dmxpict.c   [plain text]

/*
 * Copyright 2001-2004 Red Hat Inc., Durham, North Carolina.
 *
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation on the rights to use, copy, modify, merge,
 * publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial
 * portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NON-INFRINGEMENT.  IN NO EVENT SHALL RED HAT AND/OR THEIR SUPPLIERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

/*
 * Authors:
 *   Kevin E. Martin <kem@redhat.com>
 *
 */

/** \file
 *  Provide support for the RENDER extension (version 0.8).
 */

#ifdef HAVE_DMX_CONFIG_H
#include <dmx-config.h>
#endif

#include "dmx.h"
#include "dmxsync.h"
#include "dmxpict.h"
#include "dmxwindow.h"
#include "dmxpixmap.h"

#include "fb.h"
#include "pixmapstr.h"
#include "dixstruct.h"

#include <X11/extensions/render.h>
#include <X11/extensions/renderproto.h>
#include "picture.h"
#include "picturestr.h"
#include "mipict.h"
#include "fbpict.h"

#undef Xmalloc
#undef Xcalloc
#undef Xrealloc
#undef Xfree



extern int RenderErrBase;
extern int (*ProcRenderVector[RenderNumberRequests])(ClientPtr);

static int (*dmxSaveRenderVector[RenderNumberRequests])(ClientPtr);


static int dmxProcRenderCreateGlyphSet(ClientPtr client);
static int dmxProcRenderFreeGlyphSet(ClientPtr client);
static int dmxProcRenderAddGlyphs(ClientPtr client);
static int dmxProcRenderFreeGlyphs(ClientPtr client);
static int dmxProcRenderCompositeGlyphs(ClientPtr client);
static int dmxProcRenderSetPictureTransform(ClientPtr client);
static int dmxProcRenderSetPictureFilter(ClientPtr client);
#if 0
/* FIXME: Not (yet) supported */
static int dmxProcRenderCreateCursor(ClientPtr client);
static int dmxProcRenderCreateAnimCursor(ClientPtr client);
#endif

/** Catch errors that might occur when allocating Glyph Sets.  Errors
 *  are saved in dmxGlyphLastError for later handling. */
static int dmxGlyphLastError;
static int dmxGlyphErrorHandler(Display *dpy, XErrorEvent *ev)
{
    dmxGlyphLastError = ev->error_code;
    return 0;
}


/** Initialize the Proc Vector for the RENDER extension.  The functions
 *  here cannot be handled by the mi layer RENDER hooks either because
 *  the required information is no longer available when it reaches the
 *  mi layer or no mi layer hooks exist.  This function is called from
 *  InitOutput() since it should be initialized only once per server
 *  generation. */
void dmxInitRender(void)
{
    int i;

    for (i = 0; i < RenderNumberRequests; i++)
        dmxSaveRenderVector[i] = ProcRenderVector[i];

    ProcRenderVector[X_RenderCreateGlyphSet]
	= dmxProcRenderCreateGlyphSet;
    ProcRenderVector[X_RenderFreeGlyphSet]
	= dmxProcRenderFreeGlyphSet;
    ProcRenderVector[X_RenderAddGlyphs]
	= dmxProcRenderAddGlyphs;
    ProcRenderVector[X_RenderFreeGlyphs]
	= dmxProcRenderFreeGlyphs;
    ProcRenderVector[X_RenderCompositeGlyphs8]
	= dmxProcRenderCompositeGlyphs;
    ProcRenderVector[X_RenderCompositeGlyphs16]
	= dmxProcRenderCompositeGlyphs;
    ProcRenderVector[X_RenderCompositeGlyphs32]
	= dmxProcRenderCompositeGlyphs;
    ProcRenderVector[X_RenderSetPictureTransform]
	= dmxProcRenderSetPictureTransform;
    ProcRenderVector[X_RenderSetPictureFilter]
	= dmxProcRenderSetPictureFilter;
}

/** Reset the Proc Vector for the RENDER extension back to the original
 *  functions.  This function is called from dmxCloseScreen() during the
 *  server reset (only for screen #0). */
void dmxResetRender(void)
{
    int i;

    for (i = 0; i < RenderNumberRequests; i++)
        ProcRenderVector[i] = dmxSaveRenderVector[i];
}

/** Initialize the RENDER extension, allocate the picture privates and
 *  wrap mi function hooks.  If the shadow frame buffer is used, then
 *  call the appropriate fb initialization function. */
Bool dmxPictureInit(ScreenPtr pScreen, PictFormatPtr formats, int nformats)
{
    DMXScreenInfo    *dmxScreen = &dmxScreens[pScreen->myNum];
    PictureScreenPtr  ps;

    /* The shadow framebuffer only relies on FB to be initialized */
    if (dmxShadowFB) return fbPictureInit(pScreen, formats, nformats);

    if (!miPictureInit(pScreen, formats, nformats))
	return FALSE;

    if (!dixRequestPrivate(dmxPictPrivateKey, sizeof(dmxPictPrivRec)))
	return FALSE;

    ps = GetPictureScreen(pScreen);

    DMX_WRAP(CreatePicture,      dmxCreatePicture,      dmxScreen, ps);
    DMX_WRAP(DestroyPicture,     dmxDestroyPicture,     dmxScreen, ps);

    DMX_WRAP(ChangePictureClip,  dmxChangePictureClip,  dmxScreen, ps);
    DMX_WRAP(DestroyPictureClip, dmxDestroyPictureClip, dmxScreen, ps);

    DMX_WRAP(ChangePicture,      dmxChangePicture,      dmxScreen, ps);
    DMX_WRAP(ValidatePicture,    dmxValidatePicture,    dmxScreen, ps);

    DMX_WRAP(Composite,          dmxComposite,          dmxScreen, ps);
    DMX_WRAP(Glyphs,             dmxGlyphs,             dmxScreen, ps);
    DMX_WRAP(CompositeRects,     dmxCompositeRects,     dmxScreen, ps);

