FontInstance.cpp revision 74db6d40ffb3195ae8bb71a5b31642c06eccac6d
/*
* FontInstance.cpp
* testICU
*
* Authors:
* fred
* bulia byak <buliabyak@users.sf.net>
*
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#ifndef PANGO_ENABLE_ENGINE
#define PANGO_ENABLE_ENGINE
#endif
#include <ft2build.h>
#include FT_OUTLINE_H
#include FT_BBOX_H
#include FT_TRUETYPE_TAGS_H
#include FT_TRUETYPE_TABLES_H
#include FT_GLYPH_H
#include <pango/pangoft2.h>
#include <2geom/pathvector.h>
#include <2geom/path-sink.h>
#include "libnrtype/font-glyph.h"
#include "libnrtype/font-instance.h"
#include "livarot/Path.h"
#include "util/unordered-containers.h"
struct font_style_hash : public std::unary_function<font_style, size_t> {
size_t operator()(font_style const &x) const;
};
struct font_style_equal : public std::binary_function<font_style, font_style, bool> {
bool operator()(font_style const &a, font_style const &b) const;
};
static const double STROKE_WIDTH_THREASHOLD = 0.01;
size_t font_style_hash::operator()(const font_style &x) const {
int h = 0;
int n = static_cast<int>(floor(100 * x.stroke_width));
h *= 12186;
h += n;
n = (x.vertical) ? 1:0;
h *= 12186;
h += n;
if ( x.stroke_width >= STROKE_WIDTH_THREASHOLD ) {
n = x.stroke_cap * 10 + x.stroke_join + static_cast<int>(x.stroke_miter_limit * 100);
h *= 12186;
h += n;
if ( x.nbDash > 0 ) {
n = x.nbDash;
h *= 12186;
h += n;
n = static_cast<int>(floor(100 * x.dash_offset));
h *= 12186;
h += n;
for (int i = 0; i < x.nbDash; i++) {
n = static_cast<int>(floor(100 * x.dashes[i]));
h *= 12186;
h += n;
}
}
}
return h;
}
bool font_style_equal::operator()(const font_style &a,const font_style &b) const {
bool same = true;
for (int i = 0; (i < 6) && same; i++) {
same = ( static_cast<int>(100 * a.transform[i]) == static_cast<int>(100 * b.transform[i]) );
}
same &= ( a.vertical == b.vertical )
&& ( a.stroke_width > STROKE_WIDTH_THREASHOLD ) == ( b.stroke_width > STROKE_WIDTH_THREASHOLD );
if ( same && ( a.stroke_width > STROKE_WIDTH_THREASHOLD ) ) {
same = ( a.stroke_cap == b.stroke_cap )
&& ( a.stroke_join == b.stroke_join )
&& ( static_cast<int>(a.stroke_miter_limit * 100) == static_cast<int>(b.stroke_miter_limit * 100) )
&& ( a.nbDash == b.nbDash );
if ( same && ( a.nbDash > 0 ) ) {
same = ( static_cast<int>(floor(100 * a.dash_offset)) == static_cast<int>(floor(100 * b.dash_offset)) );
for (int i = 0; (i < a.nbDash) && same; i++) {
same = ( static_cast<int>(floor(100 * a.dashes[i])) == static_cast<int>(floor(100 * b.dashes[i])) );
}
}
}
return same;
}
#ifndef USE_PANGO_WIN32
/*
* Outline extraction
*/
struct FT2GeomData {
FT2GeomData(Geom::PathBuilder &b, double s)
: builder(b)
, last(0, 0)
, scale(s)
{}
Geom::PathBuilder &builder;
Geom::Point last;
double scale;
};
// Note: Freetype 2.2.1 redefined function signatures for functions to be placed in an
// FT_Outline_Funcs structure. This is needed to keep backwards compatibility with the
// 2.1.x series.
