1 /*
2 * Copyright (C) 2005, 2008, 2010 Apple Inc. All rights reserved.
3 * Copyright (C) 2006 Alexey Proskuryakov
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
15 * its contributors may be used to endorse or promote products derived
16 * from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
19 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
22 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
24 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
25 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #include "config.h"
31 #include "SimpleFontData.h"
32
33 #include "Font.h"
34 #include "FontCache.h"
35
36 #if ENABLE(SVG_FONTS)
37 #include "SVGFontData.h"
38 #include "SVGFontElement.h"
39 #include "SVGFontFaceElement.h"
40 #include "SVGGlyphElement.h"
41 #endif
42
43 #include <wtf/MathExtras.h>
44 #include <wtf/UnusedParam.h>
45
46 using namespace std;
47
48 namespace WebCore {
49
SimpleFontData(const FontPlatformData & platformData,bool isCustomFont,bool isLoading,bool isTextOrientationFallback)50 SimpleFontData::SimpleFontData(const FontPlatformData& platformData, bool isCustomFont, bool isLoading, bool isTextOrientationFallback)
51 : m_maxCharWidth(-1)
52 , m_avgCharWidth(-1)
53 , m_platformData(platformData)
54 , m_treatAsFixedPitch(false)
55 , m_isCustomFont(isCustomFont)
56 , m_isLoading(isLoading)
57 , m_isTextOrientationFallback(isTextOrientationFallback)
58 , m_isBrokenIdeographFallback(false)
59 , m_hasVerticalGlyphs(false)
60 {
61 platformInit();
62 platformGlyphInit();
63 platformCharWidthInit();
64 }
65
66 #if ENABLE(SVG_FONTS)
SimpleFontData(PassOwnPtr<SVGFontData> svgFontData,int size,bool syntheticBold,bool syntheticItalic)67 SimpleFontData::SimpleFontData(PassOwnPtr<SVGFontData> svgFontData, int size, bool syntheticBold, bool syntheticItalic)
68 : m_platformData(FontPlatformData(size, syntheticBold, syntheticItalic))
69 , m_treatAsFixedPitch(false)
70 , m_svgFontData(svgFontData)
71 , m_isCustomFont(true)
72 , m_isLoading(false)
73 , m_isTextOrientationFallback(false)
74 , m_isBrokenIdeographFallback(false)
75 , m_hasVerticalGlyphs(false)
76 {
77 SVGFontFaceElement* svgFontFaceElement = m_svgFontData->svgFontFaceElement();
78 unsigned unitsPerEm = svgFontFaceElement->unitsPerEm();
79
80 float scale = size;
81 if (unitsPerEm)
82 scale /= unitsPerEm;
83
84 float xHeight = svgFontFaceElement->xHeight() * scale;
85 float ascent = svgFontFaceElement->ascent() * scale;
86 float descent = svgFontFaceElement->descent() * scale;
87 float lineGap = 0.1f * size;
88
89 SVGFontElement* associatedFontElement = svgFontFaceElement->associatedFontElement();
90 if (!xHeight) {
91 // Fallback if x_heightAttr is not specified for the font element.
92 Vector<SVGGlyph> letterXGlyphs;
93 associatedFontElement->getGlyphIdentifiersForString(String("x", 1), letterXGlyphs);
94 xHeight = letterXGlyphs.isEmpty() ? 2 * ascent / 3 : letterXGlyphs.first().horizontalAdvanceX * scale;
95 }
96
97 m_fontMetrics.setUnitsPerEm(unitsPerEm);
98 m_fontMetrics.setAscent(ascent);
99 m_fontMetrics.setDescent(descent);
100 m_fontMetrics.setLineGap(lineGap);
101 m_fontMetrics.setLineSpacing(roundf(ascent) + roundf(descent) + roundf(lineGap));
102 m_fontMetrics.setXHeight(xHeight);
103
104 Vector<SVGGlyph> spaceGlyphs;
105 associatedFontElement->getGlyphIdentifiersForString(String(" ", 1), spaceGlyphs);
106 m_spaceWidth = spaceGlyphs.isEmpty() ? xHeight : spaceGlyphs.first().horizontalAdvanceX * scale;
107
108 Vector<SVGGlyph> numeralZeroGlyphs;
109 associatedFontElement->getGlyphIdentifiersForString(String("0", 1), numeralZeroGlyphs);
110 m_avgCharWidth = numeralZeroGlyphs.isEmpty() ? m_spaceWidth : numeralZeroGlyphs.first().horizontalAdvanceX * scale;
111
112 Vector<SVGGlyph> letterWGlyphs;
113 associatedFontElement->getGlyphIdentifiersForString(String("W", 1), letterWGlyphs);
114 m_maxCharWidth = letterWGlyphs.isEmpty() ? ascent : letterWGlyphs.first().horizontalAdvanceX * scale;
115
116 // FIXME: is there a way we can get the space glyph from the SVGGlyph above?
