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, 75 deletions

diff --git a/mi/miwindow.c b/mi/miwindow.c
index 6ca2e1e38..cab67ea07 100644
--- a/mi/miwindow.c
+++ b/mi/miwindow.c
@@ -113,18 +113,6 @@ miClearToBackground(pWin, x, y, w, h, generateExposures)
 
     pScreen = pWin->drawable.pScreen;
     REGION_INIT(pScreen, &reg, &box, 1);
-    if (pWin->backStorage)
-    {
-	/*
-	 * If the window has backing-store on, call through the
-	 * ClearToBackground vector to handle the special semantics
-	 * (i.e. things backing store is to be cleared out and
-	 * an Expose event is to be generated for those areas in backing
-	 * store if generateExposures is TRUE).
-	 */
-	pBSReg = (* pScreen->ClearBackingStore)(pWin, x, y, w, h,
-						 generateExposures);
-    }
 
     REGION_INTERSECT(pScreen, &reg, &reg, &pWin->clipList);
     if (generateExposures)
@@ -631,7 +619,6 @@ miSlideAndSizeWindow(pWin, x, y, w, h, pSib)
     RegionPtr	destClip;	/* portions of destination already written */
     RegionPtr	oldWinClip = NULL;	/* old clip list for window */
     RegionPtr	borderVisible = NullRegion; /* visible area of the border */
-    RegionPtr	bsExposed = NullRegion;	    /* backing store exposures */
     Bool	shrunk = FALSE; /* shrunk in an inner dimension */
     Bool	moved = FALSE;	/* window position changed */
 #ifdef DO_SAVE_UNDERS
@@ -735,8 +722,6 @@ miSlideAndSizeWindow(pWin, x, y, w, h, pSib)
     if (WasViewable)
     {
 	pRegion = REGION_CREATE(pScreen, NullBox, 1);
-	if (pWin->backStorage)
-	    REGION_COPY(pScreen, pRegion, &pWin->clipList);
 
 	if (pLayerWin == pWin)
 	    anyMarked |= (*pScreen->MarkOverlappedWindows)(pWin, pFirstChange,
@@ -769,21 +754,6 @@ miSlideAndSizeWindow(pWin, x, y, w, h, pSib)
 
     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)
     {
 	/* avoid the border */
@@ -932,17 +902,6 @@ miSlideAndSizeWindow(pWin, x, y, w, h, pSib)
 	REGION_DESTROY(pScreen, pRegion);
 	if (destClip)
 	    REGION_DESTROY(pScreen, destClip);
-	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 (anyMarked)
 	    (*pScreen->HandleExposures)(pLayerWin->parent);
 #ifdef DO_SAVE_UNDERS
@@ -955,11 +914,6 @@ miSlideAndSizeWindow(pWin, x, y, w, h, pSib)
 	    (*pScreen->PostValidateTree)(pLayerWin->parent, pFirstChange,
 					  VTOther);
     }
-    else if (bsExposed)
-    {
-	(*pScreen->WindowExposures) (pWin, NullRegion, bsExposed);
-	REGION_DESTROY(pScreen, bsExposed);
-    }
     if (pWin->realized)
 	WindowsRestructured ();
 }
@@ -986,7 +940,7 @@ miSetShape(pWin)
     Bool	WasViewable = (Bool)(pWin->viewable);
     ScreenPtr 	pScreen = pWin->drawable.pScreen;
     Bool	anyMarked = FALSE;
-    RegionPtr	pOldClip = NULL, bsExposed;
+    RegionPtr	pOldClip = NULL;
 #ifdef DO_SAVE_UNDERS
     Bool	dosave = FALSE;
 #endif
@@ -1018,12 +972,6 @@ miSetShape(pWin)
 
     if (WasViewable)
     {
-	if (pWin->backStorage)
-	{
-	    pOldClip = REGION_CREATE(pScreen, NullBox, 1);
-	    REGION_COPY(pScreen, pOldClip, &pWin->clipList);
-	}
-
 	anyMarked |= (*pScreen->MarkOverlappedWindows)(pWin, pWin,
 						(WindowPtr *)NULL);
 
@@ -1038,28 +986,6 @@ miSetShape(pWin)
 	    (*pScreen->ValidateTree)(pLayerWin->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)
     {
 	if (anyMarked)