    DMX_WRAP(Trapezoids,         dmxTrapezoids,         dmxScreen, ps);
    DMX_WRAP(Triangles,          dmxTriangles,          dmxScreen, ps);
    DMX_WRAP(TriStrip,           dmxTriStrip,           dmxScreen, ps);
    DMX_WRAP(TriFan,             dmxTriFan,             dmxScreen, ps);

    return TRUE;
}


/** Find the appropriate format on the requested screen given the
 *  internal format requested.  The list of formats is searched
 *  sequentially as the XRenderFindFormat() function does not always
 *  find the appropriate format when a specific format is requested. */
static XRenderPictFormat *dmxFindFormat(DMXScreenInfo *dmxScreen,
					PictFormatPtr pFmt)
{
    XRenderPictFormat *pFormat = NULL;
    int                i       = 0;

    if (!pFmt || !dmxScreen->beDisplay) return pFormat;

    while (1) {
	pFormat = XRenderFindFormat(dmxScreen->beDisplay, 0, 0, i++);
	if (!pFormat) break;

	if (pFormat->type             != pFmt->type)             continue;
	if (pFormat->depth            != pFmt->depth)            continue;
	if (pFormat->direct.red       != pFmt->direct.red)       continue;
	if (pFormat->direct.redMask   != pFmt->direct.redMask)   continue;
	if (pFormat->direct.green     != pFmt->direct.green)     continue;
	if (pFormat->direct.greenMask != pFmt->direct.greenMask) continue;
	if (pFormat->direct.blue      != pFmt->direct.blue)      continue;
	if (pFormat->direct.blueMask  != pFmt->direct.blueMask)  continue;
	if (pFormat->direct.alpha     != pFmt->direct.alpha)     continue;
	if (pFormat->direct.alphaMask != pFmt->direct.alphaMask) continue;

	/* We have a match! */
	break;
    }

    return pFormat;
}

/** Free \a glyphSet on back-end screen number \a idx. */
Bool dmxBEFreeGlyphSet(ScreenPtr pScreen, GlyphSetPtr glyphSet)
{
    dmxGlyphPrivPtr  glyphPriv = DMX_GET_GLYPH_PRIV(glyphSet);
    int              idx       = pScreen->myNum;
    DMXScreenInfo   *dmxScreen = &dmxScreens[idx];

    if (glyphPriv->glyphSets[idx]) {
	XRenderFreeGlyphSet(dmxScreen->beDisplay, glyphPriv->glyphSets[idx]);
	glyphPriv->glyphSets[idx] = (GlyphSet)0;
	return TRUE;
    }

    return FALSE;
}

/** Create \a glyphSet on the backend screen number \a idx. */
int dmxBECreateGlyphSet(int idx, GlyphSetPtr glyphSet)
{
    XRenderPictFormat *pFormat;
    DMXScreenInfo     *dmxScreen = &dmxScreens[idx];
    dmxGlyphPrivPtr    glyphPriv = DMX_GET_GLYPH_PRIV(glyphSet);
    PictFormatPtr      pFmt      = glyphSet->format;
    int              (*oldErrorHandler)(Display *, XErrorEvent *);

    pFormat = dmxFindFormat(dmxScreen, pFmt);
    if (!pFormat) {
	return BadMatch;
    }

    dmxGlyphLastError = 0;
    oldErrorHandler = XSetErrorHandler(dmxGlyphErrorHandler);

    /* Catch when this fails */
    glyphPriv->glyphSets[idx]
	= XRenderCreateGlyphSet(dmxScreen->beDisplay, pFormat);

    XSetErrorHandler(oldErrorHandler);

    if (dmxGlyphLastError) {
	return dmxGlyphLastError;
    }

    return Success;
}

/** Create a Glyph Set on each screen.  Save the glyphset ID from each
 *  screen in the Glyph Set's private structure.  Fail if the format
 *  requested is not available or if the Glyph Set cannot be created on
 *  the screen. */
static int dmxProcRenderCreateGlyphSet(ClientPtr client)
{
    int  ret;
    REQUEST(xRenderCreateGlyphSetReq);

    ret = dmxSaveRenderVector[stuff->renderReqType](client);

    if (ret == Success) {
	GlyphSetPtr        glyphSet;
	dmxGlyphPrivPtr    glyphPriv;
	int                i;

	/* Look up glyphSet that was just created ???? */
	/* Store glyphsets from backends in glyphSet->devPrivate ????? */
	/* Make sure we handle all errors here!! */
	
	glyphSet = SecurityLookupIDByType(client, stuff->gsid, GlyphSetType,
					  DixDestroyAccess);
	glyphPriv = xalloc(sizeof(dmxGlyphPrivRec));
	if (!glyphPriv) return BadAlloc;
        glyphPriv->glyphSets = NULL;
        MAXSCREENSALLOC_RETURN(glyphPriv->glyphSets, BadAlloc);
	DMX_SET_GLYPH_PRIV(glyphSet, glyphPriv);

	for (i = 0; i < dmxNumScreens; i++) {
	    DMXScreenInfo *dmxScreen = &dmxScreens[i];
	    int beret;

	    if (!dmxScreen->beDisplay) {
		glyphPriv->glyphSets[i] = 0;
		continue;
	    }

	    if ((beret = dmxBECreateGlyphSet(i, glyphSet)) != Success) {
		int  j;

		/* Free the glyph sets we've allocated thus far */
		for (j = 0; j < i; j++)
		    dmxBEFreeGlyphSet(screenInfo.screens[j], glyphSet);

		/* Free the resource created by render */
		FreeResource(stuff->gsid, RT_NONE);

		return beret;
	    }
	}
    }

    return ret;
}

/** Free the previously allocated Glyph Sets for each screen. */
static int dmxProcRenderFreeGlyphSet(ClientPtr client)
{
    GlyphSetPtr  glyphSet;
    REQUEST(xRenderFreeGlyphSetReq);

    REQUEST_SIZE_MATCH(xRenderFreeGlyphSetReq);
    glyphSet = SecurityLookupIDByType(client, stuff->glyphset, GlyphSetType,
				      DixDestroyAccess);

    if (glyphSet && glyphSet->refcnt == 1) {
	dmxGlyphPrivPtr  glyphPriv = DMX_GET_GLYPH_PRIV(glyphSet);
	int              i;

	for (i = 0; i < dmxNumScreens; i++) {
	    DMXScreenInfo *dmxScreen = &dmxScreens[i];
	    
	    if (dmxScreen->beDisplay) {
		if (dmxBEFreeGlyphSet(screenInfo.screens[i], glyphSet))
		    dmxSync(dmxScreen, FALSE);
	    }
	}

