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pjs/gfx/thebes/gfxOS2Fonts.cpp

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/* vim: set sw=4 sts=4 et cin: */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is OS/2 code in Thebes.
*
* The Initial Developer of the Original Code is
* Peter Weilbacher <mozilla@Weilbacher.org>.
* Portions created by the Initial Developer are Copyright (C) 2006-2007
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* authors of code taken from gfxPangoFonts:
* Mozilla Foundation
* Vladimir Vukicevic <vladimir@mozilla.com>
* Masayuki Nakano <masayuki@d-toybox.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "gfxContext.h"
#include "gfxOS2Platform.h"
#include "gfxOS2Surface.h"
#include "gfxOS2Fonts.h"
#include "nsTArray.h"
#include "gfxAtoms.h"
#include "nsIPlatformCharset.h"
#include "mozilla/Preferences.h"
using namespace mozilla;
/**********************************************************************
* class gfxOS2Font
**********************************************************************/
gfxOS2Font::gfxOS2Font(gfxOS2FontEntry *aFontEntry, const gfxFontStyle *aFontStyle)
: gfxFont(aFontEntry, aFontStyle),
mFontFace(nsnull), mScaledFont(nsnull),
mMetrics(nsnull), mAdjustedSize(0),
mHinting(FC_HINT_MEDIUM), mAntialias(FcTrue)
{
#ifdef DEBUG_thebes_2
printf("gfxOS2Font[%p]::gfxOS2Font(%p \"%s\", aFontStyle)\n",
(void *)this, (void *)aFontEntry,
NS_LossyConvertUTF16toASCII(aFontEntry->Name()).get());
#endif
// try to get the preferences for hinting, antialias, and embolden options
PRInt32 value;
nsresult rv = Preferences::GetInt("gfx.os2.font.hinting", &value);
if (NS_SUCCEEDED(rv) && value >= FC_HINT_NONE && value <= FC_HINT_FULL) {
mHinting = value;
}
mAntialias = Preferences::GetBool("gfx.os2.font.antialiasing", mAntialias);
#ifdef DEBUG_thebes_2
printf(" font display options: hinting=%d, antialiasing=%s\n",
mHinting, mAntialias ? "on" : "off");
#endif
}
gfxOS2Font::~gfxOS2Font()
{
#ifdef DEBUG_thebes_2
printf("gfxOS2Font[%#x]::~gfxOS2Font()\n", (unsigned)this);
#endif
if (mFontFace) {
cairo_font_face_destroy(mFontFace);
}
if (mScaledFont) {
cairo_scaled_font_destroy(mScaledFont);
}
delete mMetrics;
mFontFace = nsnull;
mScaledFont = nsnull;
mMetrics = nsnull;
}
// fill font metrics structure with default values in case of error
static void FillMetricsDefaults(gfxFont::Metrics *aMetrics)
{
aMetrics->emAscent = 0.8 * aMetrics->emHeight;
aMetrics->emDescent = 0.2 * aMetrics->emHeight;
aMetrics->maxAscent = aMetrics->emAscent;
aMetrics->maxDescent = aMetrics->maxDescent;
aMetrics->maxHeight = aMetrics->emHeight;
aMetrics->internalLeading = 0.0;
aMetrics->externalLeading = 0.2 * aMetrics->emHeight;
aMetrics->spaceWidth = 0.5 * aMetrics->emHeight;
aMetrics->maxAdvance = aMetrics->spaceWidth;
aMetrics->aveCharWidth = aMetrics->spaceWidth;
aMetrics->zeroOrAveCharWidth = aMetrics->spaceWidth;
aMetrics->xHeight = 0.5 * aMetrics->emHeight;
aMetrics->underlineSize = aMetrics->emHeight / 14.0;
aMetrics->underlineOffset = -aMetrics->underlineSize;
aMetrics->strikeoutOffset = 0.25 * aMetrics->emHeight;
aMetrics->strikeoutSize = aMetrics->underlineSize;
aMetrics->superscriptOffset = aMetrics->xHeight;
aMetrics->subscriptOffset = aMetrics->xHeight;
}
// Snap a line to pixels while keeping the center and size of the
// line as close to the original position as possible.
static void SnapLineToPixels(gfxFloat& aOffset, gfxFloat& aSize)
{
gfxFloat snappedSize = NS_MAX(floor(aSize + 0.5), 1.0);
// Correct offset for change in size
gfxFloat offset = aOffset - 0.5 * (aSize - snappedSize);
// Snap offset
aOffset = floor(offset + 0.5);
aSize = snappedSize;
}
// gfxOS2Font::GetMetrics()
// return the metrics of the current font using the gfxFont metrics structure.
