mibstore.c

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 *	Perform a PutImage, routing output to backing-store as needed.
 *
 * Results:
 *	None.
 *
 * Side Effects:
 *
 *-----------------------------------------------------------------------
 */
static void
miBSPutImage(pDrawable, pGC, depth, x, y, w, h, leftPad, format, pBits)
    DrawablePtr	  pDrawable;
    GCPtr   	  pGC;
    int		  depth;
    int	    	  x;
    int	    	  y;
    int	    	  w;
    int	    	  h;
    int		  leftPad;
    int	    	  format;
    char    	  *pBits;
{
    SETUP_BACKING (pDrawable, pGC);

    PROLOGUE(pGC);

    (*pGC->ops->PutImage)(pDrawable, pGC,
		     depth, x, y, w, h, leftPad, format, pBits);
    (*pBackingGC->ops->PutImage)(pBackingDrawable, pBackingGC,
		     depth, x - pBackingStore->x, y - pBackingStore->y,
		     w, h, leftPad, format, pBits);

    EPILOGUE (pGC);
}

/*-
 *-----------------------------------------------------------------------
 * miBSDoCopy --
 *	Perform a CopyArea or CopyPlane within a window that has backing
 *	store enabled.
 *
 * Results:
 *	TRUE if the copy was performed or FALSE if a regular one should
 *	be done.
 *
 * Side Effects:
 *	Things are copied (no s***!)
 *
 * Notes:
 *	The idea here is to form two regions that cover the source box.
 *	One contains the exposed rectangles while the other contains
 *	the obscured ones. An array of <box, drawable> pairs is then
 *	formed where the <box> indicates the area to be copied and the
 *	<drawable> indicates from where it is to be copied (exposed regions
 *	come from the screen while obscured ones come from the backing
 *	pixmap). The array 'sequence' is then filled with the indices of
 *	the pairs in the order in which they should be copied to prevent
 *	things from getting screwed up. A call is also made through the
 *	backingGC to take care of any copying into the backing pixmap.
 *
 *-----------------------------------------------------------------------
 */
static Bool
miBSDoCopy(pWin, pGC, srcx, srcy, w, h, dstx, dsty, plane, copyProc, ppRgn)
    WindowPtr	  pWin;	    	    /* Window being scrolled */
    GCPtr   	  pGC;	    	    /* GC we're called through */
    int	    	  srcx;	    	    /* X of source rectangle */
    int	    	  srcy;	    	    /* Y of source rectangle */
    int	    	  w;	    	    /* Width of source rectangle */
    int	    	  h;	    	    /* Height of source rectangle */
    int	    	  dstx;	    	    /* X of destination rectangle */
    int	    	  dsty;	    	    /* Y of destination rectangle */
    unsigned long plane;    	    /* Plane to copy (0 for CopyArea) */
    RegionPtr  	  (*copyProc)();    /* Procedure to call to perform the copy */
    RegionPtr	  *ppRgn;	    /* resultant Graphics Expose region */
{
    RegionPtr 	    	pRgnExp;    /* Exposed region */
    RegionPtr	  	pRgnObs;    /* Obscured region */
    BoxRec	  	box;	    /* Source box (screen coord) */
    struct BoxDraw {
	BoxPtr	  	pBox;	    	/* Source box */
	enum {
	    win, pix
	}   	  	source;	    	/* Place from which to copy */
    }	    	  	*boxes;	    /* Array of box/drawable pairs covering
				     * source box. */
    int  	  	*sequence;  /* Sequence of boxes to move */
    register int  	i, j, k, l, y;
    register BoxPtr	pBox;
    int	    	  	dx, dy, nrects;
    Bool    	  	graphicsExposures;
    RegionPtr	  	(*pixCopyProc)();
    int			numRectsExp, numRectsObs;
    BoxPtr		pBoxExp, pBoxObs;

    SETUP_BACKING (pWin, pGC);

    /*
     * Create a region of exposed boxes in pRgnExp.
     */
    box.x1 = srcx + pWin->drawable.x;
    box.x2 = box.x1 + w;
    box.y1 = srcy + pWin->drawable.y;
    box.y2 = box.y1 + h;
    
    pRgnExp = REGION_CREATE(pGC->pScreen, &box, 1);
    REGION_INTERSECT(pGC->pScreen, pRgnExp, pRgnExp, &pWin->clipList);
    pRgnObs = REGION_CREATE(pGC->pScreen, NULL, 1);
    REGION_INVERSE( pGC->pScreen, pRgnObs, pRgnExp, &box);