/* *** BEGIN #if HACK *** */
#if FREETYPE_MAJOR == 2 && FREETYPE_MINOR >= 2
typedef FT_Vector const FREETYPE_VECTOR;
#else
typedef FT_Vector FREETYPE_VECTOR;
#endif
// outline as returned by freetype -> livarot Path
// see nr-type-ft2.cpp for the freetype -> artBPath on which this code is based
static int ft2_move_to(FREETYPE_VECTOR *to, void * i_user)
{
FT2GeomData *user = (FT2GeomData*)i_user;
Geom::Point p(to->x, to->y);
// printf("m t=%f %f\n",p[0],p[1]);
user->builder.moveTo(p * user->scale);
user->last = p;
return 0;
}
static int ft2_line_to(FREETYPE_VECTOR *to, void *i_user)
{
FT2GeomData *user = (FT2GeomData*)i_user;
Geom::Point p(to->x, to->y);
// printf("l t=%f %f\n",p[0],p[1]);
user->builder.lineTo(p * user->scale);
user->last = p;
return 0;
}
static int ft2_conic_to(FREETYPE_VECTOR *control, FREETYPE_VECTOR *to, void *i_user)
{
FT2GeomData *user = (FT2GeomData*)i_user;
Geom::Point p(to->x, to->y), c(control->x, control->y);
user->builder.quadTo(c * user->scale, p * user->scale);
// printf("b c=%f %f t=%f %f\n",c[0],c[1],p[0],p[1]);
user->last = p;
return 0;
}
static int ft2_cubic_to(FREETYPE_VECTOR *control1, FREETYPE_VECTOR *control2, FREETYPE_VECTOR *to, void *i_user)
{
FT2GeomData *user = (FT2GeomData*)i_user;
Geom::Point p(to->x, to->y);
Geom::Point c1(control1->x, control1->y);
Geom::Point c2(control2->x, control2->y);
// printf("c c1=%f %f c2=%f %f t=%f %f\n",c1[0],c1[1],c2[0],c2[1],p[0],p[1]);
//user->theP->CubicTo(p,3*(c1-user->last),3*(p-c2));
user->builder.curveTo(c1 * user->scale, c2 * user->scale, p * user->scale);
user->last = p;
return 0;
}
#endif
/* *** END #if HACK *** */
/*
*
*/
font_instance::font_instance(void) :
pFont(0),
descr(0),
refCount(0),
parent(0),
nbGlyph(0),
maxGlyph(0),
glyphs(0),
theFace(0)
{
//printf("font instance born\n");
_ascent = _ascent_max = 0.8;
_descent = _descent_max = 0.2;
_xheight = 0.5;
// Default baseline values, alphabetic is reference
_baselines[ SP_CSS_BASELINE_AUTO ] = 0.0;
_baselines[ SP_CSS_BASELINE_ALPHABETIC ] = 0.0;
_baselines[ SP_CSS_BASELINE_IDEOGRAPHIC ] = -_descent;
_baselines[ SP_CSS_BASELINE_HANGING ] = 0.8 * _ascent;
_baselines[ SP_CSS_BASELINE_MATHEMATICAL ] = 0.8 * _xheight;
_baselines[ SP_CSS_BASELINE_CENTRAL ] = 0.5 - _descent;
_baselines[ SP_CSS_BASELINE_MIDDLE ] = 0.5 * _xheight;
_baselines[ SP_CSS_BASELINE_TEXT_BEFORE_EDGE ] = _ascent;
_baselines[ SP_CSS_BASELINE_TEXT_AFTER_EDGE ] = -_descent;
}
font_instance::~font_instance(void)
{
if ( parent ) {
parent->UnrefFace(this);
parent = 0;
}
//printf("font instance death\n");
if ( pFont ) {
FreeTheFace();
g_object_unref(pFont);
pFont = 0;
}
if ( descr ) {
pango_font_description_free(descr);
descr = 0;
}
// if ( theFace ) FT_Done_Face(theFace); // owned by pFont. don't touch
theFace = 0;
for (int i=0;i<nbGlyph;i++) {
if ( glyphs[i].pathvector ) {
delete glyphs[i].pathvector;
}
}
if ( glyphs ) {
free(glyphs);
glyphs = 0;
}
nbGlyph = 0;
maxGlyph = 0;
}
void font_instance::Ref(void)
{
refCount++;
