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Side by Side Diff: Source/platform/fonts/win/GlyphPageTreeNodeWin.cpp

Issue 179723005: Remove GDI font rendering code for windows (Closed) Base URL: svn://svn.chromium.org/blink/trunk
Patch Set: Created 6 years, 9 months ago
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1 /*
2 * Copyright (c) 2008, 2009, 2012 Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met:
7 *
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 * * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #include <windows.h>
32 #include "config.h"
33 #include <vector>
34
35 #include "platform/fonts/Character.h"
36 #include "platform/fonts/Font.h"
37 #include "platform/fonts/GlyphPageTreeNode.h"
38 #include "platform/fonts/SimpleFontData.h"
39 #include "platform/fonts/win/FontPlatformDataWin.h"
40 #include "platform/fonts/win/UniscribeHelperTextRun.h"
41 #include "platform/win/HWndDC.h"
42 #include "platform/win/SystemInfo.h"
43
44 namespace WebCore {
45
46 // Fills one page of font data pointers with 0 to indicate that there
47 // are no glyphs for the characters.
48 static void fillEmptyGlyphs(GlyphPage* page)
49 {
50 for (int i = 0; i < GlyphPage::size; ++i)
51 page->setGlyphDataForIndex(i, 0, 0);
52 }
53
54 // Convert characters to glyph ids by GetGlyphIndices(), during which, we
55 // ensure the font is loaded in memory to make it work in a sandboxed process.
56 static bool getGlyphIndices(HFONT font, HDC dc, const UChar* characters, unsigne d charactersLength, WORD* glyphBuffer, DWORD flag)
57 {
58 if (GetGlyphIndices(dc, characters, charactersLength, glyphBuffer, flag) != GDI_ERROR)
59 return true;
60 if (FontPlatformData::ensureFontLoaded(font)) {
61 if (GetGlyphIndices(dc, characters, charactersLength, glyphBuffer, flag) != GDI_ERROR)
62 return true;
63 // FIXME: Handle gracefully the error if this call also fails.
64 // See http://crbug.com/6401
65 WTF_LOG_ERROR("Unable to get the glyph indices after second attempt");
66 }
67 return false;
68 }
69
70 // Initializes space glyph
71 static bool initSpaceGlyph(HFONT font, HDC dc, Glyph* spaceGlyph)
72 {
73 static wchar_t space = ' ';
74 return getGlyphIndices(font, dc, &space, 1, spaceGlyph, 0);
75 }
76
77 // Fills |length| glyphs starting at |offset| in a |page| in the Basic
78 // Multilingual Plane (<= U+FFFF). The input buffer size should be the
79 // same as |length|. We can use the standard Windows GDI functions here.
80 // Returns true if any glyphs were found.
81 static bool fillBMPGlyphs(unsigned offset,
82 unsigned length,
83 UChar* buffer,
84 GlyphPage* page,
85 const SimpleFontData* fontData)
86 {
87 HWndDC dc(0);
88 HGDIOBJ oldFont = SelectObject(dc, fontData->platformData().hfont());
89
90 TEXTMETRIC tm = {0};
91 if (!GetTextMetrics(dc, &tm)) {
92 if (FontPlatformData::ensureFontLoaded(fontData->platformData().hfont()) ) {
93 if (!GetTextMetrics(dc, &tm)) {
94 // FIXME: Handle gracefully the error if this call also fails.
95 // See http://crbug.com/6401
96 WTF_LOG_ERROR("Unable to get the text metrics after second attem pt");
97
98 SelectObject(dc, oldFont);
99 fillEmptyGlyphs(page);
100 return false;
101 }
102 } else {
103 SelectObject(dc, oldFont);
104 fillEmptyGlyphs(page);
105 return false;
106 }
107 }
108
109 // FIXME: GetGlyphIndices() sets each item of localGlyphBuffer[]
110 // with the one of the values listed below.
111 // * With the GGI_MARK_NONEXISTING_GLYPHS flag
112 // + If the font has a glyph available for the character,
113 // localGlyphBuffer[i] > 0x0.
114 // + If the font does not have glyphs available for the character,
115 // localGlyphBuffer[i] = 0x1F (TrueType Collection?) or
116 // 0xFFFF (OpenType?).
117 // * Without the GGI_MARK_NONEXISTING_GLYPHS flag
118 // + If the font has a glyph available for the character,
119 // localGlyphBuffer[i] > 0x0.
120 // + If the font does not have glyphs available for the character,
121 // localGlyphBuffer[i] = 0x80.
122 // (Windows automatically assigns the glyph for a box character to
123 // prevent ExtTextOut() from returning errors.)
124 // To avoid from hurting the rendering performance, this code just
125 // tells WebKit whether or not the all glyph indices for the given
126 // characters are 0x80 (i.e. a possibly-invalid glyph) and let it
127 // use alternative fonts for the characters.
128 // Although this may cause a problem, it seems to work fine as far as I
129 // have tested. (Obviously, I need more tests.)
130 WORD localGlyphBuffer[GlyphPage::size];
131
132 // FIXME: I find some Chinese characters can not be correctly displayed
133 // when call GetGlyphIndices without flag GGI_MARK_NONEXISTING_GLYPHS,
134 // because the corresponding glyph index is set as 0x20 when current font
135 // does not have glyphs available for the character. According a blog post
136 // http://blogs.msdn.com/michkap/archive/2006/06/28/649791.aspx
137 // I think we should switch to the way about calling GetGlyphIndices with
138 // flag GGI_MARK_NONEXISTING_GLYPHS, it should be OK according the
139 // description of MSDN.
