[PATCH] Accumulate graphics exposures incrementally in PanoramiXCopyArea/Plane.

[Jamey Sharp]

This fuses two loops in each function, eliminating an intermediate
MAXSCREENS-sized array from each.

Aside from being more efficient, I believe this is equivalent to the
previous implementation, since
- each per-screen GC has the graphicsExposures flag set the same way,
  and
- the REGION_* macros ignore their screen argument.

Signed-off-by: Jamey Sharp <jamey at minilop.net>
---
After sending the last version I noticed that CopyPlane had the same
pattern, so this version applies the same transformation to both.

On Fri, Apr 23, 2010 at 8:26 PM, Keith Packard <keithp at keithp.com> wrote:
> I've reviewed this as best I can,

Thanks for the review! Besides adding CopyPlane to the patch, I revised
the commit message to be more certain since you confirmed my
assumptions. I'd appreciate review of the new changes; the original
hunks are unchanged.

> but I'd like to see someone actually give it a try.

I'd appreciate that too. I'd prefer testing on this version of the patch
since it's more comprehensive.


 Xext/panoramiXprocs.c |   62 ++++++++++++++++++++----------------------------
 1 files changed, 26 insertions(+), 36 deletions(-)

diff --git a/Xext/panoramiXprocs.c b/Xext/panoramiXprocs.c
index 3baa8f9..2bb1542 100644
--- a/Xext/panoramiXprocs.c
+++ b/Xext/panoramiXprocs.c
@@ -1092,10 +1092,12 @@ int PanoramiXCopyArea(ClientPtr client)
     } else {
 	DrawablePtr pDst = NULL, pSrc = NULL;
 	GCPtr pGC = NULL;
-	RegionPtr pRgn[MAXSCREENS];
+	RegionRec totalReg;
 	int rc;
 
+	REGION_NULL(unusedScreen, &totalReg);
 	FOR_NSCREENS_BACKWARD(j) {
+	    RegionPtr pRgn;
 	    stuff->dstDrawable = dst->info[j].id;
 	    stuff->srcDrawable = src->info[j].id;
 	    stuff->gc          = gc->info[j].id;
@@ -1124,37 +1126,30 @@ int PanoramiXCopyArea(ClientPtr client)
  	    } else
 		pSrc = pDst;
 
-	    pRgn[j] = (*pGC->ops->CopyArea)(pSrc, pDst, pGC, 
+	    pRgn = (*pGC->ops->CopyArea)(pSrc, pDst, pGC,
 				stuff->srcX, stuff->srcY,
 				stuff->width, stuff->height, 
 				stuff->dstX, stuff->dstY);
+	    if(pGC->graphicsExposures && pRgn) {
+	       if(srcIsRoot) {
+		   REGION_TRANSLATE(unusedScreen, pRgn,
+			    panoramiXdataPtr[j].x, panoramiXdataPtr[j].y);
+	       }
+	       REGION_APPEND(unusedScreen, &totalReg, pRgn);
+	       REGION_DESTROY(unusedScreen, pRgn);
+	    }
 
-	    if(dstShared) {
-		while(j--) pRgn[j] = NULL;
+	    if(dstShared)
 		break;
-	    }
 	}
 
 	if(pGC->graphicsExposures) {
 	    ScreenPtr pScreen = pDst->pScreen;
-	    RegionRec totalReg;
 	    Bool overlap;
-
-	    REGION_NULL(pScreen, &totalReg);
-	    FOR_NSCREENS_BACKWARD(j) {
-		if(pRgn[j]) {
-		   if(srcIsRoot) {
-		       REGION_TRANSLATE(pScreen, pRgn[j], 
-				panoramiXdataPtr[j].x, panoramiXdataPtr[j].y);
-		   }
-		   REGION_APPEND(pScreen, &totalReg, pRgn[j]);
-		   REGION_DESTROY(pScreen, pRgn[j]);
-		}
-	    }
-	    REGION_VALIDATE(pScreen, &totalReg, &overlap);
+	    REGION_VALIDATE(unusedScreen, &totalReg, &overlap);
 	    (*pScreen->SendGraphicsExpose)(
 		client, &totalReg, stuff->dstDrawable, X_CopyArea, 0);
-	    REGION_UNINIT(pScreen, &totalReg);
+	    REGION_UNINIT(unusedScreen, &totalReg);
 	}
 	
 	result = client->noClientException;
@@ -1173,7 +1168,7 @@ int PanoramiXCopyPlane(ClientPtr client)
     Bool		srcShared, dstShared;
     DrawablePtr 	psrcDraw, pdstDraw = NULL;
     GCPtr 		pGC = NULL;
-    RegionPtr 		pRgn[MAXSCREENS];
+    RegionRec		totalReg;
     REQUEST(xCopyPlaneReq);
 
     REQUEST_SIZE_MATCH(xCopyPlaneReq);
@@ -1208,7 +1203,9 @@ int PanoramiXCopyPlane(ClientPtr client)
     srcx = stuff->srcX; srcy = stuff->srcY;
     dstx = stuff->dstX; dsty = stuff->dstY;
  
+    REGION_NULL(unusedScreen, &totalReg);
     FOR_NSCREENS_BACKWARD(j) {
+	RegionPtr pRgn;
 	stuff->dstDrawable = dst->info[j].id;
 	stuff->srcDrawable = src->info[j].id;
 	stuff->gc          = gc->info[j].id;
@@ -1241,33 +1238,26 @@ int PanoramiXCopyPlane(ClientPtr client)
 	    return(BadValue);
 	}
 
-	pRgn[j] = (*pGC->ops->CopyPlane)(psrcDraw, pdstDraw, pGC, 
+	pRgn = (*pGC->ops->CopyPlane)(psrcDraw, pdstDraw, pGC,
 				stuff->srcX, stuff->srcY,
 				stuff->width, stuff->height, 
 				stuff->dstX, stuff->dstY, stuff->bitPlane);
+	if(pGC->graphicsExposures && pRgn) {
+	    REGION_APPEND(unusedScreen, &totalReg, pRgn);
+	    REGION_DESTROY(unusedScreen, pRgn);
+	}
 
-	if(dstShared) {
-	    while(j--) pRgn[j] = NULL;
+	if(dstShared)
 	    break;
-	}
     }
 
     if(pGC->graphicsExposures) {
 	ScreenPtr pScreen = pdstDraw->pScreen;
-	RegionRec totalReg;
 	Bool overlap;
-
-	REGION_NULL(pScreen, &totalReg);
-	FOR_NSCREENS_BACKWARD(j) {
-	    if(pRgn[j]) {
-		REGION_APPEND(pScreen, &totalReg, pRgn[j]);
-		REGION_DESTROY(pScreen, pRgn[j]);
-	    }
-	}
-	REGION_VALIDATE(pScreen, &totalReg, &overlap);
+	REGION_VALIDATE(unusedScreen, &totalReg, &overlap);
 	(*pScreen->SendGraphicsExpose)(
 		client, &totalReg, stuff->dstDrawable, X_CopyPlane, 0);
-	REGION_UNINIT(pScreen, &totalReg);
+	REGION_UNINIT(unusedScreen, &totalReg);
     }
 
     return (client->noClientException);
-- 
1.7.0