transition.

 gsk/gl/gskgldriver.c        | 44 ++++++++++++++++++++++++++-------
 gsk/gl/gskgldriverprivate.h | 13 +++++++---
 gsk/gl/gskglrenderer.c      | 59 +++++++++++++++++++++++++++++----------------
 3 files changed, 82 insertions(+), 34 deletions(-)
---
diff --git a/gsk/gl/gskgldriver.c b/gsk/gl/gskgldriver.c
index 08e19a980f..8d101b93df 100644
--- a/gsk/gl/gskgldriver.c
+++ b/gsk/gl/gskgldriver.c
@@ -541,16 +541,37 @@ gsk_gl_driver_get_texture_for_texture (GskGLDriver *self,
   return t->texture_id;
 }
 
+static guint
+texture_key_hash (gconstpointer v)
+{
+  const GskTextureKey *k = (GskTextureKey *)v;
+
+  return GPOINTER_TO_UINT (k->pointer)
+         + (guint)(k->scale*100)
+         + (guint)k->filter;
+}
+
+static gboolean
+texture_key_equal (gconstpointer v1, gconstpointer v2)
+{
+  const GskTextureKey *k1 = (GskTextureKey *)v1;
+  const GskTextureKey *k2 = (GskTextureKey *)v2;
+
+  return k1->pointer == k2->pointer &&
+         k1->scale == k2->scale &&
+         k1->filter == k2->filter;
+}
+
 int
-gsk_gl_driver_get_texture_for_pointer (GskGLDriver *self,
-                                       gpointer     pointer)
+gsk_gl_driver_get_texture_for_key (GskGLDriver   *self,
+                                   GskTextureKey *key)
 {
   int id = 0;
 
   if (G_UNLIKELY (self->pointer_textures == NULL))
-    self->pointer_textures = g_hash_table_new (NULL, NULL);
+    self->pointer_textures = g_hash_table_new_full (texture_key_hash, texture_key_equal, g_free, NULL);
 
-  id = GPOINTER_TO_INT (g_hash_table_lookup (self->pointer_textures, pointer));
+  id = GPOINTER_TO_INT (g_hash_table_lookup (self->pointer_textures, key));
 
   if (id != 0)
     {
@@ -566,14 +587,19 @@ gsk_gl_driver_get_texture_for_pointer (GskGLDriver *self,
 }
 
 void
-gsk_gl_driver_set_texture_for_pointer (GskGLDriver *self,
-                                       gpointer     pointer,
-                                       int          texture_id)
+gsk_gl_driver_set_texture_for_key (GskGLDriver   *self,
+                                   GskTextureKey *key,
+                                   int            texture_id)
 {
+  GskTextureKey *k;
+
   if (G_UNLIKELY (self->pointer_textures == NULL))
-    self->pointer_textures = g_hash_table_new (NULL, NULL);
+    self->pointer_textures = g_hash_table_new_full (texture_key_hash, texture_key_equal, g_free, NULL);
+
+  k = g_new (GskTextureKey, 1);
+  *k = *key;
 
-  g_hash_table_insert (self->pointer_textures, pointer, GINT_TO_POINTER (texture_id));
+  g_hash_table_insert (self->pointer_textures, k, GINT_TO_POINTER (texture_id));
 }
 
 int
diff --git a/gsk/gl/gskgldriverprivate.h b/gsk/gl/gskgldriverprivate.h
index 22c5ef8cb3..406b959372 100644
--- a/gsk/gl/gskgldriverprivate.h
+++ b/gsk/gl/gskgldriverprivate.h
@@ -21,6 +21,11 @@ typedef struct {
   guint texture_id;
 } TextureSlice;
 
+typedef struct {
+  gpointer pointer;
+  float scale;
+  int filter;
+} GskTextureKey;
 
 GskGLDriver *   gsk_gl_driver_new                       (GdkGLContext    *context);
 GdkGLContext   *gsk_gl_driver_get_gl_context            (GskGLDriver     *driver);
@@ -34,10 +39,10 @@ int             gsk_gl_driver_get_texture_for_texture   (GskGLDriver     *driver
                                                          GdkTexture      *texture,
                                                          int              min_filter,
                                                          int              mag_filter);
-int             gsk_gl_driver_get_texture_for_pointer   (GskGLDriver     *driver,
-                                                         gpointer         pointer);
-void            gsk_gl_driver_set_texture_for_pointer   (GskGLDriver     *driver,
-                                                         gpointer         pointer,
+int             gsk_gl_driver_get_texture_for_key       (GskGLDriver     *driver,
+                                                         GskTextureKey   *key);
+void            gsk_gl_driver_set_texture_for_key       (GskGLDriver     *driver,
+                                                         GskTextureKey   *key,
                                                          int              texture_id);
 int             gsk_gl_driver_create_texture            (GskGLDriver     *driver,
                                                          float            width,
diff --git a/gsk/gl/gskglrenderer.c b/gsk/gl/gskglrenderer.c
index 27d1c48cbd..edc2fd2618 100644
--- a/gsk/gl/gskglrenderer.c
+++ b/gsk/gl/gskglrenderer.c
@@ -572,12 +572,17 @@ render_fallback_node (GskGLRenderer   *self,
   cairo_t *cr;
   int cached_id;
   int texture_id;
+  GskTextureKey key;
 
   if (surface_width <= 0 ||
       surface_height <= 0)
     return;
 
-  cached_id = gsk_gl_driver_get_texture_for_pointer (self->gl_driver, node);
+  key.pointer = node;
+  key.scale = scale;
+  key.filter = GL_NEAREST;
+
+  cached_id = gsk_gl_driver_get_texture_for_key (self->gl_driver, &key);
 
   if (cached_id != 0)
     {
@@ -659,7 +664,7 @@ render_fallback_node (GskGLRenderer   *self,
   cairo_surface_destroy (surface);
   cairo_surface_destroy (rendered_surface);
 
