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 49 static inline float scaleEmToUnits(float x, int unitsPerEm) 50 { 51 return unitsPerEm ? x / static_cast<float>(unitsPerEm) : x; 52 } 53 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 } 105 106 void SimpleFontData::platformCharWidthInit() 107 { 108 // charwidths are set in platformInit. 109 } 110 111 void SimpleFontData::platformDestroy() 112 { 113 } 114 115 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 } 124 125 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 } 134 135 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 } 144 145 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 } 151 152 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 } 176 177 FloatRect SimpleFontData::platformBoundsForGlyph(Glyph) const 178 { 179 return FloatRect(); 180 } 181 182 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