        MAXSCREENSFREE(glyphPriv->glyphSets);
	xfree(glyphPriv);
	DMX_SET_GLYPH_PRIV(glyphSet, NULL);
    }

    return dmxSaveRenderVector[stuff->renderReqType](client);
}

/** Add glyphs to the Glyph Set on each screen. */
static int dmxProcRenderAddGlyphs(ClientPtr client)
{
    int  ret;
    REQUEST(xRenderAddGlyphsReq);

    ret = dmxSaveRenderVector[stuff->renderReqType](client);

    if (ret == Success) {
	GlyphSetPtr      glyphSet;
	dmxGlyphPrivPtr  glyphPriv;
	int              i;
	int              nglyphs;
	CARD32          *gids;
	Glyph           *gidsCopy;
	xGlyphInfo      *gi;
	CARD8           *bits;
	int              nbytes;

	glyphSet = SecurityLookupIDByType(client, stuff->glyphset,
					  GlyphSetType, DixReadAccess);
	glyphPriv = DMX_GET_GLYPH_PRIV(glyphSet);

	nglyphs = stuff->nglyphs;
	gids = (CARD32 *)(stuff + 1);
	gi = (xGlyphInfo *)(gids + nglyphs);
	bits = (CARD8 *)(gi + nglyphs);
	nbytes = ((stuff->length << 2) -
		  sizeof(xRenderAddGlyphsReq) -
		  (sizeof(CARD32) + sizeof(xGlyphInfo)) * nglyphs);

        gidsCopy = xalloc(sizeof(*gidsCopy) * nglyphs);
        for (i = 0; i < nglyphs; i++) gidsCopy[i] = gids[i];

	/* FIXME: Will this ever fail? */
	for (i = 0; i < dmxNumScreens; i++) {
	    DMXScreenInfo *dmxScreen = &dmxScreens[i];

	    if (dmxScreen->beDisplay) {
		XRenderAddGlyphs(dmxScreen->beDisplay,
				 glyphPriv->glyphSets[i],
				 gidsCopy,
				 (XGlyphInfo *)gi,
				 nglyphs,
				 (char *)bits,
				 nbytes);
		dmxSync(dmxScreen, FALSE);
	    }
	}
        xfree(gidsCopy);
    }

    return ret;
}

/** Free glyphs from the Glyph Set for each screen. */
static int dmxProcRenderFreeGlyphs(ClientPtr client)
{
    GlyphSetPtr  glyphSet;
    REQUEST(xRenderFreeGlyphsReq);

    REQUEST_AT_LEAST_SIZE(xRenderFreeGlyphsReq);
    glyphSet = SecurityLookupIDByType(client, stuff->glyphset, GlyphSetType,
				      DixWriteAccess);

    if (glyphSet) {
	dmxGlyphPrivPtr  glyphPriv = DMX_GET_GLYPH_PRIV(glyphSet);
	int              i;
	int              nglyphs;
	Glyph           *gids;

	nglyphs = ((client->req_len << 2) - sizeof(xRenderFreeGlyphsReq)) >> 2;
	if (nglyphs) {
            gids    = xalloc(sizeof(*gids) * nglyphs);
            for (i = 0; i < nglyphs; i++)
                gids[i] = ((CARD32 *)(stuff + 1))[i];
            
	    for (i = 0; i < dmxNumScreens; i++) {
		DMXScreenInfo *dmxScreen = &dmxScreens[i];

		if (dmxScreen->beDisplay) {
		    XRenderFreeGlyphs(dmxScreen->beDisplay,
				      glyphPriv->glyphSets[i], gids, nglyphs);
		    dmxSync(dmxScreen, FALSE);
		}
	    }
            xfree(gids);
	}
    }

    return dmxSaveRenderVector[stuff->renderReqType](client);
}

/** Composite glyphs on each screen into the requested picture.  If
 *  either the src or dest picture has not been allocated due to lazy
 *  window creation, this request will gracefully return. */
static int dmxProcRenderCompositeGlyphs(ClientPtr client)
{
    int  ret;
    REQUEST(xRenderCompositeGlyphsReq);

    ret = dmxSaveRenderVector[stuff->renderReqType](client);

    /* For the following to work with PanoramiX, it assumes that Render
     * wraps the ProcRenderVector after dmxRenderInit has been called.
     */
    if (ret == Success) {
	PicturePtr         pSrc;
	dmxPictPrivPtr     pSrcPriv;
	PicturePtr         pDst;
	dmxPictPrivPtr     pDstPriv;
	PictFormatPtr      pFmt;
	XRenderPictFormat *pFormat;
	int                size;

	int                scrnNum;
	DMXScreenInfo     *dmxScreen;

	CARD8             *buffer;
	CARD8             *end;
	int                space;

	int                nglyph;
	char              *glyphs;
	char              *curGlyph;

	xGlyphElt         *elt;
	int                nelt;
	XGlyphElt8        *elts;
	XGlyphElt8        *curElt;

	GlyphSetPtr        glyphSet;
	dmxGlyphPrivPtr    glyphPriv;

	pSrc = SecurityLookupIDByType(client, stuff->src, PictureType,
				      DixReadAccess);
	pSrcPriv = DMX_GET_PICT_PRIV(pSrc);
	if (!pSrcPriv->pict)
	    return ret;

	pDst = SecurityLookupIDByType(client, stuff->dst, PictureType,
				      DixWriteAccess);
	pDstPriv = DMX_GET_PICT_PRIV(pDst);
	if (!pDstPriv->pict)
	    return ret;

	scrnNum = pDst->pDrawable->pScreen->myNum;
	dmxScreen = &dmxScreens[scrnNum];

