/************************************************************************* ** SVGTree.cpp ** ** ** ** This file is part of dvisvgm -- a fast DVI to SVG converter ** ** Copyright (C) 2005-2016 Martin Gieseking ** ** ** ** This program is free software; you can redistribute it and/or ** ** modify it under the terms of the GNU General Public License as ** ** published by the Free Software Foundation; either version 3 of ** ** the License, or (at your option) any later version. ** ** ** ** This program 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 General Public License for more details. ** ** ** ** You should have received a copy of the GNU General Public License ** ** along with this program; if not, see . ** *************************************************************************/ #include #include #include #include #include "BoundingBox.h" #include "DependencyGraph.h" #include "DVIToSVG.h" #include "Font.h" #include "FontManager.h" #include "SVGTree.h" #include "XMLDocument.h" #include "XMLNode.h" #include "XMLString.h" using namespace std; // static class variables bool SVGTree::CREATE_STYLE=true; bool SVGTree::USE_FONTS=true; bool SVGTree::CREATE_USE_ELEMENTS=false; bool SVGTree::RELATIVE_PATH_CMDS=false; bool SVGTree::MERGE_CHARS=true; double SVGTree::ZOOM_FACTOR=1.0; SVGTree::SVGTree () : _vertical(false), _font(0), _color(Color::BLACK), _matrix(1) { _xchanged = _ychanged = false; _fontnum = 0; reset(); } /** Clears the SVG tree and initializes the root element. */ void SVGTree::reset () { _doc.clear(); _root = new XMLElementNode("svg"); _root->addAttribute("version", "1.1"); _root->addAttribute("xmlns", "http://www.w3.org/2000/svg"); _root->addAttribute("xmlns:xlink", "http://www.w3.org/1999/xlink"); _doc.setRootNode(_root); _page = _text = _span = _defs = 0; } /** Sets the bounding box of the document. * @param[in] bbox bounding box in PS point units */ void SVGTree::setBBox (const BoundingBox &bbox) { if (ZOOM_FACTOR >= 0) { _root->addAttribute("width", XMLString(bbox.width()*ZOOM_FACTOR)+"pt"); _root->addAttribute("height", XMLString(bbox.height()*ZOOM_FACTOR)+"pt"); } _root->addAttribute("viewBox", bbox.toSVGViewBox()); } void SVGTree::setColor (const Color &c) { if (!_font.get() || _font.get()->color() == Color::BLACK) _color.set(c); } void SVGTree::setFont (int num, const Font *font) { _font.set(font); _fontnum = num; // set default color assigned to the font if (font->color() != Color::BLACK && _color.get() != font->color()) _color.set(font->color()); } /** Starts a new page. * @param[in] pageno number of new page */ void SVGTree::newPage (int pageno) { _page = new XMLElementNode("g"); if (pageno >= 0) _page->addAttribute("id", string("page")+XMLString(pageno)); _root->append(_page); _text = _span = 0; while (!_pageContainerStack.empty()) _pageContainerStack.pop(); } void SVGTree::appendToDefs (XMLNode *node) { if (!_defs) { _defs = new XMLElementNode("defs"); _root->prepend(_defs); } _defs->append(node); } void SVGTree::appendToPage (XMLNode *node) { if (_pageContainerStack.empty()) _page->append(node); else _pageContainerStack.top()->append(node); if (node != _text) // if the appended node differ from text element currently in use, _text = 0; // then force creating a new text element for the following characters } void SVGTree::prependToPage (XMLNode *node) { if (_pageContainerStack.empty()) _page->prepend(node); else _pageContainerStack.top()->prepend(node); } /** Appends a single charater to the current text node. If necessary, and depending on output mode * and further output states, new XML elements (text, tspan, g, ...) are created. * @param[in] c character to be added * @param[in] x x coordinate * @param[in] y y coordinate * @param[in] font font to be used */ void SVGTree::appendChar (int c, double x, double y, const Font &font) { XMLElementNode *node=_span; if (USE_FONTS) { // changes of fonts and transformations require a new text element if (!MERGE_CHARS || !