xserver/dix/glyphcurs.c

/************************************************************************

Copyright 1987, 1998  The Open Group

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Copyright 1987 by Digital Equipment Corporation, Maynard, Massachusetts.

                        All Rights Reserved

Permission to use, copy, modify, and distribute this software and its 
documentation for any purpose and without fee is hereby granted, 
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 Digital not be
used in advertising or publicity pertaining to distribution of the
software without specific, written prior permission.  

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************************************************************************/

/* $Xorg: glyphcurs.c,v 1.4 2001/02/09 02:04:40 xorgcvs Exp $ */

#include "misc.h"
#include "fontstruct.h"
#include "dixfontstr.h"
#include "scrnintstr.h"
#include "gcstruct.h"
#include "resource.h"
#include "dix.h"
#include "cursorstr.h"
#include "opaque.h"
#include "servermd.h"


/*
    get the bits out of the font in a portable way.  to avoid
dealing with padding and such-like, we draw the glyph into
a bitmap, then read the bits out with GetImage, which
uses server-natural format.
    since all screens return the same bitmap format, we'll just use
the first one we find.
    the character origin lines up with the hotspot in the
cursor metrics.
*/

int
ServerBitsFromGlyph(FontPtr pfont, unsigned ch, register CursorMetricPtr cm, unsigned char **ppbits)
{
    register ScreenPtr pScreen;
    register GCPtr pGC;
    xRectangle rect;
    PixmapPtr ppix;
    long nby;
    char *pbits;
    ChangeGCVal gcval[3];
    unsigned char char2b[2];

    /* turn glyph index into a protocol-format char2b */
    char2b[0] = (unsigned char)(ch >> 8);
    char2b[1] = (unsigned char)(ch & 0xff);

    pScreen = screenInfo.screens[0];
    nby = BitmapBytePad(cm->width) * (long)cm->height;
    pbits = (char *)xalloc(nby);
    if (!pbits)
	return BadAlloc;
    /* zeroing the (pad) bits seems to help some ddx cursor handling */
    bzero(pbits, nby);

    ppix = (PixmapPtr)(*pScreen->CreatePixmap)(pScreen, cm->width,
					       cm->height, 1);
    pGC = GetScratchGC(1, pScreen);
    if (!ppix || !pGC)
    {
	if (ppix)
	    (*pScreen->DestroyPixmap)(ppix);
	if (pGC)
	    FreeScratchGC(pGC);
	xfree(pbits);
	return BadAlloc;
    }

    rect.x = 0;
    rect.y = 0;
    rect.width = cm->width;
    rect.height = cm->height;

    /* fill the pixmap with 0 */
    gcval[0].val = GXcopy;
    gcval[1].val = 0;
    gcval[2].ptr = (pointer)pfont;
    dixChangeGC(NullClient, pGC, GCFunction | GCForeground | GCFont,
		NULL, gcval);
    ValidateGC((DrawablePtr)ppix, pGC);
    (*pGC->ops->PolyFillRect)((DrawablePtr)ppix, pGC, 1, &rect);

    /* draw the glyph */
    gcval[0].val = 1;
    dixChangeGC(NullClient, pGC, GCForeground, NULL, gcval);
    ValidateGC((DrawablePtr)ppix, pGC);
    (*pGC->ops->PolyText16)((DrawablePtr)ppix, pGC, cm->xhot, cm->yhot,
			    1, (unsigned short *)char2b);
    (*pScreen->GetImage)((DrawablePtr)ppix, 0, 0, cm->width, cm->height,
			 XYPixmap, 1, pbits);
    *ppbits = (unsigned char *)pbits;
    FreeScratchGC(pGC);
    (*pScreen->DestroyPixmap)(ppix);
    return Success;
}


Bool
CursorMetricsFromGlyph(register FontPtr pfont, unsigned ch, register CursorMetricPtr cm)
{
    CharInfoPtr 	pci;
    unsigned long	nglyphs;
    CARD8		chs[2];
    FontEncoding	encoding;

    chs[0] = ch >> 8;
    chs[1] = ch;
    encoding = (FONTLASTROW(pfont) == 0) ? Linear16Bit : TwoD16Bit;
    if (encoding == Linear16Bit)
    {
	if (ch < pfont->info.firstCol || pfont->info.lastCol < ch)
	    return FALSE;
    }
    else
    {
	if (chs[0] < pfont->info.firstRow || pfont->info.lastRow < chs[0])
	    return FALSE;
	if (chs[1] < pfont->info.firstCol || pfont->info.lastCol < chs[1])
	    return FALSE;
    }
    (*pfont->get_glyphs) (pfont, 1, chs, encoding, &nglyphs, &pci);
    if (nglyphs == 0)
	return FALSE;
    cm->width = pci->metrics.rightSideBearing - pci->metrics.leftSideBearing;
    cm->height = pci->metrics.descent + pci->metrics.ascent;
    if (pci->metrics.leftSideBearing > 0)
    {
	cm->width += pci->metrics.leftSideBearing;
	cm->xhot = 0;
    }
    else
    {
	cm->xhot = -pci->metrics.leftSideBearing;
	if (pci->metrics.rightSideBearing < 0)
	    cm->width -= pci->metrics.rightSideBearing;
    }
    if (pci->metrics.ascent < 0)
    {
	cm->height -= pci->metrics.ascent;
	cm->yhot = 0;
    }
    else
    {
	cm->yhot = pci->metrics.ascent;
	if (pci->metrics.descent < 0)
	    cm->height -= pci->metrics.descent;
    }
    return TRUE;
}