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-ft.h>
42#include <cairo.h>
43#include <fontconfig/fcfreetype.h>
44#include <wtf/MathExtras.h>
45
46namespace WebCore {
47
48void SimpleFontData::platformInit()
49{
50    cairo_font_extents_t font_extents;
51    cairo_text_extents_t text_extents;
52    cairo_scaled_font_extents(m_platformData.scaledFont(), &font_extents);
53
54    m_fontMetrics.setAscent(font_extents.ascent);
55    m_fontMetrics.setDescent(font_extents.descent);
56
57    // There seems to be some rounding error in cairo (or in how we
58    // use cairo) with some fonts, like DejaVu Sans Mono, which makes
59    // cairo report a height smaller than ascent + descent, which is
60    // wrong and confuses WebCore's layout system. Workaround this
61    // while we figure out what's going on.
62    float lineSpacing = font_extents.height;
63    if (lineSpacing < font_extents.ascent + font_extents.descent)
64        lineSpacing = font_extents.ascent + font_extents.descent;
65
66    m_fontMetrics.setLineSpacing(lroundf(lineSpacing));
67    m_fontMetrics.setLineGap(lineSpacing - font_extents.ascent - font_extents.descent);
68
69    cairo_scaled_font_text_extents(m_platformData.scaledFont(), "x", &text_extents);
70    m_fontMetrics.setXHeight(text_extents.height);
71
72    cairo_scaled_font_text_extents(m_platformData.scaledFont(), " ", &text_extents);
73    m_spaceWidth = static_cast<float>(text_extents.x_advance);
74
75    m_syntheticBoldOffset = m_platformData.syntheticBold() ? 1.0f : 0.f;
76}
77
78void SimpleFontData::platformCharWidthInit()
79{
80    m_avgCharWidth = 0.f;
81    m_maxCharWidth = 0.f;
82    initCharWidths();
83}
84
85void SimpleFontData::platformDestroy()
86{
87}
88
89SimpleFontData* SimpleFontData::scaledFontData(const FontDescription& fontDescription, float scaleFactor) const
90{
91    return new SimpleFontData(FontPlatformData(cairo_scaled_font_get_font_face(m_platformData.scaledFont()),
92        scaleFactor * fontDescription.computedSize(), m_platformData.syntheticBold(), m_platformData.syntheticOblique()),
93        isCustomFont(), false);
94}
95
96SimpleFontData* SimpleFontData::smallCapsFontData(const FontDescription& fontDescription) const
97{
98    if (!m_derivedFontData)
99        m_derivedFontData = DerivedFontData::create(isCustomFont());
100    // FIXME: I think we want to ask FontConfig for the right font again.
101    if (!m_derivedFontData->smallCaps)
102        m_derivedFontData->smallCaps = scaledFontData(fontDescription, .7);
103
104    return m_derivedFontData->smallCaps.get();
105}
106
107SimpleFontData* SimpleFontData::emphasisMarkFontData(const FontDescription& fontDescription) const
108{
109    if (!m_derivedFontData)
110        m_derivedFontData = DerivedFontData::create(isCustomFont());
111    if (!m_derivedFontData->emphasisMark)
112        m_derivedFontData->emphasisMark = scaledFontData(fontDescription, .5);
113
114    return m_derivedFontData->emphasisMark.get();
115}
116
117bool SimpleFontData::containsCharacters(const UChar* characters, int length) const
118{
119    FT_Face face = cairo_ft_scaled_font_lock_face(m_platformData.scaledFont());
120
121    if (!face)
122        return false;
123
124    for (int i = 0; i < length; i++) {
125        if (FcFreeTypeCharIndex(face, characters[i]) == 0) {
126            cairo_ft_scaled_font_unlock_face(m_platformData.scaledFont());
127            return false;
128        }
129    }
130
131    cairo_ft_scaled_font_unlock_face(m_platformData.scaledFont());
132
133    return true;
134}
135
136void SimpleFontData::determinePitch()
137{
138    m_treatAsFixedPitch = m_platformData.isFixedPitch();
139}
140
141FloatRect SimpleFontData::platformBoundsForGlyph(Glyph) const
142{
143    return FloatRect();
144}
145
146float SimpleFontData::platformWidthForGlyph(Glyph glyph) const
147{
148    ASSERT(m_platformData.scaledFont());
149
150    cairo_glyph_t cglyph = { glyph, 0, 0 };
151    cairo_text_extents_t extents;
152    cairo_scaled_font_glyph_extents(m_platformData.scaledFont(), &cglyph, 1, &extents);
153
154    float w = (float)m_spaceWidth;
155    if (cairo_scaled_font_status(m_platformData.scaledFont()) == CAIRO_STATUS_SUCCESS && extents.x_advance)
156        w = (float)extents.x_advance;
157
158    return w;
159}
160
161}
162