gecko-dev/gfx/thebes/gfxDWriteShaper.cpp

300 строки
12 KiB
C++

/* -*- 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 "gfxDWriteShaper.h"
#include "gfxWindowsPlatform.h"
#include <dwrite.h>
#include "gfxDWriteTextAnalysis.h"
#include "nsCRT.h"
#define MAX_RANGE_LENGTH 25000
bool
gfxDWriteShaper::InitTextRun(gfxContext *aContext,
gfxTextRun *aTextRun,
const PRUnichar *aString,
PRUint32 aRunStart,
PRUint32 aRunLength,
PRInt32 aRunScript)
{
HRESULT hr;
// TODO: Handle TEST_DISABLE_OPTIONAL_LIGATURES
DWRITE_READING_DIRECTION readingDirection =
aTextRun->IsRightToLeft()
? DWRITE_READING_DIRECTION_RIGHT_TO_LEFT
: DWRITE_READING_DIRECTION_LEFT_TO_RIGHT;
gfxDWriteFont *font = static_cast<gfxDWriteFont*>(mFont);
gfxTextRun::CompressedGlyph g;
nsRefPtr<IDWriteTextAnalyzer> analyzer;
hr = gfxWindowsPlatform::GetPlatform()->GetDWriteFactory()->
CreateTextAnalyzer(getter_AddRefs(analyzer));
if (FAILED(hr)) {
return false;
}
/**
* There's an internal 16-bit limit on some things inside the analyzer.
* to be on the safe side here we split up any ranges over MAX_RANGE_LENGTH
* characters.
* TODO: Figure out what exactly is going on, and what is a safe number, and
* why.
*/
bool result = true;
UINT32 rangeOffset = 0;
while (rangeOffset < aRunLength) {
PRUint32 rangeLen = NS_MIN<PRUint32>(aRunLength - rangeOffset,
MAX_RANGE_LENGTH);
if (rangeOffset + rangeLen < aRunLength) {
// Iterate backwards to find a decent place to break shaping:
// look for a whitespace char, and if that's not found then
// at least a char where IsClusterStart is true.
// However, we never iterate back further than half-way;
// if a decent break is not found by then, we just chop anyway
// at the original range length.
PRUint32 adjRangeLen = 0;
const PRUnichar *rangeStr = aString + aRunStart + rangeOffset;
for (PRUint32 i = rangeLen; i > MAX_RANGE_LENGTH / 2; i--) {
if (nsCRT::IsAsciiSpace(rangeStr[i])) {
adjRangeLen = i;
break;
}
if (adjRangeLen == 0 &&
aTextRun->IsClusterStart(aRunStart + rangeOffset + i)) {
adjRangeLen = i;
}
}
if (adjRangeLen != 0) {
rangeLen = adjRangeLen;
}
}
PRUint32 rangeStart = aRunStart + rangeOffset;
rangeOffset += rangeLen;
TextAnalysis analysis(aString + rangeStart, rangeLen,
NULL,
readingDirection);
TextAnalysis::Run *runHead;
DWRITE_LINE_BREAKPOINT *linebreaks;
hr = analysis.GenerateResults(analyzer, &runHead, &linebreaks);
if (FAILED(hr)) {
NS_WARNING("Analyzer failed to generate results.");
result = false;
break;
}
PRUint32 appUnitsPerDevPixel = aTextRun->GetAppUnitsPerDevUnit();
UINT32 maxGlyphs = 0;
trymoreglyphs:
if ((PR_UINT32_MAX - 3 * rangeLen / 2 + 16) < maxGlyphs) {
// This isn't going to work, we're going to cross the UINT32 upper
// limit. Next range it is.
continue;
}
maxGlyphs += 3 * rangeLen / 2 + 16;
nsAutoTArray<UINT16, 400> clusters;
nsAutoTArray<UINT16, 400> indices;
nsAutoTArray<DWRITE_SHAPING_TEXT_PROPERTIES, 400> textProperties;
nsAutoTArray<DWRITE_SHAPING_GLYPH_PROPERTIES, 400> glyphProperties;
if (!clusters.SetLength(rangeLen) ||
!indices.SetLength(maxGlyphs) ||
!textProperties.SetLength(maxGlyphs) ||
!glyphProperties.SetLength(maxGlyphs)) {
continue;
}
UINT32 actualGlyphs;
hr = analyzer->GetGlyphs(aString + rangeStart, rangeLen,
font->GetFontFace(), FALSE,
readingDirection == DWRITE_READING_DIRECTION_RIGHT_TO_LEFT,
&runHead->mScript, NULL, NULL, NULL, NULL, 0,
maxGlyphs, clusters.Elements(), textProperties.Elements(),
indices.Elements(), glyphProperties.Elements(), &actualGlyphs);
if (hr == HRESULT_FROM_WIN32(ERROR_INSUFFICIENT_BUFFER)) {
// We increase the amount of glyphs and try again.