	/* Note: If the back-end display has been detached, then it
	 * should not be possible to reach here since the pSrcPriv->pict
	 * and pDstPriv->pict will have already been set to 0.
	 */
	if (!dmxScreen->beDisplay)
	    return ret;

	if (stuff->maskFormat)
	    pFmt = SecurityLookupIDByType(client, stuff->maskFormat,
					  PictFormatType, DixReadAccess);
	else
	    pFmt = NULL;

	pFormat = dmxFindFormat(dmxScreen, pFmt);

	switch (stuff->renderReqType) {
	case X_RenderCompositeGlyphs8:  size = sizeof(CARD8);  break;
	case X_RenderCompositeGlyphs16: size = sizeof(CARD16); break;
	case X_RenderCompositeGlyphs32: size = sizeof(CARD32); break;
        default:                        return BadPictOp; /* Can't happen */
	}

	buffer = (CARD8 *)(stuff + 1);
	end = (CARD8 *)stuff + (stuff->length << 2);
	nelt = 0;
	nglyph = 0;
	while (buffer + sizeof(xGlyphElt) < end) {
	    elt = (xGlyphElt *)buffer;
	    buffer += sizeof(xGlyphElt);

	    if (elt->len == 0xff) {
		buffer += 4;
	    } else {
		nelt++;
		nglyph += elt->len;
		space = size * elt->len;
		if (space & 3) space += 4 - (space & 3);
		buffer += space;
	    }
	}

	/* The following only works for Render version > 0.2 */

	/* All of the XGlyphElt* structure sizes are identical */
	elts = xalloc(nelt * sizeof(XGlyphElt8));
	if (!elts)
	    return BadAlloc;

	glyphs = xalloc(nglyph * size);
	if (!glyphs) {
	    xfree(elts);
	    return BadAlloc;
	}

	buffer = (CARD8 *)(stuff + 1);
	end = (CARD8 *)stuff + (stuff->length << 2);
	curGlyph = glyphs;
	curElt = elts;

	glyphSet = SecurityLookupIDByType(client, stuff->glyphset,
					  GlyphSetType, DixReadAccess);
	glyphPriv = DMX_GET_GLYPH_PRIV(glyphSet);

	while (buffer + sizeof(xGlyphElt) < end) {
	    elt = (xGlyphElt *)buffer;
	    buffer += sizeof(xGlyphElt);

	    if (elt->len == 0xff) {
		glyphSet = SecurityLookupIDByType(client,
						  *((CARD32 *)buffer),
						  GlyphSetType,
						  DixReadAccess);
		glyphPriv = DMX_GET_GLYPH_PRIV(glyphSet);
		buffer += 4;
	    } else {
		curElt->glyphset = glyphPriv->glyphSets[scrnNum];
		curElt->xOff = elt->deltax;
		curElt->yOff = elt->deltay;
		curElt->nchars = elt->len;
		curElt->chars = curGlyph;

		memcpy(curGlyph, buffer, size*elt->len);
		curGlyph += size * elt->len;

		curElt++;

		space = size * elt->len;
		if (space & 3) space += 4 - (space & 3);
		buffer += space;
	    }
	}

	switch (stuff->renderReqType) {
	case X_RenderCompositeGlyphs8:
	    XRenderCompositeText8(dmxScreen->beDisplay, stuff->op,
				  pSrcPriv->pict, pDstPriv->pict,
				  pFormat,
				  stuff->xSrc, stuff->ySrc,
				  0, 0, elts, nelt);
	    break;
	case X_RenderCompositeGlyphs16:
	    XRenderCompositeText16(dmxScreen->beDisplay, stuff->op,
				   pSrcPriv->pict, pDstPriv->pict,
				   pFormat,
				   stuff->xSrc, stuff->ySrc,
				   0, 0, (XGlyphElt16 *)elts, nelt);
	    break;
	case X_RenderCompositeGlyphs32:
	    XRenderCompositeText32(dmxScreen->beDisplay, stuff->op,
				   pSrcPriv->pict, pDstPriv->pict,
				   pFormat,
				   stuff->xSrc, stuff->ySrc,
				   0, 0, (XGlyphElt32 *)elts, nelt);
	    break;
	}

	dmxSync(dmxScreen, FALSE);

	xfree(elts);
	xfree(glyphs);
    }

    return ret;
}

/** Set the picture transform on each screen. */
static int dmxProcRenderSetPictureTransform(ClientPtr client)
{
    DMXScreenInfo  *dmxScreen;
    PicturePtr      pPicture;
    dmxPictPrivPtr  pPictPriv;
    XTransform      xform;
    REQUEST(xRenderSetPictureTransformReq);

    REQUEST_SIZE_MATCH(xRenderSetPictureTransformReq);
    VERIFY_PICTURE(pPicture, stuff->picture, client, DixWriteAccess,
		   RenderErrBase + BadPicture);

    /* For the following to work with PanoramiX, it assumes that Render
     * wraps the ProcRenderVector after dmxRenderInit has been called.
     */
    dmxScreen = &dmxScreens[pPicture->pDrawable->pScreen->myNum];
    pPictPriv = DMX_GET_PICT_PRIV(pPicture);

    if (pPictPriv->pict) {
	xform.matrix[0][0] = stuff->transform.matrix11;
	xform.matrix[0][1] = stuff->transform.matrix12;
	xform.matrix[0][2] = stuff->transform.matrix13;
	xform.matrix[1][0] = stuff->transform.matrix21;
	xform.matrix[1][1] = stuff->transform.matrix22;
	xform.matrix[1][2] = stuff->transform.matrix23;
	xform.matrix[2][0] = stuff->transform.matrix31;
	xform.matrix[2][1] = stuff->transform.matrix32;
	xform.matrix[2][2] = stuff->transform.matrix33;

	XRenderSetPictureTransform(dmxScreen->beDisplay,
				   pPictPriv->pict,
				   &xform);
	dmxSync(dmxScreen, FALSE);
    }

    return dmxSaveRenderVector[stuff->renderReqType](client);
}

/** Set the picture filter on each screen. */
static int dmxProcRenderSetPictureFilter(ClientPtr client)
{
    DMXScreenInfo  *dmxScreen;
    PicturePtr      pPicture;
    dmxPictPrivPtr  pPictPriv;
    char           *filter;
    XFixed         *params;
    int             nparams;
    REQUEST(xRenderSetPictureFilterReq);

    REQUEST_AT_LEAST_SIZE(xRenderSetPictureFilterReq);
    VERIFY_PICTURE(pPicture, stuff->picture, client, DixWriteAccess,
		   RenderErrBase + BadPicture);