// If the metrics are not available yet, compute them using the FreeType
// function on the font. (This is partly based on the respective function from
// gfxPangoFonts)
const gfxFont::Metrics& gfxOS2Font::GetMetrics()
{
#ifdef DEBUG_thebes_1
printf("gfxOS2Font[%#x]::GetMetrics()\n", (unsigned)this);
#endif
if (mMetrics) {
return *mMetrics;
}
// whatever happens below, we can always create the metrics
mMetrics = new gfxFont::Metrics;
mSpaceGlyph = 0;
// round size to integer pixels, this is to get full pixels for layout
// together with internal/external leading (see below)
mMetrics->emHeight = floor(GetStyle()->size + 0.5);
cairo_scaled_font_t* scaledFont = CairoScaledFont();
if (!scaledFont) {
FillMetricsDefaults(mMetrics);
return *mMetrics;
}
FT_Face face = cairo_ft_scaled_font_lock_face(scaledFont);
if (!face) {
// Abort here already, otherwise we crash in the following
// this can happen if the font-size requested is zero.
FillMetricsDefaults(mMetrics);
return *mMetrics;
}
if (!face->charmap) {
// Also abort, if the charmap isn't loaded; then the char
// lookups won't work. This happens for fonts without Unicode
// charmap.
cairo_ft_scaled_font_unlock_face(scaledFont);
FillMetricsDefaults(mMetrics);
return *mMetrics;
}
// compute font scaling factors
gfxFloat emUnit = 1.0 * face->units_per_EM;
gfxFloat xScale = face->size->metrics.x_ppem / emUnit;
gfxFloat yScale = face->size->metrics.y_ppem / emUnit;
FT_UInt gid; // glyph ID
// properties of space
gid = FT_Get_Char_Index(face, ' ');
if (gid) {
// Load glyph into glyph slot. Use load_default here to get results in
// 26.6 fractional pixel format which is what is used for all other
// characters in gfxOS2FontGroup::CreateGlyphRunsFT.
FT_Load_Glyph(face, gid, FT_LOAD_DEFAULT);
// glyph width doesn't work for spaces, use advance instead
mMetrics->spaceWidth = face->glyph->advance.x >> 6;
// save the space glyph
mSpaceGlyph = gid;
} else {
NS_ASSERTION(gid, "this font doesn't have a space glyph!");
mMetrics->spaceWidth = face->max_advance_width * xScale;
}
// properties of 'x', also use its width as average width
gid = FT_Get_Char_Index(face, 'x'); // select the glyph
if (gid) {
// Load glyph into glyph slot. Here, use no_scale to get font units.
FT_Load_Glyph(face, gid, FT_LOAD_NO_SCALE);
mMetrics->xHeight = face->glyph->metrics.height * yScale;
mMetrics->aveCharWidth = face->glyph->metrics.horiAdvance * xScale;
} else {
// this font doesn't have an 'x'...
// fake these metrics using a fraction of the font size
mMetrics->xHeight = mMetrics->emHeight * 0.5;
mMetrics->aveCharWidth = mMetrics->emHeight * 0.5;
}
// properties of '0', for 'ch' units
gid = FT_Get_Char_Index(face, '0');
if (gid) {
FT_Load_Glyph(face, gid, FT_LOAD_NO_SCALE);
mMetrics->zeroOrAveCharWidth = face->glyph->metrics.horiAdvance * xScale;
} else {
// this font doesn't have a '0'
mMetrics->zeroOrAveCharWidth = mMetrics->aveCharWidth;
}
// compute an adjusted size if we need to
if (mAdjustedSize == 0 && GetStyle()->sizeAdjust != 0) {
gfxFloat aspect = mMetrics->xHeight / GetStyle()->size;
mAdjustedSize = GetStyle()->GetAdjustedSize(aspect);
mMetrics->emHeight = mAdjustedSize;
}
// now load the OS/2 TrueType table to access some more properties
TT_OS2 *os2 = (TT_OS2 *)FT_Get_Sfnt_Table(face, ft_sfnt_os2);
if (os2 && os2->version != 0xFFFF) { // should be there if not old Mac font
// if we are here we can improve the avgCharWidth
mMetrics->aveCharWidth = NS_MAX(mMetrics->aveCharWidth,
os2->xAvgCharWidth * xScale);
mMetrics->superscriptOffset = NS_MAX(os2->ySuperscriptYOffset * yScale, 1.0);
// some fonts have the incorrect sign (from gfxPangoFonts)
mMetrics->subscriptOffset = NS_MAX(fabs(os2->ySubscriptYOffset * yScale),
1.0);
mMetrics->strikeoutOffset = os2->yStrikeoutPosition * yScale;
mMetrics->strikeoutSize = os2->yStrikeoutSize * yScale;
} else {
// use fractions of emHeight instead of xHeight for these to be more robust
mMetrics->superscriptOffset = mMetrics->emHeight * 0.5;
