/************************************************************************* ** PSPreviewFilter.cpp ** ** ** ** This file is part of dvisvgm -- a fast DVI to SVG converter ** ** Copyright (C) 2005-2020 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 "InputBuffer.hpp" #include "InputReader.hpp" #include "PSInterpreter.hpp" #include "PSPreviewFilter.hpp" #include "SpecialActions.hpp" using namespace std; /** Activates this filter so that the PS code will be redirected through it if * it's hooked into the PSInterpreter. */ void PSPreviewFilter::activate () { if (_tightpage) // reactivate filter? _active = true; else { // first activation? _tightpage = _active = false; // try to retrieve version string of preview package set in the PS header section if (psInterpreter().executeRaw("SDict begin currentdict/preview@version known{preview@version}{0}ifelse end", 1)) _version = psInterpreter().rawData()[0]; // check if tightpage option was set if (_version != "0" && psInterpreter().executeRaw("SDict begin preview@tightpage end", 1)) { _tightpage = (psInterpreter().rawData()[0] == "true"); _active = true; } } _boxExtents.clear(); } /** Tries to extract the bounding box information from a chunk of PostScript code. * @param[in] code pointer to buffer with PS code to filter * @param[in] len number of bytes in buffer */ void PSPreviewFilter::execute (const char *code, size_t len) { // If the "tightpage" option was set in the TeX file, 7 integers representing the // extent of the bounding box are present at the begin of each page. if (!_tightpage) psInterpreter().execute(code, len); else { // Read bounding box information pushed on the operand stack by the preview package. // It consists of 7 values in DVI units: // adj_left, adj_bottom, adj_right, adj_top, height, depth, width, // where the first 4 values are set by \PreviewBorder or \PreviewBbAdjust. They denote // the border adjustments to create additional space around the graphics. // The baseline of the tight box extends from (0,0) to (tight_width, 0). CharInputBuffer ib(code, len); BufferInputReader ir(ib); ir.skipSpace(); int val; while (ir.parseInt(val) && _boxExtents.size() <= 7) { _boxExtents.push_back(val); ir.skipSpace(); } } _active = false; // no further processing required } /** Returns the bounding box defined by the preview package. */ bool PSPreviewFilter::getBoundingBox (BoundingBox &bbox) const { if (_boxExtents.size() < 7) return false; const double leftX = _boxExtents[0]*_dvi2bp; bbox = BoundingBox(leftX, -height(), width()+leftX, depth()); return true; } /** Returns the box height in PS points, or -1 if no data was found or read yet. */ double PSPreviewFilter::height () const { return _boxExtents.size() > 4 ? (_boxExtents[4]+_boxExtents[3])*_dvi2bp : -1; } /** Returns the box depth in PS points, or -1 if no data was found or read yet. */ double PSPreviewFilter::depth () const { return _boxExtents.size() > 5 ? (_boxExtents[5]-_boxExtents[1])*_dvi2bp : -1; } /** Returns the box width in PS points, or -1 if no data was found or read yet. */ double PSPreviewFilter::width () const { return _boxExtents.size() > 6 ? (_boxExtents[6]+_boxExtents[2]-_boxExtents[0])*_dvi2bp : -1; }