1/*
2 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
3 *           (C) 1999 Antti Koivisto (koivisto@kde.org)
4 *           (C) 2000 Dirk Mueller (mueller@kde.org)
5 * Copyright (C) 2003, 2006, 2007, 2008, 2009, 2010 Apple Inc.
6 *
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Library General Public License for more details.
16 *
17 * You should have received a copy of the GNU Library General Public License
18 * along with this library; see the file COPYING.LIB.  If not, write to
19 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
20 * Boston, MA 02110-1301, USA.
21 */
22
23#import "config.h"
24#import "Font.h"
25
26#import "GlyphBuffer.h"
27#import "GraphicsContext.h"
28#import "Logging.h"
29#import "SimpleFontData.h"
30#import "WebCoreSystemInterface.h"
31#import <AppKit/AppKit.h>
32
33#define SYNTHETIC_OBLIQUE_ANGLE 14
34
35#ifdef __LP64__
36#define URefCon void*
37#else
38#define URefCon UInt32
39#endif
40
41using namespace std;
42
43namespace WebCore {
44
45bool Font::canReturnFallbackFontsForComplexText()
46{
47    return true;
48}
49
50bool Font::canExpandAroundIdeographsInComplexText()
51{
52    return true;
53}
54
55// CTFontGetVerticalTranslationsForGlyphs is different on Snow Leopard.  It returns values for a font-size of 1
56// without unitsPerEm applied.  We have to apply a transform that scales up to the point size and that also
57// divides by unitsPerEm.
58static bool hasBrokenCTFontGetVerticalTranslationsForGlyphs()
59{
60// Chromium runs the same binary on both Leopard and Snow Leopard, so the check has to happen at runtime.
61#if PLATFORM(CHROMIUM)
62    static bool isCached = false;
63    static bool result;
64
65    if (!isCached) {
66        SInt32 majorVersion = 0;
67        SInt32 minorVersion = 0;
68        Gestalt(gestaltSystemVersionMajor, &majorVersion);
69        Gestalt(gestaltSystemVersionMinor, &minorVersion);
70        result = majorVersion == 10 && minorVersion == 6;
71        isCached = true;
72    }
73    return result;
74#elif defined(BUILDING_ON_SNOW_LEOPARD)
75    return true;
76#else
77    return false;
78#endif
79}
80
81static void showGlyphsWithAdvances(const FloatPoint& point, const SimpleFontData* font, CGContextRef context, const CGGlyph* glyphs, const CGSize* advances, size_t count)
82{
83    CGContextSetTextPosition(context, point.x(), point.y());
84
85    const FontPlatformData& platformData = font->platformData();
86    if (!platformData.isColorBitmapFont()) {
87        CGAffineTransform savedMatrix;
88        bool isVertical = font->platformData().orientation() == Vertical;
89        if (isVertical) {
90            CGAffineTransform rotateLeftTransform = CGAffineTransformMake(0, -1, 1, 0, 0, 0);
91            savedMatrix = CGContextGetTextMatrix(context);
92            CGAffineTransform runMatrix = CGAffineTransformConcat(savedMatrix, rotateLeftTransform);
93            CGContextSetTextMatrix(context, runMatrix);
94
95            CGAffineTransform translationsTransform;
96            if (hasBrokenCTFontGetVerticalTranslationsForGlyphs()) {
97                translationsTransform = CGAffineTransformMake(platformData.m_size, 0, 0, platformData.m_size, 0, 0);
98                translationsTransform = CGAffineTransformConcat(translationsTransform, rotateLeftTransform);
99                CGFloat unitsPerEm = CGFontGetUnitsPerEm(platformData.cgFont());
100                translationsTransform = CGAffineTransformConcat(translationsTransform, CGAffineTransformMakeScale(1 / unitsPerEm, 1 / unitsPerEm));
101            } else {
102                translationsTransform = rotateLeftTransform;
103            }
104            Vector<CGSize, 256> translations(count);