117 m_spaceGlyph = 0;
118 m_zeroWidthSpaceGlyph = 0;
119 determinePitch();
120 m_missingGlyphData.fontData = this;
121 m_missingGlyphData.glyph = 0;
122 }
123 #endif
124
125 #if !(PLATFORM(QT) && !HAVE(QRAWFONT))
126 // Estimates of avgCharWidth and maxCharWidth for platforms that don't support accessing these values from the font.
initCharWidths()127 void SimpleFontData::initCharWidths()
128 {
129 GlyphPage* glyphPageZero = GlyphPageTreeNode::getRootChild(this, 0)->page();
130
131 // Treat the width of a '0' as the avgCharWidth.
132 if (m_avgCharWidth <= 0.f && glyphPageZero) {
133 static const UChar32 digitZeroChar = '0';
134 Glyph digitZeroGlyph = glyphPageZero->glyphDataForCharacter(digitZeroChar).glyph;
135 if (digitZeroGlyph)
136 m_avgCharWidth = widthForGlyph(digitZeroGlyph);
137 }
138
139 // If we can't retrieve the width of a '0', fall back to the x height.
140 if (m_avgCharWidth <= 0.f)
141 m_avgCharWidth = m_fontMetrics.xHeight();
142
143 if (m_maxCharWidth <= 0.f)
144 m_maxCharWidth = max(m_avgCharWidth, m_fontMetrics.floatAscent());
145 }
146
platformGlyphInit()147 void SimpleFontData::platformGlyphInit()
148 {
149 GlyphPage* glyphPageZero = GlyphPageTreeNode::getRootChild(this, 0)->page();
150 if (!glyphPageZero) {
151 LOG_ERROR("Failed to get glyph page zero.");
152 m_spaceGlyph = 0;
153 m_spaceWidth = 0;
154 determinePitch();
155 m_zeroWidthSpaceGlyph = 0;
156 m_missingGlyphData.fontData = this;
157 m_missingGlyphData.glyph = 0;
158 return;
159 }
160
161 m_zeroWidthSpaceGlyph = glyphPageZero->glyphDataForCharacter(0).glyph;
162
163 // Nasty hack to determine if we should round or ceil space widths.
164 // If the font is monospace or fake monospace we ceil to ensure that
165 // every character and the space are the same width. Otherwise we round.
166 m_spaceGlyph = glyphPageZero->glyphDataForCharacter(' ').glyph;
167 float width = widthForGlyph(m_spaceGlyph);
168 m_spaceWidth = width;
169 determinePitch();
170
171 // Force the glyph for ZERO WIDTH SPACE to have zero width, unless it is shared with SPACE.
172 // Helvetica is an example of a non-zero width ZERO WIDTH SPACE glyph.
173 // See <http://bugs.webkit.org/show_bug.cgi?id=13178>
174 // Ask for the glyph for 0 to avoid paging in ZERO WIDTH SPACE. Control characters, including 0,
175 // are mapped to the ZERO WIDTH SPACE glyph.
