brl/mutter
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

[cogl-draw-buffer] fix Cogl -> GL viewport coord conversion

Browse Source 
Before we call glViewport we need to convert Cogl viewport coordinates
(where the origin is defined to be top left) to OpenGL coordinates
(where the origin is defined to be bottom left)

We weren't considering that offscreen rendering is always upside down
and in this case Cogl coordinates == OpenGL coordinates.
This commit is contained in:
Robert Bragg 2009-10-31 00:00:33 +00:00
parent 149e3e168a
commit 90dbae5aa9
1 changed files with 11 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
clutter/cogl/cogl/cogl-draw-buffer.c
View File

@ -567,10 +567,17 @@ _cogl_draw_buffer_flush_state (CoglHandle handle,
if (ctx->dirty_gl_viewport)
{
int gl_viewport_y;
/* Convert the Cogl viewport y offset to an OpenGL viewport y offset
* (NB: OpenGL defines its window and viewport origins to be bottom
* left, while Cogl defines them to be top left.) */
int gl_viewport_y = draw_buffer->height -
* NB: OpenGL defines its window and viewport origins to be bottom
* left, while Cogl defines them to be top left.
* NB: We render upside down to offscreen draw buffers so we don't
* need to convert the y offset in this case. */
if (cogl_is_offscreen (draw_buffer))
gl_viewport_y = draw_buffer->viewport_y;
else
gl_viewport_y = draw_buffer->height -
(draw_buffer->viewport_y + draw_buffer->viewport_height);
GE (glViewport (draw_buffer->viewport_x,