FontCascadeCocoa.mm [plain text]
/*
* Copyright (C) 1999 Lars Knoll (knoll@kde.org)
* (C) 1999 Antti Koivisto (koivisto@kde.org)
* (C) 2000 Dirk Mueller (mueller@kde.org)
* Copyright (C) 2003, 2006-2011, 2016 Apple Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#import "config.h"
#import "FontCascade.h"
#import "ComplexTextController.h"
#import "DashArray.h"
#import "Font.h"
#import "GlyphBuffer.h"
#import "GraphicsContext.h"
#import "LayoutRect.h"
#import "Logging.h"
#import <pal/spi/cg/CoreGraphicsSPI.h>
#import <pal/spi/cocoa/CoreTextSPI.h>
#if USE(APPKIT)
#import <AppKit/AppKit.h>
#endif
#import <wtf/MathExtras.h>
#if PLATFORM(IOS_FAMILY)
#import <pal/ios/UIKitSoftLink.h>
#import <pal/spi/ios/CoreUISPI.h>
#import <wtf/SoftLinking.h>
SOFT_LINK_PRIVATE_FRAMEWORK(CoreUI)
SOFT_LINK_CLASS(CoreUI, CUICatalog)
SOFT_LINK_CLASS(CoreUI, CUIStyleEffectConfiguration)
#endif
namespace WebCore {
// Confusingly, even when CGFontRenderingGetFontSmoothingDisabled() returns true, CGContextSetShouldSmoothFonts() still impacts text
// rendering, which is why this function uses the "subpixel antialiasing" rather than "smoothing" terminology.
bool FontCascade::isSubpixelAntialiasingAvailable()
{
#if HAVE(CG_FONT_RENDERING_GET_FONT_SMOOTHING_DISABLED)
static bool subpixelAntialiasingEnabled;
static std::once_flag onceFlag;
std::call_once(onceFlag, [&] () {
subpixelAntialiasingEnabled = !CGFontRenderingGetFontSmoothingDisabled();
});
return subpixelAntialiasingEnabled;
#elif PLATFORM(MAC)
return true;
#else
return false;
#endif
}
bool FontCascade::canReturnFallbackFontsForComplexText()
{
return true;
}
bool FontCascade::canExpandAroundIdeographsInComplexText()
{
return true;
}
static inline void fillVectorWithHorizontalGlyphPositions(Vector<CGPoint, 256>& positions, CGContextRef context, const CGSize* advances, unsigned count)
{
CGAffineTransform matrix = CGAffineTransformInvert(CGContextGetTextMatrix(context));
positions[0] = CGPointZero;
for (unsigned i = 1; i < count; ++i) {
CGSize advance = CGSizeApplyAffineTransform(advances[i - 1], matrix);
positions[i].x = positions[i - 1].x + advance.width;
positions[i].y = positions[i - 1].y + advance.height;
}
}
static inline bool shouldUseLetterpressEffect(const GraphicsContext& context)
{
#if ENABLE(LETTERPRESS)
return context.textDrawingMode() & TextModeLetterpress;
#else
UNUSED_PARAM(context);
return false;
#endif
}
static void showLetterpressedGlyphsWithAdvances(const FloatPoint& point, const Font& font, GraphicsContext& coreContext, const CGGlyph* glyphs, const CGSize* advances, unsigned count)
{
#if ENABLE(LETTERPRESS)
if (!count)
return;
const FontPlatformData& platformData = font.platformData();
if (platformData.orientation() == FontOrientation::Vertical) {
// FIXME: Implement support for vertical text. See <rdar://problem/13737298>.