105            CTFontGetVerticalTranslationsForGlyphs(platformData.ctFont(), glyphs, translations.data(), count);
106
107            CGAffineTransform transform = CGAffineTransformInvert(CGContextGetTextMatrix(context));
108
109            CGPoint position = FloatPoint(point.x(), point.y() + font->fontMetrics().floatAscent(IdeographicBaseline) - font->fontMetrics().floatAscent());
110            Vector<CGPoint, 256> positions(count);
111            for (size_t i = 0; i < count; ++i) {
112                CGSize translation = CGSizeApplyAffineTransform(translations[i], translationsTransform);
113                positions[i] = CGPointApplyAffineTransform(CGPointMake(position.x - translation.width, position.y + translation.height), transform);
114                position.x += advances[i].width;
115                position.y += advances[i].height;
116            }
117            CGContextShowGlyphsAtPositions(context, glyphs, positions.data(), count);
118            CGContextSetTextMatrix(context, savedMatrix);
119        } else
120            CGContextShowGlyphsWithAdvances(context, glyphs, advances, count);
121    }
122#if !defined(BUILDING_ON_TIGER) && !defined(BUILDING_ON_LEOPARD) && !defined(BUILDING_ON_SNOW_LEOPARD)
123    else {
124        if (!count)
125            return;
126
127        Vector<CGPoint, 256> positions(count);
128        CGAffineTransform matrix = CGAffineTransformInvert(CGContextGetTextMatrix(context));
129        positions[0] = CGPointZero;
130        for (size_t i = 1; i < count; ++i) {
131            CGSize advance = CGSizeApplyAffineTransform(advances[i - 1], matrix);
132            positions[i].x = positions[i - 1].x + advance.width;
133            positions[i].y = positions[i - 1].y + advance.height;
134        }
135        CTFontDrawGlyphs(platformData.ctFont(), glyphs, positions.data(), count, context);
136    }
137#endif
138}
139
140void Font::drawGlyphs(GraphicsContext* context, const SimpleFontData* font, const GlyphBuffer& glyphBuffer, int from, int numGlyphs, const FloatPoint& point) const
141{
142    CGContextRef cgContext = context->platformContext();
143
144    bool shouldSmoothFonts = true;
145    bool changeFontSmoothing = false;
146
147    switch(fontDescription().fontSmoothing()) {
148    case Antialiased: {
149        context->setShouldAntialias(true);
150        shouldSmoothFonts = false;
151        changeFontSmoothing = true;
152        break;
153    }
154    case SubpixelAntialiased: {
155        context->setShouldAntialias(true);
156        shouldSmoothFonts = true;
157        changeFontSmoothing = true;
158        break;
159    }
160    case NoSmoothing: {
161        context->setShouldAntialias(false);
162        shouldSmoothFonts = false;
163        changeFontSmoothing = true;
164        break;
165    }
166    case AutoSmoothing: {
167        // For the AutoSmooth case, don't do anything! Keep the default settings.
168        break;
169    }
170    default:
171        ASSERT_NOT_REACHED();
172    }
173
174    if (!shouldUseSmoothing()) {
175        shouldSmoothFonts = false;
176        changeFontSmoothing = true;
177    }
178
179    bool originalShouldUseFontSmoothing = false;
180    if (changeFontSmoothing) {
181        originalShouldUseFontSmoothing = wkCGContextGetShouldSmoothFonts(cgContext);
182        CGContextSetShouldSmoothFonts(cgContext, shouldSmoothFonts);
183    }
184
185    const FontPlatformData& platformData = font->platformData();
186    NSFont* drawFont;
187    if (!isPrinterFont()) {
188        drawFont = [platformData.font() screenFont];
189        if (drawFont != platformData.font())
190            // We are getting this in too many places (3406411); use ERROR so it only prints on debug versions for now. (We should debug this also, eventually).
