/** * This file is part of the html renderer for KDE. * * 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 Apple Computer, 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. * */ #include "config.h" #include "Font.h" #include "CharacterNames.h" #include "FloatRect.h" #include "FontCache.h" #include "FontFallbackList.h" #include "IntPoint.h" #include "GlyphBuffer.h" #include "TextStyle.h" #include #include #if USE(ICU_UNICODE) #include #endif using namespace WTF; using namespace Unicode; namespace WebCore { // According to http://www.unicode.org/Public/UNIDATA/UCD.html#Canonical_Combining_Class_Values const uint8_t hiraganaKatakanaVoicingMarksCombiningClass = 8; const uint8_t Font::gRoundingHackCharacterTable[256] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 /*\t*/, 1 /*\n*/, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 /*space*/, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 /*-*/, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 /*?*/, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 /*no-break space*/, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; Font::CodePath Font::codePath = Auto; struct WidthIterator { WidthIterator(const Font* font, const TextRun& run, const TextStyle& style); void advance(int to, GlyphBuffer* glyphBuffer = 0); bool advanceOneCharacter(float& width, GlyphBuffer* glyphBuffer = 0); const Font* m_font; const TextRun& m_run; int m_end; const TextStyle& m_style; unsigned m_currentCharacter; float m_runWidthSoFar; float m_padding; float m_padPerSpace; float m_finalRoundingWidth; private: UChar32 normalizeVoicingMarks(int currentCharacter); }; WidthIterator::WidthIterator(const Font* font, const TextRun& run, const TextStyle& style) : m_font(font) , m_run(run) , m_end(run.length()) , m_style(style) , m_currentCharacter(0) , m_runWidthSoFar(0) , m_finalRoundingWidth(0) { // If the padding is non-zero, count the number of spaces in the run // and divide that by the padding for per space addition. m_padding = m_style.padding(); if (!m_padding) m_padPerSpace = 0; else { float numSpaces = 0; for (int i = 0; i < run.length(); i++) if (Font::treatAsSpace(m_run[i])) numSpaces++; if (numSpaces == 0) m_padPerSpace = 0; else m_padPerSpace = ceilf(m_style.padding() / numSpaces); } } void WidthIterator::advance(int offset, GlyphBuffer* glyphBuffer) { if (offset > m_end) offset = m_end; int currentCharacter = m_currentCharacter; const UChar* cp = m_run.data(currentCharacter); bool rtl = m_style.rtl(); bool attemptFontSubstitution = m_style.attemptFontSubstitution(); bool hasExtraSpacing = m_font->letterSpacing() || m_font->wordSpacing() || m_padding; float runWidthSoFar = m_runWidthSoFar; float lastRoundingWidth = m_finalRoundingWidth; while (currentCharacter < offset) { UChar32 c = *cp; unsigned clusterLength = 1; if (c >= 0x3041) { if (c <= 0x30FE) { // Deal with Hiragana and Katakana voiced and semi-voiced syllables. // Normalize into composed form, and then look for glyph with base + combined mark. // Check above for character range to minimize performance impact. UChar32 normalized = normalizeVoicingMarks(currentCharacter); if (normalized) { c = normalized; clusterLength = 2; } } else if (U16_IS_SURROGATE(c)) { if (!U16_IS_SURROGATE_LEAD(c)) break; // Do we have a surrogate pair? If so, determine the full Unicode (32 bit) // code point before glyph lookup. // Make sure we have another character and it's a low surrogate. if (currentCharacter + 1 >= m_run.length()) break; UChar low = cp[1]; if (!U16_IS_TRAIL(low)) break; c = U16_GET_SUPPLEMENTARY(c, low); clusterLength = 2; } } const GlyphData& glyphData = m_font->glyphDataForCharacter(c, cp, clusterLength, rtl, attemptFontSubstitution); Glyph glyph = glyphData.glyph; const FontData* fontData = glyphData.fontData; ASSERT(fontData); // Now that we have a glyph and font data, get its width. float width; if (c == '\t' && m_style.allowTabs()) { float tabWidth = m_font->tabWidth(); width = tabWidth - fmodf(m_style.xPos() + runWidthSoFar, tabWidth); } else { width = fontData->widthForGlyph(glyph); // We special case spaces in two ways when applying word rounding. // First, we round spaces to an adjusted width in all fonts. // Second, in fixed-pitch fonts we ensure that all characters that // match