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gecko-dev/gfx/thebes/gfxDWriteFonts.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 Foundation code.
*
* The Initial Developer of the Original Code is Mozilla Foundation.
* Portions created by the Initial Developer are Copyright (C) 2010
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Bas Schouten <bschouten@mozilla.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 "gfxDWriteFonts.h"
#include "gfxDWriteShaper.h"
#include "gfxHarfBuzzShaper.h"
#ifdef MOZ_GRAPHITE
#include "gfxGraphiteShaper.h"
#endif
#include "gfxDWriteFontList.h"
#include "gfxContext.h"
#include <dwrite.h>
#include "gfxDWriteTextAnalysis.h"
#include "harfbuzz/hb-blob.h"
// Chosen this as to resemble DWrite's own oblique face style.
#define OBLIQUE_SKEW_FACTOR 0.3
// This is also in gfxGDIFont.cpp. Would be nice to put it somewhere common,
// but we can't declare it in the gfxFont.h or gfxFontUtils.h headers
// because those are exported, and the cairo headers aren't.
static inline cairo_antialias_t
GetCairoAntialiasOption(gfxFont::AntialiasOption anAntialiasOption)
{
switch (anAntialiasOption) {
default:
case gfxFont::kAntialiasDefault:
return CAIRO_ANTIALIAS_DEFAULT;
case gfxFont::kAntialiasNone:
return CAIRO_ANTIALIAS_NONE;
case gfxFont::kAntialiasGrayscale:
return CAIRO_ANTIALIAS_GRAY;
case gfxFont::kAntialiasSubpixel:
return CAIRO_ANTIALIAS_SUBPIXEL;
}
}
// Code to determine whether Windows is set to use ClearType font smoothing;
// based on private functions in cairo-win32-font.c
#ifndef SPI_GETFONTSMOOTHINGTYPE
#define SPI_GETFONTSMOOTHINGTYPE 0x200a
#endif
#ifndef FE_FONTSMOOTHINGCLEARTYPE
#define FE_FONTSMOOTHINGCLEARTYPE 2
#endif
static bool
HasClearType()
{
OSVERSIONINFO versionInfo;
versionInfo.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
return (GetVersionEx(&versionInfo) &&
(versionInfo.dwMajorVersion > 5 ||
(versionInfo.dwMajorVersion == 5 &&
versionInfo.dwMinorVersion >= 1))); // XP or newer
}
static bool
UsingClearType()
{
BOOL fontSmoothing;
if (!SystemParametersInfo(SPI_GETFONTSMOOTHING, 0, &fontSmoothing, 0) ||
!fontSmoothing)
{
return false;
}
if (!HasClearType()) {
return false;
}
UINT type;
if (SystemParametersInfo(SPI_GETFONTSMOOTHINGTYPE, 0, &type, 0) &&
type == FE_FONTSMOOTHINGCLEARTYPE)
{
return true;
}
return false;
}
////////////////////////////////////////////////////////////////////////////////
// gfxDWriteFont
gfxDWriteFont::gfxDWriteFont(gfxFontEntry *aFontEntry,
const gfxFontStyle *aFontStyle,
bool aNeedsBold,
AntialiasOption anAAOption)
: gfxFont(aFontEntry, aFontStyle, anAAOption)
, mCairoFontFace(nsnull)
, mMetrics(nsnull)
, mNeedsOblique(false)
, mNeedsBold(aNeedsBold)
, mUseSubpixelPositions(false)
, mAllowManualShowGlyphs(true)
{
gfxDWriteFontEntry *fe =
static_cast<gfxDWriteFontEntry*>(aFontEntry);
nsresult rv;
DWRITE_FONT_SIMULATIONS sims = DWRITE_FONT_SIMULATIONS_NONE;
if ((GetStyle()->style & (FONT_STYLE_ITALIC | FONT_STYLE_OBLIQUE)) &&
!fe->IsItalic()) {
// For this we always use the font_matrix for uniformity. Not the
// DWrite simulation.