return;
}
CGContextRef context = coreContext.platformContext();
CGContextSetTextPosition(context, point.x(), point.y());
Vector<CGPoint, 256> positions(count);
fillVectorWithHorizontalGlyphPositions(positions, context, advances, count);
CTFontRef ctFont = platformData.ctFont();
CGContextSetFontSize(context, CTFontGetSize(ctFont));
static CUICatalog *catalog = PAL::softLink_UIKit__UIKitGetTextEffectsCatalog();
if (!catalog)
return;
static CUIStyleEffectConfiguration *styleConfiguration;
if (!styleConfiguration) {
styleConfiguration = [allocCUIStyleEffectConfigurationInstance() init];
styleConfiguration.useSimplifiedEffect = YES;
}
#if HAVE(OS_DARK_MODE_SUPPORT)
styleConfiguration.appearanceName = coreContext.useDarkAppearance() ? @"UIAppearanceDark" : @"UIAppearanceLight";
#endif
CGContextSetFont(context, adoptCF(CTFontCopyGraphicsFont(ctFont, nullptr)).get());
CGContextSetFontSize(context, platformData.size());
[catalog drawGlyphs:glyphs atPositions:positions.data() inContext:context withFont:ctFont count:count stylePresetName:@"_UIKitNewLetterpressStyle" styleConfiguration:styleConfiguration foregroundColor:CGContextGetFillColorAsColor(context)];
CGContextSetFont(context, nullptr);
CGContextSetFontSize(context, 0);
#else
UNUSED_PARAM(point);
UNUSED_PARAM(font);
UNUSED_PARAM(coreContext);
UNUSED_PARAM(glyphs);
UNUSED_PARAM(advances);
UNUSED_PARAM(count);
#endif
}
static void showGlyphsWithAdvances(const FloatPoint& point, const Font& font, CGContextRef context, const CGGlyph* glyphs, const CGSize* advances, unsigned count)
{
if (!count)
return;
CGContextSetTextPosition(context, point.x(), point.y());
const FontPlatformData& platformData = font.platformData();
Vector<CGPoint, 256> positions(count);
if (platformData.orientation() == FontOrientation::Vertical) {
CGAffineTransform rotateLeftTransform = CGAffineTransformMake(0, -1, 1, 0, 0, 0);
CGAffineTransform textMatrix = CGContextGetTextMatrix(context);
CGAffineTransform runMatrix = CGAffineTransformConcat(textMatrix, rotateLeftTransform);
ScopedTextMatrix savedMatrix(runMatrix, context);
Vector<CGSize, 256> translations(count);
CTFontGetVerticalTranslationsForGlyphs(platformData.ctFont(), glyphs, translations.data(), count);
CGAffineTransform transform = CGAffineTransformInvert(CGContextGetTextMatrix(context));
CGPoint position = FloatPoint(point.x(), point.y() + font.fontMetrics().floatAscent(IdeographicBaseline) - font.fontMetrics().floatAscent());
for (unsigned i = 0; i < count; ++i) {
CGSize translation = CGSizeApplyAffineTransform(translations[i], rotateLeftTransform);
positions[i] = CGPointApplyAffineTransform(CGPointMake(position.x - translation.width, position.y + translation.height), transform);
position.x += advances[i].width;
position.y += advances[i].height;
}
CTFontDrawGlyphs(platformData.ctFont(), glyphs, positions.data(), count, context);
} else {
fillVectorWithHorizontalGlyphPositions(positions, context, advances, count);
CTFontDrawGlyphs(platformData.ctFont(), glyphs, positions.data(), count, context);
}
}
static void setCGFontRenderingMode(GraphicsContext& context)
{
CGContextRef cgContext = context.platformContext();
CGContextSetShouldAntialiasFonts(cgContext, true);
CGAffineTransform contextTransform = CGContextGetCTM(cgContext);
bool isTranslationOrIntegralScale = WTF::isIntegral(contextTransform.a) && WTF::isIntegral(contextTransform.d) && contextTransform.b == 0.f && contextTransform.c == 0.f;
bool isRotated = ((contextTransform.b || contextTransform.c) && (contextTransform.a || contextTransform.d));
bool doSubpixelQuantization = isTranslationOrIntegralScale || (!isRotated && context.shouldSubpixelQuantizeFonts());
CGContextSetShouldSubpixelPositionFonts(cgContext, true);
CGContextSetShouldSubpixelQuantizeFonts(cgContext, doSubpixelQuantization);
