87 lines
1.4 KiB
C++
87 lines
1.4 KiB
C++
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#include <fstream>
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#include <string>
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#include <iostream>
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#include "pnm.h"
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using namespace std;
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namespace pnm
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{
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bool read_header(std::ifstream& istr, Format& type, unsigned int& width, unsigned int& height)
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{
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// check magic
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if (istr.get() != 'P' )
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{
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return false;
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}
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char c_type = static_cast<char>(istr.get());
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if (c_type == '6')
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{
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type = Format::PPM;
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}
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else if (c_type == '5')
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{
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type = Format::PGM;
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}
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else
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{
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cerr << "Invalid PNM format." << endl;
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return false;
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}
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if (istr.get() != '\n')
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{
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return false;
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}
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// skip comments
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while (istr.peek() == '#')
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{
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std::string line;
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std::getline(istr, line);
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}
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// get size
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istr >> width >> height;
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if (width == 0 || height == 0)
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{
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return false;
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}
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// get maxvalue
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if (istr.get() != '\n')
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{
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return false;
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}
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int max_value = -1;
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istr >> max_value;
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if (max_value > 255)
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{
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return false;
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}
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if (istr.get() != '\n')
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{
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return false;
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}
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return true;
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}
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bool write_header(std::ofstream& ostr, Format type, unsigned int width, unsigned int height)
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{
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if (type == Format::PGM)
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ostr << "P5" << endl;
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if (type == Format::PPM)
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ostr << "P6" << endl;
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ostr << width << " " << height << endl;
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ostr << "255" << endl;
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return true;
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}
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} // end of namespace pnm
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