mNeedsOblique = true;
}
if (aNeedsBold) {
sims |= DWRITE_FONT_SIMULATIONS_BOLD;
}
rv = fe->CreateFontFace(getter_AddRefs(mFontFace), sims);
if (NS_FAILED(rv)) {
mIsValid = false;
return;
}
ComputeMetrics(anAAOption);
#ifdef MOZ_GRAPHITE
if (FontCanSupportGraphite()) {
mGraphiteShaper = new gfxGraphiteShaper(this);
}
#endif
if (FontCanSupportHarfBuzz()) {
mHarfBuzzShaper = new gfxHarfBuzzShaper(this);
}
}
gfxDWriteFont::~gfxDWriteFont()
{
if (mCairoFontFace) {
cairo_font_face_destroy(mCairoFontFace);
}
if (mScaledFont) {
cairo_scaled_font_destroy(mScaledFont);
}
delete mMetrics;
}
gfxFont*
gfxDWriteFont::CopyWithAntialiasOption(AntialiasOption anAAOption)
{
return new gfxDWriteFont(static_cast<gfxDWriteFontEntry*>(mFontEntry.get()),
&mStyle, mNeedsBold, anAAOption);
}
void
gfxDWriteFont::CreatePlatformShaper()
{
mPlatformShaper = new gfxDWriteShaper(this);
}
const gfxFont::Metrics&
gfxDWriteFont::GetMetrics()
{
return *mMetrics;
}
bool
gfxDWriteFont::GetFakeMetricsForArialBlack(DWRITE_FONT_METRICS *aFontMetrics)
{
gfxFontStyle style(mStyle);
style.weight = 700;
bool needsBold;
gfxFontEntry *fe = mFontEntry->Family()->FindFontForStyle(style, needsBold);
if (!fe || fe == mFontEntry) {
return false;
}
nsRefPtr<gfxFont> font = fe->FindOrMakeFont(&style, needsBold);
gfxDWriteFont *dwFont = static_cast<gfxDWriteFont*>(font.get());
dwFont->mFontFace->GetMetrics(aFontMetrics);
return true;
}
void
gfxDWriteFont::ComputeMetrics(AntialiasOption anAAOption)
{
DWRITE_FONT_METRICS fontMetrics;
if (!(mFontEntry->Weight() == 900 &&
!mFontEntry->IsUserFont() &&
mFontEntry->FamilyName().EqualsLiteral("Arial") &&
GetFakeMetricsForArialBlack(&fontMetrics)))
{
mFontFace->GetMetrics(&fontMetrics);
}
if (mStyle.sizeAdjust != 0.0) {
gfxFloat aspect = (gfxFloat)fontMetrics.xHeight /
fontMetrics.designUnitsPerEm;
mAdjustedSize = mStyle.GetAdjustedSize(aspect);
} else {
mAdjustedSize = mStyle.size;
}
// Note that GetMeasuringMode depends on mAdjustedSize
if ((anAAOption == gfxFont::kAntialiasDefault &&
UsingClearType() &&
GetMeasuringMode() == DWRITE_MEASURING_MODE_NATURAL) ||
anAAOption == gfxFont::kAntialiasSubpixel)
{
mUseSubpixelPositions = true;
// note that this may be reset to FALSE if we determine that a bitmap
// strike is going to be used
}
gfxDWriteFontEntry *fe =
static_cast<gfxDWriteFontEntry*>(mFontEntry.get());
if (fe->IsCJKFont() && HasBitmapStrikeForSize(NS_lround(mAdjustedSize))) {
mAdjustedSize = NS_lround(mAdjustedSize);
mUseSubpixelPositions = false;
// if we have bitmaps, we need to tell Cairo NOT to use subpixel AA,
// to avoid the manual-subpixel codepath in cairo-d2d-surface.cpp
// which fails to render bitmap glyphs (see bug 626299).
// This option will be passed to the cairo_dwrite_scaled_font_t
// after creation.
