| /* | |
| * Copyright (C) 2003, 2006, 2008 Apple Inc. All rights reserved. | |
| * 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 "WidthIterator.h" | |
| #include "Font.h" | |
| #include "GlyphBuffer.h" | |
| #include "SimpleFontData.h" | |
| #include <wtf/MathExtras.h> | |
| #if USE(ICU_UNICODE) | |
| #include <unicode/unorm.h> | |
| #endif | |
| using namespace WTF; | |
| using namespace Unicode; | |
| using namespace std; | |
| namespace WebCore { | |
| // According to http://www.unicode.org/Public/UNIDATA/UCD.html#Canonical_Combining_Class_Values | |
| static const uint8_t hiraganaKatakanaVoicingMarksCombiningClass = 8; | |
| WidthIterator::WidthIterator(const Font* font, const TextRun& run, HashSet<const SimpleFontData*>* fallbackFonts, bool accountForGlyphBounds) | |
| : m_font(font) | |
| , m_run(run) | |
| , m_end(run.length()) | |
| , m_currentCharacter(0) | |
| , m_runWidthSoFar(0) | |
| , m_finalRoundingWidth(0) | |
| , m_fallbackFonts(fallbackFonts) | |
| , m_accountForGlyphBounds(accountForGlyphBounds) | |
| , m_maxGlyphBoundingBoxY(numeric_limits<float>::min()) | |
| , m_minGlyphBoundingBoxY(numeric_limits<float>::max()) | |
| , m_firstGlyphOverflow(0) | |
| , m_lastGlyphOverflow(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_run.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_run.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_run.rtl(); | |
| bool hasExtraSpacing = (m_font->letterSpacing() || m_font->wordSpacing() || m_padding) && !m_run.spacingDisabled(); | |
| float runWidthSoFar = m_runWidthSoFar; | |
| float lastRoundingWidth = m_finalRoundingWidth; | |
| FloatRect bounds; | |
| const SimpleFontData* primaryFont = m_font->primaryFont(); | |
| const SimpleFontData* lastFontData = primaryFont; | |
| 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, rtl); | |
| Glyph glyph = glyphData.glyph; | |
| const SimpleFontData* fontData = glyphData.fontData; | |
| ASSERT(fontData); | |
| // Now that we have a glyph and font data, get its width. | |
| float width; | |
| if (c == '\t' && m_run.allowTabs()) { | |
| float tabWidth = m_font->tabWidth(); | |
| width = tabWidth - fmodf(m_run.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->spaceWidth() && (fontData->pitch() == FixedPitch || glyph == fontData->spaceGlyph()) && m_run.applyWordRounding()) | |
| width = fontData->adjustedSpaceWidth(); | |
| } | |
| if (fontData != lastFontData && width) { | |
| lastFontData = fontData; | |
| if (m_fallbackFonts && fontData != primaryFont) { | |
| // FIXME: This does a little extra work that could be avoided if | |
| // glyphDataForCharacter() returned whether it chose to use a small caps font. | |
| if (!m_font->isSmallCaps() || c == toUpper(c)) | |
| m_fallbackFonts->add(fontData); | |
| else { | |
| const GlyphData& uppercaseGlyphData = m_font->glyphDataForCharacter(toUpper(c), rtl); | |
| if (uppercaseGlyphData.fontData != primaryFont) | |
| m_fallbackFonts->add(uppercaseGlyphData.fontData); | |
| } | |
| } | |
| } | |
| 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(); | |
| } | |
| } | |
| if (m_accountForGlyphBounds) { | |
| bounds = fontData->boundsForGlyph(glyph); | |
| if (!currentCharacter) | |
| m_firstGlyphOverflow = max<float>(0, -bounds.x()); | |
| } | |
| // 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_run.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_run.applyWordRounding() && currentCharacter < m_run.length() && Font::isRoundingHackCharacter(*cp)) | |
| || (m_run.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; | |
| if (m_accountForGlyphBounds) { | |
| m_maxGlyphBoundingBoxY = max(m_maxGlyphBoundingBoxY, bounds.bottom()); | |
| m_minGlyphBoundingBoxY = min(m_minGlyphBoundingBoxY, bounds.y()); | |
| m_lastGlyphOverflow = max<float>(0, bounds.right() - width); | |
| } | |
| } | |
| 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<const QChar*>(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; | |
| } | |
| } |