//char *tc=pango_font_description_to_string(descr);
//printf("font %x %s ref'd %i\n",this,tc,refCount);
//free(tc);
}
void font_instance::Unref(void)
{
refCount--;
//char *tc=pango_font_description_to_string(descr);
//printf("font %x %s unref'd %i\n",this,tc,refCount);
//free(tc);
if ( refCount <= 0 ) {
delete this;
}
}
void font_instance::InitTheFace()
{
if (theFace == NULL && pFont != NULL) {
#ifdef USE_PANGO_WIN32
if ( !theFace ) {
LOGFONT *lf=pango_win32_font_logfont(pFont);
g_assert(lf != NULL);
theFace=pango_win32_font_cache_load(parent->pangoFontCache,lf);
g_free(lf);
}
XFORM identity = {1.0, 0.0, 0.0, 1.0, 0.0, 0.0};
SetWorldTransform(parent->hScreenDC, &identity);
SetGraphicsMode(parent->hScreenDC, GM_COMPATIBLE);
SelectObject(parent->hScreenDC,theFace);
#else
theFace=pango_fc_font_lock_face(PANGO_FC_FONT(pFont));
if ( theFace ) {
FT_Select_Charmap(theFace,ft_encoding_unicode) && FT_Select_Charmap(theFace,ft_encoding_symbol);
}
#endif
FindFontMetrics();
}
}
void font_instance::FreeTheFace()
{
#ifdef USE_PANGO_WIN32
SelectObject(parent->hScreenDC,GetStockObject(SYSTEM_FONT));
pango_win32_font_cache_unload(parent->pangoFontCache,theFace);
#else
pango_fc_font_unlock_face(PANGO_FC_FONT(pFont));
#endif
theFace=NULL;
}
void font_instance::InstallFace(PangoFont* iFace)
{
if ( !iFace ) {
return;
}
pFont=iFace;
iFace = NULL;
InitTheFace();
if ( pFont && IsOutlineFont() == false ) {
FreeTheFace();
if ( pFont ) {
g_object_unref(pFont);
}
pFont=NULL;
}
}
bool font_instance::IsOutlineFont(void)
{
if ( pFont == NULL ) {
return false;
}
InitTheFace();
#ifdef USE_PANGO_WIN32
TEXTMETRIC tm;
return GetTextMetrics(parent->hScreenDC,&tm) && tm.tmPitchAndFamily&(TMPF_TRUETYPE|TMPF_DEVICE);
#else
return FT_IS_SCALABLE(theFace);
#endif
}
int font_instance::MapUnicodeChar(gunichar c)
{
int res = 0;
if ( pFont ) {
#ifdef USE_PANGO_WIN32
res = pango_win32_font_get_glyph_index(pFont, c);
#else
theFace = pango_fc_font_lock_face(PANGO_FC_FONT(pFont));
if ( c > 0xf0000 ) {
res = CLAMP(c, 0xf0000, 0x1fffff) - 0xf0000;
} else {
res = FT_Get_Char_Index(theFace, c);
}
pango_fc_font_unlock_face(PANGO_FC_FONT(pFont));
#endif
}
return res;
}
#ifdef USE_PANGO_WIN32
static inline Geom::Point pointfx_to_nrpoint(const POINTFX &p, double scale)
{
return Geom::Point(*(long*)&p.x / 65536.0 * scale,
*(long*)&p.y / 65536.0 * scale);
}
#endif
void font_instance::LoadGlyph(int glyph_id)
{
if ( pFont == NULL ) {
return;
}
InitTheFace();
#ifndef USE_PANGO_WIN32
if ( !FT_IS_SCALABLE(theFace) ) {
return; // bitmap font
}
#endif
if ( id_to_no.find(glyph_id) == id_to_no.end() ) {
Geom::PathBuilder path_builder;
if ( nbGlyph >= maxGlyph ) {
maxGlyph=2*nbGlyph+1;
glyphs=(font_glyph*)realloc(glyphs,maxGlyph*sizeof(font_glyph));
}
font_glyph n_g;
n_g.pathvector=NULL;
n_g.bbox[0]=n_g.bbox[1]=n_g.bbox[2]=n_g.bbox[3]=0;
n_g.h_advance = 0;
n_g.v_advance = 0;
n_g.h_width = 0;
n_g.v_width = 0;
bool doAdd=false;
#ifdef USE_PANGO_WIN32
#ifndef GGO_UNHINTED // For compatibility with old SDKs.
