1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
|
/*
* 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 <windows.h>
#include <vector>
#include "ChromiumBridge.h"
#include "Font.h"
#include "GlyphPageTreeNode.h"
#include "SimpleFontData.h"
#include "UniscribeHelperTextRun.h"
#include "WindowsVersion.h"
namespace WebCore {
// Fills one page of font data pointers with 0 to indicate that there
// are no glyphs for the characters.
static void fillEmptyGlyphs(GlyphPage* page)
{
for (int i = 0; i < GlyphPage::size; ++i)
page->setGlyphDataForIndex(i, 0, 0);
}
// Lazily initializes space glyph
static Glyph initSpaceGlyph(HDC dc, Glyph* spaceGlyph)
{
if (*spaceGlyph)
return *spaceGlyph;
static wchar_t space = ' ';
GetGlyphIndices(dc, &space, 1, spaceGlyph, 0);
return *spaceGlyph;
}
// Fills |length| glyphs starting at |offset| in a |page| in the Basic
// Multilingual Plane (<= U+FFFF). The input buffer size should be the
// same as |length|. We can use the standard Windows GDI functions here.
// Returns true if any glyphs were found.
static bool fillBMPGlyphs(unsigned offset,
unsigned length,
UChar* buffer,
GlyphPage* page,
const SimpleFontData* fontData,
bool recurse)
{
HDC dc = GetDC((HWND)0);
HGDIOBJ oldFont = SelectObject(dc, fontData->platformData().hfont());
TEXTMETRIC tm = {0};
if (!GetTextMetrics(dc, &tm)) {
SelectObject(dc, oldFont);
ReleaseDC(0, dc);
if (recurse) {
if (ChromiumBridge::ensureFontLoaded(fontData->platformData().hfont()))
return fillBMPGlyphs(offset, length, buffer, page, fontData, false);
else {
fillEmptyGlyphs(page);
return false;
}
} else {
// FIXME: Handle gracefully the error if this call also fails.
// See http://crbug.com/6401
LOG_ERROR("Unable to get the text metrics after second attempt");
fillEmptyGlyphs(page);
return false;
}
}
// FIXME: GetGlyphIndices() sets each item of localGlyphBuffer[]
// with the one of the values listed below.
// * With the GGI_MARK_NONEXISTING_GLYPHS flag
// + If the font has a glyph available for the character,
// localGlyphBuffer[i] > 0x0.
// + If the font does not have glyphs available for the character,
// localGlyphBuffer[i] = 0x1F (TrueType Collection?) or
// 0xFFFF (OpenType?).
// * Without the GGI_MARK_NONEXISTING_GLYPHS flag
// + If the font has a glyph available for the character,
// localGlyphBuffer[i] > 0x0.
// + If the font does not have glyphs available for the character,
// localGlyphBuffer[i] = 0x80.
// (Windows automatically assigns the glyph for a box character to
// prevent ExtTextOut() from returning errors.)
// To avoid from hurting the rendering performance, this code just
// tells WebKit whether or not the all glyph indices for the given
// characters are 0x80 (i.e. a possibly-invalid glyph) and let it
// use alternative fonts for the characters.
// Although this may cause a problem, it seems to work fine as far as I
// have tested. (Obviously, I need more tests.)
WORD localGlyphBuffer[GlyphPage::size];
// FIXME: I find some Chinese characters can not be correctly displayed
// when call GetGlyphIndices without flag GGI_MARK_NONEXISTING_GLYPHS,
// because the corresponding glyph index is set as 0x20 when current font
// does not have glyphs available for the character. According a blog post
// http://blogs.msdn.com/michkap/archive/2006/06/28/649791.aspx
// I think we should switch to the way about calling GetGlyphIndices with
// flag GGI_MARK_NONEXISTING_GLYPHS, it should be OK according the
// description of MSDN.
// Also according to Jungshik and Hironori's suggestion and modification
// we treat turetype and raster Font as different way when windows version
// is less than Vista.
