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1 /*
2  * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
3  * Copyright (C) 2006 Michael Emmel mike.emmel@gmail.com
4  * Copyright (C) 2007, 2008 Alp Toker <alp@atoker.com>
5  * Copyright (C) 2007 Holger Hans Peter Freyther
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1.  Redistributions of source code must retain the above copyright
13  *     notice, this list of conditions and the following disclaimer.
14  * 2.  Redistributions in binary form must reproduce the above copyright
15  *     notice, this list of conditions and the following disclaimer in the
16  *     documentation and/or other materials provided with the distribution.
17  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
18  *     its contributors may be used to endorse or promote products derived
19  *     from this software without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
22  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
23  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
24  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
25  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
26  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
28  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include "config.h"
34 #include "SimpleFontData.h"
35 
36 #include "FloatRect.h"
37 #include "Font.h"
38 #include "FontCache.h"
39 #include "FontDescription.h"
40 #include "GlyphBuffer.h"
41 #include <cairo.h>
42 #include <unicode/uchar.h>
43 #include <unicode/unorm.h>
44 #include <wtf/MathExtras.h>
45 
46 namespace WebCore {
47 
platformInit()48 void SimpleFontData::platformInit()
49 {
50     cairo_font_extents_t font_extents;
51     cairo_text_extents_t text_extents;
52     cairo_scaled_font_extents(m_platformData.m_scaledFont, &font_extents);
53     m_ascent = static_cast<int>(font_extents.ascent);
54     m_descent = static_cast<int>(font_extents.descent);
55     m_lineSpacing = static_cast<int>(font_extents.height);
56     // There seems to be some rounding error in cairo (or in how we
57     // use cairo) with some fonts, like DejaVu Sans Mono, which makes
58     // cairo report a height smaller than ascent + descent, which is
59     // wrong and confuses WebCore's layout system. Workaround this
60     // while we figure out what's going on.
61     if (m_lineSpacing < m_ascent + m_descent)
62         m_lineSpacing = m_ascent + m_descent;
63     cairo_scaled_font_text_extents(m_platformData.m_scaledFont, "x", &text_extents);
64     m_xHeight = text_extents.height;
65     cairo_scaled_font_text_extents(m_platformData.m_scaledFont, " ", &text_extents);
66     m_spaceWidth =  static_cast<int>(text_extents.x_advance);
67     m_lineGap = m_lineSpacing - m_ascent - m_descent;
68     m_syntheticBoldOffset = m_platformData.syntheticBold() ? 1.0f : 0.f;
69 }
70 
platformCharWidthInit()71 void SimpleFontData::platformCharWidthInit()
72 {
73     m_avgCharWidth = 0.f;
74     m_maxCharWidth = 0.f;
75     initCharWidths();
76 }
77 
platformDestroy()78 void SimpleFontData::platformDestroy()
79 {
80     delete m_smallCapsFontData;
81     m_smallCapsFontData = 0;
82 }
83 
smallCapsFontData(const FontDescription & fontDescription) const84 SimpleFontData* SimpleFontData::smallCapsFontData(const FontDescription& fontDescription) const
85 {
86     if (!m_smallCapsFontData) {
87         FontDescription desc = FontDescription(fontDescription);
88         desc.setComputedSize(0.70f*fontDescription.computedSize());
89         const FontPlatformData* pdata = new FontPlatformData(desc, desc.family().family());
90         m_smallCapsFontData = new SimpleFontData(*pdata);
91     }
92     return m_smallCapsFontData;
93 }
94 
containsCharacters(const UChar * characters,int length) const95 bool SimpleFontData::containsCharacters(const UChar* characters, int length) const
96 {
97     FT_Face face = cairo_ft_scaled_font_lock_face(m_platformData.m_scaledFont);
98 
99     if (!face)
100         return false;
101 
102     for (int i = 0; i < length; i++) {
103         if (FcFreeTypeCharIndex(face, characters[i]) == 0) {
104             cairo_ft_scaled_font_unlock_face(m_platformData.m_scaledFont);
105             return false;
106         }
107     }
108 
109     cairo_ft_scaled_font_unlock_face(m_platformData.m_scaledFont);
110 
111     return true;
112 }
113 
determinePitch()114 void SimpleFontData::determinePitch()
115 {
116     m_treatAsFixedPitch = m_platformData.isFixedPitch();
117 }
118 
platformWidthForGlyph(Glyph glyph) const119 float SimpleFontData::platformWidthForGlyph(Glyph glyph) const
120 {
121     ASSERT(m_platformData.m_scaledFont);
122 
123     cairo_glyph_t cglyph = { glyph, 0, 0 };
124     cairo_text_extents_t extents;
125     cairo_scaled_font_glyph_extents(m_platformData.m_scaledFont, &cglyph, 1, &extents);
126 
127     float w = (float)m_spaceWidth;
128     if (cairo_scaled_font_status(m_platformData.m_scaledFont) == CAIRO_STATUS_SUCCESS && extents.x_advance != 0)
129         w = (float)extents.x_advance;
130     return w;
131 }
132 
setFont(cairo_t * cr) const133 void SimpleFontData::setFont(cairo_t* cr) const
134 {
135     ASSERT(cr);
136     m_platformData.setFont(cr);
137 }
138 
139 }
140