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pjs/gfx/thebes/gfxHarfBuzzShaper.cpp

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/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* ***** 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 Mozilla Corporation code.
*
* The Initial Developer of the Original Code is Mozilla Corporation.
* Portions created by the Initial Developer are Copyright (C) 2009-2010
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Jonathan Kew <jfkthame@gmail.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 "prtypes.h"
#include "prmem.h"
#include "nsString.h"
#include "nsBidiUtils.h"
#include "nsMathUtils.h"
#include "gfxTypes.h"
#include "gfxContext.h"
#include "gfxPlatform.h"
#include "gfxHarfBuzzShaper.h"
#include "gfxFontUtils.h"
#include "gfxUnicodeProperties.h"
#include "harfbuzz/hb-unicode.h"
#include "harfbuzz/hb-ot.h"
#include "nsUnicodeRange.h"
#include "nsCRT.h"
#define FloatToFixed(f) (65536 * (f))
#define FixedToFloat(f) ((f) * (1.0 / 65536.0))
using namespace mozilla; // for AutoSwap_* types
/*
* Creation and destruction; on deletion, release any font tables we're holding
*/
gfxHarfBuzzShaper::gfxHarfBuzzShaper(gfxFont *aFont)
: gfxFontShaper(aFont),
mHBFace(nsnull),
mHBLanguage(nsnull),
mHmtxTable(nsnull),
mNumLongMetrics(0),
mCmapTable(nsnull),
mCmapFormat(-1),
mSubtableOffset(0),
mUVSTableOffset(0),
mUseHintedWidths(aFont->ProvidesHintedWidths())
{
}
gfxHarfBuzzShaper::~gfxHarfBuzzShaper()
{
hb_blob_destroy(mCmapTable);
hb_blob_destroy(mHmtxTable);
hb_face_destroy(mHBFace);
}
/*
* HarfBuzz callback access to font table data
*/
// callback for HarfBuzz to get a font table (in hb_blob_t form)
// from the shaper (passed as aUserData)
static hb_blob_t *
HBGetTable(hb_tag_t aTag, void *aUserData)
{
gfxHarfBuzzShaper *shaper = static_cast<gfxHarfBuzzShaper*>(aUserData);
return shaper->GetFont()->GetFontTable(aTag);
}
/*
* HarfBuzz font callback functions; user_data is a ptr to a
* FontCallbackData struct
*/
struct FontCallbackData {
FontCallbackData(gfxHarfBuzzShaper *aShaper, gfxContext *aContext)
: mShaper(aShaper), mContext(aContext)
{ }
gfxHarfBuzzShaper *mShaper;
gfxContext *mContext;
};
#define UNICODE_BMP_LIMIT 0x10000
hb_codepoint_t
gfxHarfBuzzShaper::GetGlyph(hb_codepoint_t unicode,
hb_codepoint_t variation_selector) const
{
// we only instantiate a harfbuzz shaper if there's a cmap available
NS_ASSERTION(mFont->GetFontEntry()->HasCmapTable(),
"we cannot be using this font!");
NS_ASSERTION(mCmapTable && (mCmapFormat > 0) && (mSubtableOffset > 0),
"cmap data not correctly set up, expect disaster");
const PRUint8* data = (const PRUint8*)hb_blob_lock(mCmapTable);
hb_codepoint_t gid;
switch (mCmapFormat) {
case 4:
gid = unicode < UNICODE_BMP_LIMIT ?
