1 /*
2 * Copyright (C) 2006, 2007 Apple Inc. All Rights Reserved.
3 * Copyright (c) 2008, 2009, Google Inc. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met:
8 *
9 * * Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * * Redistributions in binary form must reproduce the above
12 * copyright notice, this list of conditions and the following disclaimer
13 * in the documentation and/or other materials provided with the
14 * distribution.
15 * * Neither the name of Google Inc. nor the names of its
16 * contributors may be used to endorse or promote products derived from
17 * this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include "config.h"
33 #include "SimpleFontData.h"
34
35 #include "FloatRect.h"
36 #include "Font.h"
37 #include "FontCache.h"
38 #include "FontDescription.h"
39 #include "PlatformBridge.h"
40 #include <wtf/MathExtras.h>
41
42 #include <unicode/uchar.h>
43 #include <unicode/unorm.h>
44 #include <objidl.h>
45 #include <mlang.h>
46
47 namespace WebCore {
48
scaleEmToUnits(float x,int unitsPerEm)49 static inline float scaleEmToUnits(float x, int unitsPerEm)
50 {
51 return unitsPerEm ? x / static_cast<float>(unitsPerEm) : x;
52 }
53
platformInit()54 void SimpleFontData::platformInit()
55 {
56 if (!m_platformData.size()) {
57 m_fontMetrics.reset();
58 m_avgCharWidth = 0;
59 m_maxCharWidth = 0;
60 return;
61 }
62
63 HDC dc = GetDC(0);
64 HGDIOBJ oldFont = SelectObject(dc, m_platformData.hfont());
65
66 TEXTMETRIC textMetric = {0};
67 if (!GetTextMetrics(dc, &textMetric)) {
68 if (PlatformBridge::ensureFontLoaded(m_platformData.hfont())) {
69 // Retry GetTextMetrics.
70 // FIXME: Handle gracefully the error if this call also fails.
71 // See http://crbug.com/6401.
72 if (!GetTextMetrics(dc, &textMetric))
73 LOG_ERROR("Unable to get the text metrics after second attempt");
74 }
75 }
76
77 m_avgCharWidth = textMetric.tmAveCharWidth;
78 m_maxCharWidth = textMetric.tmMaxCharWidth;
79
80 // FIXME: Access ascent/descent/lineGap with floating point precision.
81 float ascent = textMetric.tmAscent;
82 float descent = textMetric.tmDescent;
83 float lineGap = textMetric.tmExternalLeading;
84 float xHeight = ascent * 0.56f; // Best guess for xHeight for non-Truetype fonts.
85
86 OUTLINETEXTMETRIC outlineTextMetric;
87 if (GetOutlineTextMetrics(dc, sizeof(outlineTextMetric), &outlineTextMetric) > 0) {
88 // This is a TrueType font. We might be able to get an accurate xHeight.
89 GLYPHMETRICS glyphMetrics = {0};
90 MAT2 identityMatrix = {{0, 1}, {0, 0}, {0, 0}, {0, 1}};
91 DWORD len = GetGlyphOutlineW(dc, 'x', GGO_METRICS, &glyphMetrics, 0, 0, &identityMatrix);
92 if (len != GDI_ERROR && glyphMetrics.gmBlackBoxY > 0)
93 xHeight = static_cast<float>(glyphMetrics.gmBlackBoxY);
94 }
95
96 m_fontMetrics.setAscent(ascent);
97 m_fontMetrics.setDescent(descent);
98 m_fontMetrics.setLineGap(lineGap);
99 m_fontMetrics.setXHeight(xHeight);
100 m_fontMetrics.setLineSpacing(ascent + descent + lineGap);
101
102 SelectObject(dc, oldFont);
103 ReleaseDC(0, dc);
104 }
105
platformCharWidthInit()106 void SimpleFontData::platformCharWidthInit()
107 {
108 // charwidths are set in platformInit.