140 // Also according to Jungshik and Hironori's suggestion and modification
141 // we treat turetype and raster Font as different way when windows version
142 // is less than Vista.
143 if (!getGlyphIndices(fontData->platformData().hfont(), dc, buffer, length, l ocalGlyphBuffer, GGI_MARK_NONEXISTING_GLYPHS)) {
144 SelectObject(dc, oldFont);
145 fillEmptyGlyphs(page);
146 return false;
147 }
148
149 // Copy the output to the GlyphPage
150 bool haveGlyphs = false;
151 int invalidGlyph = 0xFFFF;
152 const DWORD cffTableTag = 0x20464643; // 4-byte identifier for OpenType CFF table ('CFF ').
153 if (!isWindowsVistaOrGreater() && !(tm.tmPitchAndFamily & TMPF_TRUETYPE) && (GetFontData(dc, cffTableTag, 0, 0, 0) == GDI_ERROR))
154 invalidGlyph = 0x1F;
155
156 Glyph spaceGlyph = 0; // Glyph for a space. Lazily filled.
157 bool spaceGlyphInitialized = false;
158
159 for (unsigned i = 0; i < length; i++) {
160 UChar c = buffer[i];
161 Glyph glyph = localGlyphBuffer[i];
162 const SimpleFontData* glyphFontData = fontData;
163 // When this character should be a space, we ignore whatever the font
164 // says and use a space. Otherwise, if fonts don't map one of these
165 // space or zero width glyphs, we will get a box.
166 if (Character::treatAsSpace(c)) {
167 // Hard code the glyph indices for characters that should be
168 // treated like spaces.
169 if (!spaceGlyphInitialized) {
170 // If initSpaceGlyph fails, spaceGlyph stays 0 (= glyph is not p resent).
171 initSpaceGlyph(fontData->platformData().hfont(), dc, &spaceGlyph );
172 spaceGlyphInitialized = true;
173 if (spaceGlyph)
174 haveGlyphs = true;
175 }
176 glyph = spaceGlyph;
177 } else if (glyph == invalidGlyph) {
178 // WebKit expects both the glyph index and FontData
179 // pointer to be 0 if the glyph is not present
180 glyph = 0;
181 glyphFontData = 0;
182 } else
183 haveGlyphs = true;
184 page->setGlyphDataForCharacter(offset + i, glyph, glyphFontData);
185 }
186
187 SelectObject(dc, oldFont);
188 return haveGlyphs;
189 }
190
191 // For non-BMP characters, each is two words (UTF-16) and the input buffer
192 // size is 2 * |length|. Since GDI doesn't know how to handle non-BMP
193 // characters, we must use Uniscribe to tell us the glyph indices.
194 //
195 // We don't want to call this in the case of "regular" characters since some
196 // fonts may not have the correct combining rules for accents. See the notes
197 // at the bottom of ScriptGetCMap. We can't use ScriptGetCMap, though, since
198 // it doesn't seem to support UTF-16, despite what this blog post says:
199 // http://blogs.msdn.com/michkap/archive/2006/06/29/650680.aspx
200 //
201 // So we fire up the full Uniscribe doohicky, give it our string, and it will
202 // correctly handle the UTF-16 for us. The hard part is taking this and getting
203 // the glyph indices back out that correspond to the correct input characters,
204 // since they may be missing.
205 //
206 // Returns true if any glyphs were found.
207 static bool fillNonBMPGlyphs(unsigned offset,
208 unsigned length,
209 UChar* buffer,
210 GlyphPage* page,
211 const SimpleFontData* fontData)
212 {
213 bool haveGlyphs = false;
214
215 UniscribeHelperTextRun state(buffer, length * 2, false,
216 fontData->platformData().hfont(),
217 fontData->platformData().scriptCache(),
218 fontData->platformData().scriptFontProperties() );
219 state.setInhibitLigate(true);
220 state.setDisableFontFallback(true);
221 state.init();
222
223 for (unsigned i = 0; i < length; i++) {
224 // Each character in this input buffer is a surrogate pair, which
225 // consists of two UChars. So, the offset for its i-th character is
226 // (i * 2).
227 WORD glyph = state.firstGlyphForCharacter(i * 2);
228 if (glyph) {
229 haveGlyphs = true;
230 page->setGlyphDataForIndex(offset + i, glyph, fontData);
231 } else
232 // Clear both glyph and fontData fields.
233 page->setGlyphDataForIndex(offset + i, 0, 0);
234 }
235 return haveGlyphs;
236 }
237
238 // We're supposed to return true if there are any glyphs in the range
239 // specified by |offset| and |length| in our font,
240 // false if there are none.
241 bool GlyphPage::fill(unsigned offset, unsigned length, UChar* characterBuffer,
242 unsigned bufferLength, const SimpleFontData* fontData)
243 {
244 // We have to handle BMP and non-BMP characters differently.
245 // FIXME: Add assertions to make sure that buffer is entirely in BMP
246 // or entirely in non-BMP.
247 if (bufferLength == length)
248 return fillBMPGlyphs(offset, length, characterBuffer, this, fontData);
249
250 if (bufferLength == 2 * length) {
251 // A non-BMP input buffer will be twice as long as output glyph buffer
252 // because each character in the non-BMP input buffer will be
253 // represented by a surrogate pair (two UChar's).
254 return fillNonBMPGlyphs(offset, length, characterBuffer, this, fontData) ;
255 }
256
257 ASSERT_NOT_REACHED();
258 return false;
259 }
260
261 } // namespace WebCore
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