1 files changed, 13 insertions, 0 deletions
diff --git a/src/mesa/main/dd.h b/src/mesa/main/dd.h
index 3746e4685c..e1f3ad5452 100644
--- a/src/mesa/main/dd.h
+++ b/src/mesa/main/dd.h
@@ -515,6 +515,19 @@ struct dd_function_table {
    void (*FreeTexImageData)( GLcontext *ctx, struct gl_texture_image *tImage );
 
    /**
+    * Note: no context argument.  This function doesn't initially look
+    * like it belongs here, except that the driver is the only entity
+    * that knows for sure how the texture memory is allocated - via
+    * the above callbacks.  There is then an argument that the driver
+    * knows what memcpy paths might be fast.  Typically this is invoked with
+    * 
+    * to -- a pointer into texture memory allocated by NewTextureImage() above.
+    * from -- a pointer into client memory or a mesa temporary.
+    * sz -- nr bytes to copy.
+    */
+   void (*TextureMemCpy)( void *to, const void *from, size_t sz );
+
+   /**
     * Called by glAreTextureResident().
     */
    GLboolean (*IsTextureResident)( GLcontext *ctx,