109 }
110
platformDestroy()111 void SimpleFontData::platformDestroy()
112 {
113 }
114
scaledFontData(const FontDescription & fontDescription,float scaleFactor) const115 SimpleFontData* SimpleFontData::scaledFontData(const FontDescription& fontDescription, float scaleFactor) const
116 {
117 LOGFONT winFont;
118 GetObject(m_platformData.hfont(), sizeof(LOGFONT), &winFont);
119 float scaledSize = scaleFactor * fontDescription.computedSize();
120 winFont.lfHeight = -lroundf(scaledSize);
121 HFONT hfont = CreateFontIndirect(&winFont);
122 return new SimpleFontData(FontPlatformData(hfont, scaledSize), isCustomFont(), false);
123 }
124
smallCapsFontData(const FontDescription & fontDescription) const125 SimpleFontData* SimpleFontData::smallCapsFontData(const FontDescription& fontDescription) const
126 {
127 if (!m_derivedFontData)
128 m_derivedFontData = DerivedFontData::create(isCustomFont());
129 if (!m_derivedFontData->smallCaps)
130 m_derivedFontData->smallCaps = scaledFontData(fontDescription, .7);
131
132 return m_derivedFontData->smallCaps.get();
133 }
134
emphasisMarkFontData(const FontDescription & fontDescription) const135 SimpleFontData* SimpleFontData::emphasisMarkFontData(const FontDescription& fontDescription) const
136 {
137 if (!m_derivedFontData)
138 m_derivedFontData = DerivedFontData::create(isCustomFont());
139 if (!m_derivedFontData->emphasisMark)
140 m_derivedFontData->emphasisMark = scaledFontData(fontDescription, .5);
141
142 return m_derivedFontData->emphasisMark.get();
143 }
144
containsCharacters(const UChar * characters,int length) const145 bool SimpleFontData::containsCharacters(const UChar* characters, int length) const
146 {
147 // This used to be implemented with IMLangFontLink2, but since that code has
148 // been disabled, this would always return false anyway.
149 return false;
150 }
151
determinePitch()152 void SimpleFontData::determinePitch()
153 {
154 // TEXTMETRICS have this. Set m_treatAsFixedPitch based off that.
155 HDC dc = GetDC(0);
156 HGDIOBJ oldFont = SelectObject(dc, m_platformData.hfont());
157
158 // Yes, this looks backwards, but the fixed pitch bit is actually set if the font
159 // is *not* fixed pitch. Unbelievable but true.
160 TEXTMETRIC textMetric = {0};
161 if (!GetTextMetrics(dc, &textMetric)) {
162 if (PlatformBridge::ensureFontLoaded(m_platformData.hfont())) {
163 // Retry GetTextMetrics.
164 // FIXME: Handle gracefully the error if this call also fails.
165 // See http://crbug.com/6401.
166 if (!GetTextMetrics(dc, &textMetric))
167 LOG_ERROR("Unable to get the text metrics after second attempt");
168 }
169 }
170
171 m_treatAsFixedPitch = ((textMetric.tmPitchAndFamily & TMPF_FIXED_PITCH) == 0);
172
173 SelectObject(dc, oldFont);
174 ReleaseDC(0, dc);
175 }
176
platformBoundsForGlyph(Glyph) const177 FloatRect SimpleFontData::platformBoundsForGlyph(Glyph) const
178 {
179 return FloatRect();
180 }
181
platformWidthForGlyph(Glyph glyph) const182 float SimpleFontData::platformWidthForGlyph(Glyph glyph) const
183 {
184 if (!m_platformData.size())
185 return 0;
186
187 HDC dc = GetDC(0);
188 HGDIOBJ oldFont = SelectObject(dc, m_platformData.hfont());
189
190 int width = 0;
191 if (!GetCharWidthI(dc, glyph, 1, 0, &width)) {
192 // Ask the browser to preload the font and retry.
193 if (PlatformBridge::ensureFontLoaded(m_platformData.hfont())) {
194 // FIXME: Handle gracefully the error if this call also fails.
195 // See http://crbug.com/6401.
196 if (!GetCharWidthI(dc, glyph, 1, 0, &width))
197 LOG_ERROR("Unable to get the char width after second attempt");
198 }
199 }
200
201 SelectObject(dc, oldFont);
202 ReleaseDC(0, dc);
203
204 return static_cast<float>(width);
205 }
206
207 } // namespace WebCore
208