/*
 *
 * Copyright © 1999 Keith Packard
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of Keith Packard not be used in
 * advertising or publicity pertaining to distribution of the software without
 * specific, written prior permission.  Keith Packard makes no
 * representations about the suitability of this software for any purpose.  It
 * is provided "as is" without express or implied warranty.
 *
 * KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL KEITH PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

#include "exa_priv.h"

#include "mipict.h"

/*
 * These functions wrap the low-level fb rendering functions and
 * synchronize framebuffer/accelerated drawing by stalling until
 * the accelerator is idle
 */

/**
 * Calls exaPrepareAccess with EXA_PREPARE_SRC for the tile, if that is the
 * current fill style.
 *
 * Solid doesn't use an extra pixmap source, and Stippled/OpaqueStippled are
 * 1bpp and never in fb, so we don't worry about them.
 * We should worry about them for completeness sake and going forward.
 */
void
exaPrepareAccessGC(GCPtr pGC)
{
    if (pGC->stipple)
        exaPrepareAccess(&pGC->stipple->drawable, EXA_PREPARE_MASK);
    if (pGC->fillStyle == FillTiled)
	exaPrepareAccess(&pGC->tile.pixmap->drawable, EXA_PREPARE_SRC);
}

/**
 * Finishes access to the tile in the GC, if used.
 */
void
exaFinishAccessGC(GCPtr pGC)
{
    if (pGC->fillStyle == FillTiled)
	exaFinishAccess(&pGC->tile.pixmap->drawable, EXA_PREPARE_SRC);
    if (pGC->stipple)
        exaFinishAccess(&pGC->stipple->drawable, EXA_PREPARE_MASK);
}

#if DEBUG_TRACE_FALL
char
exaDrawableLocation(DrawablePtr pDrawable)
{
    return exaDrawableIsOffscreen(pDrawable) ? 's' : 'm';
}
#endif /* DEBUG_TRACE_FALL */

void
ExaCheckFillSpans (DrawablePtr pDrawable, GCPtr pGC, int nspans,
		   DDXPointPtr ppt, int *pwidth, int fSorted)
{
    EXA_PRE_FALLBACK_GC(pGC);
    EXA_FALLBACK(("to %p (%c)\n", pDrawable, exaDrawableLocation(pDrawable)));
    exaPrepareAccess (pDrawable, EXA_PREPARE_DEST);
    exaPrepareAccessGC (pGC);
    pGC->ops->FillSpans (pDrawable, pGC, nspans, ppt, pwidth, fSorted);
    exaFinishAccessGC (pGC);
    exaFinishAccess (pDrawable, EXA_PREPARE_DEST);
    EXA_POST_FALLBACK_GC(pGC);
}

void
ExaCheckSetSpans (DrawablePtr pDrawable, GCPtr pGC, char *psrc,
		 DDXPointPtr ppt, int *pwidth, int nspans, int fSorted)
{
    EXA_PRE_FALLBACK_GC(pGC);
    EXA_FALLBACK(("to %p (%c)\n", pDrawable, exaDrawableLocation(pDrawable)));
    exaPrepareAccess (pDrawable, EXA_PREPARE_DEST);
    pGC->ops->SetSpans (pDrawable, pGC, psrc, ppt, pwidth, nspans, fSorted);
    exaFinishAccess (pDrawable, EXA_PREPARE_DEST);
    EXA_POST_FALLBACK_GC(pGC);
}

void
ExaCheckPutImage (DrawablePtr pDrawable, GCPtr pGC, int depth,
		 int x, int y, int w, int h, int leftPad, int format,
		 char *bits)
{
    PixmapPtr pPixmap = exaGetDrawablePixmap(pDrawable);
    ExaPixmapPriv(pPixmap);

