[gtk+/wip/otte/rendernode] gsk: Add fallback code to renderers

[Benjamin Otte <otte src gnome org>]

commit f2411e08f7c2caf9fdbe0a9838a350f1047f7dbf
Author: Benjamin Otte <otte redhat com>
Date:   Tue Dec 13 04:20:04 2016 +0100

    gsk: Add fallback code to renderers
    
    This code makes renderers fall back to Cairo rendering if they don't
    know how to handle a render node's type.
    
    This allows adding new render nodes with impunity.

 gsk/gskglrenderer.c       |   32 +++++++++++++++++++++++++++++++-
 gsk/gskvulkanrenderpass.c |    6 +++++-
 2 files changed, 36 insertions(+), 2 deletions(-)
---
diff --git a/gsk/gskglrenderer.c b/gsk/gskglrenderer.c
index 5cbb0a0..829e50a 100644
--- a/gsk/gskglrenderer.c
+++ b/gsk/gskglrenderer.c
@@ -760,8 +760,38 @@ gsk_gl_renderer_add_render_item (GskGLRenderer           *self,
       return;
 
     case GSK_NOT_A_RENDER_NODE:
-    default:
+      g_assert_not_reached ();
       return;
+
+    default:
+      {
+        graphene_rect_t bounds;
+        cairo_surface_t *surface;
+        cairo_t *cr;
+
+        gsk_render_node_get_bounds (node, &bounds);
+
+        surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
+                                              ceil (bounds.size.width),
+                                              ceil (bounds.size.height));
+        cr = cairo_create (surface);
+        cairo_translate (cr, bounds.origin.x, bounds.origin.y);
+
+        gsk_render_node_draw (node, cr);
+        
+        cairo_destroy (cr);
+
+        /* Upload the Cairo surface to a GL texture */
+        item.render_data.texture_id = gsk_gl_driver_create_texture (self->gl_driver,
+                                                                    item.size.width,
+                                                                    item.size.height);
+        gsk_gl_driver_bind_source_texture (self->gl_driver, item.render_data.texture_id);
+        gsk_gl_driver_init_texture_with_surface (self->gl_driver,
+                                                 item.render_data.texture_id,
+                                                 surface,
+                                                 GL_NEAREST, GL_NEAREST);
+      }
+      break;
     }
 
   /* Create the vertex buffers holding the geometry of the quad */
diff --git a/gsk/gskvulkanrenderpass.c b/gsk/gskvulkanrenderpass.c
index 62af7e3..7df4421 100644
--- a/gsk/gskvulkanrenderpass.c
+++ b/gsk/gskvulkanrenderpass.c
@@ -72,10 +72,14 @@ gsk_vulkan_render_pass_add_node (GskVulkanRenderPass     *self,
   switch (gsk_render_node_get_node_type (node))
     {
     case GSK_NOT_A_RENDER_NODE:
-    default:
       g_assert_not_reached ();
       break;
 
+    default:
+      op.type = GSK_VULKAN_OP_FALLBACK;
+      g_array_append_val (self->render_ops, op);
+      break;
+
     case GSK_CAIRO_NODE:
       op.type = GSK_VULKAN_OP_SURFACE;
       g_array_append_val (self->render_ops, op);