mMetrics->subscriptOffset = mMetrics->emHeight * 0.2;
mMetrics->strikeoutOffset = mMetrics->emHeight * 0.3;
mMetrics->strikeoutSize = face->underline_thickness * yScale;
}
SnapLineToPixels(mMetrics->strikeoutOffset, mMetrics->strikeoutSize);
// seems that underlineOffset really has to be negative
mMetrics->underlineOffset = face->underline_position * yScale;
mMetrics->underlineSize = face->underline_thickness * yScale;
// descents are negative in FT but Thebes wants them positive
mMetrics->emAscent = face->ascender * yScale;
mMetrics->emDescent = -face->descender * yScale;
mMetrics->maxHeight = face->height * yScale;
// the max units determine frame heights, better be generous
mMetrics->maxAscent = NS_MAX(face->bbox.yMax * yScale,
mMetrics->emAscent);
mMetrics->maxDescent = NS_MAX(-face->bbox.yMin * yScale,
mMetrics->emDescent);
mMetrics->maxAdvance = NS_MAX(face->max_advance_width * xScale,
mMetrics->aveCharWidth);
// leadings are not available directly (only for WinFNTs);
// better compute them on our own, to get integer values and make
// layout happy (see // LockedFTFace::GetMetrics in gfxPangoFonts.cpp)
mMetrics->internalLeading = floor(mMetrics->maxHeight
- mMetrics->emHeight + 0.5);
gfxFloat lineHeight = floor(mMetrics->maxHeight + 0.5);
mMetrics->externalLeading = lineHeight
- mMetrics->internalLeading - mMetrics->emHeight;
SanitizeMetrics(mMetrics, PR_FALSE);
#ifdef DEBUG_thebes_1
printf("gfxOS2Font[%#x]::GetMetrics():\n"
" %s (%s)\n"
" emHeight=%f == %f=gfxFont::style.size == %f=adjSz\n"
" maxHeight=%f xHeight=%f\n"
" aveCharWidth=%f(x) zeroOrAveWidth=%f(0) spaceWidth=%f\n"
" supOff=%f SubOff=%f strOff=%f strSz=%f\n"
" undOff=%f undSz=%f intLead=%f extLead=%f\n"
" emAsc=%f emDesc=%f maxH=%f\n"
" maxAsc=%f maxDes=%f maxAdv=%f\n",
(unsigned)this,
NS_LossyConvertUTF16toASCII(GetName()).get(),
os2 && os2->version != 0xFFFF ? "has OS/2 table" : "no OS/2 table!",
mMetrics->emHeight, GetStyle()->size, mAdjustedSize,
mMetrics->maxHeight, mMetrics->xHeight,
mMetrics->aveCharWidth, mMetrics->zeroOrAveCharWidth, mMetrics->spaceWidth,
mMetrics->superscriptOffset, mMetrics->subscriptOffset,
mMetrics->strikeoutOffset, mMetrics->strikeoutSize,
mMetrics->underlineOffset, mMetrics->underlineSize,
mMetrics->internalLeading, mMetrics->externalLeading,
mMetrics->emAscent, mMetrics->emDescent, mMetrics->maxHeight,
mMetrics->maxAscent, mMetrics->maxDescent, mMetrics->maxAdvance
);
#endif
cairo_ft_scaled_font_unlock_face(scaledFont);
return *mMetrics;
}
// weight list copied from fontconfig.h
// unfortunately, the OS/2 version so far only supports regular and bold
static const PRInt8 nFcWeight = 2; // 10; // length of weight list
static const int fcWeight[] = {
//FC_WEIGHT_THIN,
//FC_WEIGHT_EXTRALIGHT, // == FC_WEIGHT_ULTRALIGHT
//FC_WEIGHT_LIGHT,
//FC_WEIGHT_BOOK,
FC_WEIGHT_REGULAR, // == FC_WEIGHT_NORMAL
//FC_WEIGHT_MEDIUM,
//FC_WEIGHT_DEMIBOLD, // == FC_WEIGHT_SEMIBOLD
FC_WEIGHT_BOLD,
//FC_WEIGHT_EXTRABOLD, // == FC_WEIGHT_ULTRABOLD
//FC_WEIGHT_BLACK // == FC_WEIGHT_HEAVY
};
// gfxOS2Font::CairoFontFace()
// return a font face usable by cairo for font rendering
// if none was created yet, use FontConfig patterns based on the current style
// to create a new font face
cairo_font_face_t *gfxOS2Font::CairoFontFace()
{
#ifdef DEBUG_thebes_2
printf("gfxOS2Font[%#x]::CairoFontFace()\n", (unsigned)this);
#endif
if (!mFontFace) {
#ifdef DEBUG_thebes
printf("gfxOS2Font[%#x]::CairoFontFace(): create it for %s, %f\n",
(unsigned)this, NS_LossyConvertUTF16toASCII(GetName()).get(), GetStyle()->size);
#endif
FcPattern *fcPattern = FcPatternCreate();
// add (family) name to pattern
// convert name because FC stores it in UTF8 while we have it in UTF16
FcPatternAddString(fcPattern, FC_FAMILY,
(FcChar8 *)NS_ConvertUTF16toUTF8(GetName()).get());
// The requirements outlined in gfxFont.h are difficult to meet without
// having a table of available font weights, so we map the gfxFont
// weight to possible FontConfig weights.
