path: root/Build/source/texk/web2c/xetexdir/XeTeXFontInst.cpp

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 Copyright (c) 2009 by Jonathan Kew

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/*
 *   file name:  XeTeXFontInst.cpp
 *
 *   created on: 2005-10-22
 *   created by: Jonathan Kew
 *	
 *	originally based on PortableFontInstance.cpp from ICU
 */

#include "XeTeXFontInst.h"
#include "XeTeXLayoutInterface.h"
#include "XeTeXswap.h"

#ifdef XETEX_MAC
#include <Carbon/Carbon.h>
#endif

#include "XeTeX_ext.h"

#include "sfnt.h"

#include <string.h>


XeTeXFontInst::XeTeXFontInst(float pointSize, int &status)
    : fPointSize(pointSize)
    , fUnitsPerEM(0)
    , fAscent(0)
    , fDescent(0)
    , fItalicAngle(0)
    , fMetricsTable(NULL)
    , fNumLongMetrics(0)
    , fNumGlyphs(0)
    , fNumGlyphsInited(false)
    , fVertical(false)
    , fFilename(NULL)
    , hbFont(NULL)
{
	// the concrete subclass is responsible to call initialize()
}

XeTeXFontInst::~XeTeXFontInst()
{
	if (fMetricsTable != NULL)
		deleteTable(fMetricsTable);
}

void XeTeXFontInst::initialize(int &status)
{
    const HEADTable *headTable = NULL;
    const HHEATable *dirHeadTable = NULL;
    const POSTTable *postTable = NULL;

    // dispose of any cached metrics table
    if (fMetricsTable != NULL) {
	    deleteTable(fMetricsTable);
    	fMetricsTable = NULL;
    }
    
    // read unitsPerEm from 'head' table
    headTable = (const HEADTable *) readFontTable(kHEAD);

    if (headTable == NULL) {
        status = 1;
        goto error_exit;
    }

    fUnitsPerEM = SWAP(headTable->unitsPerEm);
    deleteTable(headTable);

	// we use the fact that 'hhea' and 'vhea' have the same format!
    dirHeadTable = (const HHEATable *) readFontTable(fVertical ? kVHEA : kHHEA);

    if (dirHeadTable == NULL) {
        status = 1;
        goto error_exit;
    }

    fAscent  = unitsToPoints((float)(int16_t)SWAP(dirHeadTable->ascent));
    fDescent = unitsToPoints((float)(int16_t)SWAP(dirHeadTable->descent));

    fNumLongMetrics = SWAP(dirHeadTable->numOfLongHorMetrics);

    deleteTable(dirHeadTable);

    postTable = (const POSTTable *) readFontTable(kPOST);

    if (postTable != NULL) {
		fItalicAngle = Fix2D(SWAP(UInt32(postTable->italicAngle)));
		deleteTable(postTable);
    }

    return;

error_exit:
    return;
}

void XeTeXFontInst::setLayoutDirVertical(bool vertical)
{
	fVertical = vertical;
	int	status = 0;
	initialize(status);
}

void XeTeXFontInst::deleteTable(const void *table) const
{
    free((void *) table);
}

const void *XeTeXFontInst::getFontTable(OTTag tableTag) const
{
    return FontTableCache::find(tableTag);
}

const void *XeTeXFontInst::getFontTable(OTTag tableTag, uint32_t *length) const
{
    return FontTableCache::find(tableTag, length);
}

const void *XeTeXFontInst::readFontTable(OTTag tableTag) const
{
    uint32_t len;

    return readTable(tableTag, &len);
}

const void *XeTeXFontInst::readFontTable(OTTag tableTag, uint32_t& len) const
{
    return readTable(tableTag, &len);
}

uint16_t XeTeXFontInst::getNumGlyphs() const
{
    if (!fNumGlyphsInited) {
        const MAXPTable *maxpTable = (MAXPTable *) readFontTable(kMAXP);

        if (maxpTable != NULL) {
			XeTeXFontInst *realThis = (XeTeXFontInst *) this;
            realThis->fNumGlyphs = SWAP(maxpTable->numGlyphs);
            deleteTable(maxpTable);
			realThis->fNumGlyphsInited = true;
		}
    }

	return fNumGlyphs;
}

void XeTeXFontInst::getGlyphAdvance(GlyphID glyph, realpoint &advance) const
{
    if (fMetricsTable == NULL) {
        XeTeXFontInst *realThis = (XeTeXFontInst *) this;
        // we use the fact that 'hmtx' and 'vmtx' have the same format
        realThis->fMetricsTable = (const HMTXTable *) readFontTable(fVertical ? kVMTX : kHMTX);
    }

    uint16_t index = glyph;

    if (glyph >= getNumGlyphs() || fMetricsTable == NULL) {
        advance.x = advance.y = 0;
        return;
    }

    if (glyph >= fNumLongMetrics) {
        index = fNumLongMetrics - 1;
    }

    advance.x = unitsToPoints(SWAP(fMetricsTable->hMetrics[index].advanceWidth));
    advance.y = 0;
}

float
XeTeXFontInst::getGlyphWidth(GlyphID gid)
{
	realpoint	advance;
	getGlyphAdvance(gid, advance);
	return advance.x;
}

void
XeTeXFontInst::getGlyphHeightDepth(GlyphID gid, float* ht, float* dp)
{
	GlyphBBox	bbox;
	getGlyphBounds(gid, &bbox);
	
	if (ht)
		*ht = bbox.yMax;
	if (dp)
		*dp = -bbox.yMin;
}

void
XeTeXFontInst::getGlyphSidebearings(GlyphID gid, float* lsb, float* rsb)
{
	realpoint	adv;
	getGlyphAdvance(gid, adv);

	GlyphBBox	bbox;
	getGlyphBounds(gid, &bbox);

	if (lsb)
		*lsb = bbox.xMin;
	if (rsb)
		*rsb = adv.x - bbox.xMax;
}

float
XeTeXFontInst::getGlyphItalCorr(GlyphID gid)
{
	float	rval = 0.0;

	realpoint	adv;
	getGlyphAdvance(gid, adv);

	GlyphBBox	bbox;
	getGlyphBounds(gid, &bbox);
	
	if (bbox.xMax > adv.x)
		rval = bbox.xMax - adv.x;
	
	return rval;
}

GlyphID
XeTeXFontInst::mapGlyphToIndex(const char* glyphName) const
	/* default implementation, may be overridden (e.g. by Freetype-based XeTeXFontInst_ */
{
    uint32_t	len;
    const char *p = (const char*)readFontTable(kPOST, len);
    if (p != NULL)
		return findGlyphInPostTable(p, len, glyphName);
	else
		return 0;
}

const char*
XeTeXFontInst::getGlyphName(GlyphID gid, int& nameLen)
{
    uint32_t	len;
    const char *p = (const char*)readFontTable(kPOST, len);
    if (p != NULL)
		return getGlyphNamePtr(p, len, gid, &nameLen);
	else
		return NULL;
}