mAllowManualShowGlyphs = false;
}
mMetrics = new gfxFont::Metrics;
::memset(mMetrics, 0, sizeof(*mMetrics));
mFUnitsConvFactor = float(mAdjustedSize / fontMetrics.designUnitsPerEm);
mMetrics->xHeight = fontMetrics.xHeight * mFUnitsConvFactor;
mMetrics->maxAscent = ceil(fontMetrics.ascent * mFUnitsConvFactor);
mMetrics->maxDescent = ceil(fontMetrics.descent * mFUnitsConvFactor);
mMetrics->maxHeight = mMetrics->maxAscent + mMetrics->maxDescent;
mMetrics->emHeight = mAdjustedSize;
mMetrics->emAscent = mMetrics->emHeight *
mMetrics->maxAscent / mMetrics->maxHeight;
mMetrics->emDescent = mMetrics->emHeight - mMetrics->emAscent;
mMetrics->maxAdvance = mAdjustedSize;
// try to get the true maxAdvance value from 'hhea'
PRUint8 *tableData;
PRUint32 len;
void *tableContext = NULL;
BOOL exists;
HRESULT hr =
mFontFace->TryGetFontTable(DWRITE_MAKE_OPENTYPE_TAG('h', 'h', 'e', 'a'),
(const void**)&tableData,
&len,
&tableContext,
&exists);
if (SUCCEEDED(hr)) {
if (exists && len >= sizeof(mozilla::HheaTable)) {
const mozilla::HheaTable* hhea =
reinterpret_cast<const mozilla::HheaTable*>(tableData);
mMetrics->maxAdvance =
PRUint16(hhea->advanceWidthMax) * mFUnitsConvFactor;
}
mFontFace->ReleaseFontTable(tableContext);
}
mMetrics->internalLeading = NS_MAX(mMetrics->maxHeight - mMetrics->emHeight, 0.0);
mMetrics->externalLeading = ceil(fontMetrics.lineGap * mFUnitsConvFactor);
UINT16 glyph = (PRUint16)GetSpaceGlyph();
mMetrics->spaceWidth = MeasureGlyphWidth(glyph);
// try to get aveCharWidth from the OS/2 table, fall back to measuring 'x'
// if the table is not available or if using hinted/pixel-snapped widths
if (mUseSubpixelPositions) {
mMetrics->aveCharWidth = 0;
hr = mFontFace->TryGetFontTable(DWRITE_MAKE_OPENTYPE_TAG('O', 'S', '/', '2'),
(const void**)&tableData,
&len,
&tableContext,
&exists);
if (SUCCEEDED(hr)) {
if (exists && len >= 4) {
// Not checking against sizeof(mozilla::OS2Table) here because older
// versions of the table have different sizes; we only need the first
// two 16-bit fields here.
const mozilla::OS2Table* os2 =
reinterpret_cast<const mozilla::OS2Table*>(tableData);
mMetrics->aveCharWidth =
PRInt16(os2->xAvgCharWidth) * mFUnitsConvFactor;
}
mFontFace->ReleaseFontTable(tableContext);
}
}
UINT32 ucs;
if (mMetrics->aveCharWidth < 1) {
ucs = L'x';
if (SUCCEEDED(mFontFace->GetGlyphIndicesA(&ucs, 1, &glyph))) {
mMetrics->aveCharWidth = MeasureGlyphWidth(glyph);
}
if (mMetrics->aveCharWidth < 1) {
// Let's just assume the X is square.
mMetrics->aveCharWidth = fontMetrics.xHeight * mFUnitsConvFactor;
}
}
ucs = L'0';
if (SUCCEEDED(mFontFace->GetGlyphIndicesA(&ucs, 1, &glyph))) {
mMetrics->zeroOrAveCharWidth = MeasureGlyphWidth(glyph);
}
if (mMetrics->zeroOrAveCharWidth < 1) {
mMetrics->zeroOrAveCharWidth = mMetrics->aveCharWidth;
}
mMetrics->underlineOffset =
fontMetrics.underlinePosition * mFUnitsConvFactor;
mMetrics->underlineSize =
fontMetrics.underlineThickness * mFUnitsConvFactor;
mMetrics->strikeoutOffset =
fontMetrics.strikethroughPosition * mFUnitsConvFactor;
mMetrics->strikeoutSize =
fontMetrics.strikethroughThickness * mFUnitsConvFactor;
mMetrics->superscriptOffset = 0;
mMetrics->subscriptOffset = 0;
SanitizeMetrics(mMetrics, GetFontEntry()->mIsBadUnderlineFont);
#if 0
printf("Font: %p (%s) size: %f\n", this,
NS_ConvertUTF16toUTF8(GetName()).get(), mStyle.size);