PRInt8 weight = GetStyle()->ComputeWeight();
// gfxFont weight FC weight
// 400 80
// 700 200
PRInt16 fcW = 40 * weight - 80; // match gfxFont weight to base FC weight
// find the correct weight in the list
PRInt8 i = 0;
while (i < nFcWeight && fcWeight[i] < fcW) {
i++;
}
if (i < 0) {
i = 0;
} else if (i >= nFcWeight) {
i = nFcWeight - 1;
}
fcW = fcWeight[i];
// add weight to pattern
FcPatternAddInteger(fcPattern, FC_WEIGHT, fcW);
PRUint8 fcProperty;
// add style to pattern
switch (GetStyle()->style) {
case FONT_STYLE_ITALIC:
fcProperty = FC_SLANT_ITALIC;
break;
case FONT_STYLE_OBLIQUE:
fcProperty = FC_SLANT_OBLIQUE;
break;
case FONT_STYLE_NORMAL:
default:
fcProperty = FC_SLANT_ROMAN;
}
FcPatternAddInteger(fcPattern, FC_SLANT, fcProperty);
// add the size we want
FcPatternAddDouble(fcPattern, FC_PIXEL_SIZE,
mAdjustedSize ? mAdjustedSize : GetStyle()->size);
// finally find a matching font
FcResult fcRes;
FcPattern *fcMatch = FcFontMatch(NULL, fcPattern, &fcRes);
// Most code that depends on FcFontMatch() assumes it won't fail,
// then crashes when it does. For now, at least, substitute the
// default serif font when it fails to avoid those crashes.
if (!fcMatch) {
//#ifdef DEBUG
printf("Could not match font for:\n"
" family=%s, weight=%d, slant=%d, size=%f\n",
NS_LossyConvertUTF16toASCII(GetName()).get(),
GetStyle()->weight, GetStyle()->style, GetStyle()->size);
//#endif
// FcPatternAddString() will free the existing FC_FAMILY string
FcPatternAddString(fcPattern, FC_FAMILY, (FcChar8*)"SERIF");
fcMatch = FcFontMatch(NULL, fcPattern, &fcRes);
//#ifdef DEBUG
printf("Attempt to substitute default SERIF font %s\n",
fcMatch ? "succeeded" : "failed");
//#endif
}
FcPatternDestroy(fcPattern);
if (fcMatch) {
int w = FC_WEIGHT_REGULAR;
FcPatternGetInteger(fcMatch, FC_WEIGHT, 0, &w);
if (fcW >= FC_WEIGHT_DEMIBOLD && w < FC_WEIGHT_DEMIBOLD) {
// if we want a bold font, but the selected font doesn't have a
// bold counterpart, artificially embolden it
FcPatternAddBool(fcMatch, FC_EMBOLDEN, FcTrue);
}
FcPatternAddBool(fcMatch, FC_ANTIALIAS, mAntialias);
FcPatternAddInteger(fcMatch, FC_HINT_STYLE, mHinting);
// and ask cairo to return a font face for this
mFontFace = cairo_ft_font_face_create_for_pattern(fcMatch);
FcPatternDestroy(fcMatch);
}
}
NS_ASSERTION(mFontFace, "Failed to make font face");
return mFontFace;
}
cairo_scaled_font_t *gfxOS2Font::CairoScaledFont()
{
#ifdef DEBUG_thebes_2
printf("gfxOS2Font[%#x]::CairoScaledFont()\n", (unsigned)this);
#endif
if (mScaledFont) {
return mScaledFont;
}
#ifdef DEBUG_thebes_2
printf("gfxOS2Font[%#x]::CairoScaledFont(): create it for %s, %f\n",
(unsigned)this, NS_LossyConvertUTF16toASCII(GetName()).get(), GetStyle()->size);
#endif
double size = mAdjustedSize ? mAdjustedSize : GetStyle()->size;
cairo_matrix_t identityMatrix;
cairo_matrix_init_identity(&identityMatrix);
cairo_matrix_t fontMatrix;
// synthetic oblique by skewing via the font matrix
if (!mFontEntry->mItalic &&
(mStyle.style & (FONT_STYLE_ITALIC | FONT_STYLE_OBLIQUE)))
{
const double kSkewFactor = 0.2126; // 12 deg skew as used in e.g. ftview
cairo_matrix_init(&fontMatrix, size, 0, -kSkewFactor*size, size, 0, 0);
} else {
cairo_matrix_init_scale(&fontMatrix, size, size);