#define GGO_UNHINTED 0x0100
#endif
MAT2 identity = {{0,1},{0,0},{0,0},{0,1}};
OUTLINETEXTMETRIC otm;
GetOutlineTextMetrics(parent->hScreenDC, sizeof(otm), &otm);
GLYPHMETRICS metrics;
DWORD bufferSize=GetGlyphOutline (parent->hScreenDC, glyph_id, GGO_GLYPH_INDEX | GGO_NATIVE | GGO_UNHINTED, &metrics, 0, NULL, &identity);
double scale=1.0/parent->fontSize;
n_g.h_advance = metrics.gmCellIncX * scale;
n_g.v_advance = otm.otmTextMetrics.tmHeight * scale;
n_g.h_width = metrics.gmBlackBoxX * scale;
n_g.v_width = metrics.gmBlackBoxY * scale;
if ( bufferSize == GDI_ERROR) {
// shit happened
} else if ( bufferSize == 0) {
// character has no visual representation, but is valid (eg whitespace)
doAdd=true;
} else {
char *buffer = new char[bufferSize];
if ( GetGlyphOutline (parent->hScreenDC, glyph_id, GGO_GLYPH_INDEX | GGO_NATIVE | GGO_UNHINTED, &metrics, bufferSize, buffer, &identity) <= 0 ) {
// shit happened
} else {
// Platform SDK is rubbish, read KB87115 instead
DWORD polyOffset=0;
while ( polyOffset < bufferSize ) {
TTPOLYGONHEADER const *polyHeader=(TTPOLYGONHEADER const *)(buffer+polyOffset);
if (polyOffset+polyHeader->cb > bufferSize) break;
if (polyHeader->dwType == TT_POLYGON_TYPE) {
path_builder.moveTo(pointfx_to_nrpoint(polyHeader->pfxStart, scale));
DWORD curveOffset=polyOffset+sizeof(TTPOLYGONHEADER);
while ( curveOffset < polyOffset+polyHeader->cb ) {
TTPOLYCURVE const *polyCurve=(TTPOLYCURVE const *)(buffer+curveOffset);
POINTFX const *p=polyCurve->apfx;
POINTFX const *endp=p+polyCurve->cpfx;
switch (polyCurve->wType) {
case TT_PRIM_LINE:
while ( p != endp )
path_builder.lineTo(pointfx_to_nrpoint(*p++, scale));
break;
case TT_PRIM_QSPLINE:
{
g_assert(polyCurve->cpfx >= 2);
// The list of points specifies one or more control points and ends with the end point.
// The intermediate points (on the curve) are the points between the control points.
