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/*
* Copyright (c) 2008, 2009, Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "SimpleFontData.h"
#include "Font.h"
#include "FontCache.h"
#include "FloatRect.h"
#include "FontDescription.h"
#include "Logging.h"
#include "VDMXParser.h"
#include "SkFontHost.h"
#include "SkPaint.h"
#include "SkTime.h"
#include "SkTypeface.h"
#include "SkTypes.h"
namespace WebCore {
// Smallcaps versions of fonts are 70% the size of the normal font.
static const float smallCapsFraction = 0.7f;
static const float emphasisMarkFraction = .5;
// This is the largest VDMX table which we'll try to load and parse.
static const size_t maxVDMXTableSize = 1024 * 1024; // 1 MB
void SimpleFontData::platformInit()
{
if (!m_platformData.size()) {
m_fontMetrics.reset();
m_avgCharWidth = 0;
m_maxCharWidth = 0;
return;
}
SkPaint paint;
SkPaint::FontMetrics metrics;
m_platformData.setupPaint(&paint);
paint.getFontMetrics(&metrics);
const SkFontID fontID = m_platformData.uniqueID();
static const uint32_t vdmxTag = SkSetFourByteTag('V', 'D', 'M', 'X');
int pixelSize = m_platformData.size() + 0.5;
int vdmxAscent, vdmxDescent;
bool isVDMXValid = false;
size_t vdmxSize = SkFontHost::GetTableSize(fontID, vdmxTag);
if (vdmxSize && vdmxSize < maxVDMXTableSize) {
uint8_t* vdmxTable = (uint8_t*) fastMalloc(vdmxSize);
if (vdmxTable
&& SkFontHost::GetTableData(fontID, vdmxTag, 0, vdmxSize, vdmxTable) == vdmxSize
&& parseVDMX(&vdmxAscent, &vdmxDescent, vdmxTable, vdmxSize, pixelSize))
isVDMXValid = true;
fastFree(vdmxTable);
}
float ascent;
float descent;
// Beware those who step here: This code is designed to match Win32 font
// metrics *exactly*.
if (isVDMXValid) {
ascent = vdmxAscent;
descent = -vdmxDescent;
} else {
SkScalar height = -metrics.fAscent + metrics.fDescent + metrics.fLeading;
ascent = SkScalarRound(-metrics.fAscent);
descent = SkScalarRound(height) - ascent;
}
m_fontMetrics.setAscent(ascent);
m_fontMetrics.setDescent(descent);
float xHeight;
if (metrics.fXHeight)
xHeight = metrics.fXHeight;
else {
// hack taken from the Windows port
xHeight = ascent * 0.56f;
}
float lineGap = SkScalarToFloat(metrics.fLeading);
m_fontMetrics.setLineGap(lineGap);
m_fontMetrics.setXHeight(xHeight);
m_fontMetrics.setLineSpacing(lroundf(ascent) + lroundf(descent) + lroundf(lineGap));
if (m_orientation == Vertical) {
static const uint32_t vheaTag = SkSetFourByteTag('v', 'h', 'e', 'a');
static const uint32_t vorgTag = SkSetFourByteTag('V', 'O', 'R', 'G');
size_t vheaSize = SkFontHost::GetTableSize(fontID, vheaTag);
size_t vorgSize = SkFontHost::GetTableSize(fontID, vorgTag);
if ((vheaSize <= 0) && (vorgSize <= 0))
m_orientation = Horizontal;
}
// In WebKit/WebCore/platform/graphics/SimpleFontData.cpp, m_spaceWidth is
// calculated for us, but we need to calculate m_maxCharWidth and
// m_avgCharWidth in order for text entry widgets to be sized correctly.
SkScalar xRange = metrics.fXMax - metrics.fXMin;
m_maxCharWidth = SkScalarRound(xRange * SkScalarRound(m_platformData.size()));
if (metrics.fAvgCharWidth)
m_avgCharWidth = SkScalarRound(metrics.fAvgCharWidth);
else {
m_avgCharWidth = xHeight;
GlyphPage* glyphPageZero = GlyphPageTreeNode::getRootChild(this, 0)->page();
if (glyphPageZero) {
static const UChar32 x_char = 'x';
const Glyph xGlyph = glyphPageZero->glyphDataForCharacter(x_char).glyph;
if (xGlyph)
m_avgCharWidth = widthForGlyph(xGlyph);
}
}
}
void SimpleFontData::platformCharWidthInit()
{
// charwidths are set in platformInit.
}
void SimpleFontData::platformDestroy()
{
}
SimpleFontData* SimpleFontData::scaledFontData(const FontDescription& fontDescription, float scaleFactor) const
{
const float scaledSize = lroundf(fontDescription.computedSize() * scaleFactor);
return new SimpleFontData(FontPlatformData(m_platformData, scaledSize), isCustomFont(), false);
}
SimpleFontData* SimpleFontData::smallCapsFontData(const FontDescription& fontDescription) const
{
if (!m_derivedFontData)
m_derivedFontData = DerivedFontData::create(isCustomFont());
if (!m_derivedFontData->smallCaps)
m_derivedFontData->smallCaps = scaledFontData(fontDescription, smallCapsFraction);
return m_derivedFontData->smallCaps.get();
}
SimpleFontData* SimpleFontData::emphasisMarkFontData(const FontDescription& fontDescription) const
{
if (!m_derivedFontData)
m_derivedFontData = DerivedFontData::create(isCustomFont());
if (!m_derivedFontData->emphasisMark)
m_derivedFontData->emphasisMark = scaledFontData(fontDescription, emphasisMarkFraction);
return m_derivedFontData->emphasisMark.get();
}
bool SimpleFontData::containsCharacters(const UChar* characters, int length) const
{
SkPaint paint;
static const unsigned maxBufferCount = 64;
uint16_t glyphs[maxBufferCount];
m_platformData.setupPaint(&paint);
paint.setTextEncoding(SkPaint::kUTF16_TextEncoding);
while (length > 0) {
int n = SkMin32(length, SK_ARRAY_COUNT(glyphs));
// textToGlyphs takes a byte count so we double the character count.
int count = paint.textToGlyphs(characters, n * 2, glyphs);
for (int i = 0; i < count; i++) {
if (0 == glyphs[i])
return false; // missing glyph
}
characters += n;
length -= n;
}
return true;
}
void SimpleFontData::determinePitch()
{
m_treatAsFixedPitch = platformData().isFixedPitch();
}
FloatRect SimpleFontData::platformBoundsForGlyph(Glyph) const
{
return FloatRect();
}
float SimpleFontData::platformWidthForGlyph(Glyph glyph) const
{
if (!m_platformData.size())
return 0;
SkASSERT(sizeof(glyph) == 2); // compile-time assert
SkPaint paint;
m_platformData.setupPaint(&paint);
paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
SkScalar width = paint.measureText(&glyph, 2);
// Though WebKit supports non-integral advances, Skia only supports them
// for "subpixel" (distinct from LCD subpixel antialiasing) text, which
// we don't use.
return round(SkScalarToFloat(width));
}
} // namespace WebCore
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