1/*
2 * Copyright (C) 2006, 2007, 2008, 2009 Apple 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
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
16 * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
17 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
18 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
19 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
20 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
22 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 */
24
25#include "config.h"
26#include "platform/fonts/Font.h"
27
28#include "platform/fonts/Character.h"
29#include "platform/fonts/FontFallbackList.h"
30#include "platform/fonts/GlyphBuffer.h"
31#include "platform/fonts/SimpleFontData.h"
32#include "platform/fonts/harfbuzz/HarfBuzzShaper.h"
33#include "platform/fonts/mac/ComplexTextController.h"
34#include "platform/geometry/IntRect.h"
35#include "platform/graphics/GraphicsContext.h"
36#include "platform/text/TextRun.h"
37#include "wtf/MathExtras.h"
38
39using namespace std;
40
41namespace WebCore {
42
43static bool preferHarfBuzz(const Font* font)
44{
45    const FontDescription& description = font->fontDescription();
46    return description.featureSettings() && description.featureSettings()->size() > 0;
47}
48
49FloatRect Font::selectionRectForComplexText(const TextRun& run, const FloatPoint& point, int h,
50                                            int from, int to) const
51{
52    if (preferHarfBuzz(this)) {
53        HarfBuzzShaper shaper(this, run);
54        if (shaper.shape())
55            return shaper.selectionRect(point, h, from, to);
56    }
57    ComplexTextController controller(this, run);
58    controller.advance(from);
59    float beforeWidth = controller.runWidthSoFar();
60    controller.advance(to);
61    float afterWidth = controller.runWidthSoFar();
62
63    // Using roundf() rather than ceilf() for the right edge as a compromise to ensure correct caret positioning
64    if (run.rtl()) {
65        float totalWidth = controller.totalWidth();
66        return FloatRect(floorf(point.x() + totalWidth - afterWidth), point.y(), roundf(point.x() + totalWidth - beforeWidth) - floorf(point.x() + totalWidth - afterWidth), h);
67    }
68
69    return FloatRect(floorf(point.x() + beforeWidth), point.y(), roundf(point.x() + afterWidth) - floorf(point.x() + beforeWidth), h);
70}
71
72float Font::getGlyphsAndAdvancesForComplexText(const TextRunPaintInfo& runInfo, GlyphBuffer& glyphBuffer, ForTextEmphasisOrNot forTextEmphasis) const
73{
74    float initialAdvance;
75
76    ComplexTextController controller(this, runInfo.run, false, 0, forTextEmphasis);
77    controller.advance(runInfo.from);
78    float beforeWidth = controller.runWidthSoFar();
79    controller.advance(runInfo.to, &glyphBuffer);
80
81    if (glyphBuffer.isEmpty())
82        return 0;
83
84    float afterWidth = controller.runWidthSoFar();
85
86    if (runInfo.run.rtl()) {
87        initialAdvance = controller.totalWidth() + controller.finalRoundingWidth() - afterWidth;
88        glyphBuffer.reverse();
89    } else
90        initialAdvance = beforeWidth;
91
92    return initialAdvance;
93}
94
95void Font::drawComplexText(GraphicsContext* context, const TextRunPaintInfo& runInfo, const FloatPoint& point) const
96{
97    if (preferHarfBuzz(this)) {
98        GlyphBuffer glyphBuffer;
99        HarfBuzzShaper shaper(this, runInfo.run);
100        shaper.setDrawRange(runInfo.from, runInfo.to);
101        if (shaper.shape(&glyphBuffer)) {
102            drawGlyphBuffer(context, runInfo, glyphBuffer, point);
103            return;
104        }
105    }
106    // This glyph buffer holds our glyphs + advances + font data for each glyph.
107    GlyphBuffer glyphBuffer;
108
109    float startX = point.x() + getGlyphsAndAdvancesForComplexText(runInfo, glyphBuffer);
110
111    // We couldn't generate any glyphs for the run.  Give up.
112    if (glyphBuffer.isEmpty())
113        return;
114
115    // Draw the glyph buffer now at the starting point returned in startX.
