xserver/glx/xfont.c

/*
 * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
 * Copyright (C) 1991-2000 Silicon Graphics, Inc. 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
 * 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 including the dates of first publication and
 * either this permission notice or a reference to
 * http://oss.sgi.com/projects/FreeB/
 * 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 NONINFRINGEMENT. IN NO EVENT SHALL
 * SILICON GRAPHICS, INC. 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.
 *
 * Except as contained in this notice, the name of Silicon Graphics, Inc.
 * shall not be used in advertising or otherwise to promote the sale, use or
 * other dealings in this Software without prior written authorization from
 * Silicon Graphics, Inc.
 */

#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif

#include "glxserver.h"
#include "glxutil.h"
#include "unpack.h"
#include "g_disptab.h"
#include "glapitable.h"
#include "glapi.h"
#include "glthread.h"
#include "dispatch.h"
#include "indirect_dispatch.h"
#include <GL/gl.h>
#include <pixmapstr.h>
#include <windowstr.h>
#include <dixfontstr.h>

extern XID clientErrorValue;	/* imported kludge from dix layer */

/*
** Make a single GL bitmap from a single X glyph
*/
static int __glXMakeBitmapFromGlyph(FontPtr font, CharInfoPtr pci)
{
    int i, j;
    int widthPadded;	/* width of glyph in bytes, as padded by X */
    int allocBytes;	/* bytes to allocate to store bitmap */
    int w;		/* width of glyph in bits */
    int h;		/* height of glyph */
    register unsigned char *pglyph;
    register unsigned char *p;
    unsigned char *allocbuf;
#define __GL_CHAR_BUF_SIZE 2048
    unsigned char buf[__GL_CHAR_BUF_SIZE];

    w = GLYPHWIDTHPIXELS(pci);
    h = GLYPHHEIGHTPIXELS(pci);
    widthPadded = GLYPHWIDTHBYTESPADDED(pci);

    /*
    ** Use the local buf if possible, otherwise malloc.
    */
    allocBytes = widthPadded * h;
    if (allocBytes <= __GL_CHAR_BUF_SIZE) {
	p = buf;
	allocbuf = 0;
    } else {
	p = (unsigned char *) xalloc(allocBytes);
	if (!p)
	    return BadAlloc;
	allocbuf = p;
    }

    /*
    ** We have to reverse the picture, top to bottom
    */

    pglyph = FONTGLYPHBITS(FONTGLYPHS(font), pci) + (h-1)*widthPadded;
    for (j=0; j < h; j++) {
	for (i=0; i < widthPadded; i++) {
	    p[i] = pglyph[i];
	}
	pglyph -= widthPadded;
	p += widthPadded;
    }
    CALL_Bitmap( GET_DISPATCH(), (w, h, -pci->metrics.leftSideBearing,
				  pci->metrics.descent,
				  pci->metrics.characterWidth, 0, 
				  allocbuf ? allocbuf : buf) );

    if (allocbuf) {
	xfree(allocbuf);
    }
    return Success;
#undef __GL_CHAR_BUF_SIZE
}

/*
** Create a GL bitmap for each character in the X font.  The bitmap is stored
** in a display list.
*/

static int 
MakeBitmapsFromFont(FontPtr pFont, int first, int count, int list_base)
{
    unsigned long   i, nglyphs;
    CARD8	    chs[2];		/* the font index we are going after */
    CharInfoPtr	    pci;
    int rv;				/* return value */
    int encoding = (FONTLASTROW(pFont) == 0) ? Linear16Bit : TwoD16Bit;
    
    CALL_PixelStorei( GET_DISPATCH(), (GL_UNPACK_SWAP_BYTES, FALSE) );
    CALL_PixelStorei( GET_DISPATCH(), (GL_UNPACK_LSB_FIRST, BITMAP_BIT_ORDER == LSBFirst) );
    CALL_PixelStorei( GET_DISPATCH(), (GL_UNPACK_ROW_LENGTH, 0) );
    CALL_PixelStorei( GET_DISPATCH(), (GL_UNPACK_SKIP_ROWS, 0) );
    CALL_PixelStorei( GET_DISPATCH(), (GL_UNPACK_SKIP_PIXELS, 0) );
    CALL_PixelStorei( GET_DISPATCH(), (GL_UNPACK_ALIGNMENT, GLYPHPADBYTES) );
    for (i=0; i < count; i++) {
	chs[0] = (first + i) >> 8;	/* high byte is first byte */
	chs[1] = first + i;

	(*pFont->get_glyphs)(pFont, 1, chs, (FontEncoding)encoding, 
		&nglyphs, &pci);

	/*
	** Define a display list containing just a glBitmap() call.
	*/
	CALL_NewList( GET_DISPATCH(), (list_base + i, GL_COMPILE) );
	if (nglyphs ) {
	    rv = __glXMakeBitmapFromGlyph(pFont, pci);
	    if (rv) {
		return rv;
	    }
	}
	CALL_EndList( GET_DISPATCH(), () );
    }
    return Success;
}

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

int __glXDisp_UseXFont(__GLXclientState *cl, GLbyte *pc)
{
    ClientPtr client = cl->client;
    xGLXUseXFontReq *req;
    FontPtr pFont;
    GC *pGC;
    GLuint currentListIndex;
    __GLXcontext *cx;
    int error;

    req = (xGLXUseXFontReq *) pc;
    cx = __glXForceCurrent(cl, req->contextTag, &error);
    if (!cx) {
	return error;
    }

    CALL_GetIntegerv( GET_DISPATCH(), (GL_LIST_INDEX, (GLint*) &currentListIndex) );
    if (currentListIndex != 0) {
	/*
	** A display list is currently being made.  It is an error
	** to try to make a font during another lists construction.
	*/
	client->errorValue = cx->id;
	return __glXError(GLXBadContextState);
    }

    /*
    ** Font can actually be either the ID of a font or the ID of a GC
    ** containing a font.
    */

    error = dixLookupResourceByType((pointer *)&pFont,
				    req->font, RT_FONT,
				    client, DixReadAccess);
    if (error != Success) {
	error = dixLookupResourceByType((pointer *)&pGC,
					req->font, RT_GC,
					client, DixReadAccess);
        if (error != Success) {
	    client->errorValue = req->font;
            return error == BadGC ? BadFont : error;
	}
	pFont = pGC->font;
    }

    return MakeBitmapsFromFont(pFont, req->first, req->count,
				    req->listBase);
}