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Diffstat (limited to 'ksvg/impl/libs/libtext2path/src/Converter.cpp')
| -rw-r--r-- | ksvg/impl/libs/libtext2path/src/Converter.cpp | 505 |
1 files changed, 505 insertions, 0 deletions
diff --git a/ksvg/impl/libs/libtext2path/src/Converter.cpp b/ksvg/impl/libs/libtext2path/src/Converter.cpp new file mode 100644 index 00000000..7810b417 --- /dev/null +++ b/ksvg/impl/libs/libtext2path/src/Converter.cpp @@ -0,0 +1,505 @@ +/* + Copyright (C) 2003 Nikolas Zimmermann <wildfox@kde.org> + This file is part of the KDE project + + 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 + aint 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 <math.h> + +#include "myboost/shared_ptr.hpp" +#include <fontconfig/fontconfig.h> +#include <fribidi/fribidi.h> +#include <fribidi/fribidi_types.h> + +#include "Font.h" +#include "Glyph.h" +#include "Tools.h" +#include "Rectangle.h" +#include "Converter.h" +#include "QtUnicode.h" +#include "GlyphTracer.h" + +// Macros +#define FT_TRUNC(x) ((x) >> 6) +#define FT_TOFLOAT(x) ((x) * (1.0 / 64.0)) +#define FT_FROMFLOAT(x) ((int) floor ((x) * 64.0 + 0.5)) + +const double deg2rad = 0.017453292519943295769; // pi/180 + +using namespace T2P; + +// Font engine. The core component. +Converter::Converter(GlyphTracer *tracer) : m_glyphTracer(tracer) +{ + m_init = false; + m_kerning = true; + m_library = 0; +} + +Converter::~Converter() +{ + if(m_glyphTracer) + delete m_glyphTracer; + + m_fontCache.clear(); + m_glyphCache.clear(); + + // Close FreeType2 library + if(m_library) + FT_Done_FreeType(m_library); +} + +void Converter::init() +{ + // Initialize FreeType2 + m_init = (FT_Init_FreeType(&m_library) == 0); +} + +bool Converter::ready() +{ + return m_init; +} + +void Converter::setKerning(bool mode) +{ + m_kerning = mode; +} + +// Lookup font in cache or create new font +SharedFont Converter::requestFont(const FontVisualParams *params) +{ + std::string cacheKey = cacheFontKey(params); + SharedFont cached = m_fontCache.find(cacheKey); + + // If not available in cache, create new one and cache it :) + if(cached) + { + delete params; + return cached; + } + else + { + // Create a new Font + SharedFont newFont(new Font(this)); + + // Load the font + if(!newFont->load(params)) + { + delete params; + return SharedFont(); + } + + // Append to cache + m_fontCache.insert(cacheKey, newFont); + return newFont; + } +} + +GlyphAffinePair *Converter::requestGlyph(GlyphRenderParams *params, Rectangle &bbox, Affine &affine, bool onlyLatin) +{ + // 1. Select glyph to have glyphIndex information, + // needed to generate the cache lookup key + selectGlyph(params); + + SharedGlyph cached = m_glyphCache.find(cacheGlyphKey(params)); + + // If not available in cache, render new one and cache it :) + // If we're mixing ie. japanese and latin characters (TTB layout), + // then we also have to re-calculate the glyph again with the appropriate rotation matrix (Niko) + if(!cached || !onlyLatin) + cached = calcGlyph(params, affine, onlyLatin); + + // Correct bezier path by setting up the correct scaling matrix + // and multiplying with the current glyph affine + double fontSize = params->font()->fontParams()->size(); + + T2P::Affine correctAffine; + correctAffine.scale(0.001 * fontSize, -0.001 * fontSize); + correctAffine *= affine; + + // Get bbox information + Point p1(FT_TRUNC(cached->ftBbox()->xMin), FT_TRUNC(cached->ftBbox()->yMin)); + Point p2(FT_TRUNC(cached->ftBbox()->xMax), FT_TRUNC(cached->ftBbox()->yMax)); + + bbox.setA(affine.mapPoint(p1)); + bbox.setB(affine.mapPoint(p2)); + + return new GlyphAffinePair(cached.get(), correctAffine); +} + +void Converter::selectGlyph(GlyphRenderParams *params) +{ + // 1. Select glyph + test if it exists + // | + // |-> if it doesn't exist, replace by a '?' and check if exists + // |-> if it does exist, use it! + params->setGlyphIndex(FT_Get_Char_Index(params->font()->fontFace(), (FT_ULong) params->character())); + + if(params->glyphIndex() == 