    EXA_PRE_FALLBACK_GC(pGC);
    EXA_FALLBACK(("to %p (%c)\n", pDrawable, exaDrawableLocation(pDrawable)));
    if (!pExaScr->prepare_access_reg || !pExaPixmap->pDamage ||
	exaGCReadsDestination(pDrawable, pGC->planemask, pGC->fillStyle,
			      pGC->alu, pGC->clientClipType))
	exaPrepareAccess (pDrawable, EXA_PREPARE_DEST);
    else
	pExaScr->prepare_access_reg(pPixmap, EXA_PREPARE_DEST,
				    DamagePendingRegion(pExaPixmap->pDamage));
    pGC->ops->PutImage (pDrawable, pGC, depth, x, y, w, h, leftPad, format, bits);
    exaFinishAccess (pDrawable, EXA_PREPARE_DEST);
    EXA_POST_FALLBACK_GC(pGC);
}

void
ExaCheckCopyNtoN (DrawablePtr pSrc, DrawablePtr pDst,  GCPtr pGC,
	     BoxPtr	pbox, int nbox, int dx, int dy, Bool	reverse, 
	     Bool upsidedown, Pixel bitplane, void *closure)
{
    RegionRec reg;
    int xoff, yoff;
    EXA_PRE_FALLBACK_GC(pGC);
    EXA_FALLBACK(("from %p to %p (%c,%c)\n", pSrc, pDst,
		  exaDrawableLocation(pSrc), exaDrawableLocation(pDst)));

    if (pExaScr->prepare_access_reg) {
	PixmapPtr pPixmap = exaGetDrawablePixmap(pSrc);

	exaGetDrawableDeltas(pSrc, pPixmap, &xoff, &yoff);
	REGION_INIT(pScreen, &reg, pbox, nbox);
	REGION_TRANSLATE(pScreen, &reg, xoff + dx, yoff + dy);
	pExaScr->prepare_access_reg(pPixmap, EXA_PREPARE_SRC, &reg);
	REGION_UNINIT(pScreen, &reg);
    } else
	exaPrepareAccess (pSrc, EXA_PREPARE_SRC);

    if (pExaScr->prepare_access_reg &&
	!exaGCReadsDestination(pDst, pGC->planemask, pGC->fillStyle,
			       pGC->alu, pGC->clientClipType)) {
	PixmapPtr pPixmap = exaGetDrawablePixmap(pDst);

	exaGetDrawableDeltas(pSrc, pPixmap, &xoff, &yoff);
	REGION_INIT(pScreen, &reg, pbox, nbox);
	REGION_TRANSLATE(pScreen, &reg, xoff, yoff);
	pExaScr->prepare_access_reg(pPixmap, EXA_PREPARE_DEST, &reg);
	REGION_UNINIT(pScreen, &reg);
    } else
	exaPrepareAccess (pDst, EXA_PREPARE_DEST);

    /* This will eventually call fbCopyNtoN, with some calculation overhead. */
    while (nbox--) {
	pGC->ops->CopyArea (pSrc, pDst, pGC, pbox->x1 - pSrc->x + dx, pbox->y1 - pSrc->y + dy, 
			pbox->x2 - pbox->x1, pbox->y2 - pbox->y1, pbox->x1 - pDst->x, pbox->y1 - pDst->y);
	pbox++;
    }
    exaFinishAccess (pSrc, EXA_PREPARE_SRC);
    exaFinishAccess (pDst, EXA_PREPARE_DEST);
    EXA_POST_FALLBACK_GC(pGC);
}

static void
ExaFallbackPrepareReg(DrawablePtr pDrawable,
		      GCPtr pGC,
		      int x, int y, int width, int height,
		      int index, Bool checkReads)
{
    ScreenPtr pScreen = pDrawable->pScreen;
    ExaScreenPriv(pScreen);

    if (pExaScr->prepare_access_reg &&
	!(checkReads && exaGCReadsDestination(pDrawable,
					      pGC->planemask,
					      pGC->fillStyle,
					      pGC->alu,
					      pGC->clientClipType))) {
	BoxRec box;
	RegionRec reg;
	int xoff, yoff;
	PixmapPtr pPixmap = exaGetDrawablePixmap(pDrawable);

	exaGetDrawableDeltas(pDrawable, pPixmap, &xoff, &yoff);
	box.x1 = pDrawable->x + x + xoff;
	box.y1 = pDrawable->y + y + yoff;
	box.x2 = box.x1 + width;
	box.y2 = box.y1 + height;