176 if (m_zeroWidthSpaceGlyph == m_spaceGlyph) {
177 m_zeroWidthSpaceGlyph = 0;
178 LOG_ERROR("Font maps SPACE and ZERO WIDTH SPACE to the same glyph. Glyph width will not be overridden.");
179 }
180
181 m_missingGlyphData.fontData = this;
182 m_missingGlyphData.glyph = 0;
183 }
184 #endif
185
~SimpleFontData()186 SimpleFontData::~SimpleFontData()
187 {
188 #if ENABLE(SVG_FONTS)
189 if (!m_svgFontData || !m_svgFontData->svgFontFaceElement())
190 #endif
191 platformDestroy();
192
193 if (!isCustomFont())
194 GlyphPageTreeNode::pruneTreeFontData(this);
195 }
196
fontDataForCharacter(UChar32) const197 const SimpleFontData* SimpleFontData::fontDataForCharacter(UChar32) const
198 {
199 return this;
200 }
201
isSegmented() const202 bool SimpleFontData::isSegmented() const
203 {
204 return false;
205 }
206
verticalRightOrientationFontData() const207 SimpleFontData* SimpleFontData::verticalRightOrientationFontData() const
208 {
209 if (!m_derivedFontData)
210 m_derivedFontData = DerivedFontData::create(isCustomFont());
211 if (!m_derivedFontData->verticalRightOrientation) {
212 FontPlatformData verticalRightPlatformData(m_platformData);
213 verticalRightPlatformData.setOrientation(Horizontal);
214 m_derivedFontData->verticalRightOrientation = adoptPtr(new SimpleFontData(verticalRightPlatformData, isCustomFont(), false, true));
215 }
216 return m_derivedFontData->verticalRightOrientation.get();
217 }
218
uprightOrientationFontData() const219 SimpleFontData* SimpleFontData::uprightOrientationFontData() const
220 {
221 if (!m_derivedFontData)
222 m_derivedFontData = DerivedFontData::create(isCustomFont());
223 if (!m_derivedFontData->uprightOrientation)
224 m_derivedFontData->uprightOrientation = adoptPtr(new SimpleFontData(m_platformData, isCustomFont(), false, true));
225 return m_derivedFontData->uprightOrientation.get();
226 }
227
brokenIdeographFontData() const228 SimpleFontData* SimpleFontData::brokenIdeographFontData() const
229 {
230 if (!m_derivedFontData)
231 m_derivedFontData = DerivedFontData::create(isCustomFont());
232 if (!m_derivedFontData->brokenIdeograph) {
233 m_derivedFontData->brokenIdeograph = adoptPtr(new SimpleFontData(m_platformData, isCustomFont(), false));
234 m_derivedFontData->brokenIdeograph->m_isBrokenIdeographFallback = true;
235 }
236 return m_derivedFontData->brokenIdeograph.get();
237 }
238
239 #ifndef NDEBUG
description() const240 String SimpleFontData::description() const
241 {
242 if (isSVGFont())
243 return "[SVG font]";
244 if (isCustomFont())
245 return "[custom font]";
246
247 return platformData().description();
248 }
249 #endif
250
create(bool forCustomFont)251 PassOwnPtr<SimpleFontData::DerivedFontData> SimpleFontData::DerivedFontData::create(bool forCustomFont)
252 {
253 return adoptPtr(new DerivedFontData(forCustomFont));
254 }
255
~DerivedFontData()256 SimpleFontData::DerivedFontData::~DerivedFontData()
257 {
258 if (!forCustomFont)
259 return;
260
261 if (smallCaps)
262 GlyphPageTreeNode::pruneTreeCustomFontData(smallCaps.get());
263 if (emphasisMark)
264 GlyphPageTreeNode::pruneTreeCustomFontData(emphasisMark.get());
265 if (brokenIdeograph)
266 GlyphPageTreeNode::pruneTreeCustomFontData(brokenIdeograph.get());
267 if (verticalRightOrientation)
268 GlyphPageTreeNode::pruneTreeCustomFontData(verticalRightOrientation.get());
269 if (uprightOrientation)
270 GlyphPageTreeNode::pruneTreeCustomFontData(uprightOrientation.get());
271 }
272
273 } // namespace WebCore
274