0) + params->setGlyphIndex(FT_Get_Char_Index(params->font()->fontFace(), '?')); + + // 2. Load glyph into font's glyphSlot, according to the GlyphLayoutParams + int flags = FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING | FT_LOAD_NO_BITMAP; + + // 3. Don't pass FT_LOAD_VERTICAL_LAYOUT on TTB layouts when rendering + // a latin glyph because it needs to be rotated... + if(params->layout()->tb()) + { + Script script; + SCRIPT_FOR_CHAR(script, params->character()) + if(script != Latin || params->layout()->glyphOrientationVertical() == 0) + flags |= FT_LOAD_VERTICAL_LAYOUT; + } + + FT_Error error = FT_Load_Glyph(params->font()->fontFace(), params->glyphIndex(), flags); + if(error) + params->setGlyphIndex(0); +} + +SharedGlyph Converter::calcGlyph(const GlyphRenderParams *params, Affine &affine, bool onlyLatin) +{ + // 2. Apply kerning if needed + if(m_kerning && params->lastGlyph() != 0 && params->glyphIndex() != 0) + { + FT_Vector kerningVector; + double kx, ky; + + FT_Get_Kerning(params->font()->fontFace(), params->lastGlyph(), params->glyphIndex(), ft_kerning_default, &kerningVector); + + kx = FT_TRUNC(kerningVector.x); + ky = FT_TRUNC(kerningVector.y); + + affine.dx() += kx + affine.m21() * ky; + + // Only apply y kerning in TB mode + if(params->layout()->tb()) + affine.dy() += kx + affine.m22() * ky; + } + + // 3. Prepare path tracing + FT_OutlineGlyph ftGlyph; + FT_Get_Glyph(params->font()->fontFace()->glyph, reinterpret_cast<FT_Glyph *>(&ftGlyph)); + + // 3a. Prepare tracing matrix + Affine traceAffine; + traceAffine.scale(1000.0 / params->font()->fontFace()->units_per_EM); + + // 3b. Enable character rotation, if needed + if(params->layout()->tb()) + { + Script script; + SCRIPT_FOR_CHAR(script, params->character()) + if(!onlyLatin && script == Latin) + { + FT_Matrix matrix; + + double angle = deg2rad * params->layout()->glyphOrientationVertical(); + matrix.xx = (FT_Fixed)( cos(angle) * 0x10000L); + matrix.xy = (FT_Fixed)(-sin(angle) * 0x10000L); + matrix.yx = (FT_Fixed)( sin(angle) * 0x10000L); + matrix.yy = (FT_Fixed)( cos(angle) * 0x10000L); + + FT_Glyph_Transform(reinterpret_cast<FT_Glyph>(ftGlyph), &matrix, 0); + } + } + + // 4. Begin path tracing + // - Setup glyphOutlineing glyph + // - Start tracing + // - Close path + FT_Outline *ftOut = &ftGlyph->outline; + + SharedGlyph glyphOutline(new Glyph()); + glyphOutline->setBezierPath(m_glyphTracer->allocBezierPath(ftOut->n_points * 2 + ftOut->n_contours + 1)); + glyphOutline->setAffine(traceAffine); + + FT_Outline_Decompose(ftOut, m_glyphTracer->outlineFuncs(), glyphOutline.get()); + + m_glyphTracer->closePath(glyphOutline.get()); + + // 5. Determine bounding box (aka "cbox") + FT_Glyph_Get_CBox(reinterpret_cast<FT_Glyph>(ftGlyph), ft_glyph_bbox_unscaled, glyphOutline->ftBbox()); + + // 6. Cache glyph! + m_glyphCache.insert(cacheGlyphKey(params), glyphOutline); + + FT_Done_Glyph(reinterpret_cast<FT_Glyph>(ftGlyph)); + + return glyphOutline; +} + +GlyphSet *Converter::calcString(Font *font, const unsigned short *text, unsigned int length, Affine &affine, const GlyphLayoutParams *params, BezierPath *bpath) +{ + unsigned short *bidi = 0; + + // 0. Apply BiDi Rules + if(params->useBidi()) + { + FriBidiCharType baseDir = FRIBIDI_TYPE_N; + FriBidiChar *unicodeIn = new FriBidiChar[length + 1]; + FriBidiChar *unicodeOut = new FriBidiChar[length + 1]; + bidi = new unsigned short[length + 1]; + + for(unsigned int i = 0; i < length; i++) + unicodeIn[i] = text[i]; + + fribidi_log2vis(unicodeIn, length, &baseDir, unicodeOut, 0, 0, 0); + + for(unsigned int i = 0; i < length; i++) + bidi[i] = unicodeOut[i]; + + bidi[length] = 0; + delete []unicodeIn; + delete []unicodeOut; + } + else + bidi = const_cast<unsigned short *>(text); + + // Detect character rotation if needed, + // probably working in 0.1% of the cases :/ + Script script; + bool onlyLatin = true; + for(unsigned int i = 