	REGION_INIT(pScreen, &reg, &box, 1);
	pExaScr->prepare_access_reg(pPixmap, index, &reg);
	REGION_UNINIT(pScreen, &reg);
    } else
	exaPrepareAccess(pDrawable, index);
}


RegionPtr
ExaCheckCopyArea (DrawablePtr pSrc, DrawablePtr pDst, GCPtr pGC,
		 int srcx, int srcy, int w, int h, int dstx, int dsty)
{
    RegionPtr ret;

    EXA_PRE_FALLBACK_GC(pGC);
    EXA_FALLBACK(("from %p to %p (%c,%c)\n", pSrc, pDst,
		  exaDrawableLocation(pSrc), exaDrawableLocation(pDst)));
    ExaFallbackPrepareReg(pSrc, pGC, srcx, srcy, w, h,
			  EXA_PREPARE_SRC, FALSE);
    ExaFallbackPrepareReg(pDst, pGC, dstx, dsty, w, h,
			  EXA_PREPARE_DEST, TRUE);
    ret = pGC->ops->CopyArea (pSrc, pDst, pGC, srcx, srcy, w, h, dstx, dsty);
    exaFinishAccess (pSrc, EXA_PREPARE_SRC);
    exaFinishAccess (pDst, EXA_PREPARE_DEST);
    EXA_POST_FALLBACK_GC(pGC);

    return ret;
}

RegionPtr
ExaCheckCopyPlane (DrawablePtr pSrc, DrawablePtr pDst, GCPtr pGC,
		  int srcx, int srcy, int w, int h, int dstx, int dsty,
		  unsigned long bitPlane)
{
    RegionPtr ret;

    EXA_PRE_FALLBACK_GC(pGC);
    EXA_FALLBACK(("from %p to %p (%c,%c)\n", pSrc, pDst,
		  exaDrawableLocation(pSrc), exaDrawableLocation(pDst)));
    ExaFallbackPrepareReg(pSrc, pGC, srcx, srcy, w, h,
			  EXA_PREPARE_SRC, FALSE);
    ExaFallbackPrepareReg(pDst, pGC, dstx, dsty, w, h,
			  EXA_PREPARE_DEST, TRUE);
    ret = pGC->ops->CopyPlane (pSrc, pDst, pGC, srcx, srcy, w, h, dstx, dsty,
		       bitPlane);
    exaFinishAccess (pSrc, EXA_PREPARE_SRC);
    exaFinishAccess (pDst, EXA_PREPARE_DEST);
    EXA_POST_FALLBACK_GC(pGC);

    return ret;
}

void
ExaCheckPolyPoint (DrawablePtr pDrawable, GCPtr pGC, int mode, int npt,
		  DDXPointPtr pptInit)
{
    EXA_PRE_FALLBACK_GC(pGC);
    EXA_FALLBACK(("to %p (%c)\n", pDrawable, exaDrawableLocation(pDrawable)));
    exaPrepareAccess (pDrawable, EXA_PREPARE_DEST);
    pGC->ops->PolyPoint (pDrawable, pGC, mode, npt, pptInit);
    exaFinishAccess (pDrawable, EXA_PREPARE_DEST);
    EXA_POST_FALLBACK_GC(pGC);
}

void
ExaCheckPolylines (DrawablePtr pDrawable, GCPtr pGC,
		  int mode, int npt, DDXPointPtr ppt)
{
    EXA_PRE_FALLBACK_GC(pGC);
    EXA_FALLBACK(("to %p (%c), width %d, mode %d, count %d\n",
		  pDrawable, exaDrawableLocation(pDrawable),
		  pGC->lineWidth, mode, npt));

    exaPrepareAccess (pDrawable, EXA_PREPARE_DEST);
    exaPrepareAccessGC (pGC);
    pGC->ops->Polylines (pDrawable, pGC, mode, npt, ppt);
    exaFinishAccessGC (pGC);
    exaFinishAccess (pDrawable, EXA_PREPARE_DEST);
    EXA_POST_FALLBACK_GC(pGC);
}

