Implement core protocol backing store exclusively in terms of Composite.

Composite's automatic redirection is a more general mechanism than the
ad-hoc BS machinery, so it's much prettier to implement the one in terms
of the other.  Composite now wraps ChangeWindowAttributes and activates
automatic redirection for windows with backing store requested.  The old
backing store infrastructure is completely gutted: ABI-visible structures
retain the function pointers, but they never get called, and all the
open-coded conditionals throughout the DIX layer to implement BS are gone.

Note that this is still not a strictly complete implementation of backing
store, since Composite will throw the bits away on unmap and therefore
WhenMapped and Always hints are equivalent.

1 files changed, 1 insertions, 70 deletions

diff --git a/mi/mioverlay.c b/mi/mioverlay.c
index 9701001d6..1dbb85da5 100644
--- a/mi/mioverlay.c
+++ b/mi/mioverlay.c
@@ -1025,8 +1025,6 @@ miOverlayWindowExposures(
     RegionPtr   exposures = prgn;
     ScreenPtr pScreen = pWin->drawable.pScreen;
 
-    if (pWin->backStorage && prgn)
-	exposures = (*pScreen->RestoreAreas)(pWin, prgn);
     if ((prgn && !REGION_NIL(prgn)) || 
 	(exposures && !REGION_NIL(exposures)) || other_exposed)
     {
@@ -1066,16 +1064,6 @@ miOverlayWindowExposures(
 		REGION_INTERSECT(pScreen, prgn, prgn, &pTree->clipList);
 	    } else
 		REGION_INTERSECT(pScreen, prgn, prgn, &pWin->clipList);
-
-	    /* need to clear out new areas of backing store, too */
-	    if (pWin->backStorage)
-		(void) (*pScreen->ClearBackingStore)(
-					     pWin,
-					     box.x1 - pWin->drawable.x,
-					     box.y1 - pWin->drawable.y,
-					     box.x2 - box.x1,
-					     box.y2 - box.y1,
-					     FALSE);
 	}
 	if (prgn && !REGION_NIL(prgn))
 	    (*pScreen->PaintWindowBackground)(
@@ -1172,7 +1160,6 @@ miOverlayResizeWindow(
     RegionPtr	oldWinClip = NULL, oldWinClip2 = NULL;	
     RegionPtr	borderVisible = NullRegion; 
     RegionPtr	borderVisible2 = NullRegion; 
-    RegionPtr	bsExposed = NullRegion;	    /* backing store exposures */
     Bool	shrunk = FALSE; /* shrunk in an inner dimension */
     Bool	moved = FALSE;	/* window position changed */
 #ifdef DO_SAVE_UNDERS
@@ -1299,8 +1286,6 @@ miOverlayResizeWindow(
 
     if (WasViewable) {
 	pRegion = REGION_CREATE(pScreen, NullBox, 1);
-	if (pWin->backStorage)
-	    REGION_COPY(pScreen, pRegion, &pWin->clipList);
 
 	(*pScreen->MarkOverlappedWindows)(pWin, pFirstChange, NULL);
 
@@ -1326,17 +1311,6 @@ miOverlayResizeWindow(
 
     GravityTranslate (x, y, oldx, oldy, dw, dh, pWin->bitGravity, &nx, &ny);
 