0; i < length; i++) + { + SCRIPT_FOR_CHAR(script, bidi[i]) + if(script != Latin) + { + onlyLatin = false; + break; + } + } + + // 1. Set initial font size + double fontSize = font->fontParams()->size(); + FT_Set_Char_Size(font->fontFace(), FT_FROMFLOAT(fontSize), FT_FROMFLOAT(fontSize), 0, 0); + + // 2. Compute positioning metrics + // - See http://www.freetype.org/freetype2/docs/tutorial/stepX.html (X = 1 or 2) + int pixelHeight = (int) (FT_TOFLOAT(font->fontFace()->size->metrics.ascender - font->fontFace()->size->metrics.descender) * affine.m22()); + int pixelBaseline = (int) (FT_TOFLOAT(font->fontFace()->size->metrics.ascender) * affine.m22()); + int pixelUnderlinePosition = (int) (((font->fontFace()->ascender - font->fontFace()->underline_position - font->fontFace()->underline_thickness / 2) * fontSize / font->fontFace()->units_per_EM) * affine.m22()); + int pixelUnderlineThickness = T2PMAX(1, (int) ((font->fontFace()->underline_thickness * fontSize / font->fontFace()->units_per_EM) * affine.m22())); + + // 3. Prepare needed variables for the rendering loop + // - rendering params (layout, font...) + // - bounding box (per glyph, overall) + // - glyph matrix (overall) + // - resulting glyph sets + GlyphRenderParams *renderParams = new GlyphRenderParams(); + renderParams->setFont(font); + renderParams->setLayout(params); + renderParams->setLastGlyph(0); + renderParams->setGlyphIndex(0); + + Affine glyphAffine(affine); + Rectangle bbox, currentBbox; + GlyphSet *result = new GlyphSet(); + + // Align to path start, if bpath != 0 + Point pathPoint, pathTangent, pathNormal; + double pathLength = 0, pathAdvance = 0; + double startOffset = params->textPathStartOffset(); + + if(bpath) + { + pathLength = bpath->length(); + bpath->pointTangentNormalAt(startOffset, &pathPoint, &pathTangent); + + glyphAffine.dx() = pathPoint.x(); + glyphAffine.dy() = pathPoint.y(); + glyphAffine.rotate(atan2(pathTangent.y(), pathTangent.x())); + + std::cout << "[T2P] Starting textPath at: " << pathPoint.x() << ", " << pathPoint.y() << std::endl; + } + + // <tspan> elements can have different baseline-shift's + // baseline-shift support (Niko) + double baseline = 0; + if(!params->baselineShift().empty()) + { + if(params->baselineShift() == "sub") + baseline += fontSize / 5 + 1; + else if(params->baselineShift() == "super") + baseline -= fontSize / 3 + 1; + else + { + std::string temp = params->baselineShift(); + if(temp.find("%") > 0) + baseline -= (atof(temp.c_str()) / 100.0) * fontSize; + else + baseline -= atoi(temp.c_str()); + } + + if(!params->tb()) + glyphAffine.translate(0, baseline); + else + glyphAffine.translate(-baseline, 0); + } + + // 4. Enter main rendering loop + for(unsigned int i = 0; i < length; i++) + { + // 4a. Modify character to render + renderParams->setCharacter(bidi[i]); + + // 4c. Get glyph outline + GlyphAffinePair *glyphOutline = requestGlyph(renderParams, currentBbox, glyphAffine, onlyLatin); + m_glyphTracer->correctGlyph(glyphOutline); + + // 4d. Save advance values + result->m_glyphXAdvance.push_back((font->fontFace()->glyph->advance.x * fontSize / font->fontFace()->units_per_EM) * affine.m11()); + result->m_glyphYAdvance.push_back((font->fontFace()->glyph->advance.y * fontSize / font->fontFace()->units_per_EM) * affine.m22()); + + // 4e. Misc + // - union current + overall bounding box + // - add glyph to list of glyphs + // - apply letter & word spacing + if(renderParams->glyphIndex() != 0) + { + // Remember last glyph for kerning + renderParams->setLastGlyph(renderParams->glyphIndex()); + + // Union current + overall bounding box + bbox.bboxUnion(bbox, currentBbox); + + // Move glyph locations for the next glyph to be + // rendered apply letter & word spacing + bool addGlyph = true; + if(!params->tb()) + { + if(bpath) + { + double advance = startOffset + (pathAdvance / pathLength); + if(advance < 0.0 || advance > 1.0) // dont render off-path glyphs + addGlyph = false; + + pathAdvance += (result->m_glyphXAdvance.back() + params->letterSpacing() * affine.m11()) + ((bidi[(i + 1)] == ' ') ? params->wordSpacing() * affine.m11() : 0); + + std::cout << "[T2P] Adjusting textPath advance: " << pathAdvance << " Path Length: " << pathLength << " StartOffset: " << startOffset << " Position in Path (relative 0-1): " << pathAdvance/pathLength << " Adjusted by offset: " << startOffset + (pathAdvance / pathLength) << std::endl; + + bpath->pointTangentNormalAt(startOffset + (pathAdvance / pathLength), &pathPoint, &pathTangent, &pathNormal); + + glyphAffine.m11() = affine.m11(); + glyphAffine.m12() = affine.m12(); + glyphAffine.m21() = affine.m21(); + glyphAffine.m22() = affine.m22(); + glyphAffine.dx() = pathPoint.x(); + glyphAffine.dy() = pathPoint.y(); + + glyphAffine.rotateAround(atan2(pathTangent.y(), pathTangent.x()), Point(result->m_glyphXAdvance.back() / 2, result->m_glyphYAdvance.back() / 2)); + + std::cout << "[T2P] Aligning textPath to: " << pathPoint.x() << ", " << pathPoint.y() << std::endl; + if(!params->tb()) + glyphAffine.translate(0, baseline); + else + glyphAffine.translate(-baseline, 0); + } + else + glyphAffine.dx() += (result->m_glyphXAdvance.back() + params->letterSpacing() * affine.m11()) + ((bidi[(i + 1)] == ' ') ? params->wordSpacing() * affine.m11() : 0); + } + else + { + double advy = result->m_glyphYAdvance.back(); + + Script script; + SCRIPT_FOR_CHAR(script, bidi[i]) + if(!onlyLatin && script == Latin && params->glyphOrientationVertical() != 0) + advy = result->m_glyphXAdvance.back(); + + glyphAffine.dy() += (advy + params->letterSpacing() * affine.m22()) + ((bidi[(i + 1)] == ' ') ? params->wordSpacing() * affine.m22() : 0); + } + + // Copy bezier path/affine pair + if(addGlyph) + { + result->m_set.push_back(glyphOutline); + result->m_glyphCount++; + } + else + delete glyphOutline; + } + } + + // 5. Fill out resulting data structures + result->m_underlinePosition = pixelUnderlinePosition; + result->m_overlinePosition = pixelHeight - pixelUnderlinePosition; + result->m_strikeThroughPosition = (result->m_underlinePosition + result->m_overlinePosition) / 2; + result->m_pixelBaseline = pixelBaseline; + result->m_underlineThickness = pixelUnderlineThickness; + + result->m_xpen = glyphAffine.dx() - affine.dx(); + result->m_ypen = glyphAffine.dy() - affine.dy(); + + result->m_bboxX = T2PMAX(1, int(bbox.a().x())); + result->m_bboxY = T2PMAX(1, int(bbox.a().y() - int(pixelHeight / 2))); + result->m_height = T2PMAX(1, int(bbox.b().y() - bbox.a().y())); + + // Correct bounding box information also on + // vertical layouts! (Niko) + if(!params->tb()) + { + if(bpath) + result->m_width = int(pathAdvance); + else + result->m_width = T2PMAX(1, int(bbox.b().x() - bbox.a().x())); + } + else + result->m_width = T2PMAX(1, pixelHeight); + + // 6. Cleanup memory + if(text != bidi) + delete []bidi; + + delete renderParams; + + // 7. Eventually, dump cache statistics + // m_glyphCache.dump(); + // m_fontCache.dump(); + + return result; +} + +std::string Converter::cacheFontKey(const FontVisualParams *params) const +{ + // TODO: Tune the key + std::string key; + + key += Tools::joinList('|', const_cast<FontVisualParams *>(params)->fontList()); + key += Tools::a2str(params->weight()); + key += Tools::a2str(params->slant()); + key += Tools::a2str(params->size()); + + // std::cout << "Font cache key: " << key << std::endl; + return key; +} + +std::string Converter::cacheGlyphKey(const GlyphRenderParams *params) const +{ + // TODO: Tune the key + std::string key; + + key += params->font()->fontFile(); + key += Tools::a2str(params->character()); + key += Tools::a2str(params->glyphIndex()); + key += Tools::a2str(params->font()->fontParams()->size()); + key += Tools::a2str(params->font()->fontParams()->weight()); + key += Tools::a2str(params->font()->fontParams()->slant()); + + // std::cout << "Glyph cache key: " << key << std::endl; + return key; +} +// vim:ts=4:noet |