}
cairo_font_face_t * face = CairoFontFace();
if (!face)
return nsnull;
cairo_font_options_t *fontOptions = cairo_font_options_create();
mScaledFont = cairo_scaled_font_create(face, &fontMatrix,
&identityMatrix, fontOptions);
cairo_font_options_destroy(fontOptions);
NS_ASSERTION(cairo_scaled_font_status(mScaledFont) == CAIRO_STATUS_SUCCESS,
"Failed to make scaled font");
return mScaledFont;
}
bool gfxOS2Font::SetupCairoFont(gfxContext *aContext)
{
#ifdef DEBUG_thebes_2
printf("gfxOS2Font[%#x]::SetupCairoFont(%#x)\n",
(unsigned)this, (unsigned) aContext);
#endif
// gfxPangoFont checks the CTM but Windows doesn't so leave away here, too
// this implicitely ensures that mScaledFont is created if NULL
cairo_scaled_font_t *scaledFont = CairoScaledFont();
if (!scaledFont || cairo_scaled_font_status(scaledFont) != CAIRO_STATUS_SUCCESS) {
// Don't cairo_set_scaled_font as that would propagate the error to
// the cairo_t, precluding any further drawing.
return PR_FALSE;
}
cairo_set_scaled_font(aContext->GetCairo(), scaledFont);
return PR_TRUE;
}
/**
* Look up the font in the gfxFont cache. If we don't find it, create one.
* In either case, add a ref and return it ---
* except for OOM in which case we do nothing and return null.
*/
already_AddRefed<gfxOS2Font> gfxOS2Font::GetOrMakeFont(const nsAString& aName,
const gfxFontStyle *aStyle)
{
nsRefPtr<gfxOS2FontEntry> fe = new gfxOS2FontEntry(aName);
nsRefPtr<gfxFont> font =
gfxFontCache::GetCache()->Lookup(static_cast<gfxFontEntry *>(fe), aStyle);
if (!font) {
font = new gfxOS2Font(fe, aStyle);
if (!font)
return nsnull;
gfxFontCache::GetCache()->AddNew(font);
}
gfxFont *f = nsnull;
font.swap(f);
return static_cast<gfxOS2Font *>(f);
}
/**********************************************************************
* class gfxOS2FontGroup
**********************************************************************/
gfxOS2FontGroup::gfxOS2FontGroup(const nsAString& aFamilies,
const gfxFontStyle* aStyle,
gfxUserFontSet *aUserFontSet)
: gfxFontGroup(aFamilies, aStyle, aUserFontSet)
{
#ifdef DEBUG_thebes_2
printf("gfxOS2FontGroup[%#x]::gfxOS2FontGroup(\"%s\", %#x)\n",
(unsigned)this, NS_LossyConvertUTF16toASCII(aFamilies).get(),
(unsigned)aStyle);
#endif
// check for WarpSans and as we cannot display that (yet), replace
// it with Workplace Sans
int pos = 0;
if ((pos = mFamilies.Find("WarpSans", PR_FALSE, 0, -1)) > -1) {
mFamilies.Replace(pos, 8, NS_LITERAL_STRING("Workplace Sans"));
}
nsTArray<nsString> familyArray;
ForEachFont(FontCallback, &familyArray);
// To be able to easily search for glyphs in other fonts, append a few good
// replacement candidates to the list. The best ones are the Unicode fonts that
// are set up, and if the user was so clever to set up the User Defined fonts,
// then these are probable candidates, too.
nsString fontString;
gfxPlatform::GetPlatform()->GetPrefFonts(gfxAtoms::x_unicode, fontString, PR_FALSE);
ForEachFont(fontString, gfxAtoms::x_unicode, FontCallback, &familyArray);
gfxPlatform::GetPlatform()->GetPrefFonts(gfxAtoms::x_user_def, fontString, PR_FALSE);
ForEachFont(fontString, gfxAtoms::x_user_def, FontCallback, &familyArray);
// Should append some default font if there are no available fonts.