void
ExaCheckPolySegment (DrawablePtr pDrawable, GCPtr pGC,
		    int nsegInit, xSegment *pSegInit)
{
    EXA_PRE_FALLBACK_GC(pGC);
    EXA_FALLBACK(("to %p (%c) width %d, count %d\n", pDrawable,
		  exaDrawableLocation(pDrawable), pGC->lineWidth, nsegInit));

    exaPrepareAccess (pDrawable, EXA_PREPARE_DEST);
    exaPrepareAccessGC (pGC);
    pGC->ops->PolySegment (pDrawable, pGC, nsegInit, pSegInit);
    exaFinishAccessGC (pGC);
    exaFinishAccess (pDrawable, EXA_PREPARE_DEST);
    EXA_POST_FALLBACK_GC(pGC);
}

void
ExaCheckPolyArc (DrawablePtr pDrawable, GCPtr pGC,
		int narcs, xArc *pArcs)
{
    EXA_PRE_FALLBACK_GC(pGC);
    EXA_FALLBACK(("to %p (%c)\n", pDrawable, exaDrawableLocation(pDrawable)));

    exaPrepareAccess (pDrawable, EXA_PREPARE_DEST);
    exaPrepareAccessGC (pGC);
    pGC->ops->PolyArc (pDrawable, pGC, narcs, pArcs);
    exaFinishAccessGC (pGC);
    exaFinishAccess (pDrawable, EXA_PREPARE_DEST);
    EXA_POST_FALLBACK_GC(pGC);
}

void
ExaCheckPolyFillRect (DrawablePtr pDrawable, GCPtr pGC,
		     int nrect, xRectangle *prect)
{
    EXA_PRE_FALLBACK_GC(pGC);
    EXA_FALLBACK(("to %p (%c)\n", pDrawable, exaDrawableLocation(pDrawable)));

    exaPrepareAccess (pDrawable, EXA_PREPARE_DEST);
    exaPrepareAccessGC (pGC);
    pGC->ops->PolyFillRect (pDrawable, pGC, nrect, prect);
    exaFinishAccessGC (pGC);
    exaFinishAccess (pDrawable, EXA_PREPARE_DEST);
    EXA_POST_FALLBACK_GC(pGC);
}

void
ExaCheckImageGlyphBlt (DrawablePtr pDrawable, GCPtr pGC,
		      int x, int y, unsigned int nglyph,
		      CharInfoPtr *ppci, pointer pglyphBase)
{
    EXA_PRE_FALLBACK_GC(pGC);
    EXA_FALLBACK(("to %p (%c)\n", pDrawable,
		  exaDrawableLocation(pDrawable)));
    exaPrepareAccess (pDrawable, EXA_PREPARE_DEST);
    exaPrepareAccessGC (pGC);
    pGC->ops->ImageGlyphBlt (pDrawable, pGC, x, y, nglyph, ppci, pglyphBase);
    exaFinishAccessGC (pGC);
    exaFinishAccess (pDrawable, EXA_PREPARE_DEST);
    EXA_POST_FALLBACK_GC(pGC);
}

void
ExaCheckPolyGlyphBlt (DrawablePtr pDrawable, GCPtr pGC,
		     int x, int y, unsigned int nglyph,
		     CharInfoPtr *ppci, pointer pglyphBase)
{
    EXA_PRE_FALLBACK_GC(pGC);
    EXA_FALLBACK(("to %p (%c), style %d alu %d\n", pDrawable,
		  exaDrawableLocation(pDrawable), pGC->fillStyle, pGC->alu));
    exaPrepareAccess (pDrawable, EXA_PREPARE_DEST);
    exaPrepareAccessGC (pGC);
    pGC->ops->PolyGlyphBlt (pDrawable, pGC, x, y, nglyph, ppci, pglyphBase);
    exaFinishAccessGC (pGC);
    exaFinishAccess (pDrawable, EXA_PREPARE_DEST);
    EXA_POST_FALLBACK_GC(pGC);
}