}
void FontCascade::drawGlyphs(GraphicsContext& context, const Font& font, const GlyphBuffer& glyphBuffer, unsigned from, unsigned numGlyphs, const FloatPoint& anchorPoint, FontSmoothingMode smoothingMode)
{
const FontPlatformData& platformData = font.platformData();
if (!platformData.size())
return;
CGContextRef cgContext = context.platformContext();
bool shouldAntialias = true;
bool shouldSmoothFonts = true;
if (!font.allowsAntialiasing())
smoothingMode = FontSmoothingMode::NoSmoothing;
switch (smoothingMode) {
case FontSmoothingMode::Antialiased:
shouldSmoothFonts = false;
break;
case FontSmoothingMode::AutoSmoothing:
case FontSmoothingMode::SubpixelAntialiased:
shouldAntialias = true;
break;
case FontSmoothingMode::NoSmoothing:
shouldAntialias = false;
shouldSmoothFonts = false;
break;
}
if (!shouldUseSmoothing())
shouldSmoothFonts = false;
#if !PLATFORM(IOS_FAMILY)
bool originalShouldUseFontSmoothing = CGContextGetShouldSmoothFonts(cgContext);
if (shouldSmoothFonts != originalShouldUseFontSmoothing)
CGContextSetShouldSmoothFonts(cgContext, shouldSmoothFonts);
#endif
bool originalShouldAntialias = CGContextGetShouldAntialias(cgContext);
if (shouldAntialias != originalShouldAntialias)
CGContextSetShouldAntialias(cgContext, shouldAntialias);
bool useLetterpressEffect = shouldUseLetterpressEffect(context);
FloatPoint point = anchorPoint;
CGAffineTransform matrix = CGAffineTransformIdentity;
if (!platformData.isColorBitmapFont())
matrix = CTFontGetMatrix(platformData.font());
matrix.b = -matrix.b;
matrix.d = -matrix.d;
if (platformData.syntheticOblique()) {
static float obliqueSkew = tanf(syntheticObliqueAngle() * piFloat / 180);
if (platformData.orientation() == FontOrientation::Vertical) {
if (font.isTextOrientationFallback())
matrix = CGAffineTransformConcat(matrix, CGAffineTransformMake(1, obliqueSkew, 0, 1, 0, 0));
else
matrix = CGAffineTransformConcat(matrix, CGAffineTransformMake(1, -obliqueSkew, 0, 1, 0, 0));
} else
matrix = CGAffineTransformConcat(matrix, CGAffineTransformMake(1, 0, -obliqueSkew, 1, 0, 0));
}
ScopedTextMatrix restorer(matrix, cgContext);
setCGFontRenderingMode(context);
CGContextSetFontSize(cgContext, platformData.size());
FloatSize shadowOffset;
float shadowBlur;
Color shadowColor;
context.getShadow(shadowOffset, shadowBlur, shadowColor);
AffineTransform contextCTM = context.getCTM();
float syntheticBoldOffset = font.syntheticBoldOffset();
if (syntheticBoldOffset && !contextCTM.isIdentityOrTranslationOrFlipped()) {
FloatSize horizontalUnitSizeInDevicePixels = contextCTM.mapSize(FloatSize(1, 0));
float horizontalUnitLengthInDevicePixels = sqrtf(horizontalUnitSizeInDevicePixels.width() * horizontalUnitSizeInDevicePixels.width() + horizontalUnitSizeInDevicePixels.height() * horizontalUnitSizeInDevicePixels.height());
if (horizontalUnitLengthInDevicePixels) {
// Make sure that a scaled down context won't blow up the gap between the glyphs.
syntheticBoldOffset = std::min(syntheticBoldOffset, syntheticBoldOffset / horizontalUnitLengthInDevicePixels);
}
};
bool hasSimpleShadow = context.textDrawingMode() == TextModeFill && shadowColor.isValid() && !shadowBlur && !platformData.isColorBitmapFont() && (!context.shadowsIgnoreTransforms() || contextCTM.isIdentityOrTranslationOrFlipped()) && !context.isInTransparencyLayer();
if (hasSimpleShadow) {
// Paint simple shadows ourselves instead of relying on CG shadows, to avoid losing subpixel antialiasing.
context.clearShadow();
Color fillColor = context.fillColor();
Color shadowFillColor = shadowColor.colorWithAlphaMultipliedBy(fillColor.alphaAsFloat());
context.setFillColor(shadowFillColor);
float shadowTextX = point.x() + shadowOffset.width();
// If shadows are ignoring transforms, then we haven't applied the Y coordinate flip yet, so down is negative.