gfxFontUtils::MapCharToGlyphFormat4(data + mSubtableOffset, unicode) : 0;
break;
case 12:
gid = gfxFontUtils::MapCharToGlyphFormat12(data + mSubtableOffset, unicode);
break;
default:
NS_WARNING("unsupported cmap format, glyphs will be missing");
gid = 0;
break;
}
if (gid && variation_selector && mUVSTableOffset) {
hb_codepoint_t varGID =
gfxFontUtils::MapUVSToGlyphFormat14(data + mUVSTableOffset,
unicode, variation_selector);
if (varGID) {
gid = varGID;
}
// else the variation sequence was not supported, use default mapping
// of the character code alone
}
hb_blob_unlock(mCmapTable);
return gid;
}
static hb_codepoint_t
HBGetGlyph(hb_font_t *font, hb_face_t *face, const void *user_data,
hb_codepoint_t unicode, hb_codepoint_t variation_selector)
{
const FontCallbackData *fcd =
static_cast<const FontCallbackData*>(user_data);
return fcd->mShaper->GetGlyph(unicode, variation_selector);
}
struct HMetricsHeader {
AutoSwap_PRUint32 tableVersionNumber;
AutoSwap_PRInt16 ascender;
AutoSwap_PRInt16 descender;
AutoSwap_PRInt16 lineGap;
AutoSwap_PRUint16 advanceWidthMax;
AutoSwap_PRInt16 minLeftSideBearing;
AutoSwap_PRInt16 minRightSideBearing;
AutoSwap_PRInt16 xMaxExtent;
AutoSwap_PRInt16 caretSlopeRise;
AutoSwap_PRInt16 caretSlopeRun;
AutoSwap_PRInt16 caretOffset;
AutoSwap_PRInt16 reserved[4];
AutoSwap_PRInt16 metricDataFormat;
AutoSwap_PRUint16 numberOfHMetrics;
};
struct HLongMetric {
AutoSwap_PRUint16 advanceWidth;
AutoSwap_PRInt16 lsb;
};
struct HMetrics {
HLongMetric metrics[1]; // actually numberOfHMetrics
// the variable-length metrics[] array is immediately followed by:
// AutoSwap_PRUint16 leftSideBearing[];
};
void
gfxHarfBuzzShaper::GetGlyphMetrics(gfxContext *aContext,
hb_codepoint_t glyph,
hb_glyph_metrics_t *metrics) const
{
if (mUseHintedWidths) {
metrics->x_advance = mFont->GetHintedGlyphWidth(aContext, glyph);
return;
}
// font did not implement GetHintedGlyphWidth, so get an unhinted value
// directly from the font tables
NS_ASSERTION((mNumLongMetrics > 0) && mHmtxTable != nsnull,
"font is lacking metrics, we shouldn't be here");
if (glyph >= mNumLongMetrics) {
glyph = mNumLongMetrics - 1;
}
// glyph must be valid now, because we checked during initialization
// that mNumLongMetrics is > 0, and that the hmtx table is large enough
// to contain mNumLongMetrics records
const HMetrics* hmtx =
reinterpret_cast<const HMetrics*>(hb_blob_lock(mHmtxTable));
metrics->x_advance =
FloatToFixed(mFont->FUnitsToDevUnitsFactor() *
PRUint16(hmtx->metrics[glyph].advanceWidth));
hb_blob_unlock(mHmtxTable);
// TODO: set additional metrics if/when harfbuzz needs them
}
static void
HBGetGlyphMetrics(hb_font_t *font, hb_face_t *face, const void *user_data,
hb_codepoint_t glyph, hb_glyph_metrics_t *metrics)
{
const FontCallbackData *fcd =
static_cast<const FontCallbackData*>(user_data);
fcd->mShaper->GetGlyphMetrics(fcd->mContext, glyph, metrics);
}
static hb_bool_t
HBGetContourPoint(hb_font_t *font, hb_face_t *face, const void *user_data,
unsigned int point_index, hb_codepoint_t glyph,
hb_position_t *x, hb_position_t *y)
{
/* not yet implemented - no support for used of hinted contour points
to fine-tune anchor positions in GPOS AnchorFormat2 */
return false;
}
static hb_position_t
HBGetKerning(hb_font_t *font, hb_face_t *face, const void *user_data,
hb_codepoint_t first_glyph, hb_codepoint_t second_glyph)
{
/* not yet implemented - no support for legacy TrueType kerning */
return 0;
}
/*
* HarfBuzz unicode property callbacks
*/
static hb_codepoint_t