the width of the space character have the same width as the space character. if (width == fontData->m_spaceWidth && (fontData->m_treatAsFixedPitch || glyph == fontData->m_spaceGlyph) && m_style.applyWordRounding()) width = fontData->m_adjustedSpaceWidth; } if (hasExtraSpacing) { // Account for letter-spacing. if (width && m_font->letterSpacing()) width += m_font->letterSpacing(); if (Font::treatAsSpace(c)) { // Account for padding. WebCore uses space padding to justify text. // We distribute the specified padding over the available spaces in the run. if (m_padding) { // Use left over padding if not evenly divisible by number of spaces. if (m_padding < m_padPerSpace) { width += m_padding; m_padding = 0; } else { width += m_padPerSpace; m_padding -= m_padPerSpace; } } // Account for word spacing. // We apply additional space between "words" by adding width to the space character. if (currentCharacter != 0 && !Font::treatAsSpace(cp[-1]) && m_font->wordSpacing()) width += m_font->wordSpacing(); } } // Advance past the character we just dealt with. cp += clusterLength; currentCharacter += clusterLength; // Account for float/integer impedance mismatch between CG and KHTML. "Words" (characters // followed by a character defined by isRoundingHackCharacter()) are always an integer width. // We adjust the width of the last character of a "word" to ensure an integer width. // If we move KHTML to floats we can remove this (and related) hacks. float oldWidth = width; // Force characters that are used to determine word boundaries for the rounding hack // to be integer width, so following words will start on an integer boundary. if (m_style.applyWordRounding() && Font::isRoundingHackCharacter(c)) width = ceilf(width); // Check to see if the next character is a "rounding hack character", if so, adjust // width so that the total run width will be on an integer boundary. if ((m_style.applyWordRounding() && currentCharacter < m_run.length() && Font::isRoundingHackCharacter(*cp)) || (m_style.applyRunRounding() && currentCharacter >= m_end)) { float totalWidth = runWidthSoFar + width; width += ceilf(totalWidth) - totalWidth; } runWidthSoFar += width; if (glyphBuffer) glyphBuffer->add(glyph, fontData, (rtl ? oldWidth + lastRoundingWidth : width)); lastRoundingWidth = width - oldWidth; } m_currentCharacter = currentCharacter; m_runWidthSoFar = runWidthSoFar; m_finalRoundingWidth = lastRoundingWidth; } bool WidthIterator::advanceOneCharacter(float& width, GlyphBuffer* glyphBuffer) { glyphBuffer->clear(); advance(m_currentCharacter + 1, glyphBuffer); float w = 0; for (int i = 0; i < glyphBuffer->size(); ++i) w += glyphBuffer->advanceAt(i); width = w; return !glyphBuffer->isEmpty(); } UChar32 WidthIterator::normalizeVoicingMarks(int currentCharacter) { if (currentCharacter + 1 < m_end) { if (combiningClass(m_run[currentCharacter + 1]) == hiraganaKatakanaVoicingMarksCombiningClass) { #if USE(ICU_UNICODE) // Normalize into composed form using 3.2 rules. UChar normalizedCharacters[2] = { 0, 0 }; UErrorCode uStatus = U_ZERO_ERROR; int32_t resultLength = unorm_normalize(m_run.data(currentCharacter), 2, UNORM_NFC, UNORM_UNICODE_3_2, &normalizedCharacters[0], 2, &uStatus); if (resultLength == 1 && uStatus == 0) return normalizedCharacters[0]; #elif USE(QT4_UNICODE) QString tmp(reinterpret_cast(m_run.data(currentCharacter)), 2); QString res = tmp.normalized(QString::NormalizationForm_C, QChar::Unicode_3_2); if (res.length() == 1) return res.at(0).unicode(); #endif } } return 0; } // ============================================================================================ // Font Implementation (Cross-Platform Portion) // ============================================================================================ Font::Font() : m_pageZero(0) , m_letterSpacing(0) , m_wordSpacing(0) , m_isPlatformFont(false) { } Font::Font(const FontDescription& fd, short letterSpacing, short wordSpacing) : m_fontDescription(fd) , m_pageZero(0) , m_letterSpacing(letterSpacing) , m_wordSpacing(wordSpacing) , m_isPlatformFont(false) { } Font::Font(const FontPlatformData& fontData, bool isPrinterFont) : m_fontList(new FontFallbackList) , m_pageZero(0) , m_letterSpacing(0) , m_wordSpacing(0) , m_isPlatformFont(true) { m_fontDescription.setUsePrinterFont(isPrinterFont); m_fontList->setPlatformFont(fontData); } Font::Font(const