[Mesa-dev] [PATCH] st/mesa: disallow mixed formats in a FBO

[Marek Olšák]

Some GPUs can't do it (I think most of DX9 ones).

We should later decide how Gallium will expose this feature.
---
 src/mesa/state_tracker/st_cb_fbo.c |   21 ++++++++++++++++++++-
 1 files changed, 20 insertions(+), 1 deletions(-)

diff --git a/src/mesa/state_tracker/st_cb_fbo.c b/src/mesa/state_tracker/st_cb_fbo.c
index 0df0428..e1057b1 100644
--- a/src/mesa/state_tracker/st_cb_fbo.c
+++ b/src/mesa/state_tracker/st_cb_fbo.c
@@ -529,6 +529,7 @@ st_validate_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb)
    const struct gl_renderbuffer_attachment *stencil =
          &fb->Attachment[BUFFER_STENCIL];
    GLuint i;
+   enum pipe_format first_format = PIPE_FORMAT_NONE;
 
    if (depth->Type && stencil->Type && depth->Type != stencil->Type) {
       fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
@@ -562,13 +563,31 @@ st_validate_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb)
       return;
    }
    for (i = 0; i < ctx->Const.MaxColorAttachments; i++) {
+      struct gl_renderbuffer_attachment *att =
+            &fb->Attachment[BUFFER_COLOR0 + i];
+      enum pipe_format format;
+
       if (!st_validate_attachment(ctx,
                                   screen,
-				  &fb->Attachment[BUFFER_COLOR0 + i],
+				  att,
 				  PIPE_BIND_RENDER_TARGET)) {
 	 fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
 	 return;
       }
+
+      /* Disallow mixed formats. This may be revisited later. */
+      if (att->Type != GL_NONE) {
+         format = st_renderbuffer(att->Renderbuffer)->surface->format;
+      } else {
+         continue;
+      }
+
+      if (first_format == PIPE_FORMAT_NONE) {
+         first_format = format;
+      } else if (format != first_format) {
+         fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
+         return;
+      }
    }
 }
 
-- 
1.7.1