printf(" emHeight: %f emAscent: %f emDescent: %f\n", mMetrics->emHeight, mMetrics->emAscent, mMetrics->emDescent);
printf(" maxAscent: %f maxDescent: %f maxAdvance: %f\n", mMetrics->maxAscent, mMetrics->maxDescent, mMetrics->maxAdvance);
printf(" internalLeading: %f externalLeading: %f\n", mMetrics->internalLeading, mMetrics->externalLeading);
printf(" spaceWidth: %f aveCharWidth: %f zeroOrAve: %f xHeight: %f\n",
mMetrics->spaceWidth, mMetrics->aveCharWidth, mMetrics->zeroOrAveCharWidth, mMetrics->xHeight);
printf(" uOff: %f uSize: %f stOff: %f stSize: %f supOff: %f subOff: %f\n",
mMetrics->underlineOffset, mMetrics->underlineSize, mMetrics->strikeoutOffset, mMetrics->strikeoutSize,
mMetrics->superscriptOffset, mMetrics->subscriptOffset);
#endif
}
using namespace mozilla; // for AutoSwap_* types
struct EBLCHeader {
AutoSwap_PRUint32 version;
AutoSwap_PRUint32 numSizes;
};
struct SbitLineMetrics {
PRInt8 ascender;
PRInt8 descender;
PRUint8 widthMax;
PRInt8 caretSlopeNumerator;
PRInt8 caretSlopeDenominator;
PRInt8 caretOffset;
PRInt8 minOriginSB;
PRInt8 minAdvanceSB;
PRInt8 maxBeforeBL;
PRInt8 minAfterBL;
PRInt8 pad1;
PRInt8 pad2;
};
struct BitmapSizeTable {
AutoSwap_PRUint32 indexSubTableArrayOffset;
AutoSwap_PRUint32 indexTablesSize;
AutoSwap_PRUint32 numberOfIndexSubTables;
AutoSwap_PRUint32 colorRef;
SbitLineMetrics hori;
SbitLineMetrics vert;
AutoSwap_PRUint16 startGlyphIndex;
AutoSwap_PRUint16 endGlyphIndex;
PRUint8 ppemX;
PRUint8 ppemY;
PRUint8 bitDepth;
PRUint8 flags;
};
typedef EBLCHeader EBSCHeader;
struct BitmapScaleTable {
SbitLineMetrics hori;
SbitLineMetrics vert;
PRUint8 ppemX;
PRUint8 ppemY;
PRUint8 substitutePpemX;
PRUint8 substitutePpemY;
};
bool
gfxDWriteFont::HasBitmapStrikeForSize(PRUint32 aSize)
{
PRUint8 *tableData;
PRUint32 len;
void *tableContext;
BOOL exists;
HRESULT hr =
mFontFace->TryGetFontTable(DWRITE_MAKE_OPENTYPE_TAG('E', 'B', 'L', 'C'),
(const void**)&tableData, &len,
&tableContext, &exists);
if (FAILED(hr)) {
return false;
}
bool hasStrike = false;
// not really a loop, but this lets us use 'break' to skip out of the block
// as soon as we know the answer, and skips it altogether if the table is
// not present
while (exists) {
if (len < sizeof(EBLCHeader)) {
break;
}
const EBLCHeader *hdr = reinterpret_cast<const EBLCHeader*>(tableData);
if (hdr->version != 0x00020000) {
break;
}
PRUint32 numSizes = hdr->numSizes;
if (numSizes > 0xffff) { // sanity-check, prevent overflow below
break;
}
if (len < sizeof(EBLCHeader) + numSizes * sizeof(BitmapSizeTable)) {
break;
}
const BitmapSizeTable *sizeTable =
reinterpret_cast<const BitmapSizeTable*>(hdr + 1);
for (PRUint32 i = 0; i < numSizes; ++i, ++sizeTable) {
if (sizeTable->ppemX == aSize && sizeTable->ppemY == aSize) {
// we ignore a strike that contains fewer than 4 glyphs,
// as that probably indicates a font such as Courier New
// that provides bitmaps ONLY for the "shading" characters
// U+2591..2593
hasStrike = (PRUint16(sizeTable->endGlyphIndex) >=
PRUint16(sizeTable->startGlyphIndex) + 3);
break;
}
}
// if we reach here, we didn't find a strike; unconditionally break
// out of the while-loop block
break;
}
mFontFace->ReleaseFontTable(tableContext);
if (hasStrike) {
return true;
}
// if we didn't find a real strike, check if the font calls for scaling
// another bitmap to this size