191            LOG_ERROR("Attempting to set non-screen font (%@) when drawing to screen.  Using screen font anyway, may result in incorrect metrics.",
192                [[[platformData.font() fontDescriptor] fontAttributes] objectForKey:NSFontNameAttribute]);
193    } else {
194        drawFont = [platformData.font() printerFont];
195        if (drawFont != platformData.font())
196            NSLog(@"Attempting to set non-printer font (%@) when printing.  Using printer font anyway, may result in incorrect metrics.",
197                [[[platformData.font() fontDescriptor] fontAttributes] objectForKey:NSFontNameAttribute]);
198    }
199
200    CGContextSetFont(cgContext, platformData.cgFont());
201
202    CGAffineTransform matrix = CGAffineTransformIdentity;
203    if (drawFont && !platformData.isColorBitmapFont())
204        memcpy(&matrix, [drawFont matrix], sizeof(matrix));
205    matrix.b = -matrix.b;
206    matrix.d = -matrix.d;
207    if (platformData.m_syntheticOblique)
208        matrix = CGAffineTransformConcat(matrix, CGAffineTransformMake(1, 0, -tanf(SYNTHETIC_OBLIQUE_ANGLE * acosf(0) / 90), 1, 0, 0));
209    CGContextSetTextMatrix(cgContext, matrix);
210
211    if (drawFont) {
212        wkSetCGFontRenderingMode(cgContext, drawFont);
213        CGContextSetFontSize(cgContext, 1.0f);
214    } else
215        CGContextSetFontSize(cgContext, platformData.m_size);
216
217
218    FloatSize shadowOffset;
219    float shadowBlur;
220    Color shadowColor;
221    ColorSpace shadowColorSpace;
222    ColorSpace fillColorSpace = context->fillColorSpace();
223    context->getShadow(shadowOffset, shadowBlur, shadowColor, shadowColorSpace);
224
225    bool hasSimpleShadow = context->textDrawingMode() == TextModeFill && shadowColor.isValid() && !shadowBlur && !platformData.isColorBitmapFont() && (!context->shadowsIgnoreTransforms() || context->getCTM().isIdentityOrTranslationOrFlipped());
226    if (hasSimpleShadow) {
227        // Paint simple shadows ourselves instead of relying on CG shadows, to avoid losing subpixel antialiasing.
228        context->clearShadow();
229        Color fillColor = context->fillColor();
230        Color shadowFillColor(shadowColor.red(), shadowColor.green(), shadowColor.blue(), shadowColor.alpha() * fillColor.alpha() / 255);
231        context->setFillColor(shadowFillColor, shadowColorSpace);
232        float shadowTextX = point.x() + shadowOffset.width();
233        // If shadows are ignoring transforms, then we haven't applied the Y coordinate flip yet, so down is negative.
234        float shadowTextY = point.y() + shadowOffset.height() * (context->shadowsIgnoreTransforms() ? -1 : 1);
235        showGlyphsWithAdvances(FloatPoint(shadowTextX, shadowTextY), font, cgContext, glyphBuffer.glyphs(from), glyphBuffer.advances(from), numGlyphs);
236        if (font->syntheticBoldOffset())
237            showGlyphsWithAdvances(FloatPoint(shadowTextX + font->syntheticBoldOffset(), shadowTextY), font, cgContext, glyphBuffer.glyphs(from), glyphBuffer.advances(from), numGlyphs);
238        context->setFillColor(fillColor, fillColorSpace);
239    }
240
241    showGlyphsWithAdvances(point, font, cgContext, glyphBuffer.glyphs(from), glyphBuffer.advances(from), numGlyphs);
242    if (font->syntheticBoldOffset())
243        showGlyphsWithAdvances(FloatPoint(point.x() + font->syntheticBoldOffset(), point.y()), font, cgContext, glyphBuffer.glyphs(from), glyphBuffer.advances(from), numGlyphs);
244
245    if (hasSimpleShadow)
246        context->setShadow(shadowOffset, shadowBlur, shadowColor, shadowColorSpace);
247
248    if (changeFontSmoothing)
249        CGContextSetShouldSmoothFonts(cgContext, originalShouldUseFontSmoothing);
250}
251
252}
253