python: Use transfer object to read from a surface.

src/gallium/state_trackers/python/st_sample.c

@@ -524,20 +524,33 @@ st_sample_pixel_block(enum pipe_format format,
 void
 st_sample_surface(struct pipe_surface *surface, float *rgba) 
 {
-   const struct pipe_format_block *block = &surface->block;
+   struct pipe_screen *screen = surface->texture->screen;
-   unsigned rgba_stride = surface->width*4;
+   uint rgba_stride = surface->width * 4;
+   struct pipe_transfer *transfer;
    void *raw;
-   unsigned x, y;
 
-   raw = pipe_surface_map(surface, PIPE_BUFFER_USAGE_CPU_READ);
+   transfer = screen->get_tex_transfer(screen,
-   if(!raw)
+                                       surface->texture,
+                                       surface->face,
+                                       surface->level,
+                                       surface->zslice,
+                                       PIPE_TRANSFER_READ,
+                                       0, 0,
+                                       surface->width,
+                                       surface->height);
+   if (!transfer)
       return;
 
-   for (y = 0; y < surface->nblocksy; ++y) {
+   raw = screen->transfer_map(screen, transfer);
-      for(x = 0; x < surface->nblocksx; ++x) {
+   if (raw) {
+      const struct pipe_format_block *block = &transfer->block;
+      uint x, y;
+
+      for (y = 0; y < transfer->nblocksy; ++y) {
+         for (x = 0; x < transfer->nblocksx; ++x) {
             st_sample_pixel_block(surface->format,
                                   block,
-                               (uint8_t*)raw + y*surface->stride + x*block->size, 
+                                  (uint8_t *) raw + y * transfer->stride + x * block->size,
                                   rgba + y * block->height * rgba_stride + x * block->width * 4,
                                   rgba_stride,
                                   MIN2(block->width, surface->width - x*block->width),
@@ -545,5 +558,8 @@ st_sample_surface(struct pipe_surface *surface, float *rgba)
          }
       }
 
-   pipe_surface_unmap(surface);
+      screen->transfer_unmap(screen, transfer);
+   }
+   
+   screen->tex_transfer_destroy(transfer);
 }