HBGetMirroring(hb_codepoint_t aCh)
{
return gfxUnicodeProperties::GetMirroredChar(aCh);
}
static hb_category_t
HBGetGeneralCategory(hb_codepoint_t aCh)
{
return hb_category_t(gfxUnicodeProperties::GetGeneralCategory(aCh));
}
static hb_script_t
HBGetScript(hb_codepoint_t aCh)
{
return hb_script_t(gfxUnicodeProperties::GetScriptCode(aCh));
}
static unsigned int
HBGetCombiningClass(hb_codepoint_t aCh)
{
return gfxUnicodeProperties::GetCombiningClass(aCh);
}
static unsigned int
HBGetEastAsianWidth(hb_codepoint_t aCh)
{
return gfxUnicodeProperties::GetEastAsianWidth(aCh);
}
/*
* gfxFontShaper override to initialize the text run using HarfBuzz
*/
static hb_font_funcs_t * sHBFontFuncs = nsnull;
static hb_unicode_funcs_t * sHBUnicodeFuncs = nsnull;
PRBool
gfxHarfBuzzShaper::InitTextRun(gfxContext *aContext,
gfxTextRun *aTextRun,
const PRUnichar *aString,
PRUint32 aRunStart,
PRUint32 aRunLength,
PRInt32 aRunScript)
{
// some font back-ends require this in order to get proper hinted metrics
mFont->SetupCairoFont(aContext);
if (!mHBFace) {
// set up the harfbuzz face etc the first time we use the font
if (!sHBFontFuncs) {
// static function callback pointers, initialized by the first
// harfbuzz shaper used
sHBFontFuncs = hb_font_funcs_copy(hb_font_funcs_create());
hb_font_funcs_set_glyph_func(sHBFontFuncs, HBGetGlyph);
hb_font_funcs_set_glyph_metrics_func(sHBFontFuncs,
HBGetGlyphMetrics);
hb_font_funcs_set_contour_point_func(sHBFontFuncs,
HBGetContourPoint);
hb_font_funcs_set_kerning_func(sHBFontFuncs, HBGetKerning);
sHBUnicodeFuncs = hb_unicode_funcs_copy(hb_unicode_funcs_create());
hb_unicode_funcs_set_mirroring_func(sHBUnicodeFuncs,
HBGetMirroring);
hb_unicode_funcs_set_script_func(sHBUnicodeFuncs, HBGetScript);
hb_unicode_funcs_set_general_category_func(sHBUnicodeFuncs,
HBGetGeneralCategory);
hb_unicode_funcs_set_combining_class_func(sHBUnicodeFuncs,
HBGetCombiningClass);
hb_unicode_funcs_set_eastasian_width_func(sHBUnicodeFuncs,
HBGetEastAsianWidth);
}
mHBFace = hb_face_create_for_tables(HBGetTable, nsnull, this);
// get the cmap table and find offset to our subtable
mCmapTable = mFont->GetFontTable(TRUETYPE_TAG('c','m','a','p'));
if (!mCmapTable) {
NS_WARNING("failed to load cmap, glyphs will be missing");
return PR_FALSE;
}
const PRUint8* data = (const PRUint8*)hb_blob_lock(mCmapTable);
PRBool symbol;
mCmapFormat =
gfxFontUtils::FindPreferredSubtable(data,
hb_blob_get_length(mCmapTable),
&mSubtableOffset,
&mUVSTableOffset,
&symbol);
hb_blob_unlock(mCmapTable);
if (!mUseHintedWidths) {
// if font doesn't implement hinted widths, we will be reading
// the hmtx table directly;
// read mNumLongMetrics from hhea table without caching its blob,
// and preload/cache the hmtx table
hb_blob_t *hheaTable =
mFont->GetFontTable(TRUETYPE_TAG('h','h','e','a'));
if (hheaTable &&
hb_blob_get_length(hheaTable) >= sizeof(HMetricsHeader)) {
const HMetricsHeader* hhea =
reinterpret_cast<const HMetricsHeader*>
(hb_blob_lock(hheaTable));
mNumLongMetrics = hhea->numberOfHMetrics;
hb_blob_unlock(hheaTable);
if (mNumLongMetrics > 0 &&
PRInt16(hhea->metricDataFormat) == 0) {
// no point reading hmtx if number of entries is zero!
// in that case, we won't be able to use this font
// (this method will return FALSE below if mHmtx is null)
mHmtxTable =
mFont->GetFontTable(TRUETYPE_TAG('h','m','t','x'));
if (hb_blob_get_length(mHmtxTable) <
mNumLongMetrics * sizeof(HLongMetric)) {
// hmtx table is not large enough for the claimed
// number of entries: invalid, do not use.