Font& other) : m_fontDescription(other.m_fontDescription) , m_fontList(other.m_fontList) , m_pages(other.m_pages) , m_pageZero(other.m_pageZero) , m_letterSpacing(other.m_letterSpacing) , m_wordSpacing(other.m_wordSpacing) , m_isPlatformFont(other.m_isPlatformFont) { } Font& Font::operator=(const Font& other) { m_fontDescription = other.m_fontDescription; m_fontList = other.m_fontList; m_pages = other.m_pages; m_pageZero = other.m_pageZero; m_letterSpacing = other.m_letterSpacing; m_wordSpacing = other.m_wordSpacing; m_isPlatformFont = other.m_isPlatformFont; return *this; } Font::~Font() { } // FIXME: It is unfortunate that this function needs to be passed the original cluster. // It is only required for the platform's FontCache::getFontDataForCharacters(), and it means // that this function is not correct if it transforms the character to uppercase and calls // FontCache::getFontDataForCharacters() afterwards. const GlyphData& Font::glyphDataForCharacter(UChar32 c, const UChar* cluster, unsigned clusterLength, bool mirror, bool attemptFontSubstitution) const { bool smallCaps = false; if (m_fontDescription.smallCaps() && !Unicode::isUpper(c)) { // Convert lowercase to upper. UChar32 upperC = Unicode::toUpper(c); if (upperC != c) { c = upperC; smallCaps = true; } } if (mirror) c = mirroredChar(c); unsigned pageNumber = (c / GlyphPage::size); GlyphPageTreeNode* node = pageNumber ? m_pages.get(pageNumber) : m_pageZero; if (!node) { node = GlyphPageTreeNode::getRootChild(primaryFont(), pageNumber); if (pageNumber) m_pages.set(pageNumber, node); else m_pageZero = node; } if (!attemptFontSubstitution && node->level() != 1) node = GlyphPageTreeNode::getRootChild(primaryFont(), pageNumber); while (true) { GlyphPage* page = node->page(); if (page) { const GlyphData& data = page->glyphDataForCharacter(c); if (data.glyph || !attemptFontSubstitution) { if (!smallCaps) return data; // We have a glyph for the character in question in the current page (or we've been told not to fall back). const FontData* smallCapsFontData = data.fontData->smallCapsFontData(m_fontDescription); if (!smallCapsFontData) // This should not happen, but if it does, we will return a big cap. return data; GlyphPageTreeNode* smallCapsNode = GlyphPageTreeNode::getRootChild(smallCapsFontData, pageNumber); GlyphPage* smallCapsPage = smallCapsNode->page(); if (smallCapsPage) { const GlyphData& data = smallCapsPage->glyphDataForCharacter(c); if (data.glyph || !attemptFontSubstitution) return data; } // Not attempting system fallback off the smallCapsFontData. This is the very unlikely case that // a font has the lowercase character but not its uppercase version. return smallCapsFontData->missingGlyphData(); } } else if (!attemptFontSubstitution) { if (smallCaps) { if (const FontData* smallCapsFontData = primaryFont()->smallCapsFontData(m_fontDescription)) return smallCapsFontData->missingGlyphData(); } return primaryFont()->missingGlyphData(); } if (node->isSystemFallback()) { // System fallback is character-dependent. When we get here, we // know that the character in question isn't in the system fallback // font's glyph page. Try to lazily create it here. // Convert characters that shouldn't render to zero width spaces when asking what font is // appropriate. const FontData* characterFontData; if (clusterLength == 1 && Font::treatAsZeroWidthSpace(cluster[0])) characterFontData = FontCache::getFontDataForCharacters(*this, &zeroWidthSpace, 1); else characterFontData = FontCache::getFontDataForCharacters(*this, cluster, clusterLength); if (smallCaps) characterFontData = characterFontData->smallCapsFontData(m_fontDescription); if (characterFontData) { // Got the fallback font, return the glyph page associated with // it. We also store the FontData for the glyph in the fallback // page for future use (it's lazily populated by us). GlyphPage* fallbackPage = GlyphPageTreeNode::getRootChild(characterFontData, pageNumber)->page(); const GlyphData& data = fallbackPage ? fallbackPage->glyphDataForCharacter(c) : characterFontData->missingGlyphData(); if (!smallCaps) page->setGlyphDataForCharacter(c, data.glyph, characterFontData); return data; } // Even system fallback can