Geom::Point this_control = pointfx_to_nrpoint(*p++, scale);
while ( p+1 != endp ) { // Process all "midpoints" (all points except the last)
Geom::Point new_control = pointfx_to_nrpoint(*p++, scale);
path_builder.quadTo(this_control, (new_control+this_control)/2);
this_control = new_control;
}
Geom::Point end = pointfx_to_nrpoint(*p++, scale);
path_builder.quadTo(this_control, end);
}
break;
case 3: // TT_PRIM_CSPLINE
g_assert(polyCurve->cpfx % 3 == 0);
while ( p != endp ) {
path_builder.curveTo(pointfx_to_nrpoint(p[0], scale),
pointfx_to_nrpoint(p[1], scale),
pointfx_to_nrpoint(p[2], scale));
p += 3;
}
break;
}
curveOffset += sizeof(TTPOLYCURVE)+sizeof(POINTFX)*(polyCurve->cpfx-1);
}
}
polyOffset += polyHeader->cb;
}
doAdd=true;
}
delete [] buffer;
}
#else
if (FT_Load_Glyph (theFace, glyph_id, FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING | FT_LOAD_NO_BITMAP)) {
// shit happened
} else {
if ( FT_HAS_HORIZONTAL(theFace) ) {
n_g.h_advance=((double)theFace->glyph->metrics.horiAdvance)/((double)theFace->units_per_EM);
n_g.h_width=((double)theFace->glyph->metrics.width)/((double)theFace->units_per_EM);
} else {
n_g.h_width=n_g.h_advance=((double)(theFace->bbox.xMax-theFace->bbox.xMin))/((double)theFace->units_per_EM);
}
if ( FT_HAS_VERTICAL(theFace) ) {
n_g.v_advance=((double)theFace->glyph->metrics.vertAdvance)/((double)theFace->units_per_EM);
n_g.v_width=((double)theFace->glyph->metrics.height)/((double)theFace->units_per_EM);
} else {
// CSS3 Writing modes dictates that if vertical font metrics are missing we must
// synthisize them. No method is specified. The SVG 1.1 spec suggests using the em
// height (which is not theFace->height as that includes leading). The em height
// is ascender + descender (descender positive). Note: The "Requirements for
// Japanese Text Layout" W3C document says that Japanese kanji should be "set
// solid" which implies that vertical (and horizontal) advance should be 1em.
n_g.v_width=n_g.v_advance= 1.0;
}
if ( theFace->glyph->format == ft_glyph_format_outline ) {
FT_Outline_Funcs ft2_outline_funcs = {
ft2_move_to,
ft2_line_to,
ft2_conic_to,
ft2_cubic_to,
0, 0
};
FT2GeomData user(path_builder, 1.0/((double)theFace->units_per_EM));
FT_Outline_Decompose (&theFace->glyph->outline, &ft2_outline_funcs, &user);
}
doAdd=true;
}
#endif
path_builder.flush();
if ( doAdd ) {
Geom::PathVector pv = path_builder.peek();
// close all paths
for (Geom::PathVector::iterator i = pv.begin(); i != pv.end(); ++i) {
i->close();
}
if ( !pv.empty() ) {
n_g.pathvector = new Geom::PathVector(pv);
Geom::OptRect bounds = bounds_exact(*n_g.pathvector);
if (bounds) {
n_g.bbox[0] = bounds->left();
n_g.bbox[1] = bounds->top();
n_g.bbox[2] = bounds->right();
n_g.bbox[3] = bounds->bottom();
}
}
glyphs[nbGlyph]=n_g;
id_to_no[glyph_id]=nbGlyph;
nbGlyph++;
}
} else {
}
}
bool font_instance::FontMetrics(double &ascent,double &descent,double &xheight)
{
if ( pFont == NULL ) {
return false;
}
InitTheFace();
if ( theFace == NULL ) {
return false;
}
ascent = _ascent;
descent = _descent;
xheight = _xheight;
return true;
}
bool font_instance::FontDecoration( double &underline_position, double &underline_thickness,
double &linethrough_position, double &linethrough_thickness)
{
if ( pFont == NULL ) {
return false;
}
InitTheFace();
if ( theFace == NULL ) {
return false;
}
#ifdef USE_PANGO_WIN32
OUTLINETEXTMETRIC otm;
if ( !GetOutlineTextMetrics(parent->hScreenDC,sizeof(otm),&otm) ) {
return false;
}
double scale=1.0/parent->fontSize;
underline_position = fabs(otm.otmUnderscorePosition *scale);
underline_thickness = fabs(otm.otmUnderscoreSize *scale);
linethrough_position = fabs(otm.otmStrikeoutPosition *scale);
linethrough_thickness = fabs(otm.otmStrikeoutSize *scale);
#else