GetGlyphIndices(dc, buffer, length, localGlyphBuffer, GGI_MARK_NONEXISTING_GLYPHS);
// Copy the output to the GlyphPage
bool haveGlyphs = false;
int invalidGlyph = 0xFFFF;
if (!isVistaOrNewer() && !(tm.tmPitchAndFamily & TMPF_TRUETYPE))
invalidGlyph = 0x1F;
Glyph spaceGlyph = 0; // Glyph for a space. Lazily filled.
for (unsigned i = 0; i < length; i++) {
UChar c = buffer[i];
Glyph glyph = localGlyphBuffer[i];
const SimpleFontData* glyphFontData = fontData;
// When this character should be a space, we ignore whatever the font
// says and use a space. Otherwise, if fonts don't map one of these
// space or zero width glyphs, we will get a box.
if (Font::treatAsSpace(c)) {
// Hard code the glyph indices for characters that should be
// treated like spaces.
glyph = initSpaceGlyph(dc, &spaceGlyph);
} else if (glyph == invalidGlyph) {
// WebKit expects both the glyph index and FontData
// pointer to be 0 if the glyph is not present
glyph = 0;
glyphFontData = 0;
} else
haveGlyphs = true;
page->setGlyphDataForCharacter(offset + i, glyph, glyphFontData);
}
SelectObject(dc, oldFont);
ReleaseDC(0, dc);
return haveGlyphs;
}
// For non-BMP characters, each is two words (UTF-16) and the input buffer
// size is 2 * |length|. Since GDI doesn't know how to handle non-BMP
// characters, we must use Uniscribe to tell us the glyph indices.
//
// We don't want to call this in the case of "regular" characters since some
// fonts may not have the correct combining rules for accents. See the notes
// at the bottom of ScriptGetCMap. We can't use ScriptGetCMap, though, since
// it doesn't seem to support UTF-16, despite what this blog post says:
// http://blogs.msdn.com/michkap/archive/2006/06/29/650680.aspx
//
// So we fire up the full Uniscribe doohicky, give it our string, and it will
// correctly handle the UTF-16 for us. The hard part is taking this and getting
// the glyph indices back out that correspond to the correct input characters,
// since they may be missing.
//
// Returns true if any glyphs were found.
static bool fillNonBMPGlyphs(unsigned offset,
unsigned length,
UChar* buffer,
GlyphPage* page,
const SimpleFontData* fontData)
{
bool haveGlyphs = false;
UniscribeHelperTextRun state(buffer, length * 2, false,
fontData->platformData().hfont(),
fontData->platformData().scriptCache(),
fontData->platformData().scriptFontProperties());
state.setInhibitLigate(true);
state.setDisableFontFallback(true);
state.init();
for (unsigned i = 0; i < length; i++) {
// Each character in this input buffer is a surrogate pair, which
// consists of two UChars. So, the offset for its i-th character is
// (i * 2).
WORD glyph = state.firstGlyphForCharacter(i * 2);
if (glyph) {
haveGlyphs = true;
page->setGlyphDataForIndex(offset + i, glyph, fontData);
} else
// Clear both glyph and fontData fields.
page->setGlyphDataForIndex(offset + i, 0, 0);
}
return haveGlyphs;
}
// We're supposed to return true if there are any glyphs in the range
// specified by |offset| and |length| in our font,
// false if there are none.
bool GlyphPage::fill(unsigned offset, unsigned length, UChar* characterBuffer,
unsigned bufferLength, const SimpleFontData* fontData)
{
// We have to handle BMP and non-BMP characters differently.
// FIXME: Add assertions to make sure that buffer is entirely in BMP
// or entirely in non-BMP.
if (bufferLength == length)
return fillBMPGlyphs(offset, length, characterBuffer, this, fontData, true);
if (bufferLength == 2 * length) {
// A non-BMP input buffer will be twice as long as output glyph buffer
// because each character in the non-BMP input buffer will be
// represented by a surrogate pair (two UChar's).
return fillNonBMPGlyphs(offset, length, characterBuffer, this, fontData);
}
ASSERT_NOT_REACHED();
return false;
}
} // namespace WebCore
|