GL_MESA_pack_invert

1 files changed, 9 insertions, 2 deletions

diff --git a/src/mesa/swrast/s_readpix.c b/src/mesa/swrast/s_readpix.c
index f925e791162..562d8718463 100644
--- a/src/mesa/swrast/s_readpix.c
+++ b/src/mesa/swrast/s_readpix.c
@@ -1,4 +1,4 @@
-/* $Id: s_readpix.c,v 1.15 2002/07/09 01:22:52 brianp Exp $ */
+/* $Id: s_readpix.c,v 1.16 2002/09/21 17:34:56 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -279,8 +279,15 @@ read_fast_rgba_pixels( GLcontext *ctx,
       if (0) {
 #endif
          GLchan *dest = (GLchan *) pixels
-                         + (skipRows * rowLength + skipPixels) * 4;
+                      + (skipRows * rowLength + skipPixels) * 4;
          GLint row;
+
+         if (packing->Invert) {
+            /* start at top and go down */
+            dest += (readHeight - 1) * rowLength * 4;
+            rowLength = -rowLength;
+         }
+
          for (row=0; row<readHeight; row++) {
             (*swrast->Driver.ReadRGBASpan)(ctx, readWidth, srcX, srcY,
                                         (GLchan (*)[4]) dest);