float shadowTextY = point.y() + shadowOffset.height() * (context.shadowsIgnoreTransforms() ? -1 : 1);
showGlyphsWithAdvances(FloatPoint(shadowTextX, shadowTextY), font, cgContext, glyphBuffer.glyphs(from), static_cast<const CGSize*>(glyphBuffer.advances(from)), numGlyphs);
if (syntheticBoldOffset)
showGlyphsWithAdvances(FloatPoint(shadowTextX + syntheticBoldOffset, shadowTextY), font, cgContext, glyphBuffer.glyphs(from), static_cast<const CGSize*>(glyphBuffer.advances(from)), numGlyphs);
context.setFillColor(fillColor);
}
if (useLetterpressEffect)
showLetterpressedGlyphsWithAdvances(point, font, context, glyphBuffer.glyphs(from), static_cast<const CGSize*>(glyphBuffer.advances(from)), numGlyphs);
else
showGlyphsWithAdvances(point, font, cgContext, glyphBuffer.glyphs(from), static_cast<const CGSize*>(glyphBuffer.advances(from)), numGlyphs);
if (syntheticBoldOffset)
showGlyphsWithAdvances(FloatPoint(point.x() + syntheticBoldOffset, point.y()), font, cgContext, glyphBuffer.glyphs(from), static_cast<const CGSize*>(glyphBuffer.advances(from)), numGlyphs);
if (hasSimpleShadow)
context.setShadow(shadowOffset, shadowBlur, shadowColor);
#if !PLATFORM(IOS_FAMILY)
if (shouldSmoothFonts != originalShouldUseFontSmoothing)
CGContextSetShouldSmoothFonts(cgContext, originalShouldUseFontSmoothing);
#endif
if (shouldAntialias != originalShouldAntialias)
CGContextSetShouldAntialias(cgContext, originalShouldAntialias);
}
bool FontCascade::primaryFontIsSystemFont() const
{
const auto& fontData = primaryFont();
return CTFontDescriptorIsSystemUIFont(adoptCF(CTFontCopyFontDescriptor(fontData.platformData().ctFont())).get());
}
// FIXME: Use this on all ports.
const Font* FontCascade::fontForCombiningCharacterSequence(const UChar* characters, size_t length) const
{
UChar32 baseCharacter;
size_t baseCharacterLength = 0;
U16_NEXT(characters, baseCharacterLength, length, baseCharacter);
GlyphData baseCharacterGlyphData = glyphDataForCharacter(baseCharacter, false, NormalVariant);
if (!baseCharacterGlyphData.glyph)
return nullptr;
if (length == baseCharacterLength)
return baseCharacterGlyphData.font;
bool triedBaseCharacterFont = false;
for (unsigned i = 0; !fallbackRangesAt(i).isNull(); ++i) {
const Font* font = fallbackRangesAt(i).fontForCharacter(baseCharacter);
if (!font)
continue;
#if PLATFORM(IOS_FAMILY)
if (baseCharacter >= 0x0600 && baseCharacter <= 0x06ff && font->shouldNotBeUsedForArabic())
continue;
#endif
if (font->platformData().orientation() == FontOrientation::Vertical) {
if (isCJKIdeographOrSymbol(baseCharacter) && !font->hasVerticalGlyphs())
font = &font->brokenIdeographFont();
else if (m_fontDescription.nonCJKGlyphOrientation() == NonCJKGlyphOrientation::Mixed) {
const Font& verticalRightFont = font->verticalRightOrientationFont();
Glyph verticalRightGlyph = verticalRightFont.glyphForCharacter(baseCharacter);
if (verticalRightGlyph == baseCharacterGlyphData.glyph)
font = &verticalRightFont;
} else {
const Font& uprightFont = font->uprightOrientationFont();
Glyph uprightGlyph = uprightFont.glyphForCharacter(baseCharacter);
if (uprightGlyph != baseCharacterGlyphData.glyph)
font = &uprightFont;
}
}
if (font == baseCharacterGlyphData.font)
triedBaseCharacterFont = true;
if (font->canRenderCombiningCharacterSequence(characters, length))
return font;
}
if (!triedBaseCharacterFont && baseCharacterGlyphData.font && baseCharacterGlyphData.font->canRenderCombiningCharacterSequence(characters, length))
return baseCharacterGlyphData.font;
return Font::systemFallback();
}
}