void
ExaCheckPushPixels (GCPtr pGC, PixmapPtr pBitmap,
		   DrawablePtr pDrawable,
		   int w, int h, int x, int y)
{
    EXA_PRE_FALLBACK_GC(pGC);
    EXA_FALLBACK(("from %p to %p (%c,%c)\n", pBitmap, pDrawable,
		  exaDrawableLocation(&pBitmap->drawable),
		  exaDrawableLocation(pDrawable)));
    ExaFallbackPrepareReg(pDrawable, pGC, x, y, w, h,
			  EXA_PREPARE_DEST, TRUE);
    ExaFallbackPrepareReg(&pBitmap->drawable, pGC, 0, 0, w, h,
			  EXA_PREPARE_SRC, FALSE);
    exaPrepareAccessGC (pGC);
    pGC->ops->PushPixels (pGC, pBitmap, pDrawable, w, h, x, y);
    exaFinishAccessGC (pGC);
    exaFinishAccess (&pBitmap->drawable, EXA_PREPARE_SRC);
    exaFinishAccess (pDrawable, EXA_PREPARE_DEST);
    EXA_POST_FALLBACK_GC(pGC);
}

void
ExaCheckCopyWindow(WindowPtr pWin, DDXPointRec ptOldOrg, RegionPtr prgnSrc)
{
    DrawablePtr pDrawable = &pWin->drawable;
    ScreenPtr pScreen = pDrawable->pScreen;
    EXA_PRE_FALLBACK(pScreen);
    EXA_FALLBACK(("from %p\n", pWin));

    /* Only need the source bits, the destination region will be overwritten */
    if (pExaScr->prepare_access_reg) {
	PixmapPtr pPixmap = pScreen->GetWindowPixmap(pWin);
	int xoff, yoff;

	exaGetDrawableDeltas(&pWin->drawable, pPixmap, &xoff, &yoff);
	REGION_TRANSLATE(pScreen, prgnSrc, xoff, yoff);
	pExaScr->prepare_access_reg(pPixmap, EXA_PREPARE_SRC, prgnSrc);
	REGION_TRANSLATE(pScreen, prgnSrc, -xoff, -yoff);
    } else
	exaPrepareAccess(pDrawable, EXA_PREPARE_SRC);

    swap(pExaScr, pScreen, CopyWindow);
    pScreen->CopyWindow (pWin, ptOldOrg, prgnSrc);
    swap(pExaScr, pScreen, CopyWindow);
    exaFinishAccess (pDrawable, EXA_PREPARE_SRC);
    EXA_POST_FALLBACK(pScreen);
}

void
ExaCheckGetImage(DrawablePtr pDrawable, int x, int y, int w, int h,
		unsigned int format, unsigned long planeMask, char *d)
{
    ScreenPtr pScreen = pDrawable->pScreen;
    EXA_PRE_FALLBACK(pScreen);
    EXA_FALLBACK(("from %p (%c)\n", pDrawable,
		  exaDrawableLocation(pDrawable)));

    ExaFallbackPrepareReg(pDrawable, NULL, x, y, w, h,
			  EXA_PREPARE_SRC, FALSE);
    swap(pExaScr, pScreen, GetImage);
    pScreen->GetImage (pDrawable, x, y, w, h, format, planeMask, d);
    swap(pExaScr, pScreen, GetImage);
    exaFinishAccess (pDrawable, EXA_PREPARE_SRC);
    EXA_POST_FALLBACK(pScreen);
}

void
ExaCheckGetSpans (DrawablePtr pDrawable,
		 int wMax,
		 DDXPointPtr ppt,
		 int *pwidth,
		 int nspans,
		 char *pdstStart)
{
    ScreenPtr pScreen = pDrawable->pScreen;