    /*
     * Translate regions into window coordinates for proper calls
     * to the copyProc, then make sure none of the obscured region sticks
     * into invalid areas of the backing pixmap.
     */
    REGION_TRANSLATE(pGC->pScreen, pRgnExp,
				      -pWin->drawable.x,
				      -pWin->drawable.y);
    REGION_TRANSLATE(pGC->pScreen, pRgnObs,
				      -pWin->drawable.x,
				      -pWin->drawable.y);
    REGION_INTERSECT(pGC->pScreen, pRgnObs, pRgnObs, &pBackingStore->SavedRegion);

    /*
     * If the obscured region is empty, there's no point being fancy.
     */
    if (!REGION_NOTEMPTY(pGC->pScreen, pRgnObs))
    {
	REGION_DESTROY(pGC->pScreen, pRgnExp);
	REGION_DESTROY(pGC->pScreen, pRgnObs);

	return (FALSE);
    }

    numRectsExp = REGION_NUM_RECTS(pRgnExp);
    pBoxExp = REGION_RECTS(pRgnExp);
    pBoxObs = REGION_RECTS(pRgnObs);
    numRectsObs = REGION_NUM_RECTS(pRgnObs);
    nrects = numRectsExp + numRectsObs;
    
    boxes = (struct BoxDraw *)ALLOCATE_LOCAL(nrects * sizeof(struct BoxDraw));
    sequence = (int *) ALLOCATE_LOCAL(nrects * sizeof(int));
    *ppRgn = NULL;

    if (!boxes || !sequence)
    {
	if (sequence) DEALLOCATE_LOCAL(sequence);
	if (boxes) DEALLOCATE_LOCAL(boxes);
	REGION_DESTROY(pGC->pScreen, pRgnExp);
	REGION_DESTROY(pGC->pScreen, pRgnObs);

	return(TRUE);
    }

    /*
     * Order the boxes in the two regions so we know from which drawable
     * to copy which box, storing the result in the boxes array
     */
    for (i = 0, j = 0, k = 0;
	 (i < numRectsExp) && (j < numRectsObs);
	 k++)
    {
	if (pBoxExp[i].y1 < pBoxObs[j].y1)
	{
	    boxes[k].pBox = &pBoxExp[i];
	    boxes[k].source = win;
	    i++;
	}
	else if ((pBoxObs[j].y1 < pBoxExp[i].y1) ||
		 (pBoxObs[j].x1 < pBoxExp[i].x1))
	{
	    boxes[k].pBox = &pBoxObs[j];
	    boxes[k].source = pix;
	    j++;
	}
	else
	{
	    boxes[k].pBox = &pBoxExp[i];
	    boxes[k].source = win;
	    i++;
	}
    }

    /*
     * Catch any leftover boxes from either region (note that only
     * one can have leftover boxes...)
     */
    if (i != numRectsExp)
    {
	do
	{
	    boxes[k].pBox = &pBoxExp[i];
	    boxes[k].source = win;
	    i++;
	    k++;
	} while (i < numRectsExp);

    }
    else
    {
	do
	{
	    boxes[k].pBox = &pBoxObs[j];
	    boxes[k].source = pix;
	    j++;
	    k++;
	} while (j < numRectsObs);
    }
    
    if (dsty <= srcy)
    {
	/*
	 * Scroll up or vertically stationary, so vertical order is ok.
	 */
	if (dstx <= srcx)
	{
	    /*
	     * Scroll left or horizontally stationary, so horizontal order
	     * is ok as well.
	     */
	    for (i = 0; i < nrects; i++)
	    {
		sequence[i] = i;
	    }
	}
	else
	{
	    /*
	     * Scroll right. Need to reverse the rectangles within each
	     * band.
	     */
	    for (i = 0, j = 1, k = 0;
		 i < nrects;
		 j = i + 1, k = i)
	    {
		y = boxes[i].pBox->y1;
		while ((j < nrects) && (boxes[j].pBox->y1 == y))
		{
		    j++;
		}
		for (j--; j >= k; j--, i++)
		{
		    sequence[i] = j;
		}
	    }
	}
    }
    else
    {
	/*
	 * Scroll down. Must reverse vertical banding, at least.
	 */
	if (dstx < srcx)
	{
	    /*
	     * Scroll left. Horizontal order is ok.
	     */
	    for (i = nrects - 1, j = i - 1, k = i, l = 0;
		 i >= 0;
		 j = i - 1, k = i)
	    {
		/*
		 * Find extent of current horizontal band, then reverse
		 * the order of the whole band.
		 */
		y = boxes[i].pBox->y1;
		while ((j >= 0) && (boxes[j].pBox->y1 == y))
		{
		    j--;
		}
		for (j++; j <= k; j++, i--, l++)
		{
		    sequence[l] = j;
		}
	    }
	}
	else
	{
	    /*
	     * Scroll right or horizontal stationary.
	     * Reverse horizontal order as well (if stationary, horizontal
	     * order can be swapped without penalty and this is faster
             * to compute).
	     */
	    for (i = 0, j = nrects - 1; i < nrects; i++, j--)
	    {
		sequence[i] = j;
	    }
	}
    }
	    