if ( theFace->units_per_EM == 0 ) {
return false; // bitmap font
}
underline_position = fabs(((double)theFace->underline_position )/((double)theFace->units_per_EM));
underline_thickness = fabs(((double)theFace->underline_thickness)/((double)theFace->units_per_EM));
// there is no specific linethrough information, mock it up from other font fields
linethrough_position = fabs(((double)theFace->ascender / 3.0 )/((double)theFace->units_per_EM));
linethrough_thickness = fabs(((double)theFace->underline_thickness)/((double)theFace->units_per_EM));
#endif
return true;
}
bool font_instance::FontSlope(double &run, double &rise)
{
run = 0.0;
rise = 1.0;
if ( pFont == NULL ) {
return false;
}
InitTheFace();
if ( theFace == NULL ) {
return false;
}
#ifdef USE_PANGO_WIN32
OUTLINETEXTMETRIC otm;
if ( !GetOutlineTextMetrics(parent->hScreenDC,sizeof(otm),&otm) ) return false;
run=otm.otmsCharSlopeRun;
rise=otm.otmsCharSlopeRise;
#else
if ( !FT_IS_SCALABLE(theFace) ) {
return false; // bitmap font
}
TT_HoriHeader *hhea = (TT_HoriHeader*)FT_Get_Sfnt_Table(theFace, ft_sfnt_hhea);
if (hhea == NULL) {
return false;
}
run = hhea->caret_Slope_Run;
rise = hhea->caret_Slope_Rise;
#endif
return true;
}
Geom::OptRect font_instance::BBox(int glyph_id)
{
int no = -1;
if ( id_to_no.find(glyph_id) == id_to_no.end() ) {
LoadGlyph(glyph_id);
if ( id_to_no.find(glyph_id) == id_to_no.end() ) {
// didn't load
} else {
no = id_to_no[glyph_id];
}
} else {
no = id_to_no[glyph_id];
}
if ( no < 0 ) {
return Geom::OptRect();
} else {
Geom::Point rmin(glyphs[no].bbox[0],glyphs[no].bbox[1]);
Geom::Point rmax(glyphs[no].bbox[2],glyphs[no].bbox[3]);
return Geom::Rect(rmin, rmax);
}
}
Geom::PathVector* font_instance::PathVector(int glyph_id)
{
int no = -1;
if ( id_to_no.find(glyph_id) == id_to_no.end() ) {
LoadGlyph(glyph_id);
if ( id_to_no.find(glyph_id) == id_to_no.end() ) {
// didn't load
} else {
no = id_to_no[glyph_id];
}
} else {
no = id_to_no[glyph_id];
}
if ( no < 0 ) return NULL;
return glyphs[no].pathvector;
}
double font_instance::Advance(int glyph_id,bool vertical)
{
int no = -1;
if ( id_to_no.find(glyph_id) == id_to_no.end() ) {
LoadGlyph(glyph_id);
if ( id_to_no.find(glyph_id) == id_to_no.end() ) {
// didn't load
} else {
no=id_to_no[glyph_id];
}
} else {
no = id_to_no[glyph_id];
}
if ( no >= 0 ) {
if ( vertical ) {
return glyphs[no].v_advance;
} else {
return glyphs[no].h_advance;
}
}
return 0;
}
// Internal function to find baselines
void font_instance::FindFontMetrics() {
// CSS2 recommends using the OS/2 values sTypoAscender and sTypoDescender for the Typographic
// ascender and descender values:
// http://www.w3.org/TR/CSS2/visudet.html#sTypoAscender
// On Windows, the typographic ascender and descender are taken from the otmMacAscent and
// otmMacDescent values:
// http://microsoft.public.win32.programmer.gdi.narkive.com/LV6k4BDh/msdn-documentation-outlinetextmetrics-clarification
// The otmAscent and otmDescent values are the maxiumum ascent and maxiumum descent of all the
// glyphs in a font.
if ( theFace ) {
#ifdef USE_PANGO_WIN32
if ( GetOutlineTextMetrics(parent->hScreenDC,sizeof(otm),&otm) ) {
double scale=1.0/parent->fontSize;
_ascent = fabs(otm.otmMacAscent * scale);
_descent = fabs(otm.otmMacDescent * scale);
_xheight = fabs(otm.otmXHeight * scale);
_ascent_max = fabs(otm.otmAscent * scale);
_descent_max = fabs(otm.otmDescent * scale);
// In CSS em size is ascent + descent... which should be 1. If not,
// adjust so it is.
double em = _ascent + _descent;
if( em > 0 ) {
_ascent /= em;
_descent /= em;
}
// May not be necessary but if OS/2 table missing or not version 2 or higher,
// xheight might be zero.
if( _xheight == 0.0 ) {
_xheight = 0.5;
}
// Baselines defined relative to alphabetic.