    EXA_PRE_FALLBACK(pScreen);
    EXA_FALLBACK(("from %p (%c)\n", pDrawable, exaDrawableLocation(pDrawable)));
    exaPrepareAccess (pDrawable, EXA_PREPARE_SRC);
    swap(pExaScr, pScreen, GetSpans);
    pScreen->GetSpans (pDrawable, wMax, ppt, pwidth, nspans, pdstStart);
    swap(pExaScr, pScreen, GetSpans);
    exaFinishAccess (pDrawable, EXA_PREPARE_SRC);
    EXA_POST_FALLBACK(pScreen);
}

static void
ExaSrcValidate(DrawablePtr pDrawable,
	       int x,
	       int y,
	       int width,
	       int height)
{
    ScreenPtr pScreen = pDrawable->pScreen;
    ExaScreenPriv(pScreen);
    PixmapPtr pPix = exaGetDrawablePixmap (pDrawable);
    BoxRec box;
    RegionRec reg;
    RegionPtr dst;
    int xoff, yoff;

    exaGetDrawableDeltas(pDrawable, pPix, &xoff, &yoff);

    box.x1 = x + xoff;
    box.y1 = y + yoff;
    box.x2 = box.x1 + width;
    box.y2 = box.y1 + height;

    dst = (pExaScr->srcPix == pPix) ? &pExaScr->srcReg :
	&pExaScr->maskReg;

    REGION_INIT(pScreen, &reg, &box, 1);
    REGION_UNION(pScreen, dst, dst, &reg);
    REGION_UNINIT(pScreen, &reg);

    if (pScreen->SourceValidate) {
        swap(pExaScr, pScreen, SourceValidate);
        pScreen->SourceValidate(pDrawable, x, y, width, height);
        swap(pExaScr, pScreen, SourceValidate);
    }
}

static Bool
ExaPrepareCompositeReg(ScreenPtr  pScreen,
		       CARD8      op,
		       PicturePtr pSrc,
		       PicturePtr pMask,
		       PicturePtr pDst,
		       INT16      xSrc,
		       INT16      ySrc,
		       INT16      xMask,
		       INT16      yMask,
		       INT16      xDst,
		       INT16      yDst,
		       CARD16     width,
		       CARD16     height)
{
    RegionRec region;
    RegionPtr dstReg = NULL;
    RegionPtr srcReg = NULL;
    RegionPtr maskReg = NULL;
    PixmapPtr pSrcPix = NULL;
    PixmapPtr pMaskPix = NULL;
    PixmapPtr pDstPix;
    ExaScreenPriv(pScreen);
    Bool ret;


    REGION_NULL(pScreen, &region);

    if (pSrc->pDrawable) {
	pSrcPix = exaGetDrawablePixmap(pSrc->pDrawable);
	REGION_NULL(pScreen, &pExaScr->srcReg);
	srcReg = &pExaScr->srcReg;
	pExaScr->srcPix = pSrcPix;
	if (pSrc != pDst)
	    REGION_TRANSLATE(pScreen, pSrc->pCompositeClip,
			     -pSrc->pDrawable->x,
			     -pSrc->pDrawable->y);
    }

    if (pMask && pMask->pDrawable) {
	pMaskPix = exaGetDrawablePixmap(pMask->pDrawable);
	REGION_NULL(pScreen, &pExaScr->maskReg);
	maskReg = &pExaScr->maskReg;
	if (pMask != pDst && pMask != pSrc)
	    REGION_TRANSLATE(pScreen, pMask->pCompositeClip,
			     -pMask->pDrawable->x,
			     -pMask->pDrawable->y);
    }

    REGION_TRANSLATE(pScreen, pDst->pCompositeClip,
		     -pDst->pDrawable->x,
		     -pDst->pDrawable->y);

    pExaScr->SavedSourceValidate = ExaSrcValidate;
    swap(pExaScr, pScreen, SourceValidate);
    ret = miComputeCompositeRegion (&region, pSrc, pMask, pDst,
				    xSrc, ySrc, xMask, yMask,
				    xDst,
				    yDst,
				    width, height);
    swap(pExaScr, pScreen, SourceValidate);