hb_blob_destroy(mHmtxTable);
mHmtxTable = nsnull;
}
}
}
hb_blob_destroy(hheaTable);
}
if (mFont->GetStyle()->languageOverride) {
mHBLanguage =
hb_ot_tag_to_language(mFont->GetStyle()->languageOverride);
} else if (mFont->GetFontEntry()->mLanguageOverride) {
mHBLanguage =
hb_ot_tag_to_language(mFont->GetFontEntry()->mLanguageOverride);
} else {
nsCString langString;
mFont->GetStyle()->language->ToUTF8String(langString);
mHBLanguage = hb_language_from_string(langString.get());
}
}
if (mCmapFormat <= 0 || (!mUseHintedWidths && !mHmtxTable)) {
// unable to shape with this font
return PR_FALSE;
}
FontCallbackData fcd(this, aContext);
hb_font_t *font = hb_font_create();
hb_font_set_funcs(font, sHBFontFuncs, nsnull, &fcd);
hb_font_set_ppem(font, mFont->GetAdjustedSize(), mFont->GetAdjustedSize());
PRUint32 scale = FloatToFixed(mFont->GetAdjustedSize()); // 16.16 fixed-point
hb_font_set_scale(font, scale, scale);
// aRunStart and aRunLength define the section of the textRun and of
// aString that is to be drawn with this particular font
PRBool disableLigatures =
(aTextRun->GetFlags() &
gfxTextRunFactory::TEXT_DISABLE_OPTIONAL_LIGATURES) != 0;
nsAutoTArray<hb_feature_t,20> features;
// Ligature features are enabled by default in the generic shaper,
// so we explicitly turn them off if necessary (for letter-spacing)
if (disableLigatures) {
hb_feature_t ligaOff = { HB_TAG('l','i','g','a'), 0, 0, -1 };
hb_feature_t cligOff = { HB_TAG('c','l','i','g'), 0, 0, -1 };
features.AppendElement(ligaOff);
features.AppendElement(cligOff);
}
// css features need to be merged with the existing ones, if any
const nsTArray<gfxFontFeature> *cssFeatures =
mFont->GetStyle()->featureSettings;
if (!cssFeatures) {
cssFeatures = mFont->GetFontEntry()->mFeatureSettings;
}
if (cssFeatures) {
for (PRUint32 i = 0; i < cssFeatures->Length(); ++i) {
PRUint32 j;
for (j = 0; j < features.Length(); ++j) {
if (cssFeatures->ElementAt(i).mTag == features[j].tag) {
features[j].value = cssFeatures->ElementAt(i).mValue;
break;
}
}
if (j == features.Length()) {
const gfxFontFeature& f = cssFeatures->ElementAt(i);
hb_feature_t hbf = { f.mTag, f.mValue, 0, -1 };
features.AppendElement(hbf);
}
}
}
hb_buffer_t *buffer = hb_buffer_create(aRunLength);
hb_buffer_set_unicode_funcs(buffer, sHBUnicodeFuncs);
hb_buffer_set_direction(buffer,
aTextRun->IsRightToLeft() ?
HB_DIRECTION_RTL : HB_DIRECTION_LTR);
hb_buffer_set_script(buffer, hb_script_t(aRunScript));
hb_buffer_set_language(buffer, mHBLanguage);
hb_buffer_add_utf16(buffer, reinterpret_cast<const uint16_t*>(aString + aRunStart),
aRunLength, 0, aRunLength);
hb_shape(font, mHBFace, buffer, features.Elements(), features.Length());
if (aTextRun->IsRightToLeft()) {
hb_buffer_reverse(buffer);
}
nsresult rv = SetGlyphsFromRun(aContext, aTextRun, buffer,
aRunStart, aRunLength);
NS_WARN_IF_FALSE(NS_SUCCEEDED(rv), "failed to store glyphs into textrun");
hb_buffer_destroy(buffer);
hb_font_destroy(font);
return PR_TRUE;
}
#define SMALL_GLYPH_RUN 128 // some testing indicates that 90%+ of text runs
// will fit without requiring separate allocation
// for charToGlyphArray
nsresult
gfxHarfBuzzShaper::SetGlyphsFromRun(gfxContext *aContext,
gfxTextRun *aTextRun,
hb_buffer_t *aBuffer,
PRUint32 aTextRunOffset,
PRUint32 aRunLength)
{
PRInt32 numGlyphs = hb_buffer_get_length(aBuffer);
if (numGlyphs == 0)
return NS_OK;
const hb_glyph_info_t *ginfo = hb_buffer_get_glyph_infos(aBuffer);
nsAutoTArray<gfxTextRun::DetailedGlyph,1> detailedGlyphs;
static const PRInt32 NO_GLYPH = -1;
nsAutoTArray<PRInt32,SMALL_GLYPH_RUN> charToGlyphArray;
if (!charToGlyphArray.SetLength(aRunLength))
return NS_ERROR_OUT_OF_MEMORY;
PRInt32 *charToGlyph = charToGlyphArray.Elements();
for (PRUint32 offset = 0; offset < aRunLength; ++offset) {