    /*
     * XXX: To avoid getting multiple NoExpose events from this operation,
     * we turn OFF graphicsExposures in the gc and deal with any uncopied
     * areas later, if there's something not in backing-store.
     */

    graphicsExposures = pGC->graphicsExposures;
    pGC->graphicsExposures = FALSE;
    
    dx = dstx - srcx;
    dy = dsty - srcy;

    /*
     * Figure out which copy procedure to use from the backing GC. Note we
     * must do this because some implementations (sun's, e.g.) have
     * pBackingGC a fake GC with the real one below it, thus the devPriv for
     * pBackingGC won't be what the output library expects.
     */
    if (plane != 0)
    {
	pixCopyProc = pBackingGC->ops->CopyPlane;
    }
    else
    {
	pixCopyProc = pBackingGC->ops->CopyArea;
    }
    
    for (i = 0; i < nrects; i++)
    {
	pBox = boxes[sequence[i]].pBox;
	
	/*
	 * If we're copying from the pixmap, we need to place its contents
	 * onto the screen before scrolling the pixmap itself. If we're copying
	 * from the window, we need to copy its contents into the pixmap before
	 * we scroll the window itself.
	 */
	if (boxes[sequence[i]].source == pix)
	{
	    (void) (* copyProc) (pBackingDrawable, pWin, pGC,
			  pBox->x1 - pBackingStore->x,
			  pBox->y1 - pBackingStore->y,
			  pBox->x2 - pBox->x1, pBox->y2 - pBox->y1,
			  pBox->x1 + dx, pBox->y1 + dy, plane);
	    (void) (* pixCopyProc) (pBackingDrawable, pBackingDrawable, pBackingGC,
			     pBox->x1 - pBackingStore->x,
			     pBox->y1 - pBackingStore->y,
			     pBox->x2 - pBox->x1, pBox->y2 - pBox->y1,
			     pBox->x1 + dx - pBackingStore->x,
			     pBox->y1 + dy - pBackingStore->y, plane);
	}
	else
	{
	    (void) (* pixCopyProc) (pWin, pBackingDrawable, pBackingGC,
			     pBox->x1, pBox->y1,
			     pBox->x2 - pBox->x1, pBox->y2 - pBox->y1,
			     pBox->x1 + dx - pBackingStore->x,
			     pBox->y1 + dy - pBackingStore->y, plane);
	    (void) (* copyProc) (pWin, pWin, pGC,
			  pBox->x1, pBox->y1,
			  pBox->x2 - pBox->x1, pBox->y2 - pBox->y1,
			  pBox->x1 + dx, pBox->y1 + dy, plane);
	}
    }
    DEALLOCATE_LOCAL(sequence);
    DEALLOCATE_LOCAL(boxes);