// Let's use Helv which should be available on any OS/2 system; if
// it's not there, Fontconfig replaces it with something else...
if (familyArray.Length() == 0) {
familyArray.AppendElement(NS_LITERAL_STRING("Helv"));
}
for (PRUint32 i = 0; i < familyArray.Length(); i++) {
nsRefPtr<gfxOS2Font> font = gfxOS2Font::GetOrMakeFont(familyArray[i], &mStyle);
if (font) {
mFonts.AppendElement(font);
}
}
}
gfxOS2FontGroup::~gfxOS2FontGroup()
{
#ifdef DEBUG_thebes_2
printf("gfxOS2FontGroup[%#x]::~gfxOS2FontGroup()\n", (unsigned)this);
#endif
}
gfxFontGroup *gfxOS2FontGroup::Copy(const gfxFontStyle *aStyle)
{
return new gfxOS2FontGroup(mFamilies, aStyle, mUserFontSet);
}
/**
* We use this to append an LTR or RTL Override character to the start of the
* string. This forces Pango to honour our direction even if there are neutral
* characters in the string.
*/
static PRInt32 AppendDirectionalIndicatorUTF8(bool aIsRTL, nsACString& aString)
{
static const PRUnichar overrides[2][2] = { { 0x202d, 0 }, { 0x202e, 0 }}; // LRO, RLO
AppendUTF16toUTF8(overrides[aIsRTL], aString);
return 3; // both overrides map to 3 bytes in UTF8
}
gfxTextRun *gfxOS2FontGroup::MakeTextRun(const PRUnichar* aString, PRUint32 aLength,
const Parameters* aParams, PRUint32 aFlags)
{
NS_ASSERTION(aLength > 0, "should use MakeEmptyTextRun for zero-length text");
gfxTextRun *textRun = gfxTextRun::Create(aParams, aString, aLength, this, aFlags);
if (!textRun)
return nsnull;
mEnableKerning = !(aFlags & gfxTextRunFactory::TEXT_OPTIMIZE_SPEED);
nsCAutoString utf8;
PRInt32 headerLen = AppendDirectionalIndicatorUTF8(textRun->IsRightToLeft(), utf8);
AppendUTF16toUTF8(Substring(aString, aString + aLength), utf8);
#ifdef DEBUG_thebes_2
NS_ConvertUTF8toUTF16 u16(utf8);
printf("gfxOS2FontGroup[%#x]::MakeTextRun(PRUnichar %s, %d, %#x, %d)\n",
(unsigned)this, NS_LossyConvertUTF16toASCII(u16).get(), aLength, (unsigned)aParams, aFlags);
#endif
InitTextRun(textRun, (PRUint8 *)utf8.get(), utf8.Length(), headerLen);
textRun->FetchGlyphExtents(aParams->mContext);
return textRun;
}
gfxTextRun *gfxOS2FontGroup::MakeTextRun(const PRUint8* aString, PRUint32 aLength,
const Parameters* aParams, PRUint32 aFlags)
{
#ifdef DEBUG_thebes_2
const char *cStr = reinterpret_cast<const char *>(aString);
NS_ConvertASCIItoUTF16 us(cStr, aLength);
printf("gfxOS2FontGroup[%#x]::MakeTextRun(PRUint8 %s, %d, %#x, %d)\n",
(unsigned)this, NS_LossyConvertUTF16toASCII(us).get(), aLength, (unsigned)aParams, aFlags);
#endif
NS_ASSERTION(aLength > 0, "should use MakeEmptyTextRun for zero-length text");
NS_ASSERTION(aFlags & TEXT_IS_8BIT, "8bit should have been set");
gfxTextRun *textRun = gfxTextRun::Create(aParams, aString, aLength, this, aFlags);
if (!textRun)
return nsnull;
mEnableKerning = !(aFlags & gfxTextRunFactory::TEXT_OPTIMIZE_SPEED);
const char *chars = reinterpret_cast<const char *>(aString);
bool isRTL = textRun->IsRightToLeft();
if ((aFlags & TEXT_IS_ASCII) && !isRTL) {
// We don't need to send an override character here, the characters must be all
// LTR
InitTextRun(textRun, (PRUint8 *)chars, aLength, 0);
} else {
// Although chars in not necessarily ASCII (as it may point to the low
// bytes of any UCS-2 characters < 256), NS_ConvertASCIItoUTF16 seems
// to DTRT.