    /* For the following to work with PanoramiX, it assumes that Render
     * wraps the ProcRenderVector after dmxRenderInit has been called.
     */
    dmxScreen = &dmxScreens[pPicture->pDrawable->pScreen->myNum];
    pPictPriv = DMX_GET_PICT_PRIV(pPicture);

    if (pPictPriv->pict) {
	filter  = (char *)(stuff + 1);
	params  = (XFixed *)(filter + ((stuff->nbytes + 3) & ~3));
	nparams = ((XFixed *)stuff + client->req_len) - params;

	XRenderSetPictureFilter(dmxScreen->beDisplay,
				pPictPriv->pict,
				filter,
				params,
				nparams);
	dmxSync(dmxScreen, FALSE);
    }

    return dmxSaveRenderVector[stuff->renderReqType](client);
}


/** Create a picture on the appropriate screen.  This is the actual
 *  function that creates the picture.  However, if the associated
 *  window has not yet been created due to lazy window creation, then
 *  delay the picture creation until the window is mapped. */
static Picture dmxDoCreatePicture(PicturePtr pPicture)
{
    DrawablePtr               pDraw     = pPicture->pDrawable;
    ScreenPtr                 pScreen   = pDraw->pScreen;
    DMXScreenInfo            *dmxScreen = &dmxScreens[pScreen->myNum];
    XRenderPictFormat        *pFormat;
    Drawable                  draw;

    if (pPicture->pDrawable->type == DRAWABLE_WINDOW) {
	dmxWinPrivPtr  pWinPriv = DMX_GET_WINDOW_PRIV((WindowPtr)(pDraw));

	if (!(draw = pWinPriv->window)) {
	    /* Window has not been created yet due to the window
	     * optimization.  Delay picture creation until window is
	     * mapped.
	     */
	    pWinPriv->hasPict = TRUE;
	    return 0;
	}
    } else {
	dmxPixPrivPtr  pPixPriv = DMX_GET_PIXMAP_PRIV((PixmapPtr)(pDraw));

	if (!(draw = pPixPriv->pixmap)) {
	    /* FIXME: Zero width/height pixmap?? */
	    return 0;
	}
    }

    /* This should not be reached if the back-end display has been
     * detached because the pWinPriv->window or the pPixPriv->pixmap
     * will be NULL; however, we add it here for completeness
     */
    if (!dmxScreen->beDisplay)
	return 0;

    pFormat = dmxFindFormat(dmxScreen, pPicture->pFormat);

    return XRenderCreatePicture(dmxScreen->beDisplay, draw, pFormat, 0, 0);
}

/** Create a list of pictures.  This function is called by
 *  dmxCreateAndRealizeWindow() during the lazy window creation
 *  realization process.  It creates the entire list of pictures that
 *  are associated with the given window. */
void dmxCreatePictureList(WindowPtr pWindow)
{
    PicturePtr  pPicture = GetPictureWindow(pWindow);

    while (pPicture) {
	dmxPictPrivPtr  pPictPriv = DMX_GET_PICT_PRIV(pPicture);

	/* Create the picture for this window */
	pPictPriv->pict = dmxDoCreatePicture(pPicture);

	/* ValidatePicture takes care of the state changes */

	pPicture = pPicture->pNext;
    }
}

/** Create \a pPicture on the backend. */
int dmxBECreatePicture(PicturePtr pPicture)
{
    dmxPictPrivPtr    pPictPriv = DMX_GET_PICT_PRIV(pPicture);

    /* Create picutre on BE */
    pPictPriv->pict = dmxDoCreatePicture(pPicture);

    /* Flush changes to the backend server */
    dmxValidatePicture(pPicture, (1 << (CPLastBit+1)) - 1);

    return Success;
}

/** Create a picture.  This function handles the CreatePicture
 *  unwrapping/wrapping and calls dmxDoCreatePicture to actually create
 *  the picture on the appropriate screen.  */
int dmxCreatePicture(PicturePtr pPicture)
{
    ScreenPtr         pScreen   = pPicture->pDrawable->pScreen;
    DMXScreenInfo    *dmxScreen = &dmxScreens[pScreen->myNum];
    PictureScreenPtr  ps        = GetPictureScreen(pScreen);
    dmxPictPrivPtr    pPictPriv = DMX_GET_PICT_PRIV(pPicture);
    int               ret       = Success;

    DMX_UNWRAP(CreatePicture, dmxScreen, ps);
#if 1
    if (ps->CreatePicture)
	ret = ps->CreatePicture(pPicture);
#endif

    /* Create picture on back-end server */
    pPictPriv->pict      = dmxDoCreatePicture(pPicture);
    pPictPriv->savedMask = 0;

    DMX_WRAP(CreatePicture, dmxCreatePicture, dmxScreen, ps);

    return ret;
}

/** Destroy \a pPicture on the back-end server. */
Bool dmxBEFreePicture(PicturePtr pPicture)
{
    ScreenPtr      pScreen   = pPicture->pDrawable->pScreen;
    DMXScreenInfo *dmxScreen = &dmxScreens[pScreen->myNum];
    dmxPictPrivPtr pPictPriv = DMX_GET_PICT_PRIV(pPicture);

    if (pPictPriv->pict) {
	XRenderFreePicture(dmxScreen->beDisplay, pPictPriv->pict);
	pPictPriv->pict = (Picture)0;
	return TRUE;
    }

    return FALSE;
}

/** Destroy a list of pictures that are associated with the window that
 *  is being destroyed.  This function is called by #dmxDestroyWindow().
 *  */
Bool dmxDestroyPictureList(WindowPtr pWindow)
{
    PicturePtr  pPicture = GetPictureWindow(pWindow);
    Bool        ret      = FALSE;

    while (pPicture) {
	ret |= dmxBEFreePicture(pPicture);
	pPicture = pPicture->pNext;
    }

    return ret;
}

/** Destroy a picture.  This function calls the wrapped function that
 *  frees the resources in the DMX server associated with this
 *  picture. */
void dmxDestroyPicture(PicturePtr pPicture)
{
    ScreenPtr         pScreen   = pPicture->pDrawable->pScreen;
    DMXScreenInfo    *dmxScreen = &dmxScreens[pScreen->myNum];
    PictureScreenPtr  ps        = GetPictureScreen(pScreen);

    DMX_UNWRAP(DestroyPicture, dmxScreen, ps);

    /* Destroy picture on back-end server */
    if (dmxBEFreePicture(pPicture))
	dmxSync(dmxScreen, FALSE);

