Index: lib/GL/mesa/src/drv/r200/r200_context.c
===================================================================
RCS file: /cvs/dri/xc/xc/lib/GL/mesa/src/drv/r200/r200_context.c,v
retrieving revision 1.35
diff -u -d -r1.35 r200_context.c
--- lib/GL/mesa/src/drv/r200/r200_context.c	25 Oct 2003 16:06:35 -0000	1.35
+++ lib/GL/mesa/src/drv/r200/r200_context.c	23 Nov 2003 03:17:37 -0000
@@ -593,6 +593,8 @@
 	 r200UpdateViewportOffset( newCtx->glCtx );
       }
 
+      newCtx->dri.readable = driReadPriv;
+
       _mesa_make_current2( newCtx->glCtx,
 			   (GLframebuffer *) driDrawPriv->driverPrivate,
 			   (GLframebuffer *) driReadPriv->driverPrivate );
Index: lib/GL/mesa/src/drv/r200/r200_context.h
===================================================================
RCS file: /cvs/dri/xc/xc/lib/GL/mesa/src/drv/r200/r200_context.h,v
retrieving revision 1.27
diff -u -d -r1.27 r200_context.h
--- lib/GL/mesa/src/drv/r200/r200_context.h	25 Oct 2003 16:06:35 -0000	1.27
+++ lib/GL/mesa/src/drv/r200/r200_context.h	23 Nov 2003 03:17:37 -0000
@@ -565,6 +565,14 @@
    __DRIcontextPrivate	*context;	/* DRI context */
    __DRIscreenPrivate	*screen;	/* DRI screen */
    __DRIdrawablePrivate	*drawable;	/* DRI drawable bound to this ctx */
+   __DRIdrawablePrivate	*readable;	/* DRI drawable bound to this ctx */
+
+   /**
+    * Drawable currently set for reading via Mesa's \c SetBuffer hook.  This
+    * will either be \c drawable or \c readable.
+    */
+
+   __DRIdrawablePrivate	*read_source;
 
    drmContext hwContext;
    drmLock *hwLock;
Index: lib/GL/mesa/src/drv/r200/r200_screen.c
===================================================================
RCS file: /cvs/dri/xc/xc/lib/GL/mesa/src/drv/r200/r200_screen.c,v
retrieving revision 1.20
diff -u -d -r1.20 r200_screen.c
--- lib/GL/mesa/src/drv/r200/r200_screen.c	5 Nov 2003 16:12:51 -0000	1.20
+++ lib/GL/mesa/src/drv/r200/r200_screen.c	23 Nov 2003 03:17:37 -0000
@@ -272,6 +272,7 @@
 	    (*glx_enable_extension)( psc, "GLX_MESA_swap_control" );
 	 }
 
+	 (*glx_enable_extension)( psc, "GLX_SGI_make_current_read" );
 	 (*glx_enable_extension)( psc, "GLX_MESA_swap_frame_usage" );
 
 	 if ( driCompareGLXAPIVersion( 20030818 ) >= 0 ) {
Index: lib/GL/mesa/src/drv/r200/r200_span.c
===================================================================
RCS file: /cvs/dri/xc/xc/lib/GL/mesa/src/drv/r200/r200_span.c,v
retrieving revision 1.6
diff -u -d -r1.6 r200_span.c
--- lib/GL/mesa/src/drv/r200/r200_span.c	16 Sep 2003 20:45:08 -0000	1.6
+++ lib/GL/mesa/src/drv/r200/r200_span.c	23 Nov 2003 03:17:37 -0000
@@ -47,15 +47,15 @@
 #define DBG 0
 
 #define LOCAL_VARS							\
-   r200ContextPtr rmesa = R200_CONTEXT(ctx);			\
+   r200ContextPtr rmesa = R200_CONTEXT(ctx);				\
    r200ScreenPtr r200Screen = rmesa->r200Screen;			\
    __DRIscreenPrivate *sPriv = rmesa->dri.screen;			\
-   __DRIdrawablePrivate *dPriv = rmesa->dri.drawable;			\
+   __DRIdrawablePrivate *dPriv = rmesa->dri.read_source;		\
    GLuint pitch = r200Screen->frontPitch * r200Screen->cpp;		\
    GLuint height = dPriv->h;						\
    char *buf = (char *)(sPriv->pFB +					\
 			rmesa->state.color.drawOffset +			\
-			(dPriv->x * r200Screen->cpp) +		\
+			(dPriv->x * r200Screen->cpp) +			\
 			(dPriv->y * pitch));				\
    char *read_buf = (char *)(sPriv->pFB +				\
 			     rmesa->state.pixel.readOffset +		\
@@ -65,14 +65,14 @@
    (void) read_buf; (void) buf; (void) p
 
 #define LOCAL_DEPTH_VARS						\
-   r200ContextPtr rmesa = R200_CONTEXT(ctx);			\
+   r200ContextPtr rmesa = R200_CONTEXT(ctx);				\
    r200ScreenPtr r200Screen = rmesa->r200Screen;			\
    __DRIscreenPrivate *sPriv = rmesa->dri.screen;			\
-   __DRIdrawablePrivate *dPriv = rmesa->dri.drawable;			\
+   __DRIdrawablePrivate *dPriv = rmesa->dri.read_source;		\
    GLuint height = dPriv->h;						\
    GLuint xo = dPriv->x;						\
    GLuint yo = dPriv->y;						\
-   char *buf = (char *)(sPriv->pFB + r200Screen->depthOffset);	\
+   char *buf = (char *)(sPriv->pFB + r200Screen->depthOffset);		\
    (void) buf
 
 #define LOCAL_STENCIL_VARS	LOCAL_DEPTH_VARS
@@ -300,6 +300,16 @@
 {
    r200ContextPtr rmesa = R200_CONTEXT(ctx);
 
+
+   fprintf( stderr, "read_source is the drawable (%s)\n",
+	    (bufferBit == FRONT_LEFT_BIT) ? "front" : "back" );
+
+   assert( (colorBuffer == rmesa->dri.drawable->driverPrivate)
+	   || (colorBuffer == rmesa->dri.readable->driverPrivate) );
+
+   rmesa->dri.read_source = (colorBuffer == rmesa->dri.drawable->driverPrivate)
+       ? rmesa->dri.drawable : rmesa->dri.readable;
+
    switch ( bufferBit ) {
    case FRONT_LEFT_BIT:
       if ( rmesa->doPageFlip && rmesa->sarea->pfCurrentPage == 1 ) {