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 "Font.h"
27
28#include "ComplexTextController.h"
29#include "FontGlyphs.h"
30#include "GlyphBuffer.h"
31#include "GraphicsContext.h"
32#include "IntRect.h"
33#include "LayoutRect.h"
34#include "SimpleFontData.h"
35#include "TextRun.h"
36#include <wtf/MathExtras.h>
37
38namespace WebCore {
39
40void Font::adjustSelectionRectForComplexText(const TextRun& run, LayoutRect& selectionRect, int from, int to) const
41{
42    ComplexTextController controller(this, run);
43    controller.advance(from);
44    float beforeWidth = controller.runWidthSoFar();
45    controller.advance(to);
46    float afterWidth = controller.runWidthSoFar();
47
48    if (run.rtl())
49        selectionRect.move(controller.totalWidth() - afterWidth, 0);
50    else
51        selectionRect.move(beforeWidth, 0);
52    selectionRect.setWidth(afterWidth - beforeWidth);
53}
54
55float Font::getGlyphsAndAdvancesForComplexText(const TextRun& run, int from, int to, GlyphBuffer& glyphBuffer, ForTextEmphasisOrNot forTextEmphasis) const
56{
57    float initialAdvance;
58
59    ComplexTextController controller(this, run, false, 0, forTextEmphasis);
60    controller.advance(from);
61    float beforeWidth = controller.runWidthSoFar();
62    controller.advance(to, &glyphBuffer);
63
64    if (glyphBuffer.isEmpty())
65        return 0;
66
67    float afterWidth = controller.runWidthSoFar();
68
69    if (run.rtl()) {
70        initialAdvance = controller.totalWidth() + controller.finalRoundingWidth() - afterWidth;
71        glyphBuffer.reverse(0, glyphBuffer.size());
72    } else
73        initialAdvance = beforeWidth;
74
75    return initialAdvance;
76}
77
78float Font::drawComplexText(GraphicsContext* context, const TextRun& run, const FloatPoint& point, int from, int to) const
79{
80    // This glyph buffer holds our glyphs + advances + font data for each glyph.
81    GlyphBuffer glyphBuffer;
82
83    float startX = point.x() + getGlyphsAndAdvancesForComplexText(run, from, to, glyphBuffer);
84
85    // We couldn't generate any glyphs for the run.  Give up.
86    if (glyphBuffer.isEmpty())
87        return 0;
88
89    // Draw the glyph buffer now at the starting point returned in startX.
90    FloatPoint startPoint(startX, point.y());
91    drawGlyphBuffer(context, run, glyphBuffer, startPoint);
92
93    return startPoint.x() - startX;
94}
95
96void Font::drawEmphasisMarksForComplexText(GraphicsContext* context, const TextRun& run, const AtomicString& mark, const FloatPoint& point, int from, int to) const
97{
98    GlyphBuffer glyphBuffer;
99    float initialAdvance = getGlyphsAndAdvancesForComplexText(run, from, to, glyphBuffer, ForTextEmphasis);
100
101    if (glyphBuffer.isEmpty())
102        return;
103
104    drawEmphasisMarks(context, run, glyphBuffer, mark, FloatPoint(point.x() + initialAdvance, point.y()));
105}
106
107float Font::floatWidthForComplexText(const TextRun& run, HashSet<const SimpleFontData*>* fallbackFonts, GlyphOverflow* glyphOverflow) const
108{
109    ComplexTextController controller(this, run, true, fallbackFonts);
110    if (glyphOverflow) {
111        glyphOverflow->top = std::max<int>(glyphOverflow->top, ceilf(-controller.minGlyphBoundingBoxY()) - (glyphOverflow->computeBounds ? 0 : fontMetrics().ascent()));
112        glyphOverflow->bottom = std::max<int>(glyphOverflow->bottom, ceilf(controller.maxGlyphBoundingBoxY()) - (glyphOverflow->computeBounds ? 0 : fontMetrics().descent()));
113        glyphOverflow->left = std::max<int>(0, ceilf(-controller.minGlyphBoundingBoxX()));
114        glyphOverflow->right = std::max<int>(0, ceilf(controller.maxGlyphBoundingBoxX() - controller.totalWidth()));
115    }
116    return controller.totalWidth();
117}
118
119int Font::offsetForPositionForComplexText(const TextRun& run, float x, bool includePartialGlyphs) const
120{
121    ComplexTextController controller(this, run);
122    return controller.offsetForPosition(x, includePartialGlyphs);
123}
124
125const SimpleFontData* Font::fontDataForCombiningCharacterSequence(const UChar* characters, size_t length, FontDataVariant variant) const
126{
127    UChar32 baseCharacter;
128    size_t baseCharacterLength = 0;
129    U16_NEXT(characters, baseCharacterLength, length, baseCharacter);
130
131    GlyphData baseCharacterGlyphData = glyphDataForCharacter(baseCharacter, false, variant);
132
133    if (!baseCharacterGlyphData.glyph)
134        return 0;
135
136    if (length == baseCharacterLength)
137        return baseCharacterGlyphData.fontData;
138
139    bool triedBaseCharacterFontData = false;
140
141    unsigned i = 0;
142    for (const FontData* fontData = fontDataAt(0); fontData; fontData = fontDataAt(++i)) {
143        const SimpleFontData* simpleFontData = fontData->fontDataForCharacter(baseCharacter);
144#if PLATFORM(IOS)
145        if (baseCharacter >= 0x0600 && baseCharacter <= 0x06ff && simpleFontData->shouldNotBeUsedForArabic())
146            continue;
147#endif
148        if (variant == NormalVariant) {
149            if (simpleFontData->platformData().orientation() == Vertical) {
150                if (isCJKIdeographOrSymbol(baseCharacter) && !simpleFontData->hasVerticalGlyphs()) {
151                    variant = BrokenIdeographVariant;
152                    simpleFontData = simpleFontData->brokenIdeographFontData().get();
153                } else if (m_fontDescription.nonCJKGlyphOrientation() == NonCJKGlyphOrientationVerticalRight) {
154                    SimpleFontData* verticalRightFontData = simpleFontData->verticalRightOrientationFontData().get();
155                    Glyph verticalRightGlyph = verticalRightFontData->glyphForCharacter(baseCharacter);
156                    if (verticalRightGlyph == baseCharacterGlyphData.glyph)
157                        simpleFontData = verticalRightFontData;
158                } else {
159                    SimpleFontData* uprightFontData = simpleFontData->uprightOrientationFontData().get();
160                    Glyph uprightGlyph = uprightFontData->glyphForCharacter(baseCharacter);
161                    if (uprightGlyph != baseCharacterGlyphData.glyph)
162                        simpleFontData = uprightFontData;
163                }
164            }
165        } else {
166            if (const SimpleFontData* variantFontData = simpleFontData->variantFontData(m_fontDescription, variant).get())
167                simpleFontData = variantFontData;
168        }
169
170        if (simpleFontData == baseCharacterGlyphData.fontData)
171            triedBaseCharacterFontData = true;
172
173        if (simpleFontData->canRenderCombiningCharacterSequence(characters, length))
174            return simpleFontData;
175    }
176
177    if (!triedBaseCharacterFontData && baseCharacterGlyphData.fontData && baseCharacterGlyphData.fontData->canRenderCombiningCharacterSequence(characters, length))
178        return baseCharacterGlyphData.fontData;
179
180    return SimpleFontData::systemFallback();
181}
182
183} // namespace WebCore
184