charToGlyph[offset] = NO_GLYPH;
}
for (PRInt32 i = 0; i < numGlyphs; ++i) {
PRInt32 loc = ginfo[i].cluster;
if (loc < aRunLength) {
charToGlyph[loc] = i;
}
}
nsAutoTArray<nsPoint,SMALL_GLYPH_RUN> positions;
if (!positions.SetLength(numGlyphs))
return NS_ERROR_OUT_OF_MEMORY;
float runWidth = GetGlyphPositions(aContext, aBuffer, positions,
aTextRun->GetAppUnitsPerDevUnit());
PRInt32 glyphStart = 0; // looking for a clump that starts at this glyph
PRInt32 charStart = 0; // and this char index within the range of the run
while (glyphStart < numGlyphs) {
PRBool inOrder = PR_TRUE;
PRInt32 charEnd = ginfo[glyphStart].cluster;
PRInt32 glyphEnd = glyphStart;
PRInt32 charLimit = aRunLength;
while (charEnd < charLimit) {
// This is normally executed once for each iteration of the outer loop,
// but in unusual cases where the character/glyph association is complex,
// the initial character range might correspond to a non-contiguous
// glyph range with "holes" in it. If so, we will repeat this loop to
// extend the character range until we have a contiguous glyph sequence.
charEnd += 1;
while (charEnd != charLimit && charToGlyph[charEnd] == NO_GLYPH) {
charEnd += 1;
}
// find the maximum glyph index covered by the clump so far
for (PRInt32 i = charStart; i < charEnd; ++i) {
if (charToGlyph[i] != NO_GLYPH) {
glyphEnd = PR_MAX(glyphEnd, charToGlyph[i] + 1);
// update extent of glyph range
}
}
if (glyphEnd == glyphStart + 1) {
// for the common case of a single-glyph clump,
// we can skip the following checks
break;
}
if (glyphEnd == glyphStart) {
// no glyphs, try to extend the clump
continue;
}
// check whether all glyphs in the range are associated with the characters
// in our clump; if not, we have a discontinuous range, and should extend it
// unless we've reached the end of the text
PRBool allGlyphsAreWithinCluster = PR_TRUE;
PRInt32 prevGlyphCharIndex = charStart - 1;
for (PRInt32 i = glyphStart; i < glyphEnd; ++i) {
PRInt32 glyphCharIndex = ginfo[i].cluster;
if (glyphCharIndex < charStart || glyphCharIndex >= charEnd) {
allGlyphsAreWithinCluster = PR_FALSE;
break;
}
if (glyphCharIndex <= prevGlyphCharIndex) {
inOrder = PR_FALSE;
}
prevGlyphCharIndex = glyphCharIndex;
}
if (allGlyphsAreWithinCluster) {
break;
}
}
NS_ASSERTION(glyphStart < glyphEnd,
"character/glyph clump contains no glyphs!");
NS_ASSERTION(charStart != charEnd,
"character/glyph clump contains no characters!");
// Now charStart..charEnd is a ligature clump, corresponding to glyphStart..glyphEnd;
// Set baseCharIndex to the char we'll actually attach the glyphs to (1st of ligature),
// and endCharIndex to the limit (position beyond the last char),
// adjusting for the offset of the stringRange relative to the textRun.
PRInt32 baseCharIndex, endCharIndex;
while (charEnd < aRunLength && charToGlyph[charEnd] == NO_GLYPH)
charEnd++;
baseCharIndex = charStart;
endCharIndex = charEnd;
// Then we check if the clump falls outside our actual string range;
// if so, just go to the next.
if (baseCharIndex >= aRunLength) {
glyphStart = glyphEnd;
charStart = charEnd;
continue;
}
// Ensure we won't try to go beyond the valid length of the textRun's text
endCharIndex = PR_MIN(endCharIndex, aRunLength);
// Now we're ready to set the glyph info in the textRun;
// measure the glyph width of the first (perhaps only) glyph,
// to see if it is "Simple"
nscoord advance;
if (glyphStart < numGlyphs-1) {
advance = positions[glyphStart+1].x - positions[glyphStart].x;
} else {
advance = positions[0].x + runWidth - positions[glyphStart].x;
}
PRInt32 glyphsInClump = glyphEnd - glyphStart;
// Check for default-ignorable char that didn't get filtered, combined,
// etc by the shaping process, and remove from the run.
