st/mesa: implement a simple cache for glDrawPixels

Instead of discarding the texture we created, keep it around in case
the next glDrawPixels draws the same image again.  This is intended
to help application which draw the same image several times in a row,
either within a frame or subsequent frames.

Reviewed-by: Charmaine Lee <[email protected]>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/mesa/state_tracker/st_context.h b/src/mesa/state_tracker/st_context.h
index 1701c618ebf..f960c64cbe8 100644
--- a/src/mesa/state_tracker/st_context.h
+++ b/src/mesa/state_tracker/st_context.h
@@ -217,6 +217,14 @@ struct st_context
       void *vert_shaders[2];   /**< ureg shaders */
    } drawpix;
 
+   struct {
+      GLsizei width, height;
+      GLenum format, type;
+      const void *user_pointer;  /**< Last user 'pixels' pointer */
+      void *image;               /**< Copy of the glDrawPixels image data */
+      struct pipe_resource *texture;
+   } drawpix_cache;
+
    /** for glClear */
    struct {
       struct pipe_rasterizer_state raster;