goto trymoreglyphs;
}
if (FAILED(hr)) {
NS_WARNING("Analyzer failed to get glyphs.");
result = false;
break;
}
WORD gID = indices[0];
nsAutoTArray<FLOAT, 400> advances;
nsAutoTArray<DWRITE_GLYPH_OFFSET, 400> glyphOffsets;
if (!advances.SetLength(actualGlyphs) ||
!glyphOffsets.SetLength(actualGlyphs)) {
continue;
}
if (!static_cast<gfxDWriteFont*>(mFont)->mUseSubpixelPositions) {
hr = analyzer->GetGdiCompatibleGlyphPlacements(
aString + rangeStart,
clusters.Elements(),
textProperties.Elements(),
rangeLen,
indices.Elements(),
glyphProperties.Elements(),
actualGlyphs,
font->GetFontFace(),
font->GetAdjustedSize(),
1.0,
nsnull,
FALSE,
FALSE,
FALSE,
&runHead->mScript,
NULL,
NULL,
NULL,
0,
advances.Elements(),
glyphOffsets.Elements());
} else {
hr = analyzer->GetGlyphPlacements(aString + rangeStart,
clusters.Elements(),
textProperties.Elements(),
rangeLen,
indices.Elements(),
glyphProperties.Elements(),
actualGlyphs,
font->GetFontFace(),
font->GetAdjustedSize(),
FALSE,
FALSE,
&runHead->mScript,
NULL,
NULL,
NULL,
0,
advances.Elements(),
glyphOffsets.Elements());
}
if (FAILED(hr)) {
NS_WARNING("Analyzer failed to get glyph placements.");
result = false;
break;
}
nsAutoTArray<gfxTextRun::DetailedGlyph,1> detailedGlyphs;
for (unsigned int c = 0; c < rangeLen; c++) {
PRUint32 k = clusters[c];
PRUint32 absC = rangeStart + c;
if (c > 0 && k == clusters[c - 1]) {
g.SetComplex(aTextRun->IsClusterStart(absC), false, 0);
aTextRun->SetGlyphs(absC, g, nsnull);
// This is a cluster continuation. No glyph here.
continue;
}
// Count glyphs for this character
PRUint32 glyphCount = actualGlyphs - k;
PRUint32 nextClusterOffset;
for (nextClusterOffset = c + 1;
nextClusterOffset < rangeLen; ++nextClusterOffset) {
if (clusters[nextClusterOffset] > k) {
glyphCount = clusters[nextClusterOffset] - k;
break;
}
}
PRInt32 advance = (PRInt32)(advances[k] * appUnitsPerDevPixel);
if (glyphCount == 1 && advance >= 0 &&
glyphOffsets[k].advanceOffset == 0 &&
glyphOffsets[k].ascenderOffset == 0 &&
aTextRun->IsClusterStart(absC) &&
gfxTextRun::CompressedGlyph::IsSimpleAdvance(advance) &&
gfxTextRun::CompressedGlyph::IsSimpleGlyphID(indices[k])) {
aTextRun->SetSimpleGlyph(absC,
g.SetSimpleGlyph(advance,
indices[k]));
} else {
if (detailedGlyphs.Length() < glyphCount) {
if (!detailedGlyphs.AppendElements(
glyphCount - detailedGlyphs.Length())) {
continue;
}
}
float totalAdvance = 0;
for (unsigned int z = 0; z < glyphCount; z++) {
detailedGlyphs[z].mGlyphID = indices[k + z];
detailedGlyphs[z].mAdvance =
(PRInt32)(advances[k + z]
* appUnitsPerDevPixel);
if (readingDirection ==
DWRITE_READING_DIRECTION_RIGHT_TO_LEFT) {
detailedGlyphs[z].mXOffset =
(totalAdvance +
glyphOffsets[k + z].advanceOffset)
* appUnitsPerDevPixel;
} else {
detailedGlyphs[z].mXOffset =
glyphOffsets[k + z].advanceOffset *
appUnitsPerDevPixel;
}
detailedGlyphs[z].mYOffset =
-glyphOffsets[k + z].ascenderOffset *
appUnitsPerDevPixel;
totalAdvance += advances[k + z];
}
aTextRun->SetGlyphs(
absC,
g.SetComplex(aTextRun->IsClusterStart(absC),
true,
glyphCount),
detailedGlyphs.Elements());
}
}
}
return result;
}