hr = mFontFace->TryGetFontTable(DWRITE_MAKE_OPENTYPE_TAG('E', 'B', 'S', 'C'),
(const void**)&tableData, &len,
&tableContext, &exists);
if (FAILED(hr)) {
return false;
}
while (exists) {
if (len < sizeof(EBSCHeader)) {
break;
}
const EBSCHeader *hdr = reinterpret_cast<const EBSCHeader*>(tableData);
if (hdr->version != 0x00020000) {
break;
}
PRUint32 numSizes = hdr->numSizes;
if (numSizes > 0xffff) {
break;
}
if (len < sizeof(EBSCHeader) + numSizes * sizeof(BitmapScaleTable)) {
break;
}
const BitmapScaleTable *scaleTable =
reinterpret_cast<const BitmapScaleTable*>(hdr + 1);
for (PRUint32 i = 0; i < numSizes; ++i, ++scaleTable) {
if (scaleTable->ppemX == aSize && scaleTable->ppemY == aSize) {
hasStrike = true;
break;
}
}
break;
}
mFontFace->ReleaseFontTable(tableContext);
return hasStrike;
}
PRUint32
gfxDWriteFont::GetSpaceGlyph()
{
UINT32 ucs = L' ';
UINT16 glyph;
HRESULT hr;
hr = mFontFace->GetGlyphIndicesA(&ucs, 1, &glyph);
if (FAILED(hr)) {
return 0;
}
return glyph;
}
bool
gfxDWriteFont::SetupCairoFont(gfxContext *aContext)
{
cairo_scaled_font_t *scaledFont = CairoScaledFont();
if (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 false;
}
cairo_set_scaled_font(aContext->GetCairo(), scaledFont);
return true;
}
bool
gfxDWriteFont::IsValid()
{
return mFontFace != NULL;
}
IDWriteFontFace*
gfxDWriteFont::GetFontFace()
{
return mFontFace.get();
}
cairo_font_face_t *
gfxDWriteFont::CairoFontFace()
{
if (!mCairoFontFace) {
#ifdef CAIRO_HAS_DWRITE_FONT
mCairoFontFace =
cairo_dwrite_font_face_create_for_dwrite_fontface(
((gfxDWriteFontEntry*)mFontEntry.get())->mFont, mFontFace);
#endif
}
return mCairoFontFace;
}
cairo_scaled_font_t *
gfxDWriteFont::CairoScaledFont()
{
if (!mScaledFont) {
cairo_matrix_t sizeMatrix;
cairo_matrix_t identityMatrix;
cairo_matrix_init_scale(&sizeMatrix, mAdjustedSize, mAdjustedSize);
cairo_matrix_init_identity(&identityMatrix);
cairo_font_options_t *fontOptions = cairo_font_options_create();
if (mNeedsOblique) {
double skewfactor = OBLIQUE_SKEW_FACTOR;
cairo_matrix_t style;
cairo_matrix_init(&style,
1, //xx
0, //yx
-1 * skewfactor, //xy
1, //yy
0, //x0
0); //y0
cairo_matrix_multiply(&sizeMatrix, &sizeMatrix, &style);
}
if (mAntialiasOption != kAntialiasDefault) {
cairo_font_options_set_antialias(fontOptions,
GetCairoAntialiasOption(mAntialiasOption));
}
mScaledFont = cairo_scaled_font_create(CairoFontFace(),
&sizeMatrix,
&identityMatrix,
fontOptions);
cairo_font_options_destroy(fontOptions);
cairo_dwrite_scaled_font_allow_manual_show_glyphs(mScaledFont,
mAllowManualShowGlyphs);
gfxDWriteFontEntry *fe =
static_cast<gfxDWriteFontEntry*>(mFontEntry.get());
cairo_dwrite_scaled_font_set_force_GDI_classic(mScaledFont,
GetForceGDIClassic());
}
NS_ASSERTION(mAdjustedSize == 0.0 ||
cairo_scaled_font_status(mScaledFont)
== CAIRO_STATUS_SUCCESS,
"Failed to make scaled font");
return mScaledFont;
}
gfxFont::RunMetrics
gfxDWriteFont::Measure(gfxTextRun *aTextRun,
PRUint32 aStart, PRUint32 aEnd,
BoundingBoxType aBoundingBoxType,
gfxContext *aRefContext,
Spacing *aSpacing)
{
gfxFont::RunMetrics metrics =
gfxFont::Measure(aTextRun, aStart, aEnd,
aBoundingBoxType, aRefContext, aSpacing);
// if aBoundingBoxType is LOOSE_INK_EXTENTS
// and the underlying cairo font may be antialiased,
// we can't trust Windows to have considered all the pixels
// so we need to add "padding" to the bounds.