-    if (pWin->backStorage && ((pWin->backingStore == Always) || WasViewable)) {
-	if (!WasViewable)
-	    pRegion = &pWin->clipList; /* a convenient empty region */
-	if (pWin->bitGravity == ForgetGravity)
-	    bsExposed = (*pScreen->TranslateBackingStore)
-				(pWin, 0, 0, NullRegion, oldx, oldy);
-	else
-	    bsExposed = (*pScreen->TranslateBackingStore)
-			     (pWin, nx - x, ny - y, pRegion, oldx, oldy);
-    }
-
     if (WasViewable) {
 	miOverlayScreenPtr pPriv = MIOVERLAY_GET_SCREEN_PRIVATE(pScreen);
 	miOverlayTwoRegions TwoRegions;
@@ -1544,16 +1518,6 @@ miOverlayResizeWindow(
 	    REGION_DESTROY(pScreen, destClip);
 	if (destClip2)
 	    REGION_DESTROY(pScreen, destClip2);
-	if (bsExposed) {
-	    RegionPtr	valExposed = NullRegion;
-
-	    if (pWin->valdata)
-		valExposed = &pWin->valdata->after.exposed;
-	    (*pScreen->WindowExposures) (pWin, valExposed, bsExposed);
-	    if (valExposed)
-		REGION_EMPTY(pScreen, valExposed);
-	    REGION_DESTROY(pScreen, bsExposed);
-	}
 	(*pScreen->HandleExposures)(pWin->parent);
 #ifdef DO_SAVE_UNDERS
 	if (dosave)
@@ -1562,10 +1526,6 @@ miOverlayResizeWindow(
 	if (pScreen->PostValidateTree)
 	    (*pScreen->PostValidateTree)(pWin->parent, pFirstChange, VTOther);
     }
-    else if (bsExposed) {
-	(*pScreen->WindowExposures) (pWin, NullRegion, bsExposed);
-	REGION_DESTROY(pScreen, bsExposed);
-    }
     if (pWin->realized)
 	WindowsRestructured ();
 }
@@ -1577,7 +1537,7 @@ miOverlaySetShape(WindowPtr pWin)
 {
     Bool	WasViewable = (Bool)(pWin->viewable);
     ScreenPtr 	pScreen = pWin->drawable.pScreen;
-    RegionPtr	pOldClip = NULL, bsExposed;
+    RegionPtr	pOldClip = NULL;
 #ifdef DO_SAVE_UNDERS
     Bool	dosave = FALSE;
 #endif
@@ -1611,11 +1571,6 @@ miOverlaySetShape(WindowPtr pWin)
     ResizeChildrenWinSize(pWin, 0, 0, 0, 0);
 
     if (WasViewable) {
-	if (pWin->backStorage) {
-	    pOldClip = REGION_CREATE(pScreen, NullBox, 1);
-	    REGION_COPY(pScreen, pOldClip, &pWin->clipList);
-	}
-
 	(*pScreen->MarkOverlappedWindows)(pWin, pWin, NULL);
 
 #ifdef DO_SAVE_UNDERS
@@ -1626,26 +1581,6 @@ miOverlaySetShape(WindowPtr pWin)
 	(*pScreen->ValidateTree)(pWin->parent, NullWindow, VTOther);
     }
 
-    if (pWin->backStorage && ((pWin->backingStore == Always) || WasViewable)) {
-	if (!WasViewable)
-	    pOldClip = &pWin->clipList; /* a convenient empty region */
-	bsExposed = (*pScreen->TranslateBackingStore)
-			     (pWin, 0, 0, pOldClip,
-			      pWin->drawable.x, pWin->drawable.y);
-	if (WasViewable)
-	    REGION_DESTROY(pScreen, pOldClip);
-	if (bsExposed)
-	{
-	    RegionPtr	valExposed = NullRegion;
-    
-	    if (pWin->valdata)
-		valExposed = &pWin->valdata->after.exposed;
-	    (*pScreen->WindowExposures) (pWin, valExposed, bsExposed);
-	    if (valExposed)
-		REGION_EMPTY(pScreen, valExposed);
-	    REGION_DESTROY(pScreen, bsExposed);
-	}
-    }
     if (WasViewable) {
 	(*pScreen->HandleExposures)(pWin->parent);
 #ifdef DO_SAVE_UNDERS
@@ -1798,10 +1733,6 @@ miOverlayClearToBackground(
     box.y1 = y1; box.y2 = y2;
 
     REGION_INIT(pScreen, &reg, &box, 1);
-    if (pWin->backStorage) {
-        pBSReg = (* pScreen->ClearBackingStore)(pWin, x, y, w, h,
-                                                 generateExposures);
-    }
 
     REGION_INTERSECT(pScreen, &reg, &reg, clipList);
     if (generateExposures)