composite: Fix COW creation for Xinerama (v2)

Say you have two 800x600 screens left/right of each other.  A window
that's 200x200 at +700+0 in protocol coordinate space will appear to be
at -100+0 in the coordinate space of the right hand screen.  Put another
way: windows are in the coordinate space of their root window pixmap.

We weren't doing this translation for the COW, so when rendering came in
to it you'd see the top-left chunk of the COW on all screens.  Cool
effect and all, but wrong.

v2: Only translate when Xinerama is active [keithp]

Reviewed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Adam Jackson <ajax@redhat.com>

diff --git a/composite/compoverlay.c b/composite/compoverlay.c
index d3cfaf0..bf5434c 100644 (file)
--- a/composite/compoverlay.c
+++ b/composite/compoverlay.c
@@ -133,16 +133,19 @@ compCreateOverlayWindow(ScreenPtr pScreen)
     int result;
     int w = pScreen->width;
     int h = pScreen->height;
+    int x = 0, y = 0;
 
 #ifdef PANORAMIX
     if (!noPanoramiXExtension) {
+        x = -pScreen->x;
+        y = -pScreen->y;
         w = PanoramiXPixWidth;
         h = PanoramiXPixHeight;
     }
 #endif
 
     pWin = cs->pOverlayWin =
-        CreateWindow(cs->overlayWid, pRoot, 0, 0, w, h, 0,
+        CreateWindow(cs->overlayWid, pRoot, x, y, w, h, 0,
                      InputOutput, CWBackPixmap | CWOverrideRedirect, &attrs[0],
                      pRoot->drawable.depth,
                      serverClient, pScreen->rootVisual, &result);