diff options
author | Norbert Preining <norbert@preining.info> | 2019-09-02 13:46:59 +0900 |
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committer | Norbert Preining <norbert@preining.info> | 2019-09-02 13:46:59 +0900 |
commit | e0c6872cf40896c7be36b11dcc744620f10adf1d (patch) | |
tree | 60335e10d2f4354b0674ec22d7b53f0f8abee672 /dviware/dvisvgm/src/PSPreviewFilter.cpp |
Initial commit
Diffstat (limited to 'dviware/dvisvgm/src/PSPreviewFilter.cpp')
-rw-r--r-- | dviware/dvisvgm/src/PSPreviewFilter.cpp | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/dviware/dvisvgm/src/PSPreviewFilter.cpp b/dviware/dvisvgm/src/PSPreviewFilter.cpp new file mode 100644 index 0000000000..36f0303e0f --- /dev/null +++ b/dviware/dvisvgm/src/PSPreviewFilter.cpp @@ -0,0 +1,110 @@ +/************************************************************************* +** PSPreviewFilter.cpp ** +** ** +** This file is part of dvisvgm -- a fast DVI to SVG converter ** +** Copyright (C) 2005-2019 Martin Gieseking <martin.gieseking@uos.de> ** +** ** +** 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 <http://www.gnu.org/licenses/>. ** +*************************************************************************/ + +#include <vector> +#include "InputBuffer.hpp" +#include "InputReader.hpp" +#include "PSInterpreter.hpp" +#include "PSPreviewFilter.hpp" +#include "SpecialActions.hpp" + + +using namespace std; + +PSPreviewFilter::PSPreviewFilter (PSInterpreter &psi) + : PSFilter(psi), _active(false), _tightpage(false), _dvi2bp(1.0/65536.0) +{ +} + + +/** 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; +} |