#if 1
    if (ps->DestroyPicture)
	ps->DestroyPicture(pPicture);
#endif
    DMX_WRAP(DestroyPicture, dmxDestroyPicture, dmxScreen, ps);
}

/** Change the picture's list of clip rectangles. */
int dmxChangePictureClip(PicturePtr pPicture, int clipType,
			 pointer value, int n)
{
    ScreenPtr         pScreen   = pPicture->pDrawable->pScreen;
    DMXScreenInfo    *dmxScreen = &dmxScreens[pScreen->myNum];
    PictureScreenPtr  ps        = GetPictureScreen(pScreen);
    dmxPictPrivPtr    pPictPriv = DMX_GET_PICT_PRIV(pPicture);

    DMX_UNWRAP(ChangePictureClip, dmxScreen, ps);
#if 1
    if (ps->ChangePictureClip)
	ps->ChangePictureClip(pPicture, clipType, value, n);
#endif

    /* Change picture clip rects on back-end server */
    if (pPictPriv->pict) {
	/* The clip has already been changed into a region by the mi
	 * routine called above.
	 */
	if (clipType == CT_NONE) {
	    /* Disable clipping, show all */
	    XFixesSetPictureClipRegion(dmxScreen->beDisplay,
				       pPictPriv->pict, 0, 0, None);
	} else if (pPicture->clientClip) {
	    RegionPtr   pClip = pPicture->clientClip;
	    BoxPtr      pBox  = REGION_RECTS(pClip);
	    int         nBox  = REGION_NUM_RECTS(pClip);
	    XRectangle *pRects;
	    XRectangle *pRect;
	    int         nRects;

	    nRects = nBox;
	    pRects = pRect = xalloc(nRects * sizeof(*pRect));

	    while (nBox--) {
		pRect->x      = pBox->x1;
		pRect->y      = pBox->y1;
		pRect->width  = pBox->x2 - pBox->x1;
		pRect->height = pBox->y2 - pBox->y1;
		pBox++;
		pRect++;
	    }

	    XRenderSetPictureClipRectangles(dmxScreen->beDisplay,
					    pPictPriv->pict,
					    0, 0,
					    pRects,
					    nRects);
	    xfree(pRects);
	} else {
	    XRenderSetPictureClipRectangles(dmxScreen->beDisplay,
					    pPictPriv->pict,
					    0, 0, NULL, 0);
	}
	dmxSync(dmxScreen, FALSE);
    } else {
	/* FIXME: Handle saving clip region when offscreen */
    }

    DMX_WRAP(ChangePictureClip, dmxChangePictureClip, dmxScreen, ps);
    
    return Success;
}

/** Destroy the picture's list of clip rectangles. */
void dmxDestroyPictureClip(PicturePtr pPicture)
{
    ScreenPtr         pScreen   = pPicture->pDrawable->pScreen;
    DMXScreenInfo    *dmxScreen = &dmxScreens[pScreen->myNum];
    PictureScreenPtr  ps        = GetPictureScreen(pScreen);
    dmxPictPrivPtr    pPictPriv = DMX_GET_PICT_PRIV(pPicture);

    DMX_UNWRAP(DestroyPictureClip, dmxScreen, ps);
#if 1
    if (ps->DestroyPictureClip)
	ps->DestroyPictureClip(pPicture);
#endif

    /* Destroy picture clip rects on back-end server */
    if (pPictPriv->pict) {
	XRenderSetPictureClipRectangles(dmxScreen->beDisplay,
					pPictPriv->pict,
					0, 0, NULL, 0);
	dmxSync(dmxScreen, FALSE);
    } else {
	/* FIXME: Handle destroying clip region when offscreen */
    }

    DMX_WRAP(DestroyPictureClip, dmxDestroyPictureClip, dmxScreen, ps);
}

/** Change the attributes of the pictures.  If the picture has not yet
 *  been created due to lazy window creation, save the mask so that it
 *  can be used to appropriately initialize the picture's attributes
 *  when it is created later. */
void dmxChangePicture(PicturePtr pPicture, Mask mask)
{
    ScreenPtr         pScreen   = pPicture->pDrawable->pScreen;
    DMXScreenInfo    *dmxScreen = &dmxScreens[pScreen->myNum];
    PictureScreenPtr  ps        = GetPictureScreen(pScreen);
    dmxPictPrivPtr    pPictPriv = DMX_GET_PICT_PRIV(pPicture);

    DMX_UNWRAP(ChangePicture, dmxScreen, ps);
#if 1
    if (ps->ChangePicture)
	ps->ChangePicture(pPicture, mask);
#endif

    /* Picture attribute changes are handled in ValidatePicture */
    pPictPriv->savedMask |= mask;

    DMX_WRAP(ChangePicture, dmxChangePicture, dmxScreen, ps);
}

/** Validate the picture's attributes before rendering to it.  Update
 *  any picture attributes that have been changed by one of the higher
 *  layers. */
void dmxValidatePicture(PicturePtr pPicture, Mask mask)
{
    ScreenPtr         pScreen   = pPicture->pDrawable->pScreen;
    DMXScreenInfo    *dmxScreen = &dmxScreens[pScreen->myNum];
    PictureScreenPtr  ps        = GetPictureScreen(pScreen);
    dmxPictPrivPtr    pPictPriv = DMX_GET_PICT_PRIV(pPicture);

    DMX_UNWRAP(ValidatePicture, dmxScreen, ps);

