Hack: glyph cache debugging

Color the padding in the cache, and warn if glyphs extrude into it.

gsk/gpu/gskgldevice.c

@@ -131,6 +131,47 @@ gsk_gl_device_make_current (GskGpuDevice *device)
   gdk_gl_context_make_current (gdk_display_get_gl_context (gsk_gpu_device_get_display (device)));
 }
 
+static void
+save_texture_to_png (GdkDisplay *display,
+                     int         texture_id,
+                     int         width,
+                     int         height,
+                     const char *filename)
+{
+  GdkGLTextureBuilder *builder;
+  GdkTexture *texture;
+
+  builder = gdk_gl_texture_builder_new ();
+  gdk_gl_texture_builder_set_context (builder, gdk_display_get_gl_context (display));
+  gdk_gl_texture_builder_set_id (builder, texture_id);
+  gdk_gl_texture_builder_set_width (builder, width);
+  gdk_gl_texture_builder_set_height (builder, height);
+
+  texture = gdk_gl_texture_builder_build (builder, NULL, NULL);
+  gdk_texture_save_to_png (texture, filename);
+
+  g_object_unref (texture);
+  g_object_unref (builder);
+}
+
+static void
+gsk_gl_device_end_frame (GskGpuDevice *device)
+{
+  GskGpuImage *image;
+  static int count = 0;
+  char *filename;
+
+  image = gsk_gpu_device_get_atlas_image (device);
+
+  filename = g_strdup_printf ("atlas%d.png", count++);
+  save_texture_to_png (gsk_gpu_device_get_display (device),
+                       gsk_gl_image_peek_texture (GSK_GL_IMAGE (image)),
+                       gsk_gpu_image_get_width (image),
+                       gsk_gpu_image_get_height (image),
+                       filename);
+  g_free (filename);
+}
+
 static void
 gsk_gl_device_finalize (GObject *object)
 {
@@ -158,6 +199,7 @@ gsk_gl_device_class_init (GskGLDeviceClass *klass)
   gpu_device_class->create_upload_image = gsk_gl_device_create_upload_image;
   gpu_device_class->create_download_image = gsk_gl_device_create_download_image;
   gpu_device_class->make_current = gsk_gl_device_make_current;
+  gpu_device_class->end_frame = gsk_gl_device_end_frame;
 
   object_class->finalize = gsk_gl_device_finalize;
 }
@@ -691,4 +733,3 @@ gsk_gl_device_find_gl_format (GskGLDevice      *self,
   /* fallbacks will always fallback to a supported format */
   g_assert_not_reached ();
 }
-

gsk/gpu/gskglimage.c

@@ -316,3 +316,9 @@ gsk_gl_image_steal_texture (GskGLImage *self)
 
   return self->texture_id;
 }
+
+GLuint
+gsk_gl_image_peek_texture (GskGLImage *self)
+{
+  return self->texture_id;
+}

gsk/gpu/gskglimageprivate.h

@@ -39,4 +39,7 @@ GLenum                  gsk_gl_image_get_gl_type                        (GskGLIm
 
 GLuint                  gsk_gl_image_steal_texture                      (GskGLImage             *self);
 
+GLuint                  gsk_gl_image_peek_texture                       (GskGLImage             *self);
+
+
 G_END_DECLS

gsk/gpu/gskgpudevice.c

@@ -976,5 +976,12 @@ gsk_gpu_device_lookup_glyph_image (GskGpuDevice           *self,
   return cache->image;
 }
 
+void
+gsk_gpu_device_end_frame (GskGpuDevice *self)
+{
+  if (GSK_GPU_DEVICE_GET_CLASS (self))
+    GSK_GPU_DEVICE_GET_CLASS (self)->end_frame (self);
+}
+
 /* }}} */
 /* vim:set foldmethod=marker expandtab: */

gsk/gpu/gskgpudeviceprivate.h

@@ -42,7 +42,7 @@ struct _GskGpuDeviceClass
                                                                          gsize                   width,
                                                                          gsize                   height);
   void                  (* make_current)                                (GskGpuDevice           *self);
-
+  void                  (* end_frame)                                   (GskGpuDevice           *self);
 };
 
 GType                   gsk_gpu_device_get_type                         (void) G_GNUC_CONST;
@@ -99,6 +99,8 @@ GskGpuImage *           gsk_gpu_device_lookup_glyph_image               (GskGpuD
                                                                          graphene_point_t       *out_origin);
 
 
+void                    gsk_gpu_device_end_frame                        (GskGpuDevice           *self);
+
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(GskGpuDevice, g_object_unref)
 
 G_END_DECLS

gsk/gpu/gskgpurenderer.c

@@ -428,6 +428,7 @@ gsk_gpu_renderer_render (GskRenderer          *renderer,
   gsk_gpu_device_queue_gc (priv->device);
 
   gdk_draw_context_end_frame (priv->context);
+  gsk_gpu_device_end_frame (priv->device);
 
   g_clear_pointer (&render_region, cairo_region_destroy);
 }

gsk/gpu/gskgpuuploadop.c

@@ -555,6 +555,25 @@ gsk_gpu_upload_glyph_op_draw (GskGpuOp *op,
                                      } }
                                  });
 
+  for (int y = 0; y < self->area.height; y++)
+    {
+      int *row = (int *) (data + y * stride);
+      if (row[0] != 0 || row[self->area.width - 1] != 0)
+        g_warning ("glyph %u overflow", self->glyph);
+      row[0] = 0xff0000ff;
+      row[self->area.width - 1] = 0xff0000ff;
+    }
+
+  for (int x = 0; x < self->area.width; x++)
+    {
+      int *row0 = (int *) data;
+      int * row1 = (int *) (data + (self->area.height - 1) * stride);
+      if (row0[x] != 0 || row1[x] != 0)
+        g_warning ("glyph %u overflow", self->glyph);
+      row0[x] = 0xff0000ff;
+      row1[x] = 0xff0000ff;
+    }
+
   cairo_destroy (cr);
 
   cairo_surface_finish (surface);