// (see bugs 475968, 439831, compare also bug 445087)
if (aBoundingBoxType == LOOSE_INK_EXTENTS &&
mAntialiasOption != kAntialiasNone &&
GetMeasuringMode() == DWRITE_MEASURING_MODE_GDI_CLASSIC &&
metrics.mBoundingBox.width > 0) {
metrics.mBoundingBox.x -= aTextRun->GetAppUnitsPerDevUnit();
metrics.mBoundingBox.width += aTextRun->GetAppUnitsPerDevUnit() * 3;
}
return metrics;
}
// Access to font tables packaged in hb_blob_t form
// object attached to the Harfbuzz blob, used to release
// the table when the blob is destroyed
class FontTableRec {
public:
FontTableRec(IDWriteFontFace *aFontFace, void *aContext)
: mFontFace(aFontFace), mContext(aContext)
{ }
~FontTableRec() {
mFontFace->ReleaseFontTable(mContext);
}
private:
IDWriteFontFace *mFontFace;
void *mContext;
};
/*static*/ void
gfxDWriteFont::DestroyBlobFunc(void* aUserData)
{
FontTableRec *ftr = static_cast<FontTableRec*>(aUserData);
delete ftr;
}
hb_blob_t *
gfxDWriteFont::GetFontTable(PRUint32 aTag)
{
const void *data;
UINT32 size;
void *context;
BOOL exists;
HRESULT hr = mFontFace->TryGetFontTable(NS_SWAP32(aTag),
&data, &size, &context, &exists);
if (SUCCEEDED(hr) && exists) {
FontTableRec *ftr = new FontTableRec(mFontFace, context);
return hb_blob_create(static_cast<const char*>(data), size,
HB_MEMORY_MODE_READONLY,
DestroyBlobFunc, ftr);
}
if (mFontEntry->IsUserFont() && !mFontEntry->IsLocalUserFont()) {
// for downloaded fonts, there may be layout tables cached in the entry
// even though they're absent from the sanitized platform font
hb_blob_t *blob;
if (mFontEntry->GetExistingFontTable(aTag, &blob)) {
return blob;
}
}
return nsnull;
}
bool
gfxDWriteFont::ProvidesGlyphWidths()
{
return !mUseSubpixelPositions ||
(mFontFace->GetSimulations() & DWRITE_FONT_SIMULATIONS_BOLD);
}
PRInt32
gfxDWriteFont::GetGlyphWidth(gfxContext *aCtx, PRUint16 aGID)
{
if (!mGlyphWidths.IsInitialized()) {
mGlyphWidths.Init(200);
}
PRInt32 width = -1;
if (mGlyphWidths.Get(aGID, &width)) {
return width;
}
width = NS_lround(MeasureGlyphWidth(aGID) * 65536.0);
mGlyphWidths.Put(aGID, width);
return width;
}
bool
gfxDWriteFont::GetForceGDIClassic()
{
return static_cast<gfxDWriteFontEntry*>(mFontEntry.get())->GetForceGDIClassic() &&
cairo_dwrite_get_cleartype_rendering_mode() < 0 &&
GetAdjustedSize() <=
gfxDWriteFontList::PlatformFontList()->GetForceGDIClassicMaxFontSize();
}
DWRITE_MEASURING_MODE
gfxDWriteFont::GetMeasuringMode()
{
return GetForceGDIClassic()
? DWRITE_MEASURING_MODE_GDI_CLASSIC
: gfxWindowsPlatform::GetPlatform()->DWriteMeasuringMode();
}
gfxFloat
gfxDWriteFont::MeasureGlyphWidth(PRUint16 aGlyph)
{
DWRITE_GLYPH_METRICS metrics;
HRESULT hr;
if (mUseSubpixelPositions) {
hr = mFontFace->GetDesignGlyphMetrics(&aGlyph, 1, &metrics, FALSE);
if (SUCCEEDED(hr)) {
return metrics.advanceWidth * mFUnitsConvFactor;
}
} else {
hr = mFontFace->GetGdiCompatibleGlyphMetrics(
FLOAT(mAdjustedSize), 1.0f, nsnull,
GetMeasuringMode() == DWRITE_MEASURING_MODE_GDI_NATURAL,
&aGlyph, 1, &metrics, FALSE);
if (SUCCEEDED(hr)) {
return NS_lround(metrics.advanceWidth * mFUnitsConvFactor);
}
}
return 0;
}
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