_baselines[ SP_CSS_BASELINE_IDEOGRAPHIC ] = -_descent; // Recommendation
_baselines[ SP_CSS_BASELINE_HANGING ] = 0.8 * _ascent; // Guess
_baselines[ SP_CSS_BASELINE_MATHEMATICAL ] = 0.8 * _xheight; // Guess
_baselines[ SP_CSS_BASELINE_CENTRAL ] = 0.5 - _descent; // Definition
_baselines[ SP_CSS_BASELINE_MIDDLE ] = 0.5 * _xheight; // Definition
_baselines[ SP_CSS_BASELINE_TEXT_BEFORE_EDGE ] = _ascent; // Definition
_baselines[ SP_CSS_BASELINE_TEXT_AFTER_EDGE ] = -_descent; // Definition
MAT2 identity = {{0,1},{0,0},{0,0},{0,1}};
GLYPHMETRICS metrics;
int retval;
// Better math baseline:
// Try center of minus sign
retval = GetGlyphOutline (parent->hScreenDC, 0x2212, GGO_NATIVE | GGO_UNHINTED, &metrics, 0, NULL, &identity);
// If no minus sign, try hyphen
if( retval <= 0 )
retval = GetGlyphOutline (parent->hScreenDC, '-', GGO_NATIVE | GGO_UNHINTED, &metrics, 0, NULL, &identity);
if( retval > 0 ) {
double math = (metrics.gmptGlyphOrigin.y + 0.5 * metrics.gmBlackBoxY) * scale;
_baselines[ SP_CSS_BASELINE_MATHEMATICAL ] = math;
}
// Find hanging baseline... assume it is at top of 'म'.
retval = GetGlyphOutline (parent->hScreenDC, 0x092E, GGO_NATIVE | GGO_UNHINTED, &metrics, 0, NULL, &identity);
if( retval > 0 ) {
double hanging = metrics.gmptGlyphOrigin.y * scale;
_baselines[ SP_CSS_BASELINE_MATHEMATICAL ] = hanging;
}
}
#else
if ( theFace->units_per_EM != 0 ) { // If zero then it's a bitmap font.
TT_OS2* os2 = (TT_OS2*)FT_Get_Sfnt_Table( theFace, ft_sfnt_os2 );
if( os2 ) {
_ascent = fabs(((double)os2->sTypoAscender) / ((double)theFace->units_per_EM));
_descent = fabs(((double)os2->sTypoDescender)/ ((double)theFace->units_per_EM));
} else {
_ascent = fabs(((double)theFace->ascender) / ((double)theFace->units_per_EM));
_descent = fabs(((double)theFace->descender) / ((double)theFace->units_per_EM));
}
_ascent_max = fabs(((double)theFace->ascender) / ((double)theFace->units_per_EM));
_descent_max = fabs(((double)theFace->descender) / ((double)theFace->units_per_EM));
// In CSS em size is ascent + descent... which should be 1. If not,
// adjust so it is.
double em = _ascent + _descent;
if( em > 0 ) {
_ascent /= em;
_descent /= em;
}
// x-height
if( os2 && os2->version >= 0x0002 && os2->version != 0xffffu ) {
// Only os/2 version 2 and above have sxHeight, 0xffff marks "old Mac fonts" without table
_xheight = fabs(((double)os2->sxHeight) / ((double)theFace->units_per_EM));
} else {
// Measure 'x' height in font. Recommended option by XSL standard if no sxHeight.
FT_UInt index = FT_Get_Char_Index( theFace, 'x' );
if( index != 0 ) {
FT_Load_Glyph( theFace, index, FT_LOAD_NO_SCALE );
_xheight = (fabs)(((double)theFace->glyph->metrics.height/(double)theFace->units_per_EM));
} else {
// No 'x' in font!
_xheight = 0.5;
}
}
// Baselines defined relative to alphabetic.
