gallium: change the st_get_framebuffer_surface/texture functions

to return TRUE/FALSE if the st_framebuffer is valid, and if it is
return the surface/texture in the passed pointer.

src/gallium/state_trackers/glx/xlib/xm_api.c

@@ -1117,7 +1117,7 @@ void XMesaSwapBuffers( XMesaBuffer b )
     */
    st_notify_swapbuffers(b->stfb);
 
-   surf = st_get_framebuffer_surface(b->stfb, ST_SURFACE_BACK_LEFT);
+   st_get_framebuffer_surface(b->stfb, ST_SURFACE_BACK_LEFT, &surf);
    if (surf) {
       driver.display_surface(b, surf);
    }
@@ -1132,12 +1132,13 @@ void XMesaSwapBuffers( XMesaBuffer b )
  */
 void XMesaCopySubBuffer( XMesaBuffer b, int x, int y, int width, int height )
 {
-   struct pipe_surface *surf_front
-      = st_get_framebuffer_surface(b->stfb, ST_SURFACE_FRONT_LEFT);
-   struct pipe_surface *surf_back
-      = st_get_framebuffer_surface(b->stfb, ST_SURFACE_BACK_LEFT);
+   struct pipe_surface *surf_front;
+   struct pipe_surface *surf_back;
    struct pipe_context *pipe = NULL; /* XXX fix */
 
+   st_get_framebuffer_surface(b->stfb, ST_SURFACE_FRONT_LEFT, &surf_front);
+   st_get_framebuffer_surface(b->stfb, ST_SURFACE_BACK_LEFT, &surf_back);
+
    if (!surf_front || !surf_back)
       return;
 

src/mesa/state_tracker/st_atom_framebuffer.c

@@ -149,10 +149,9 @@ update_framebuffer_state( struct st_context *st )
       if (st->frontbuffer_status == FRONT_STATUS_COPY_OF_BACK) {
          /* copy back color buffer to front color buffer */
          struct st_framebuffer *stfb = (struct st_framebuffer *) fb;
-         struct pipe_surface *surf_front
-            = st_get_framebuffer_surface(stfb, ST_SURFACE_FRONT_LEFT);
-         struct pipe_surface *surf_back
-            = st_get_framebuffer_surface(stfb, ST_SURFACE_BACK_LEFT);
+	 struct pipe_surface *surf_front, *surf_back;
+         (void) st_get_framebuffer_surface(stfb, ST_SURFACE_FRONT_LEFT, &surf_front);
+         (void) st_get_framebuffer_surface(stfb, ST_SURFACE_BACK_LEFT, &surf_back);
 
          st->pipe->surface_copy(st->pipe,
                                 FALSE,

src/mesa/state_tracker/st_framebuffer.c

@@ -33,9 +33,9 @@
 #include "main/matrix.h"
 #include "main/renderbuffer.h"
 #include "main/scissor.h"
-#include "st_public.h"
 #include "st_context.h"
 #include "st_cb_fbo.h"
+#include "st_public.h"
 #include "pipe/p_defines.h"
 #include "pipe/p_context.h"
 #include "pipe/p_inlines.h"
@@ -230,8 +230,8 @@ st_set_framebuffer_surface(struct st_framebuffer *stfb,
 /**
  * Return the pipe_surface for the given renderbuffer.
  */
-struct pipe_surface *
-st_get_framebuffer_surface(struct st_framebuffer *stfb, uint surfIndex)
+int
+st_get_framebuffer_surface(struct st_framebuffer *stfb, uint surfIndex, struct pipe_surface **surface)
 {
    struct st_renderbuffer *strb;
 
@@ -242,13 +242,17 @@ st_get_framebuffer_surface(struct st_framebuffer *stfb, uint surfIndex)
    assert(ST_SURFACE_BACK_RIGHT == BUFFER_BACK_RIGHT);
 
    strb = st_renderbuffer(stfb->Base.Attachment[surfIndex].Renderbuffer);
-   if (strb)
-      return strb->surface;
-   return NULL;
+   if (strb) {
+      *surface = strb->surface;
+      return GL_TRUE;
+   }
+
+   *surface = NULL;
+   return GL_FALSE;
 }
 
-struct pipe_texture *
-st_get_framebuffer_texture(struct st_framebuffer *stfb, uint surfIndex)
+int
+st_get_framebuffer_texture(struct st_framebuffer *stfb, uint surfIndex, struct pipe_texture **texture)
 {
    struct st_renderbuffer *strb;
 
@@ -259,9 +263,13 @@ st_get_framebuffer_texture(struct st_framebuffer *stfb, uint surfIndex)
    assert(ST_SURFACE_BACK_RIGHT == BUFFER_BACK_RIGHT);
 
    strb = st_renderbuffer(stfb->Base.Attachment[surfIndex].Renderbuffer);
-   if (strb)
-      return strb->texture;
-   return NULL;
+   if (strb) {
+      *texture = strb->texture;
+      return GL_TRUE;
+   }
+
+   *texture = NULL;
+   return GL_FALSE;
 }
 
 /**

src/mesa/state_tracker/st_public.h

@@ -80,11 +80,11 @@ void st_set_framebuffer_surface(struct st_framebuffer *stfb,
 void st_get_framebuffer_dimensions( struct st_framebuffer *stfb,
 				    uint *width, uint *height);
 
-struct pipe_surface *st_get_framebuffer_surface(struct st_framebuffer *stfb,
-                                                uint surfIndex);
+int st_get_framebuffer_surface(struct st_framebuffer *stfb,
+                               uint surfIndex, struct pipe_surface **surface);
 
-struct pipe_texture *st_get_framebuffer_texture(struct st_framebuffer *stfb,
-                                                uint surfIndex);
+int st_get_framebuffer_texture(struct st_framebuffer *stfb,
+                               uint surfIndex, struct pipe_texture **texture);
 
 void *st_framebuffer_private( struct st_framebuffer *stfb );