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 * Copyright (C) 2007 Pioneer Research Center USA, Inc.
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1.  Redistributions of source code must retain the above copyright
14 *     notice, this list of conditions and the following disclaimer.
15 * 2.  Redistributions in binary form must reproduce the above copyright
16 *     notice, this list of conditions and the following disclaimer in the
17 *     documentation and/or other materials provided with the distribution.
18 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
19 *     its contributors may be used to endorse or promote products derived
20 *     from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
23 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
24 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
25 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
26 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
27 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
29 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34#include "config.h"
35#include "SimpleFontData.h"
36
37#include "FloatRect.h"
38#include "Font.h"
39#include "FontCache.h"
40#include "FontDescription.h"
41#include "GlyphBuffer.h"
42#include <cairo.h>
43#include <wtf/MathExtras.h>
44
45namespace WebCore {
46
47void SimpleFontData::platformInit()
48{
49    cairo_font_extents_t font_extents;
50    cairo_text_extents_t text_extents;
51    cairo_scaled_font_extents(m_platformData.m_scaledFont, &font_extents);
52
53    m_fontMetrics.setAscent(font_extents.ascent);
54    m_fontMetrics.setDescent(font_extents.descent);
55
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    float lineSpacing = font_extents.height;
62    if (lineSpacing < font_extents.ascent + font_extents.descent)
63        lineSpacing = font_extents.ascent + font_extents.descent;
64    m_fontMetrics.setLineSpacing(lroundf(lineSpacing));
65    m_fontMetrics.setLineGap(lineSpacing - font_extents.ascent - font_extents.descent);
66
67    cairo_scaled_font_text_extents(m_platformData.m_scaledFont, "x", &text_extents);
68    m_fontMetrics.setXHeight(text_extents.height);
69
70    cairo_scaled_font_text_extents(m_platformData.m_scaledFont, " ", &text_extents);
71    m_spaceWidth = static_cast<float>(text_extents.x_advance);
72
73    m_syntheticBoldOffset = m_platformData.syntheticBold() ? 1.0f : 0.f;
74}
75
76void SimpleFontData::platformCharWidthInit()
77{
78    m_avgCharWidth = 0.f;
79    m_maxCharWidth = 0.f;
80    initCharWidths();
81}
82
83void SimpleFontData::platformDestroy()
84{
85}
86
87SimpleFontData* SimpleFontData::scaledFontData(const FontDescription& fontDescription, float scaleFactor) const
88{
89    FontDescription desc = FontDescription(fontDescription);
90    desc.setSpecifiedSize(scaleFactor * fontDescription.computedSize());
91    FontPlatformData platformData(desc, desc.family().family());
92    return new SimpleFontData(platformData);
93}
94
95SimpleFontData* SimpleFontData::smallCapsFontData(const FontDescription& fontDescription) const
96{
97    if (!m_derivedFontData)
98        m_derivedFontData = DerivedFontData::create(isCustomFont());
99    if (!m_derivedFontData->smallCaps)
100        m_derivedFontData->smallCaps = scaledFontData(fontDescription, .7);
101
102    return m_derivedFontData->smallCaps.get();
103}
104
105SimpleFontData* SimpleFontData::emphasisMarkFontData(const FontDescription& fontDescription) const
106{
107    if (!m_derivedFontData)
108        m_derivedFontData = DerivedFontData::create(isCustomFont());
109    if (!m_derivedFontData->emphasisMark)
110        m_derivedFontData->emphasisMark = scaledFontData(fontDescription, .5);
111
112    return m_derivedFontData->emphasisMark.get();
113}
114
115bool SimpleFontData::containsCharacters(const UChar* characters, int length) const
116{
117    bool result = true;
118
119    PangoCoverage* coverage = pango_font_get_coverage(m_platformData.m_font, pango_language_get_default());
120
121    for (int i = 0; i < length; i++) {
122        if (PANGO_COVERAGE_NONE == pango_coverage_get(coverage, characters[i])) {
123            result = false;
124            break;
125        }
126    }
127
128    pango_coverage_unref(coverage);
129
130    return result;
131}
132
133void SimpleFontData::determinePitch()
134{
135    if (isCustomFont()) {
136        m_treatAsFixedPitch = false;
137        return;
138    }
139
140    m_treatAsFixedPitch = m_platformData.isFixedPitch();
141}
142
143FloatRect SimpleFontData::platformBoundsForGlyph(Glyph) const
144{
145    return FloatRect();
146}
147
148float SimpleFontData::platformWidthForGlyph(Glyph glyph) const
149{
150    ASSERT(m_platformData.m_scaledFont);
151
152    cairo_glyph_t cglyph = { glyph, 0, 0 };
153    cairo_text_extents_t extents;
154    cairo_scaled_font_glyph_extents(m_platformData.m_scaledFont, &cglyph, 1, &extents);
155
156    float width = (float)m_spaceWidth;
157    if (cairo_scaled_font_status(m_platformData.m_scaledFont) == CAIRO_STATUS_SUCCESS && extents.x_advance != 0)
158        width = (float)extents.x_advance;
159
160    return width;
161}
162
163}
164