[gtk+] gdkgl: Don't constantly re-create the tmp framebuffer

[Alexander Larsson <alexl src gnome org>]

commit 3c34ca3405f852b554bc05e07e460dbe9b9eae59
Author: Alexander Larsson <alexl redhat com>
Date:   Wed Nov 5 15:19:00 2014 +0100

    gdkgl: Don't constantly re-create the tmp framebuffer

 gdk/gdkgl.c               |   15 +++++++++------
 gdk/gdkglcontext.c        |   23 +++++++++++++++++++++++
 gdk/gdkglcontextprivate.h |    9 +++++++++
 3 files changed, 41 insertions(+), 6 deletions(-)
---
diff --git a/gdk/gdkgl.c b/gdk/gdkgl.c
index eaf1112..c7c847a 100644
--- a/gdk/gdkgl.c
+++ b/gdk/gdkgl.c
@@ -86,9 +86,10 @@ gdk_cairo_draw_from_gl (cairo_t              *cr,
   gboolean trivial_transform;
   cairo_surface_t *group_target;
   GdkWindow *direct_window, *impl_window;
-  GLuint framebuffer;
-  GLint alpha_size = 0;
+  guint framebuffer;
+  int alpha_size = 0;
   cairo_region_t *clip_region;
+  GdkGLContextPaintData *paint_data;
 
   impl_window = window->impl_window;
 
@@ -104,6 +105,10 @@ gdk_cairo_draw_from_gl (cairo_t              *cr,
   clip_region = gdk_cairo_region_from_clip (cr);
 
   gdk_gl_context_make_current (context);
+  paint_data = gdk_gl_context_get_paint_data (context);
+
+  if (paint_data->tmp_framebuffer == 0)
+    glGenFramebuffersEXT (1, &paint_data->tmp_framebuffer);
 
   if (source_type == GL_RENDERBUFFER)
     {
@@ -150,7 +155,7 @@ gdk_cairo_draw_from_gl (cairo_t              *cr,
 
       /* Create a framebuffer with the source renderbuffer and
          make it the current target for reads */
-      glGenFramebuffersEXT (1, &framebuffer);
+      framebuffer = paint_data->tmp_framebuffer;
       glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, framebuffer);
       glFramebufferRenderbufferEXT (GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
                                     GL_RENDERBUFFER_EXT, source);
@@ -213,7 +218,6 @@ gdk_cairo_draw_from_gl (cairo_t              *cr,
       glDisable (GL_SCISSOR_TEST);
 
       glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, 0);
-      glDeleteFramebuffersEXT (1, &framebuffer);
 
 #undef FLIP_Y
 
@@ -353,7 +357,7 @@ gdk_cairo_draw_from_gl (cairo_t              *cr,
       cairo_surface_set_device_scale (image, buffer_scale, buffer_scale);
 #endif
 
-      glGenFramebuffersEXT (1, &framebuffer);
+      framebuffer = paint_data->tmp_framebuffer;
       glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, framebuffer);
 
       if (source_type == GL_RENDERBUFFER)
@@ -378,7 +382,6 @@ gdk_cairo_draw_from_gl (cairo_t              *cr,
       glPixelStorei (GL_PACK_ROW_LENGTH, 0);
 
       glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, 0);
-      glDeleteFramebuffersEXT (1, &framebuffer);
 
       cairo_surface_mark_dirty (image);
 
diff --git a/gdk/gdkglcontext.c b/gdk/gdkglcontext.c
index 697eb2f..1628e51 100644
--- a/gdk/gdkglcontext.c
+++ b/gdk/gdkglcontext.c
@@ -87,6 +87,7 @@ typedef struct {
   guint realized : 1;
   guint use_texture_rectangle : 1;
 
+  GdkGLContextPaintData *paint_data;
 } GdkGLContextPrivate;
 
 enum {
@@ -127,6 +128,15 @@ gdk_gl_context_dispose (GObject *gobject)
 }
 
 static void
+gdk_gl_context_finalize (GObject *gobject)
+{
+  GdkGLContext *context = GDK_GL_CONTEXT (gobject);
+  GdkGLContextPrivate *priv = gdk_gl_context_get_instance_private (context);
+
+  g_clear_pointer (&priv->paint_data, g_free);
+}
+
+static void
 gdk_gl_context_set_property (GObject      *gobject,
                              guint         prop_id,
                              const GValue *value,
@@ -286,6 +296,7 @@ gdk_gl_context_class_init (GdkGLContextClass *klass)
   gobject_class->set_property = gdk_gl_context_set_property;
   gobject_class->get_property = gdk_gl_context_get_property;
   gobject_class->dispose = gdk_gl_context_dispose;
+  gobject_class->finalize = gdk_gl_context_finalize;
 
   g_object_class_install_properties (gobject_class, LAST_PROP, obj_pspecs);
 }
@@ -319,6 +330,18 @@ gdk_gl_context_end_frame (GdkGLContext   *context,
   GDK_GL_CONTEXT_GET_CLASS (context)->end_frame (context, painted, damage);
 }
 
+GdkGLContextPaintData *
+gdk_gl_context_get_paint_data (GdkGLContext *context)
+{
+
+  GdkGLContextPrivate *priv = gdk_gl_context_get_instance_private (context);
+
+  if (priv->paint_data == NULL)
+    priv->paint_data = g_new0 (GdkGLContextPaintData, 1);
+
+  return priv->paint_data;
+}
+
 gboolean
 gdk_gl_context_use_texture_rectangle (GdkGLContext *context)
 {
diff --git a/gdk/gdkglcontextprivate.h b/gdk/gdkglcontextprivate.h
index fcb82a8..cf6e578 100644
--- a/gdk/gdkglcontextprivate.h
+++ b/gdk/gdkglcontextprivate.h
@@ -54,6 +54,15 @@ void            gdk_gl_context_end_frame (GdkGLContext *context,
                                           cairo_region_t *painted,
                                           cairo_region_t *damage);
 
+
+
+typedef struct {
+  guint tmp_framebuffer;
+} GdkGLContextPaintData;
+
+GdkGLContextPaintData *gdk_gl_context_get_paint_data (GdkGLContext *context);
+
+
 G_END_DECLS
 
 #endif /* __GDK_GL_CONTEXT_PRIVATE_H__ */