NS_ConvertASCIItoUTF16 unicodeString(chars, aLength);
nsCAutoString utf8;
PRInt32 headerLen = AppendDirectionalIndicatorUTF8(isRTL, utf8);
AppendUTF16toUTF8(unicodeString, utf8);
InitTextRun(textRun, (PRUint8 *)utf8.get(), utf8.Length(), headerLen);
}
textRun->FetchGlyphExtents(aParams->mContext);
return textRun;
}
void gfxOS2FontGroup::InitTextRun(gfxTextRun *aTextRun, const PRUint8 *aUTF8Text,
PRUint32 aUTF8Length,
PRUint32 aUTF8HeaderLength)
{
CreateGlyphRunsFT(aTextRun, aUTF8Text + aUTF8HeaderLength,
aUTF8Length - aUTF8HeaderLength);
}
// Helper function to return the leading UTF-8 character in a char pointer
// as 32bit number. Also sets the length of the current character (i.e. the
// offset to the next one) in the second argument
PRUint32 getUTF8CharAndNext(const PRUint8 *aString, PRUint8 *aLength)
{
*aLength = 1;
if (aString[0] < 0x80) { // normal 7bit ASCII char
return aString[0];
}
if ((aString[0] >> 5) == 6) { // two leading ones -> two bytes
*aLength = 2;
return ((aString[0] & 0x1F) << 6) + (aString[1] & 0x3F);
}
if ((aString[0] >> 4) == 14) { // three leading ones -> three bytes
*aLength = 3;
return ((aString[0] & 0x0F) << 12) + ((aString[1] & 0x3F) << 6) +
(aString[2] & 0x3F);
}
if ((aString[0] >> 4) == 15) { // four leading ones -> four bytes
*aLength = 4;
return ((aString[0] & 0x07) << 18) + ((aString[1] & 0x3F) << 12) +
((aString[2] & 0x3F) << 6) + (aString[3] & 0x3F);
}
return aString[0];
}
void gfxOS2FontGroup::CreateGlyphRunsFT(gfxTextRun *aTextRun, const PRUint8 *aUTF8,
PRUint32 aUTF8Length)
{
#ifdef DEBUG_thebes_2
printf("gfxOS2FontGroup::CreateGlyphRunsFT(%#x, _aUTF8_, %d)\n",
(unsigned)aTextRun, /*aUTF8,*/ aUTF8Length);
for (PRUint32 i = 0; i < FontListLength(); i++) {
gfxOS2Font *font = GetFontAt(i);
printf(" i=%d, name=%s, size=%f\n", i, NS_LossyConvertUTF16toASCII(font->GetName()).get(),
font->GetStyle()->size);
}
#endif
PRUint32 lastFont = FontListLength()-1;
gfxOS2Font *font0 = GetFontAt(0);
const PRUint8 *p = aUTF8;
PRUint32 utf16Offset = 0;
gfxTextRun::CompressedGlyph g;
const PRUint32 appUnitsPerDevUnit = aTextRun->GetAppUnitsPerDevUnit();
gfxOS2Platform *platform = gfxOS2Platform::GetPlatform();
aTextRun->AddGlyphRun(font0, gfxTextRange::kFontGroup, 0, PR_FALSE);
// a textRun likely has the same font for most of the characters, so we can
// lock it before the loop for efficiency
FT_Face face0 = cairo_ft_scaled_font_lock_face(font0->CairoScaledFont());
while (p < aUTF8 + aUTF8Length) {
bool glyphFound = false;
// convert UTF-8 character and step to the next one in line
PRUint8 chLen;
PRUint32 ch = getUTF8CharAndNext(p, &chLen);
p += chLen; // move to next char
#ifdef DEBUG_thebes_2
printf("\'%c\' (%d, %#x, %s) [%#x %#x]:", (char)ch, ch, ch, ch >=0x10000 ? "non-BMP!" : "BMP", ch >=0x10000 ? H_SURROGATE(ch) : 0, ch >=0x10000 ? L_SURROGATE(ch) : 0);
#endif
if (ch == 0 || platform->noFontWithChar(ch)) {
// null bytes or missing characters cannot be displayed
aTextRun->SetMissingGlyph(utf16Offset, ch);
} else {
// Try to get a glyph from all fonts available to us.
// Once we found it in one of the fonts we quit the loop early.
// If we don't find the glyph even in the last font, we will fall
// back to searching all fonts on the system and finally set the
// missing glyph symbol after trying the last font.