    /* Change picture attributes on back-end server */
    if (pPictPriv->pict) {
	XRenderPictureAttributes  attribs;

	if (mask & CPRepeat) {
	    attribs.repeat = pPicture->repeatType;
	}
	if (mask & CPAlphaMap) {
	    if (pPicture->alphaMap) {
		dmxPictPrivPtr  pAlphaPriv;
		pAlphaPriv = DMX_GET_PICT_PRIV(pPicture->alphaMap);
		if (pAlphaPriv->pict) {
		    attribs.alpha_map = pAlphaPriv->pict;
		} else {
		    /* FIXME: alpha picture drawable has not been created?? */
		    return; /* or should this be: attribs.alpha_map = None; */
		}
	    } else {
		attribs.alpha_map = None;
	    }
	}
	if (mask & CPAlphaXOrigin)
	    attribs.alpha_x_origin = pPicture->alphaOrigin.x;
	if (mask & CPAlphaYOrigin)
	    attribs.alpha_y_origin = pPicture->alphaOrigin.y;
	if (mask & CPClipXOrigin)
	    attribs.clip_x_origin = pPicture->clipOrigin.x;
	if (mask & CPClipYOrigin)
	    attribs.clip_y_origin = pPicture->clipOrigin.y;
	if (mask & CPClipMask)
	    mask &= ~CPClipMask; /* Handled in ChangePictureClip */
	if (mask & CPGraphicsExposure)
	    attribs.graphics_exposures = pPicture->graphicsExposures;
	if (mask & CPSubwindowMode)
	    attribs.subwindow_mode = pPicture->subWindowMode;
	if (mask & CPPolyEdge)
	    attribs.poly_edge = pPicture->polyEdge;
	if (mask & CPPolyMode)
	    attribs.poly_mode = pPicture->polyMode;
	if (mask & CPDither)
	    attribs.dither = pPicture->dither;
	if (mask & CPComponentAlpha)
	    attribs.component_alpha = pPicture->componentAlpha;

	XRenderChangePicture(dmxScreen->beDisplay, pPictPriv->pict,
			     mask, &attribs);
	dmxSync(dmxScreen, FALSE);
    } else {
	pPictPriv->savedMask |= mask;
    }

#if 1
    if (ps->ValidatePicture)
	ps->ValidatePicture(pPicture, mask);
#endif

    DMX_WRAP(ValidatePicture, dmxValidatePicture, dmxScreen, ps);
}

/** Composite a picture on the appropriate screen by combining the
 *  specified rectangle of the transformed src and mask operands with
 *  the specified rectangle of the dst using op as the compositing
 *  operator.  For a complete description see the protocol document of
 *  the RENDER library. */
void dmxComposite(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;
    DMXScreenInfo    *dmxScreen = &dmxScreens[pScreen->myNum];
    PictureScreenPtr  ps        = GetPictureScreen(pScreen);
    dmxPictPrivPtr    pSrcPriv  = DMX_GET_PICT_PRIV(pSrc);
    dmxPictPrivPtr    pMaskPriv = NULL;
    dmxPictPrivPtr    pDstPriv  = DMX_GET_PICT_PRIV(pDst);

    if (pMask) pMaskPriv = DMX_GET_PICT_PRIV(pMask);

    DMX_UNWRAP(Composite, dmxScreen, ps);
#if 0
    if (ps->Composite)
	ps->Composite(op, pSrc, pMask, pDst,
		      xSrc, ySrc, xMask, yMask, xDst, yDst,
		      width, height);
#endif

    /* Composite on back-end server */
    if (pSrcPriv->pict && pDstPriv->pict &&
	((pMaskPriv && pMaskPriv->pict) || !pMaskPriv)) {
	XRenderComposite(dmxScreen->beDisplay,
			 op,
			 pSrcPriv->pict,
			 pMaskPriv ? pMaskPriv->pict : None,
			 pDstPriv->pict,
			 xSrc, ySrc,
			 xMask, yMask,
			 xDst, yDst,
			 width, height);
	dmxSync(dmxScreen, FALSE);
    }


    DMX_WRAP(Composite, dmxComposite, dmxScreen, ps);
}

/** Null function to catch when/if RENDER calls lower level mi hooks.
 *  Compositing glyphs is handled by dmxProcRenderCompositeGlyphs().
 *  This function should never be called. */
void dmxGlyphs(CARD8 op,
	       PicturePtr pSrc, PicturePtr pDst,
	       PictFormatPtr maskFormat,
	       INT16 xSrc, INT16 ySrc,
	       int nlists, GlyphListPtr lists, GlyphPtr *glyphs)
{
    /* This won't work, so we need to wrap ProcRenderCompositeGlyphs */
}

/** Fill a rectangle on the appropriate screen by combining the color
 *  with the dest picture in the area specified by the list of
 *  rectangles.  For a complete description see the protocol document of
 *  the RENDER library. */
void dmxCompositeRects(CARD8 op,
		       PicturePtr pDst,
		       xRenderColor *color,
		       int nRect, xRectangle *rects)
{
    ScreenPtr         pScreen   = pDst->pDrawable->pScreen;
    DMXScreenInfo    *dmxScreen = &dmxScreens[pScreen->myNum];
    PictureScreenPtr  ps        = GetPictureScreen(pScreen);
    dmxPictPrivPtr    pPictPriv = DMX_GET_PICT_PRIV(pDst);

    DMX_UNWRAP(CompositeRects, dmxScreen, ps);
#if 0
    if (ps->CompositeRects)
	ps->CompositeRects(op, pDst, color, nRect, rects);
#endif

    /* CompositeRects on back-end server */
    if (pPictPriv->pict) {
	XRenderFillRectangles(dmxScreen->beDisplay,
			      op,
			      pPictPriv->pict,
			      (XRenderColor *)color,
			      (XRectangle *)rects,
			      nRect);
	dmxSync(dmxScreen, FALSE);
    }

    DMX_WRAP(CompositeRects, dmxCompositeRects, dmxScreen, ps);
}

/** Indexed color visuals are not yet supported. */
Bool dmxInitIndexed(ScreenPtr pScreen, PictFormatPtr pFormat)
{
    return TRUE;
}

/** Indexed color visuals are not yet supported. */
void dmxCloseIndexed(ScreenPtr pScreen, PictFormatPtr pFormat)
{
}

/** Indexed color visuals are not yet supported. */
void dmxUpdateIndexed(ScreenPtr pScreen, PictFormatPtr pFormat,
		      int ndef, xColorItem *pdef)
{
}

/** Composite a list of trapezoids on the appropriate screen.  For a
 *  complete description see the protocol document of the RENDER
 *  library. */
void dmxTrapezoids(CARD8 op, PicturePtr pSrc, PicturePtr pDst,
		   PictFormatPtr maskFormat,
		   INT16 xSrc, INT16 ySrc,
		   int ntrap, xTrapezoid *traps)
{
    ScreenPtr         pScreen   = pDst->pDrawable->pScreen;
    DMXScreenInfo    *dmxScreen = &dmxScreens[pScreen->myNum];
    PictureScreenPtr  ps        = GetPictureScreen(pScreen);
    dmxPictPrivPtr    pSrcPriv  = DMX_GET_PICT_PRIV(pSrc);
    dmxPictPrivPtr    pDstPriv  = DMX_GET_PICT_PRIV(pDst);