// (This may be done within harfbuzz eventually.)
if (glyphsInClump == 1 && baseCharIndex + 1 == endCharIndex &&
aTextRun->FilterIfIgnorable(aTextRunOffset + baseCharIndex)) {
glyphStart = glyphEnd;
charStart = charEnd;
continue;
}
// Check if it's a simple one-to-one mapping
if (glyphsInClump == 1 &&
gfxTextRun::CompressedGlyph::IsSimpleGlyphID(ginfo[glyphStart].codepoint) &&
gfxTextRun::CompressedGlyph::IsSimpleAdvance(advance) &&
aTextRun->IsClusterStart(aTextRunOffset + baseCharIndex) &&
positions[glyphStart].y == 0)
{
gfxTextRun::CompressedGlyph g;
aTextRun->SetSimpleGlyph(aTextRunOffset + baseCharIndex,
g.SetSimpleGlyph(advance,
ginfo[glyphStart].codepoint));
} else {
// collect all glyphs in a list to be assigned to the first char;
// there must be at least one in the clump, and we already measured
// its advance, hence the placement of the loop-exit test and the
// measurement of the next glyph
while (1) {
gfxTextRun::DetailedGlyph* details =
detailedGlyphs.AppendElement();
details->mGlyphID = ginfo[glyphStart].codepoint;
details->mXOffset = 0.0f;
details->mYOffset = -positions[glyphStart].y;
details->mAdvance = advance;
if (++glyphStart >= glyphEnd)
break;
if (glyphStart < numGlyphs-1) {
advance = positions[glyphStart+1].x -
positions[glyphStart].x;
} else {
advance = positions[0].x + runWidth -
positions[glyphStart].x;
}
}
gfxTextRun::CompressedGlyph g;
g.SetComplex(aTextRun->IsClusterStart(aTextRunOffset + baseCharIndex),
PR_TRUE, detailedGlyphs.Length());
aTextRun->SetGlyphs(aTextRunOffset + baseCharIndex,
g, detailedGlyphs.Elements());
detailedGlyphs.Clear();
}
// the rest of the chars in the group are ligature continuations,
// no associated glyphs
while (++baseCharIndex != endCharIndex && baseCharIndex < aRunLength) {
gfxTextRun::CompressedGlyph g;
g.SetComplex(inOrder &&
aTextRun->IsClusterStart(aTextRunOffset + baseCharIndex),
PR_FALSE, 0);
aTextRun->SetGlyphs(aTextRunOffset + baseCharIndex, g, nsnull);
}
glyphStart = glyphEnd;
charStart = charEnd;
}
return NS_OK;
}
nscoord
gfxHarfBuzzShaper::GetGlyphPositions(gfxContext *aContext,
hb_buffer_t *aBuffer,
nsTArray<nsPoint>& aPositions,
PRUint32 aAppUnitsPerDevUnit)
{
nsPoint *outPos = aPositions.Elements();
const nsPoint *limit = outPos + hb_buffer_get_length(aBuffer);
nsPoint curPos(0, 0);
// factor to convert 16.16 fixed-point pixels to app units
float hb2appUnits = aAppUnitsPerDevUnit / 65536.0;
const hb_glyph_position_t *posInfo = hb_buffer_get_glyph_positions(aBuffer);
while (outPos < limit) {
outPos->x = posInfo->x_offset == 0 ? curPos.x :
curPos.x + NS_roundf(hb2appUnits * posInfo->x_offset);
outPos->y = posInfo->y_offset == 0 ? curPos.y :
curPos.y + NS_roundf(hb2appUnits * posInfo->y_offset);
curPos.x += NS_roundf(hb2appUnits * posInfo->x_advance);
if (posInfo->y_advance) {
curPos.y += NS_roundf(hb2appUnits * posInfo->y_advance);
}
++posInfo;
++outPos;
}
return curPos.x;
}
Ссылка в новой задаче Показать git blame Копировать постоянную ссылку