116    FloatPoint startPoint(startX, point.y());
117    drawGlyphBuffer(context, runInfo, glyphBuffer, startPoint);
118}
119
120void Font::drawEmphasisMarksForComplexText(GraphicsContext* context, const TextRunPaintInfo& runInfo, const AtomicString& mark, const FloatPoint& point) const
121{
122    GlyphBuffer glyphBuffer;
123    float initialAdvance = getGlyphsAndAdvancesForComplexText(runInfo, glyphBuffer, ForTextEmphasis);
124
125    if (glyphBuffer.isEmpty())
126        return;
127
128    drawEmphasisMarks(context, runInfo, glyphBuffer, mark, FloatPoint(point.x() + initialAdvance, point.y()));
129}
130
131float Font::floatWidthForComplexText(const TextRun& run, HashSet<const SimpleFontData*>* fallbackFonts, IntRectExtent* glyphBounds) const
132{
133    if (preferHarfBuzz(this)) {
134        HarfBuzzShaper shaper(this, run);
135        if (shaper.shape())
136            return shaper.totalWidth();
137    }
138    ComplexTextController controller(this, run, true, fallbackFonts);
139    glyphBounds->setTop(floorf(-controller.minGlyphBoundingBoxY()));
140    glyphBounds->setBottom(ceilf(controller.maxGlyphBoundingBoxY()));
141    glyphBounds->setLeft(max<int>(0, floorf(-controller.minGlyphBoundingBoxX())));
142    glyphBounds->setRight(max<int>(0, ceilf(controller.maxGlyphBoundingBoxX() - controller.totalWidth())));
143
144    return controller.totalWidth();
145}
146
147int Font::offsetForPositionForComplexText(const TextRun& run, float x, bool includePartialGlyphs) const
148{
149    if (preferHarfBuzz(this)) {
150        HarfBuzzShaper shaper(this, run);
151        if (shaper.shape())
152            return shaper.offsetForPosition(x);
153    }
154    ComplexTextController controller(this, run);
155    return controller.offsetForPosition(x, includePartialGlyphs);
156}
157
158const SimpleFontData* Font::fontDataForCombiningCharacterSequence(const UChar* characters, size_t length, FontDataVariant variant) const
159{
160    UChar32 baseCharacter;
161    size_t baseCharacterLength = 0;
162    U16_NEXT(characters, baseCharacterLength, length, baseCharacter);
163
164    GlyphData baseCharacterGlyphData = glyphDataForCharacter(baseCharacter, false, variant);
165
166    if (!baseCharacterGlyphData.glyph)
167        return 0;
168
169    if (length == baseCharacterLength)
170        return baseCharacterGlyphData.fontData;
171
172    bool triedBaseCharacterFontData = false;
173
174    unsigned i = 0;
175    for (const FontData* fontData = fontDataAt(0); fontData; fontData = fontDataAt(++i)) {
176        const SimpleFontData* simpleFontData = fontData->fontDataForCharacter(baseCharacter);
177        if (variant == NormalVariant) {
178            if (simpleFontData->platformData().orientation() == Vertical) {
179                if (Character::isCJKIdeographOrSymbol(baseCharacter) && !simpleFontData->hasVerticalGlyphs()) {
180                    variant = BrokenIdeographVariant;
181                    simpleFontData = simpleFontData->brokenIdeographFontData().get();
182                } else if (m_fontDescription.nonCJKGlyphOrientation() == NonCJKGlyphOrientationVerticalRight) {
183                    SimpleFontData* verticalRightFontData = simpleFontData->verticalRightOrientationFontData().get();
184                    Glyph verticalRightGlyph = verticalRightFontData->glyphForCharacter(baseCharacter);
185                    if (verticalRightGlyph == baseCharacterGlyphData.glyph)
186                        simpleFontData = verticalRightFontData;
187                } else {
188                    SimpleFontData* uprightFontData = simpleFontData->uprightOrientationFontData().get();
189                    Glyph uprightGlyph = uprightFontData->glyphForCharacter(baseCharacter);
190                    if (uprightGlyph != baseCharacterGlyphData.glyph)
191                        simpleFontData = uprightFontData;
192                }
193            }
194        } else {
195            if (const SimpleFontData* variantFontData = simpleFontData->variantFontData(m_fontDescription, variant).get())
196                simpleFontData = variantFontData;
197        }
198
199        if (simpleFontData == baseCharacterGlyphData.fontData)
200            triedBaseCharacterFontData = true;
201
202        if (simpleFontData->canRenderCombiningCharacterSequence(characters, length))
203            return simpleFontData;
204    }
205
206    if (!triedBaseCharacterFontData && baseCharacterGlyphData.fontData && baseCharacterGlyphData.fontData->canRenderCombiningCharacterSequence(characters, length))
207        return baseCharacterGlyphData.fontData;
208
209    return SimpleFontData::systemFallback();
210}
211
212} // namespace WebCore
213