    REGION_TRANSLATE(pScreen, pDst->pCompositeClip,
		     pDst->pDrawable->x,
		     pDst->pDrawable->y);
    if (pSrc->pDrawable && pSrc != pDst)
	REGION_TRANSLATE(pScreen, pSrc->pCompositeClip,
			 pSrc->pDrawable->x,
			 pSrc->pDrawable->y);
    if (pMask && pMask->pDrawable && pMask != pDst && pMask != pSrc)
	REGION_TRANSLATE(pScreen, pMask->pCompositeClip,
			 pMask->pDrawable->x,
			 pMask->pDrawable->y);

    if (!ret) {
	if (srcReg)
	    REGION_UNINIT(pScreen, srcReg);
	if (maskReg)
	    REGION_UNINIT(pScreen, maskReg);

	return FALSE;
    }

    /**
     * Don't limit alphamaps readbacks for now until we've figured out how that
     * should be done.
     */

    if (pSrc->alphaMap && pSrc->alphaMap->pDrawable)
	pExaScr->prepare_access_reg(exaGetDrawablePixmap(pSrc->alphaMap->pDrawable),
				    EXA_PREPARE_AUX_SRC,
				    NULL);
    if (pMask && pMask->alphaMap && pMask->alphaMap->pDrawable)
	pExaScr->prepare_access_reg(exaGetDrawablePixmap(pMask->alphaMap->pDrawable),
				    EXA_PREPARE_AUX_MASK,
				    NULL);

    if (pSrcPix)
	pExaScr->prepare_access_reg(pSrcPix,
				    EXA_PREPARE_SRC,
				    srcReg);

    if (pMaskPix)
	pExaScr->prepare_access_reg(pMaskPix,
				    EXA_PREPARE_MASK,
				    maskReg);

    if (srcReg)
	REGION_UNINIT(pScreen, srcReg);
    if (maskReg)
	REGION_UNINIT(pScreen, maskReg);

    pDstPix = exaGetDrawablePixmap(pDst->pDrawable);
    if (!exaOpReadsDestination(op)) {
	int xoff;
	int yoff;

	exaGetDrawableDeltas (pDst->pDrawable, pDstPix, &xoff, &yoff);
	REGION_TRANSLATE(pScreen, &region, pDst->pDrawable->x + xoff,
			 pDst->pDrawable->y + yoff);
	dstReg = &region;
    }

    if (pDst->alphaMap && pDst->alphaMap->pDrawable)
	pExaScr->prepare_access_reg(exaGetDrawablePixmap(pDst->alphaMap->pDrawable),
				    EXA_PREPARE_AUX_DEST,
				    dstReg);
    pExaScr->prepare_access_reg(pDstPix, EXA_PREPARE_DEST, dstReg);

    REGION_UNINIT(pScreen, &region);
    return TRUE;
}

void
ExaCheckComposite (CARD8      op,
                   PicturePtr pSrc,
                   PicturePtr pMask,
                   PicturePtr pDst,
                   INT16      xSrc,
                   INT16      ySrc,
                   INT16      xMask,
                   INT16      yMask,
                   INT16      xDst,
                   INT16      yDst,
                   CARD16     width,
                   CARD16     height)
{
    ScreenPtr pScreen = pDst->pDrawable->pScreen;
    PictureScreenPtr	ps = GetPictureScreen(pScreen);
    EXA_PRE_FALLBACK(pScreen);

    if (pExaScr->prepare_access_reg) {
	if (!ExaPrepareCompositeReg(pScreen, op, pSrc, pMask, pDst, xSrc,
				   ySrc, xMask, yMask, xDst, yDst, width,
				   height))
	    goto out_no_clip;
    } else {

	/* We need to prepare access to any separate alpha maps first,
	 * in case the driver doesn't support EXA_PREPARE_AUX*,
	 * in which case EXA_PREPARE_SRC may be used for moving them out.
	 */

	if (pSrc->alphaMap && pSrc->alphaMap->pDrawable)
	    exaPrepareAccess(pSrc->alphaMap->pDrawable, EXA_PREPARE_AUX_SRC);
	if (pMask && pMask->alphaMap && pMask->alphaMap->pDrawable)
	    exaPrepareAccess(pMask->alphaMap->pDrawable, EXA_PREPARE_AUX_MASK);
	if (pDst->alphaMap && pDst->alphaMap->pDrawable)
	    exaPrepareAccess(pDst->alphaMap->pDrawable, EXA_PREPARE_AUX_DEST);

	exaPrepareAccess (pDst->pDrawable, EXA_PREPARE_DEST);