_baselines[ SP_CSS_BASELINE_IDEOGRAPHIC ] = -_descent; // Recommendation
_baselines[ SP_CSS_BASELINE_HANGING ] = 0.8 * _ascent; // Guess
_baselines[ SP_CSS_BASELINE_MATHEMATICAL ] = 0.8 * _xheight; // Guess
_baselines[ SP_CSS_BASELINE_CENTRAL ] = 0.5 - _descent; // Definition
_baselines[ SP_CSS_BASELINE_MIDDLE ] = 0.5 * _xheight; // Definition
_baselines[ SP_CSS_BASELINE_TEXT_BEFORE_EDGE ] = _ascent; // Definition
_baselines[ SP_CSS_BASELINE_TEXT_AFTER_EDGE ] = -_descent; // Definition
// Better math baseline:
// Try center of minus sign
FT_UInt index = FT_Get_Char_Index( theFace, 0x2212 ); //'−'
// If no minus sign, try hyphen
if( index == 0 )
index = FT_Get_Char_Index( theFace, '-' );
if( index != 0 ) {
FT_Load_Glyph( theFace, index, FT_LOAD_NO_SCALE );
FT_Glyph aglyph;
FT_Get_Glyph( theFace->glyph, &aglyph );
FT_BBox acbox;
FT_Glyph_Get_CBox( aglyph, FT_GLYPH_BBOX_UNSCALED, &acbox );
double math = (acbox.yMin + acbox.yMax)/2.0/(double)theFace->units_per_EM;
_baselines[ SP_CSS_BASELINE_MATHEMATICAL ] = math;
// std::cout << "Math baseline: - bbox: y_min: " << acbox.yMin
// << " y_max: " << acbox.yMax
// << " math: " << math << std::endl;
}
// Find hanging baseline... assume it is at top of 'म'.
index = FT_Get_Char_Index( theFace, 0x092E ); // 'म'
if( index != 0 ) {
FT_Load_Glyph( theFace, index, FT_LOAD_NO_SCALE );
FT_Glyph aglyph;
FT_Get_Glyph( theFace->glyph, &aglyph );
FT_BBox acbox;
FT_Glyph_Get_CBox( aglyph, FT_GLYPH_BBOX_UNSCALED, &acbox );
double hanging = (double)acbox.yMax/(double)theFace->units_per_EM;
_baselines[ SP_CSS_BASELINE_HANGING ] = hanging;
// std::cout << "Hanging baseline: प: " << hanging << std::endl;
}
}
#endif
// const gchar *family = pango_font_description_get_family(descr);
// std::cout << "Font: " << (family?family:"null") << std::endl;
// std::cout << " ascent: " << _ascent << std::endl;
// std::cout << " descent: " << _descent << std::endl;
// std::cout << " x-height: " << _xheight << std::endl;
// std::cout << " max ascent: " << _ascent_max << std::endl;
// std::cout << " max descent: " << _descent_max << std::endl;
// std::cout << " Baselines:" << std::endl;
// std::cout << " alphabetic: " << _baselines[ SP_CSS_BASELINE_ALPHABETIC ] << std::endl;
// std::cout << " ideographic: " << _baselines[ SP_CSS_BASELINE_IDEOGRAPHIC ] << std::endl;
// std::cout << " hanging: " << _baselines[ SP_CSS_BASELINE_HANGING ] << std::endl;
// std::cout << " math: " << _baselines[ SP_CSS_BASELINE_MATHEMATICAL ] << std::endl;
// std::cout << " central: " << _baselines[ SP_CSS_BASELINE_CENTRAL ] << std::endl;
// std::cout << " middle: " << _baselines[ SP_CSS_BASELINE_MIDDLE ] << std::endl;
// std::cout << " text_before: " << _baselines[ SP_CSS_BASELINE_TEXT_BEFORE_EDGE ] << std::endl;
// std::cout << " text_after: " << _baselines[ SP_CSS_BASELINE_TEXT_AFTER_EDGE ] << std::endl;
}
}
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
indent-tabs-mode:nil
fill-column:99
End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :