[cogl] framebuffer: lazily allocate framebuffers as needed

[Robert Bragg <rbragg src gnome org>]

commit 8e8690a562395d96485115a7f437a55f8db2af77
Author: Robert Bragg <robert linux intel com>
Date:   Wed Aug 3 17:03:09 2011 +0100

    framebuffer: lazily allocate framebuffers as needed
    
    If the user doesn't explicitly allocate a CoglFramebuffer then Cogl
    should automatically allocate the framebuffer when the user starts to
    draw to the framebuffer. So this way calling cogl_framebuffer_allocate
    is only required if you are explicitly interested in checking for and
    gracefully handling failures to allocate a framebuffer. If automatic
    allocation fails then application behaviour becomes undefined.
    
    Reviewed-by: Neil Roberts <neil linux intel com>

 cogl/cogl-framebuffer.c |   10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)
---
diff --git a/cogl/cogl-framebuffer.c b/cogl/cogl-framebuffer.c
index 48a4218..a7a442c 100644
--- a/cogl/cogl-framebuffer.c
+++ b/cogl/cogl-framebuffer.c
@@ -301,8 +301,6 @@ cogl_framebuffer_clear4f (CoglFramebuffer *framebuffer,
   int scissor_x1;
   int scissor_y1;
 
-  g_return_if_fail (framebuffer->allocated);
-
   _cogl_clip_stack_get_bounds (clip_stack,
                                &scissor_x0, &scissor_y0,
                                &scissor_x1, &scissor_y1);
@@ -452,8 +450,6 @@ cogl_framebuffer_clear (CoglFramebuffer *framebuffer,
                         unsigned long buffers,
                         const CoglColor *color)
 {
-  g_return_if_fail (framebuffer->allocated);
-
   cogl_framebuffer_clear4f (framebuffer, buffers,
                             cogl_color_get_red_float (color),
                             cogl_color_get_green_float (color),
@@ -618,6 +614,8 @@ _cogl_framebuffer_init_bits (CoglFramebuffer *framebuffer)
 {
   CoglContext *ctx = framebuffer->context;
 
+  cogl_framebuffer_allocate (framebuffer, NULL);
+
   if (G_LIKELY (!framebuffer->dirty_bitmasks))
     return;
 
@@ -1383,6 +1381,10 @@ _cogl_framebuffer_flush_state (CoglFramebuffer *draw_buffer,
 {
   CoglContext *ctx = draw_buffer->context;
 
+  /* Lazily ensure the framebuffer has been allocated */
+  cogl_framebuffer_allocate (draw_buffer, NULL);
+  cogl_framebuffer_allocate (read_buffer, NULL);
+
   if (ctx->dirty_bound_framebuffer)
     {
       if (draw_buffer == read_buffer)