| /** |
| * Copyright (C) 2003, 2006 Apple Computer, Inc. |
| * Copyright (C) 2008 Holger Hans Peter Freyther |
| * |
| * 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 "FontCache.h" |
| #include "FloatRect.h" |
| #include "GlyphBuffer.h" |
| #include "GlyphPageTreeNode.h" |
| #include "IntPoint.h" |
| #include "SimpleFontData.h" |
| #include "WidthIterator.h" |
| |
| #include <wtf/unicode/Unicode.h> |
| #include <wtf/MathExtras.h> |
| |
| using namespace WTF; |
| using namespace Unicode; |
| |
| namespace WebCore { |
| |
| const GlyphData& Font::glyphDataForCharacter(UChar32 c, bool mirror, bool forceSmallCaps) const |
| { |
| bool useSmallCapsFont = forceSmallCaps; |
| if (m_fontDescription.smallCaps()) { |
| UChar32 upperC = Unicode::toUpper(c); |
| if (upperC != c) { |
| c = upperC; |
| useSmallCapsFont = 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(fontDataAt(0), pageNumber); |
| if (pageNumber) |
| m_pages.set(pageNumber, node); |
| else |
| m_pageZero = node; |
| } |
| |
| GlyphPage* page; |
| if (!useSmallCapsFont) { |
| // Fastest loop, for the common case (not small caps). |
| while (true) { |
| page = node->page(); |
| if (page) { |
| const GlyphData& data = page->glyphDataForCharacter(c); |
| if (data.fontData) |
| return data; |
| if (node->isSystemFallback()) |
| break; |
| } |
| |
| // Proceed with the fallback list. |
| node = node->getChild(fontDataAt(node->level()), pageNumber); |
| if (pageNumber) |
| m_pages.set(pageNumber, node); |
| else |
| m_pageZero = node; |
| } |
| } else { |
| while (true) { |
| page = node->page(); |
| if (page) { |
| const GlyphData& data = page->glyphDataForCharacter(c); |
| if (data.fontData) { |
| // The smallCapsFontData function should not normally return 0. |
| // But if it does, we will just render the capital letter big. |
| const SimpleFontData* smallCapsFontData = data.fontData->smallCapsFontData(m_fontDescription); |
| if (!smallCapsFontData) |
| return data; |
| |
| GlyphPageTreeNode* smallCapsNode = GlyphPageTreeNode::getRootChild(smallCapsFontData, pageNumber); |
| const GlyphPage* smallCapsPage = smallCapsNode->page(); |
| if (smallCapsPage) { |
| const GlyphData& data = smallCapsPage->glyphDataForCharacter(c); |
| if (data.fontData) |
| return data; |
| } |
| |
| // Do not attempt system fallback off the smallCapsFontData. This is the very unlikely case that |
| // a font has the lowercase character but the small caps font does not have its uppercase version. |
| return smallCapsFontData->missingGlyphData(); |
| } |
| |
| if (node->isSystemFallback()) |
| break; |
| } |
| |
| // Proceed with the fallback list. |
| node = node->getChild(fontDataAt(node->level()), pageNumber); |
| if (pageNumber) |
| m_pages.set(pageNumber, node); |
| else |
| m_pageZero = node; |
| } |
| } |
| |
| ASSERT(page); |
| ASSERT(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. |
| UChar codeUnits[2]; |
| int codeUnitsLength; |
| if (c <= 0xFFFF) { |
| UChar c16 = c; |
| if (Font::treatAsSpace(c16)) |
| codeUnits[0] = ' '; |
| else if (Font::treatAsZeroWidthSpace(c16)) |
| codeUnits[0] = zeroWidthSpace; |
| else |
| codeUnits[0] = c16; |
| codeUnitsLength = 1; |
| } else { |
| codeUnits[0] = U16_LEAD(c); |
| codeUnits[1] = U16_TRAIL(c); |
| codeUnitsLength = 2; |
| } |
| const SimpleFontData* characterFontData = fontCache()->getFontDataForCharacters(*this, codeUnits, codeUnitsLength); |
| if (useSmallCapsFont && characterFontData) |
| characterFontData = characterFontData->smallCapsFontData(m_fontDescription); |
| if (characterFontData) { |
| // Got the fallback glyph and font. |
| GlyphPage* fallbackPage = GlyphPageTreeNode::getRootChild(characterFontData, pageNumber)->page(); |
| const GlyphData& data = fallbackPage && fallbackPage->glyphDataForCharacter(c).fontData ? fallbackPage->glyphDataForCharacter(c) : characterFontData->missingGlyphData(); |
| // Cache it so we don't have to do system fallback again next time. |
| if (!useSmallCapsFont) |
| page->setGlyphDataForCharacter(c, data.glyph, data.fontData); |
| return data; |
| } |
| |
| // Even system fallback can fail; use the missing glyph in that case. |
| // FIXME: It would be nicer to use the missing glyph from the last resort font instead. |
| const GlyphData& data = primaryFont()->missingGlyphData(); |
| if (!useSmallCapsFont) |
| page->setGlyphDataForCharacter(c, data.glyph, data.fontData); |
| return data; |
| } |
| |
| void Font::setCodePath(CodePath p) |
| { |
| s_codePath = p; |
| } |
| |
| Font::CodePath Font::codePath() |
| { |
| return s_codePath; |
| } |
| |
| bool Font::canUseGlyphCache(const TextRun& run) const |
| { |
| switch (s_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 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); |
| 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 (run.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 (run.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, startPoint); |
| } |
| |
| void Font::drawGlyphBuffer(GraphicsContext* context, const GlyphBuffer& glyphBuffer, const TextRun&, const FloatPoint& point) const |
| { |
| // Draw each contiguous run of glyphs that use the same font data. |
| const SimpleFontData* 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 SimpleFontData* 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); |
| } |
| |
| float Font::floatWidthForSimpleText(const TextRun& run, GlyphBuffer* glyphBuffer) const |
| { |
| WidthIterator it(this, run); |
| it.advance(run.length(), glyphBuffer); |
| return it.m_runWidthSoFar; |
| } |
| |
| FloatRect Font::selectionRectForSimpleText(const TextRun& run, const IntPoint& point, int h, int from, int to) const |
| { |
| WidthIterator it(this, run); |
| 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 (run.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::offsetForPositionForSimpleText(const TextRun& run, int x, bool includePartialGlyphs) const |
| { |
| float delta = (float)x; |
| |
| WidthIterator it(this, run); |
| GlyphBuffer localGlyphBuffer; |
| unsigned offset; |
| if (run.rtl()) { |
| delta -= floatWidthForSimpleText(run, 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; |
| } |
| |
| } |
