[gtk] gl renderer: begin/end_frame around do_render

[Timm Bäder <baedert src gnome org>]

commit cc878ec00fb527eaa3dd65d06985d0d7431ffe4d
Author: Timm Bäder <mail baedert org>
Date:   Mon Apr 22 14:20:02 2019 +0200

    gl renderer: begin/end_frame around do_render
    
    This fixes rendering to a texture on intel hardware. The glClear calls
    would throw a GL_FRAMEBUFFER_INCOMPLETE error here, because the
    gsk_gl_driver_begin_frame() call in do_render() reset the framebuffer
    object in use.

 gsk/gl/gskgldriver.c        | 6 ++++++
 gsk/gl/gskgldriverprivate.h | 2 +-
 gsk/gl/gskglrenderer.c      | 9 +++++----
 3 files changed, 12 insertions(+), 5 deletions(-)
---
diff --git a/gsk/gl/gskgldriver.c b/gsk/gl/gskgldriver.c
index ebc3e21349..de90d84d54 100644
--- a/gsk/gl/gskgldriver.c
+++ b/gsk/gl/gskgldriver.c
@@ -206,6 +206,12 @@ gsk_gl_driver_begin_frame (GskGLDriver *self)
 #endif
 }
 
+gboolean
+gsk_gl_driver_in_frame (GskGLDriver *self)
+{
+  return self->in_frame;
+}
+
 void
 gsk_gl_driver_end_frame (GskGLDriver *self)
 {
diff --git a/gsk/gl/gskgldriverprivate.h b/gsk/gl/gskgldriverprivate.h
index 8ceecb183a..a73b62b2d0 100644
--- a/gsk/gl/gskgldriverprivate.h
+++ b/gsk/gl/gskgldriverprivate.h
@@ -28,7 +28,7 @@ int             gsk_gl_driver_get_max_texture_size      (GskGLDriver     *driver
 
 void            gsk_gl_driver_begin_frame               (GskGLDriver     *driver);
 void            gsk_gl_driver_end_frame                 (GskGLDriver     *driver);
-
+gboolean        gsk_gl_driver_in_frame                  (GskGLDriver     *driver);
 int             gsk_gl_driver_get_texture_for_texture   (GskGLDriver     *driver,
                                                          GdkTexture      *texture,
                                                          int              min_filter,
diff --git a/gsk/gl/gskglrenderer.c b/gsk/gl/gskglrenderer.c
index 7d00ecb290..1dafe4521e 100644
--- a/gsk/gl/gskglrenderer.c
+++ b/gsk/gl/gskglrenderer.c
@@ -2911,6 +2911,8 @@ gsk_gl_renderer_do_render (GskRenderer           *renderer,
       return;
     }
 
+  g_assert (gsk_gl_driver_in_frame (self->gl_driver));
+
   /* Set up the modelview and projection matrices to fit our viewport */
   graphene_matrix_init_scale (&modelview, scale_factor, scale_factor, 1.0);
   graphene_matrix_init_ortho (&projection,
@@ -2922,7 +2924,6 @@ gsk_gl_renderer_do_render (GskRenderer           *renderer,
                               ORTHO_FAR_PLANE);
   graphene_matrix_scale (&projection, 1, -1, 1);
 
-  gsk_gl_driver_begin_frame (self->gl_driver);
   gsk_gl_glyph_cache_begin_frame (&self->glyph_cache);
   gsk_gl_shadow_cache_begin_frame (&self->shadow_cache, self->gl_driver);
 
@@ -2997,8 +2998,6 @@ gsk_gl_renderer_do_render (GskRenderer           *renderer,
 
   gsk_gl_renderer_render_ops (self, render_op_builder.buffer_size);
 
-  gsk_gl_driver_end_frame (self->gl_driver);
-
 #ifdef G_ENABLE_DEBUG
   gsk_profiler_counter_inc (profiler, self->profile_counters.frames);
 
@@ -3047,7 +3046,6 @@ gsk_gl_renderer_render_texture (GskRenderer           *renderer,
   g_assert_cmphex (glCheckFramebufferStatus (GL_FRAMEBUFFER), ==, GL_FRAMEBUFFER_COMPLETE);
 
   gsk_gl_renderer_clear (self);
-  gsk_gl_driver_end_frame (self->gl_driver);
 
   /* Render the actual scene */
   gsk_gl_renderer_do_render (renderer, root, viewport, fbo_id, 1);
@@ -3057,6 +3055,7 @@ gsk_gl_renderer_render_texture (GskRenderer           *renderer,
                                 width, height,
                                 NULL, NULL);
 
+  gsk_gl_driver_end_frame (self->gl_driver);
   gsk_gl_renderer_clear_tree (self);
   return texture;
 }
@@ -3111,7 +3110,9 @@ gsk_gl_renderer_render (GskRenderer          *renderer,
   viewport.size.width = gdk_surface_get_width (surface) * self->scale_factor;
   viewport.size.height = gdk_surface_get_height (surface) * self->scale_factor;
 
+  gsk_gl_driver_begin_frame (self->gl_driver);
   gsk_gl_renderer_do_render (renderer, root, &viewport, 0, self->scale_factor);
+  gsk_gl_driver_end_frame (self->gl_driver);
 
   gdk_gl_context_make_current (self->gl_context);
   gsk_gl_renderer_clear_tree (self);