-  gsk_gl_driver_set_texture_for_pointer (self->gl_driver, node, texture_id);
+  gsk_gl_driver_set_texture_for_key (self->gl_driver, &key, texture_id);
 
   ops_set_program (builder, &self->programs->blit_program);
   ops_set_texture (builder, texture_id);
@@ -1638,6 +1643,7 @@ render_blur_node (GskGLRenderer   *self,
   const float blur_radius = gsk_blur_node_get_radius (node);
   GskRenderNode *child = gsk_blur_node_get_child (node);
   TextureRegion blurred_region;
+  GskTextureKey key;
 
   if (node_is_invisible (child))
     return;
@@ -1648,7 +1654,10 @@ render_blur_node (GskGLRenderer   *self,
       return;
     }
 
-  blurred_region.texture_id = gsk_gl_driver_get_texture_for_pointer (self->gl_driver, node);
+  key.pointer = node;
+  key.scale = ops_get_scale (builder);
+  key.filter = GL_NEAREST;
+  blurred_region.texture_id = gsk_gl_driver_get_texture_for_key (self->gl_driver, &key);
   if (blurred_region.texture_id == 0)
     blur_node (self, child, builder, blur_radius, 0, &blurred_region, NULL);
 
@@ -1660,7 +1669,7 @@ render_blur_node (GskGLRenderer   *self,
   load_offscreen_vertex_data (ops_draw (builder, NULL), node, builder); /* Render result to screen */
 
   /* Add to cache for the blur node */
-  gsk_gl_driver_set_texture_for_pointer (self->gl_driver, node, blurred_region.texture_id);
+  gsk_gl_driver_set_texture_for_key (self->gl_driver, &key, blurred_region.texture_id);
 }
 
 static inline void
@@ -1698,13 +1707,17 @@ render_inset_shadow_node (GskGLRenderer   *self,
   float texture_width;
   float texture_height;
   int blurred_texture_id;
+  GskTextureKey key;
 
   g_assert (blur_radius > 0);
 
   texture_width = ceilf ((node_outline->bounds.size.width + blur_extra) * scale);
   texture_height = ceilf ((node_outline->bounds.size.height + blur_extra) * scale);
 
-  blurred_texture_id = gsk_gl_driver_get_texture_for_pointer (self->gl_driver, node);
+  key.pointer = node;
+  key.scale = scale;
+  key.filter = GL_NEAREST;
+  blurred_texture_id = gsk_gl_driver_get_texture_for_key (self->gl_driver, &key);
   if (blurred_texture_id == 0)
     {
       const float spread = gsk_inset_shadow_node_get_spread (node) + (blur_extra / 2.0);
@@ -1800,7 +1813,7 @@ render_inset_shadow_node (GskGLRenderer   *self,
     const float ty1 = blur_extra / 2.0 * scale / texture_height;
     const float ty2 = 1.0 - ty1;
 
-    gsk_gl_driver_set_texture_for_pointer (self->gl_driver, node, blurred_texture_id);
+    gsk_gl_driver_set_texture_for_key (self->gl_driver, &key, blurred_texture_id);
 
     if (needs_clip)
       {
@@ -3400,6 +3413,8 @@ add_offscreen_ops (GskGLRenderer         *self,
   int texture_id = 0;
   int max_texture_size;
   int filter;
+  GskTextureKey key;
+  int cached_id;
 
   if (node_is_invisible (child_node))
     {
@@ -3421,18 +3436,24 @@ add_offscreen_ops (GskGLRenderer         *self,
       return TRUE;
     }
 
+  if (flags & LINEAR_FILTER)
+    filter = GL_LINEAR;
+  else
+    filter = GL_NEAREST;
+
   /* Check if we've already cached the drawn texture. */
-  {
-    const int cached_id = gsk_gl_driver_get_texture_for_pointer (self->gl_driver, child_node);
+  key.pointer = child_node;
+  key.scale = ops_get_scale (builder);
+  key.filter = filter;
+  cached_id = gsk_gl_driver_get_texture_for_key (self->gl_driver, &key);
 
-    if (cached_id != 0)
-      {
-        init_full_texture_region (texture_region_out, cached_id);
-        /* We didn't render it offscreen, but hand out an offscreen texture id */
-        *is_offscreen = TRUE;
-        return TRUE;
-      }
-  }
+  if (cached_id != 0)
+    {
+      init_full_texture_region (texture_region_out, cached_id);
+      /* We didn't render it offscreen, but hand out an offscreen texture id */
+      *is_offscreen = TRUE;
+      return TRUE;
+    }
 
   scale = ops_get_scale (builder);
   width = bounds->size.width;
@@ -3452,10 +3473,6 @@ add_offscreen_ops (GskGLRenderer         *self,
   width  = ceilf (width * scale);
   height = ceilf (height * scale);
 
-  if (flags & LINEAR_FILTER)
-    filter = GL_LINEAR;
-  else
-    filter = GL_NEAREST;
   gsk_gl_driver_create_render_target (self->gl_driver,
                                       width, height,
                                       filter, filter,
@@ -3534,7 +3551,7 @@ add_offscreen_ops (GskGLRenderer         *self,
   init_full_texture_region (texture_region_out, texture_id);
 
   if ((flags & NO_CACHE_PLZ) == 0)
-    gsk_gl_driver_set_texture_for_pointer (self->gl_driver, child_node, texture_id);
+    gsk_gl_driver_set_texture_for_key (self->gl_driver, &key, texture_id);
 
   return TRUE;
 }