for (PRUint32 i = 0; i <= lastFont; i++) {
gfxOS2Font *font = font0;
FT_Face face = face0;
if (i > 0) {
font = GetFontAt(i);
face = cairo_ft_scaled_font_lock_face(font->CairoScaledFont());
#ifdef DEBUG_thebes_2
if (i == lastFont) {
printf("Last font %d (%s) for ch=%#x (pos=%d)",
i, NS_LossyConvertUTF16toASCII(font->GetName()).get(), ch, utf16Offset);
}
#endif
}
if (!face || !face->charmap) { // don't try to use fonts with non-Unicode charmaps
if (face && face != face0)
cairo_ft_scaled_font_unlock_face(font->CairoScaledFont());
continue; // next font
}
NS_ASSERTION(!IsInvalidChar(ch), "Invalid char detected");
FT_UInt gid = FT_Get_Char_Index(face, ch); // find the glyph id
if (gid == 0 && i == lastFont) {
// missing glyph, try to find a replacement in another font
nsRefPtr<gfxOS2Font> fontX = platform->FindFontForChar(ch, font0);
if (fontX) {
font = fontX; // replace current font
cairo_ft_scaled_font_unlock_face(font->CairoScaledFont());
face = cairo_ft_scaled_font_lock_face(fontX->CairoScaledFont());
gid = FT_Get_Char_Index(face, ch);
// likely to find more chars in this font, append it
// to the font list to find it quicker next time
mFonts.AppendElement(fontX);
lastFont = FontListLength()-1;
}
}
// select the current font into the text run
aTextRun->AddGlyphRun(font, gfxTextRange::kFontGroup, utf16Offset, PR_FALSE);
PRInt32 advance = 0;
if (gid == font->GetSpaceGlyph()) {
advance = (int)(font->GetMetrics().spaceWidth * appUnitsPerDevUnit);
} else if (gid == 0) {
advance = -1; // trigger the missing glyphs case below
} else {
// find next character and its glyph -- in case they exist
// and exist in the current font face -- to compute kerning
PRUint32 chNext = 0;
FT_UInt gidNext = 0;
FT_Pos lsbDeltaNext = 0;
#ifdef DEBUG_thebes_2
printf("(kerning=%s/%s)", mEnableKerning ? "enable" : "disable", FT_HAS_KERNING(face) ? "yes" : "no");
#endif
if (mEnableKerning && FT_HAS_KERNING(face) && p < aUTF8 + aUTF8Length) {
chNext = getUTF8CharAndNext(p, &chLen);
if (chNext) {
gidNext = FT_Get_Char_Index(face, chNext);
if (gidNext && gidNext != font->GetSpaceGlyph()) {
FT_Load_Glyph(face, gidNext, FT_LOAD_DEFAULT);
lsbDeltaNext = face->glyph->lsb_delta;
}
}
}
// now load the current glyph
FT_Load_Glyph(face, gid, FT_LOAD_DEFAULT); // load glyph into the slot
advance = face->glyph->advance.x;
// now add kerning to the current glyph's advance
if (chNext && gidNext) {
FT_Vector kerning;
FT_Get_Kerning(face, gid, gidNext, FT_KERNING_DEFAULT, &kerning);
advance += kerning.x;
if (face->glyph->rsb_delta - lsbDeltaNext >= 32) {
advance -= 64;
} else if (face->glyph->rsb_delta - lsbDeltaNext < -32) {
advance += 64;
}
}
// now apply unit conversion and scaling
advance = (advance >> 6) * appUnitsPerDevUnit;
}
#ifdef DEBUG_thebes_2
printf(" gid=%d, advance=%d (%s)\n", gid, advance,
NS_LossyConvertUTF16toASCII(font->GetName()).get());
#endif
if (advance >= 0 &&
gfxTextRun::CompressedGlyph::IsSimpleAdvance(advance) &&
gfxTextRun::CompressedGlyph::IsSimpleGlyphID(gid))
{
aTextRun->SetSimpleGlyph(utf16Offset,
g.SetSimpleGlyph(advance, gid));
glyphFound = PR_TRUE;
} else if (gid == 0) {
// gid = 0 only happens when the glyph is missing from the font
if (i == lastFont) {
// set the missing glyph only when it's missing from the very
// last font
aTextRun->SetMissingGlyph(utf16Offset, ch);
}
glyphFound = PR_FALSE;
} else {
gfxTextRun::DetailedGlyph details;
details.mGlyphID = gid;
NS_ASSERTION(details.mGlyphID == gid, "Seriously weird glyph ID detected!");
details.mAdvance = advance;
details.mXOffset = 0;
details.mYOffset = 0;
g.SetComplex(aTextRun->IsClusterStart(utf16Offset), PR_TRUE, 1);
aTextRun->SetGlyphs(utf16Offset, g, &details);
glyphFound = PR_TRUE;
}
if (i > 0) {
cairo_ft_scaled_font_unlock_face(font->CairoScaledFont());
}
if (glyphFound) {
break;
}
}
} // for all fonts
NS_ASSERTION(!IS_SURROGATE(ch), "Surrogates shouldn't appear in UTF8");
if (ch >= 0x10000) {
// This character is a surrogate pair in UTF16
++utf16Offset;
}
++utf16Offset;
}
cairo_ft_scaled_font_unlock_face(font0->CairoScaledFont());
}
// append aFontName to aClosure string array, if not already present
bool gfxOS2FontGroup::FontCallback(const nsAString& aFontName,
const nsACString& aGenericName,
bool aUseFontSet,
void *aClosure)
{
nsTArray<nsString> *sa = static_cast<nsTArray<nsString>*>(aClosure);
if (!aFontName.IsEmpty() && !sa->Contains(aFontName)) {
sa->AppendElement(aFontName);
}
return PR_TRUE;
}
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