    DMX_UNWRAP(Trapezoids, dmxScreen, ps);
#if 0
    if (ps->Trapezoids)
	ps->Trapezoids(op, pSrc, pDst, maskFormat, xSrc, ySrc, ntrap, *traps);
#endif

    /* Draw trapezoids on back-end server */
    if (pDstPriv->pict) {
	XRenderPictFormat *pFormat;

	pFormat = dmxFindFormat(dmxScreen, maskFormat);
	if (!pFormat) {
	    /* FIXME: Error! */
	}

	XRenderCompositeTrapezoids(dmxScreen->beDisplay,
				   op,
				   pSrcPriv->pict,
				   pDstPriv->pict,
				   pFormat,
				   xSrc, ySrc,
				   (XTrapezoid *)traps,
				   ntrap);
	dmxSync(dmxScreen, FALSE);
    }

    DMX_WRAP(Trapezoids, dmxTrapezoids, dmxScreen, ps);
}

/** Composite a list of triangles on the appropriate screen.  For a
 *  complete description see the protocol document of the RENDER
 *  library. */
void dmxTriangles(CARD8 op, PicturePtr pSrc, PicturePtr pDst,
		  PictFormatPtr maskFormat,
		  INT16 xSrc, INT16 ySrc,
		  int ntri, xTriangle *tris)
{
    ScreenPtr         pScreen   = pDst->pDrawable->pScreen;
    DMXScreenInfo    *dmxScreen = &dmxScreens[pScreen->myNum];
    PictureScreenPtr  ps        = GetPictureScreen(pScreen);
    dmxPictPrivPtr    pSrcPriv  = DMX_GET_PICT_PRIV(pSrc);
    dmxPictPrivPtr    pDstPriv  = DMX_GET_PICT_PRIV(pDst);

    DMX_UNWRAP(Triangles, dmxScreen, ps);
#if 0
    if (ps->Triangles)
	ps->Triangles(op, pSrc, pDst, maskFormat, xSrc, ySrc, ntri, *tris);
#endif

    /* Draw trapezoids on back-end server */
    if (pDstPriv->pict) {
	XRenderPictFormat *pFormat;

	pFormat = dmxFindFormat(dmxScreen, maskFormat);
	if (!pFormat) {
	    /* FIXME: Error! */
	}

	XRenderCompositeTriangles(dmxScreen->beDisplay,
				  op,
				  pSrcPriv->pict,
				  pDstPriv->pict,
				  pFormat,
				  xSrc, ySrc,
				  (XTriangle *)tris,
				  ntri);
	dmxSync(dmxScreen, FALSE);
    }

    DMX_WRAP(Triangles, dmxTriangles, dmxScreen, ps);
}

/** Composite a triangle strip on the appropriate screen.  For a
 *  complete description see the protocol document of the RENDER
 *  library. */
void dmxTriStrip(CARD8 op, PicturePtr pSrc, PicturePtr pDst,
		 PictFormatPtr maskFormat,
		 INT16 xSrc, INT16 ySrc,
		 int npoint, xPointFixed *points)
{
    ScreenPtr         pScreen   = pDst->pDrawable->pScreen;
    DMXScreenInfo    *dmxScreen = &dmxScreens[pScreen->myNum];
    PictureScreenPtr  ps        = GetPictureScreen(pScreen);
    dmxPictPrivPtr    pSrcPriv  = DMX_GET_PICT_PRIV(pSrc);
    dmxPictPrivPtr    pDstPriv  = DMX_GET_PICT_PRIV(pDst);

    DMX_UNWRAP(TriStrip, dmxScreen, ps);
#if 0
    if (ps->TriStrip)
	ps->TriStrip(op, pSrc, pDst, maskFormat, xSrc, ySrc, npoint, *points);
#endif

    /* Draw trapezoids on back-end server */
    if (pDstPriv->pict) {
	XRenderPictFormat *pFormat;

	pFormat = dmxFindFormat(dmxScreen, maskFormat);
	if (!pFormat) {
	    /* FIXME: Error! */
	}

	XRenderCompositeTriStrip(dmxScreen->beDisplay,
				 op,
				 pSrcPriv->pict,
				 pDstPriv->pict,
				 pFormat,
				 xSrc, ySrc,
				 (XPointFixed *)points,
				 npoint);
	dmxSync(dmxScreen, FALSE);
    }

    DMX_WRAP(TriStrip, dmxTriStrip, dmxScreen, ps);
}

/** Composite a triangle fan on the appropriate screen.  For a complete
 *  description see the protocol document of the RENDER library. */
void dmxTriFan(CARD8 op, PicturePtr pSrc, PicturePtr pDst,
	       PictFormatPtr maskFormat,
	       INT16 xSrc, INT16 ySrc,
	       int npoint, xPointFixed *points)
{
    ScreenPtr         pScreen   = pDst->pDrawable->pScreen;
    DMXScreenInfo    *dmxScreen = &dmxScreens[pScreen->myNum];
    PictureScreenPtr  ps        = GetPictureScreen(pScreen);
    dmxPictPrivPtr    pSrcPriv  = DMX_GET_PICT_PRIV(pSrc);
    dmxPictPrivPtr    pDstPriv  = DMX_GET_PICT_PRIV(pDst);

    DMX_UNWRAP(TriFan, dmxScreen, ps);
#if 0
    if (ps->TriFan)
	ps->TriFan(op, pSrc, pDst, maskFormat, xSrc, ySrc, npoint, *points);
#endif

    /* Draw trapezoids on back-end server */
    if (pDstPriv->pict) {
	XRenderPictFormat *pFormat;

	pFormat = dmxFindFormat(dmxScreen, maskFormat);
	if (!pFormat) {
	    /* FIXME: Error! */
	}

	XRenderCompositeTriFan(dmxScreen->beDisplay,
			       op,
			       pSrcPriv->pict,
			       pDstPriv->pict,
			       pFormat,
			       xSrc, ySrc,
			       (XPointFixed *)points,
			       npoint);
	dmxSync(dmxScreen, FALSE);
    }

    DMX_WRAP(TriFan, dmxTriFan, dmxScreen, ps);
}