fail. // FIXME: Should the last resort font be used? const GlyphData& data = primaryFont()->missingGlyphData(); if (!smallCaps && page) page->setGlyphDataForCharacter(c, data.glyph, data.fontData); return data; } // Proceed with the fallback list. const FontData* fontData = fontDataAt(node->level()); node = node->getChild(fontData, pageNumber); if (pageNumber) m_pages.set(pageNumber, node); else m_pageZero = node; } } const FontData* Font::primaryFont() const { ASSERT(m_fontList); return m_fontList->primaryFont(this); } const FontData* Font::fontDataAt(unsigned index) const { ASSERT(m_fontList); return m_fontList->fontDataAt(this, index); } const FontData* Font::fontDataForCharacters(const UChar* characters, int length) const { ASSERT(m_fontList); return m_fontList->fontDataForCharacters(this, characters, length); } void Font::update() const { // FIXME: It is pretty crazy that we are willing to just poke into a RefPtr, but it ends up // being reasonably safe (because inherited fonts in the render tree pick up the new // style anyway. Other copies are transient, e.g., the state in the GraphicsContext, and // won't stick around long enough to get you in trouble). Still, this is pretty disgusting, // and could eventually be rectified by using RefPtrs for Fonts themselves. if (!m_fontList) m_fontList = new FontFallbackList; m_fontList->invalidate(); m_pageZero = 0; m_pages.clear(); } int Font::width(const TextRun& run) const { return width(run, TextStyle()); } int Font::width(const TextRun& run, const TextStyle& style) const { return lroundf(floatWidth(run, style)); } int Font::ascent() const { return primaryFont()->ascent(); } int Font::descent() const { return primaryFont()->descent(); } int Font::lineSpacing() const { return primaryFont()->lineSpacing(); } float Font::xHeight() const { return primaryFont()->xHeight(); } int Font::spaceWidth() const { return (int)ceilf(primaryFont()->m_adjustedSpaceWidth + m_letterSpacing); } bool Font::isFixedPitch() const { ASSERT(m_fontList); return m_fontList->isFixedPitch(this); } void Font::setCodePath(CodePath p) { codePath = p; } bool Font::canUseGlyphCache(const TextRun& run) const { switch (codePath) { case Auto: break; case Simple: return true; case Complex: return false; } // Start from 0 since drawing and highlighting also measure the characters before run->from for (int i = 0; i < run.length(); i++) { const UChar c = run[i]; if (c < 0x300) // U+0300 through U+036F Combining diacritical marks continue; if (c <= 0x36F) return false; if (c < 0x0591 || c == 0x05BE) // U+0591 through U+05CF excluding U+05BE Hebrew combining marks, Hebrew punctuation Paseq, Sof Pasuq and Nun Hafukha continue; if (c <= 0x05CF) return false; if (c < 0x0600) // U+0600 through U+1059 Arabic, Syriac, Thaana, Devanagari, Bengali, Gurmukhi, Gujarati, Oriya, Tamil, Telugu, Kannada, Malayalam, Sinhala, Thai, Lao, Tibetan, Myanmar continue; if (c <= 0x1059) return false; if (c < 0x1100) // U+1100 through U+11FF Hangul Jamo (only Ancient Korean should be left here if you precompose; Modern Korean will be precomposed as a result of step A) continue; if (c <= 0x11FF) return false; if (c < 0x1780) // U+1780 through U+18AF Khmer, Mongolian continue; if (c <= 0x18AF) return false; if (c < 0x1900) // U+1900 through U+194F Limbu (Unicode 4.0) continue; if (c <= 0x194F) return false; if (c < 0x20D0) // U+20D0 through U+20FF Combining marks for symbols continue; if (c <= 0x20FF) return false; if (c < 0xFE20) // U+FE20 through U+FE2F Combining half marks continue; if (c <= 0xFE2F) return false; } return true; } void Font::drawSimpleText(GraphicsContext* context, const TextRun& run, const TextStyle& style, const FloatPoint& point, int from, int to) const { // This glyph buffer holds our glyphs+advances+font data for each glyph. GlyphBuffer glyphBuffer; float startX = point.x(); WidthIterator it(this, run, style); it.advance(from); float beforeWidth = it.m_runWidthSoFar; it.advance(to, &glyphBuffer); // We couldn't generate any glyphs for the run. Give up. if (glyphBuffer.isEmpty()) return; float afterWidth = it.m_runWidthSoFar; if (style.rtl()) { float finalRoundingWidth = it.m_finalRoundingWidth; it.advance(run.length()); startX += finalRoundingWidth + it.m_runWidthSoFar - afterWidth; } else startX += beforeWidth; // Swap the order of the glyphs if right-to-left. if (style.rtl()) for (int i = 0, end = glyphBuffer.size() - 1; i < glyphBuffer.size() / 2; ++i, --end) glyphBuffer.swap(i, end); // Calculate the starting point of the glyphs to be displayed by adding // all the advances up to the first glyph. FloatPoint startPoint(startX, point.y()); drawGlyphBuffer(context, glyphBuffer, run, style, startPoint); } void Font::drawGlyphBuffer(GraphicsContext* context, const GlyphBuffer& glyphBuffer, const TextRun& run, const TextStyle& style, const FloatPoint& point) const { // Draw each contiguous run of glyphs that use the same font data. const FontData* fontData = glyphBuffer.fontDataAt(0); FloatSize offset = glyphBuffer.offsetAt(0); FloatPoint startPoint(point); float nextX = startPoint.x(); int lastFrom = 0; int nextGlyph = 0; while (nextGlyph < glyphBuffer.size()) { const FontData* nextFontData = glyphBuffer.fontDataAt(nextGlyph); FloatSize nextOffset = glyphBuffer.offsetAt(nextGlyph); if (nextFontData != fontData || nextOffset != offset) { drawGlyphs(context, fontData, glyphBuffer, lastFrom, nextGlyph - lastFrom, startPoint); lastFrom = nextGlyph; fontData = nextFontData; offset = nextOffset; startPoint.setX(nextX); } nextX += glyphBuffer.advanceAt(nextGlyph); nextGlyph++; } drawGlyphs(context, fontData, glyphBuffer, lastFrom, nextGlyph - lastFrom, startPoint); } void Font::drawText(GraphicsContext* context, const TextRun& run, const TextStyle& style, const FloatPoint& point, int from, int to) const { to = (to == -1 ? run.length() : to); if (canUseGlyphCache(run)) drawSimpleText(context, run, style, point, from, to); else drawComplexText(context, run, style, point, from, to); } float Font::floatWidth(const TextRun& run, const TextStyle& style) const { if (canUseGlyphCache(run)) return floatWidthForSimpleText(run, style, 0); return floatWidthForComplexText(run, style); } float Font::floatWidthForSimpleText(const TextRun& run, const TextStyle& style, GlyphBuffer* glyphBuffer) const { WidthIterator it(this, run, style); it.advance(run.length(), glyphBuffer); return it.m_runWidthSoFar; } FloatRect Font::selectionRectForText(const TextRun& run, const TextStyle& style, const IntPoint& point, int h, int from, int to) const { to = (to == -1 ? run.length() : to); if (canUseGlyphCache(run)) return selectionRectForSimpleText(run, style, point, h, from, to); return selectionRectForComplexText(run, style, point, h, from, to); } FloatRect Font::selectionRectForSimpleText(const TextRun& run, const TextStyle& style, const IntPoint& point, int h, int from, int to) const { WidthIterator it(this, run, style); it.advance(from); float beforeWidth = it.m_runWidthSoFar; it.advance(to); float afterWidth = it.m_runWidthSoFar; // Using roundf() rather than ceilf() for the right edge as a compromise to ensure correct caret positioning if (style.rtl()) { it.advance(run.length()); float totalWidth = it.m_runWidthSoFar; return FloatRect(point.x() + floorf(totalWidth - afterWidth), point.y(), roundf(totalWidth - beforeWidth) - floorf(totalWidth - afterWidth), h); } else { return FloatRect(point.x() + floorf(beforeWidth), point.y(), roundf(afterWidth) - floorf(beforeWidth), h); } } int Font::offsetForPosition(const TextRun& run, const TextStyle& style, int x, bool includePartialGlyphs) const { if (canUseGlyphCache(run)) return offsetForPositionForSimpleText(run, style, x, includePartialGlyphs); return offsetForPositionForComplexText(run, style, x, includePartialGlyphs); } int Font::offsetForPositionForSimpleText(const TextRun& run, const TextStyle& style, int x, bool includePartialGlyphs) const { float delta = (float)x; WidthIterator it(this, run, style); GlyphBuffer localGlyphBuffer; unsigned offset; if (style.rtl()) { delta -= floatWidthForSimpleText(run, style, 0); while (1) { offset = it.m_currentCharacter; float w; if (!it.advanceOneCharacter(w, &localGlyphBuffer)) break; delta += w; if (includePartialGlyphs) { if (delta - w / 2 >= 0) break; } else { if (delta >= 0) break; } } } else { while (1) { offset = it.m_currentCharacter; float w; if (!it.advanceOneCharacter(w, &localGlyphBuffer)) break; delta -= w; if (includePartialGlyphs) { if (delta + w / 2 <= 0) break; } else { if (delta <= 0) break; } } } return offset; } }