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/*************************************************************************
** ColorSpecialHandler.cpp **
** **
** This file is part of dvisvgm -- a fast DVI to SVG converter **
** Copyright (C) 2005-2018 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 <cstring>
#include <sstream>
#include <vector>
#include "ColorSpecialHandler.hpp"
#include "SpecialActions.hpp"
using namespace std;
static double read_double (istream &is) {
is.clear();
double v;
is >> v;
if (is.fail())
throw SpecialException("number expected");
return v;
}
/** Reads multiple double values from a given stream. The number of
* values read is determined by the size of the result vector.
* @param[in] is stream to be read from
* @param[out] v the resulting values */
static void read_doubles (istream &is, vector<double> &v) {
for (size_t i=0; i < v.size(); i++)
v[i] = read_double(is);
}
/** Reads a color statement from an input stream and converts it to a color object.
* A color statement has the following syntax:
* _color model_ _component values_
* Currently, the following color models are supported: rgb, cmyk, hsb and gray.
* Examples: rgb 1 0.5 0, gray 0.5
* @param[in] model the color model
* @param[in] is stream to be read from
* @return resulting Color object */
Color ColorSpecialHandler::readColor (const string &model, istream &is) {
Color color;
if (model == "rgb") {
vector<double> rgb(3);
read_doubles(is, rgb);
color.setRGB(rgb[0], rgb[1], rgb[2]);
}
else if (model == "cmyk") {
vector<double> cmyk(4);
read_doubles(is, cmyk);
color.setCMYK(cmyk[0], cmyk[1], cmyk[2], cmyk[3]);
}
else if (model == "hsb") {
vector<double> hsb(3);
read_doubles(is, hsb);
color.setHSB(hsb[0], hsb[1], hsb[2]);
}
else if (model == "gray")
color.setGray(read_double(is));
else if (!color.setPSName(model, true))
throw SpecialException("unknown color statement");
return color;
}
/** Reads the color model (rgb, cmyk, hsb, or gray) and the corresponding color compontents
* from a given input stream.
* @param[in] is stream to be read from
* @return resulting Color object */
Color ColorSpecialHandler::readColor (istream &is) {
string model;
is >> model;
return readColor(model, is);
}
bool ColorSpecialHandler::process (const string&, istream &is, SpecialActions &actions) {
string cmd;
is >> cmd;
if (cmd == "push") // color push <model> <params>
_colorStack.push(readColor(is));
else if (cmd == "pop") {
if (!_colorStack.empty()) // color pop
_colorStack.pop();
}
else { // color <model> <params>
while (!_colorStack.empty())
_colorStack.pop();
_colorStack.push(readColor(cmd, is));
}
if (_colorStack.empty())
actions.setColor(Color::BLACK);
else
actions.setColor(_colorStack.top());
return true;
}
vector<const char*> ColorSpecialHandler::prefixes() const {
vector<const char*> pfx {"color"};
return pfx;
}
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