_text || _font.changed() || _matrix.changed() || _vertical.changed()) { newTextNode(x, y); node = _text; _color.changed(true); } if (MERGE_CHARS && (_xchanged || _ychanged || (_color.changed() && _color.get() != Color::BLACK))) { // if drawing position was explicitly changed, create a new tspan element _span = new XMLElementNode("tspan"); if (_xchanged) { if (_vertical) { // align glyphs designed for horizontal layout properly if (const PhysicalFont *pf = dynamic_cast(_font.get())) if (!pf->getMetrics()->verticalLayout()) x += pf->scaledAscent()/2.5; // move vertical baseline to the right by strikethrough offset } _span->addAttribute("x", x); _xchanged = false; } if (_ychanged) { _span->addAttribute("y", y); _ychanged = false; } if (_color.get() != font.color()) { _span->addAttribute("fill", _color.get().svgColorString()); _color.changed(false); } _text->append(_span); node = _span; } if (!node) { if (!_text) newTextNode(x, y); node = _text; } node->append(XMLString(font.unicode(c), false)); if (!MERGE_CHARS && _color.get() != font.color()) { node->addAttribute("fill", _color.get().svgColorString()); _color.changed(false); } } else { if (_color.changed() || _matrix.changed()) { bool set_color = (_color.changed() && _color.get() != Color::BLACK); bool set_matrix = (_matrix.changed() && !_matrix.get().isIdentity()); if (set_color || set_matrix) { _span = new XMLElementNode("g"); if (_color.get() != Color::BLACK) _span->addAttribute("fill", _color.get().svgColorString()); if (!_matrix.get().isIdentity()) _span->addAttribute("transform", _matrix.get().getSVG()); appendToPage(_span); node = _span; _color.changed(false); _matrix.changed(false); } else if (_color.get() == Color::BLACK && _matrix.get().isIdentity()) node = _span = 0; } if (!node) node = _pageContainerStack.empty() ? _page : _pageContainerStack.top(); if (font.verticalLayout()) { // move glyph graphics so that its origin is located at the top center position GlyphMetrics metrics; font.getGlyphMetrics(c, _vertical, metrics); x -= metrics.wl; if (const PhysicalFont *pf = dynamic_cast(&font)) { // Center glyph between top and bottom border of the TFM box. // This is just an approximation used until I find a way to compute // the exact location in vertical mode. GlyphMetrics exact_metrics; pf->getExactGlyphBox(c, exact_metrics, false); y += exact_metrics.h+(metrics.d-exact_metrics.h-exact_metrics.d)/2; } else y += metrics.d; } Matrix rotation(1); if (_vertical && !font.verticalLayout()) { // alphabetic text designed for horizontal mode // must be rotated by 90 degrees if in vertical mode rotation.translate(-x, -y); rotation.rotate(90); rotation.translate(x, y); } if (CREATE_USE_ELEMENTS) { ostringstream oss; oss << "#g" << FontManager::instance().fontID(_font) << '-' << c; XMLElementNode *use = new XMLElementNode("use"); use->addAttribute("x", XMLString(x)); use->addAttribute("y", XMLString(y)); use->addAttribute("xlink:href", oss.str()); if (!rotation.isIdentity()) use->addAttribute("transform", rotation.getSVG()); node->append(use); } else { Glyph glyph; const PhysicalFont *pf = dynamic_cast(&font); if (pf && pf->getGlyph(c, glyph)) { double sx = pf->scaledSize()/pf->unitsPerEm(); double sy = -sx; ostringstream oss; glyph.writeSVG(oss, RELATIVE_PATH_CMDS, sx, sy, x, y); XMLElementNode *glyph_node = new XMLElementNode("path"); glyph_node->addAttribute("d", oss.str()); if (!rotation.isIdentity()) glyph_node->addAttribute("transform", rotation.getSVG()); node->append(glyph_node); } } } } /** Creates a new text element. This is a helper function used by appendChar(). * @param[in] x current x coordinate * @param[in] y current y coordinate */ void SVGTree::newTextNode (double x, double y) { _text = new XMLElementNode("text"); _span = 0; // no tspan in text element yet if (USE_FONTS) { const Font *font = _font.get(); if (CREATE_STYLE || !font) _text->addAttribute("class", string("f")+XMLString(_fontnum)); else { _text->addAttribute("font-family", font->name()); _text->addAttribute("font-size", XMLString(font->scaledSize())); if (font->color() != Color::BLACK) _text->addAttribute("fill", font->color().svgColorString()); } if (_vertical) { _text->addAttribute("writing-mode", "tb"); // align glyphs designed for horizontal layout properly if (const PhysicalFont *pf = dynamic_cast(_font.get())) if (!pf->getMetrics()->verticalLayout()) { // alphabetic text designed for horizontal layout? x += pf->scaledAscent()/2.5; // move vertical baseline to the right by strikethrough offset _text->addAttribute("glyph-orientation-vertical", 90); // ensure rotation } } } _text->addAttribute("x", x); _text->addAttribute("y", y); if (!_matrix.get().isIdentity()) _text->addAttribute("transform", _matrix.get().getSVG()); appendToPage(_text); _vertical.changed(false); _font.changed(false); _matrix.changed(false); _xchanged = false; _ychanged = false; } void SVGTree::transformPage (const Matrix *usermatrix) { if (usermatrix && !usermatrix->isIdentity()) _page->addAttribute("transform", usermatrix->getSVG()); } /** Creates an SVG element for a single glyph. * @param[in] c character number * @param[in] font font to extract the glyph from * @param[in] cb pointer to callback object for sending feedback to the glyph tracer (may be 0) * @return pointer to element node if glyph exists, 0 otherwise */ static XMLElementNode* createGlyphNode (int c, const PhysicalFont &font, GFGlyphTracer::Callback *cb) { Glyph glyph; if (!font.getGlyph(c, glyph, cb) || (!SVGTree::USE_FONTS && !SVGTree::CREATE_USE_ELEMENTS)) return 0; double sx=1.0, sy=1.0; double upem = font.unitsPerEm(); XMLElementNode *glyph_node=0; if (SVGTree::USE_FONTS) { double extend = font.style() ? font.style()->extend : 1; glyph_node = new XMLElementNode("glyph"); glyph_node->addAttribute("unicode", XMLString(font.unicode(c), false)); glyph_node->addAttribute("horiz-adv-x", XMLString(font.hAdvance(c)*extend)); glyph_node->addAttribute("vert-adv-y", XMLString(font.vAdvance(c))); string name = font.glyphName(c); if (!name.empty()) glyph_node->addAttribute("glyph-name", name); } else { ostringstream oss; oss << 'g' << FontManager::instance().fontID(&font) << '-' << c; glyph_node = new XMLElementNode("path"); glyph_node->addAttribute("id", oss.str()); sx = font.scaledSize()/upem; sy = -sx; } ostringstream oss; glyph.writeSVG(oss, SVGTree::RELATIVE_PATH_CMDS, sx, sy); glyph_node->addAttribute("d", oss.str()); return glyph_node; } void SVGTree::appendFontStyles (const set &fonts) { if (CREATE_STYLE && USE_FONTS && !fonts.empty() && _defs) { XMLElementNode *styleNode = new XMLElementNode("style"); styleNode->addAttribute("type", "text/css"); _root->insertAfter(styleNode, _defs); typedef map SortMap; SortMap sortmap; FORALL(fonts, set::const_iterator, it) if (!dynamic_cast(*it)) // skip virtual fonts sortmap[FontManager::instance().fontID(*it)] = *it; ostringstream style; // add font style definitions in ascending order FORALL(sortmap, SortMap::const_iterator, it) { style << "text.f" << it->first << ' ' << "{font-family:" << it->second->name() << ";font-size:" << XMLString(it->second->scaledSize()) << "px"; if (it->second->color() != Color::BLACK) style << ";fill:" << it->second->color().svgColorString(); style << "}\n"; } XMLCDataNode *cdata = new XMLCDataNode(style.str()); styleNode->append(cdata); } } /** Appends glyph definitions of a given font to the defs section of the SVG tree. * @param[in] font font to be appended * @param[in] chars codes of the characters whose glyph outlines should be appended * @param[in] cb pointer to callback object for sending feedback to the glyph tracer (may be 0) */ void SVGTree::append (const PhysicalFont &font, const set &chars, GFGlyphTracer::Callback *cb) { if (chars.empty()) return; if (USE_FONTS) { XMLElementNode *fontNode = new XMLElementNode("font"); string fontname = font.name(); fontNode->addAttribute("id", fontname); fontNode->addAttribute("horiz-adv-x", XMLString(font.hAdvance())); appendToDefs(fontNode); XMLElementNode *faceNode = new XMLElementNode("font-face"); faceNode->addAttribute("font-family", fontname); faceNode->addAttribute("units-per-em", XMLString(font.unitsPerEm())); if (font.type() != PhysicalFont::MF && !font.verticalLayout()) { faceNode->addAttribute("ascent", XMLString(font.ascent())); faceNode->addAttribute("descent", XMLString(font.descent())); } fontNode->append(faceNode); FORALL(chars, set::const_iterator, i) fontNode->append(createGlyphNode(*i, font, cb)); } else if (CREATE_USE_ELEMENTS && &font != font.uniqueFont()) { // If the same character is used in various sizes, we don't want to embed the complete (lengthy) path // descriptions multiple times. Because they would only differ by a scale factor, it's better to // reference the already embedded path together with a transformation attribute and let the SVG renderer // scale the glyphs properly. This is only necessary if we don't want to use font but path elements. FORALL(chars, set::const_iterator, it) { ostringstream oss; XMLElementNode *use = new XMLElementNode("use"); oss << 'g' << FontManager::instance().fontID(&font) << '-' << *it; use->addAttribute("id", oss.str()); oss.str(""); oss << "#g" << FontManager::instance().fontID(font.uniqueFont()) << '-' << *it; use->addAttribute("xlink:href", oss.str()); double scale = font.scaledSize()/font.uniqueFont()->scaledSize(); if (scale != 1.0) { oss.str(""); oss << "scale(" << scale << ')'; use->addAttribute("transform", oss.str()); } appendToDefs(use); } } else { FORALL(chars, set::const_iterator, i) appendToDefs(createGlyphNode(*i, font, cb)); } } /** Pushes a new context element that will take all following nodes added to the page. */ void SVGTree::pushContextElement (XMLElementNode *node) { if (_pageContainerStack.empty()) _page->append(node); else _pageContainerStack.top()->append(node); _pageContainerStack.push(node); _text = _span = 0; // ensure the creation of a new text element for the following characters added } /** Pops the current context element and restored the previous one. */ void SVGTree::popContextElement () { if (!_pageContainerStack.empty()) { _pageContainerStack.pop(); _text = _span = 0; // ensure the creation of a new text element for the following characters added } } /** Extracts the ID from a local URL reference like url(#abcde) */ inline string extract_id_from_url (const string &url) { return url.substr(5, url.length()-6); } /** Removes elements present in the SVH tree that are not required. * For now, only clipPath elements are removed. */ void SVGTree::removeRedundantElements () { vector clipElements; if (!_defs || !_defs->getDescendants("clipPath", 0, clipElements)) return; // collect dependencies between clipPath elements in the defs section of the SVG tree DependencyGraph idTree; for (vector::iterator it=clipElements.begin(); it != clipElements.end(); ++it) { if (const char *id = (*it)->getAttributeValue("id")) { if (const char *url = (*it)->getAttributeValue("clip-path")) idTree.insert(extract_id_from_url(url), id); else idTree.insert(id); } } // collect elements that reference a clipPath (have a clip-path attribute) vector descendants; _page->getDescendants(0, "clip-path", descendants); // remove referenced IDs and their dependencies from the dependency graph for (vector::iterator it=descendants.begin(); it != descendants.end(); ++it) { string idref = extract_id_from_url((*it)->getAttributeValue("clip-path")); idTree.removeDependencyPath(idref); } descendants.clear(); vector ids; idTree.getKeys(ids); for (vector::iterator it=ids.begin(); it != ids.end(); ++it) { XMLElementNode *node = _defs->getFirstDescendant("clipPath", "id", it->c_str()); _defs->remove(node); } }