    pGC->graphicsExposures = graphicsExposures;
    /*
     * Form union of rgnExp and rgnObs and see if covers entire area
     * to be copied.  Store the resultant region for miBSCopyArea
     * to return to dispatch which will send the appropriate expose
     * events.
     */
    REGION_UNION(pGC->pScreen, pRgnExp, pRgnExp, pRgnObs);
    box.x1 = srcx;
    box.x2 = srcx + w;
    box.y1 = srcy;
    box.y2 = srcy + h;
    if (RECT_IN_REGION(pGC->pScreen, pRgnExp, &box) == rgnIN)
    {
	REGION_EMPTY(pGC->pScreen, pRgnExp);
    }
    else
    {
	REGION_INVERSE( pGC->pScreen, pRgnExp, pRgnExp, &box);
	REGION_TRANSLATE( pGC->pScreen, pRgnExp,
					   dx + pWin->drawable.x,
 					   dy + pWin->drawable.y);
	REGION_INTERSECT( pGC->pScreen, pRgnObs, pRgnExp, &pWin->clipList);
	(*pWin->drawable.pScreen->PaintWindowBackground) (pWin,
						pRgnObs, PW_BACKGROUND);
	REGION_TRANSLATE( pGC->pScreen, pRgnExp,
					   -pWin->drawable.x,
 					   -pWin->drawable.y);
	miBSClearBackingRegion (pWin, pRgnExp);
    }
    if (graphicsExposures)
	*ppRgn = pRgnExp;
    else
	REGION_DESTROY(pGC->pScreen, pRgnExp);
    REGION_DESTROY(pGC->pScreen, pRgnObs);

    return (TRUE);
}

/*-
 *-----------------------------------------------------------------------
 * miBSCopyArea --
 *	Perform a CopyArea from the source to the destination, extracting
 *	from the source's backing-store and storing into the destination's
 *	backing-store without messing anything up. If the source and
 *	destination are different, there's not too much to worry about:
 *	we can just issue several calls to the regular CopyArea function.
 *
 * Results:
 *	None.
 *
 * Side Effects:
 *
 *-----------------------------------------------------------------------
 */
static RegionPtr
miBSCopyArea (pSrc, pDst, pGC, srcx, srcy, w, h, dstx, dsty)
    DrawablePtr	  pSrc;
    DrawablePtr	  pDst;
    GCPtr   	  pGC;
    int	    	  srcx;
    int	    	  srcy;
    int	    	  w;
    int	    	  h;
    int	    	  dstx;
    int	    	  dsty;
{
    BoxPtr	pExtents;
    long	dx, dy;
    int		bsrcx, bsrcy, bw, bh, bdstx, bdsty;
    RegionPtr	pixExposed = 0, winExposed = 0;

    SETUP_BACKING(pDst, pGC);

    PROLOGUE(pGC);

    if ((pSrc != pDst) ||
	(!miBSDoCopy((WindowPtr)pSrc, pGC, srcx, srcy, w, h, dstx, dsty,
		     (unsigned long) 0, pGC->ops->CopyArea, &winExposed)))
    {
	/*
	 * always copy to the backing store first, miBSDoCopy
	 * returns FALSE if the *source* region is disjoint
	 * from the backing store saved region.  So, copying
	 * *to* the backing store is always safe
	 */
	if (pGC->clientClipType != CT_PIXMAP)
	{
	    /*
	     * adjust srcx, srcy, w, h, dstx, dsty to be clipped to
	     * the backing store.  An unnecessary optimisation,
	     * but a useful one when GetSpans is slow.
	     */
	    pExtents = REGION_EXTENTS(pDst->pScreen,
				      (RegionPtr)pBackingGC->clientClip);
	    bsrcx = srcx;
	    bsrcy = srcy;
	    bw = w;
	    bh = h;
	    bdstx = dstx;
	    bdsty = dsty;
	    dx = pExtents->x1 - bdstx;
	    if (dx > 0)
	    {
		bsrcx += dx;
		bdstx += dx;
		bw -= dx;
	    }
	    dy = pExtents->y1 - bdsty;
	    if (dy > 0)
	    {
		bsrcy += dy;
		bdsty += dy;
		bh -= dy;
	    }
	    dx = (bdstx + bw) - pExtents->x2;
	    if (dx > 0)
		bw -= dx;
	    dy = (bdsty + bh) - pExtents->y2;
	    if (dy > 0)
		bh -= dy;
	    if (bw > 0 && bh > 0)
		pixExposed = (* pBackingGC->ops->CopyArea) (pSrc, 
			    pBackingDrawable, pBackingGC, 
			    bsrcx, bsrcy, bw, bh, bdstx - pBackingStore->x,
			    bdsty - pBackingStore->y);
	}
	else
	    pixExposed = (* pBackingGC->ops->CopyArea) (pSrc, 
			    pBackingDrawable, pBackingGC,
			    srcx, srcy, w, h,
			    dstx - pBackingStore->x, dsty - pBackingStore->y);

	winExposed = (* pGC->ops->CopyArea) (pSrc, pDst, pGC, srcx, srcy, w, h, dstx, dsty);
    }

    /*
     * compute the composite graphics exposure region
     */
    if (winExposed)
    {