	EXA_FALLBACK(("from picts %p/%p to pict %p\n",
		      pSrc, pMask, pDst));

	if (pSrc->pDrawable != NULL)
	    exaPrepareAccess (pSrc->pDrawable, EXA_PREPARE_SRC);
	if (pMask && pMask->pDrawable != NULL)
	    exaPrepareAccess (pMask->pDrawable, EXA_PREPARE_MASK);
    }

    swap(pExaScr, ps, Composite);
    ps->Composite (op,
                 pSrc,
                 pMask,
                 pDst,
                 xSrc,
                 ySrc,
                 xMask,
                 yMask,
                 xDst,
                 yDst,
                 width,
                 height);
    swap(pExaScr, ps, Composite);
    if (pMask && pMask->pDrawable != NULL)
	exaFinishAccess (pMask->pDrawable, EXA_PREPARE_MASK);
    if (pSrc->pDrawable != NULL)
	exaFinishAccess (pSrc->pDrawable, EXA_PREPARE_SRC);
    exaFinishAccess (pDst->pDrawable, EXA_PREPARE_DEST);
    if (pDst->alphaMap && pDst->alphaMap->pDrawable)
	exaFinishAccess(pDst->alphaMap->pDrawable, EXA_PREPARE_AUX_DEST);
    if (pSrc->alphaMap && pSrc->alphaMap->pDrawable)
	exaFinishAccess(pSrc->alphaMap->pDrawable, EXA_PREPARE_AUX_SRC);
    if (pMask && pMask->alphaMap && pMask->alphaMap->pDrawable)
	exaFinishAccess(pMask->alphaMap->pDrawable, EXA_PREPARE_AUX_MASK);

out_no_clip:
    EXA_POST_FALLBACK(pScreen);
}

void
ExaCheckAddTraps (PicturePtr	pPicture,
		  INT16		x_off,
		  INT16		y_off,
		  int		ntrap,
		  xTrap		*traps)
{
    ScreenPtr pScreen = pPicture->pDrawable->pScreen;
    PictureScreenPtr	ps = GetPictureScreen(pScreen);
    EXA_PRE_FALLBACK(pScreen);

    EXA_FALLBACK(("to pict %p (%c)\n",
		  exaDrawableLocation(pPicture->pDrawable)));
    exaPrepareAccess(pPicture->pDrawable, EXA_PREPARE_DEST);
    swap(pExaScr, ps, AddTraps);
    ps->AddTraps (pPicture, x_off, y_off, ntrap, traps);
    swap(pExaScr, ps, AddTraps);
    exaFinishAccess(pPicture->pDrawable, EXA_PREPARE_DEST);
    EXA_POST_FALLBACK(pScreen);
}

/**
 * Gets the 0,0 pixel of a pixmap.  Used for doing solid fills of tiled pixmaps
 * that happen to be 1x1.  Pixmap must be at least 8bpp.
 */
CARD32
exaGetPixmapFirstPixel (PixmapPtr pPixmap)
{
    switch (pPixmap->drawable.bitsPerPixel) {
    case 32:
	{
	    CARD32 pixel;

	    pPixmap->drawable.pScreen->GetImage(&pPixmap->drawable, 0, 0, 1, 1,
						ZPixmap, ~0, (char*)&pixel);
	    return pixel;
	}
    case 16:
	{
	    CARD16 pixel;

	    pPixmap->drawable.pScreen->GetImage(&pPixmap->drawable, 0, 0, 1, 1,
						ZPixmap, ~0, (char*)&pixel);
	    return pixel;
	}
    case 8:
	{
	    CARD8 pixel;

	    pPixmap->drawable.pScreen->GetImage(&pPixmap->drawable, 0, 0, 1, 1,
						ZPixmap, ~0, (char*)&pixel);
	    return pixel;
	}
    default:
	FatalError("%s called for invalid bpp %d\n", __func__,
		   pPixmap->drawable.bitsPerPixel);
    }
}