110 lines
2.1 KiB
C++
110 lines
2.1 KiB
C++
#include <psemek/gfx/pixmap.hpp>
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#include <iostream>
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namespace psemek::gfx
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{
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pixmap_monochrome read_pgm(std::istream & is)
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{
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auto fail = [](std::string str)
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{
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throw std::runtime_error("Error loading PGM image: " + str);
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};
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std::string line;
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std::getline(is, line);
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bool binary = true;
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if (line == "P2")
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{
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binary = false;
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}
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else if (line == "P5")
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{
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binary = true;
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}
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else
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fail("unknown format " + line);
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std::size_t width, height;
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std::size_t max;
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pixmap_monochrome pixmap;
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is >> width >> height >> max;
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if (max != 255)
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fail("max value " + std::to_string(max) + " is not supported");
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pixmap.resize(width, height);
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if (binary)
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is.read(reinterpret_cast<char *>(pixmap.data()), width * height * sizeof(pixmap.data()[0]));
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else
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fail("P2 format is not supported");
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if (!is)
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fail("stream error");
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return pixmap;
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}
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pixmap_rgb load_ppm(std::istream & is)
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{
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auto fail = [](std::string str)
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{
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throw std::runtime_error("Error loading PPM image: " + str);
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};
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std::string line;
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std::getline(is, line);
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bool binary = true;
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if (line == "P3")
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{
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binary = false;
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}
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else if (line == "P6")
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{
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binary = true;
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}
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else
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fail("unknown format " + line);
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std::size_t width, height;
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std::size_t max;
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pixmap_rgb pixmap;
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is >> width >> height >> max;
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if (max != 255)
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fail("max value " + std::to_string(max) + " is not supported");
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pixmap.resize(width, height);
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if (binary)
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is.read(reinterpret_cast<char *>(pixmap.data()), width * height * sizeof(pixmap.data()[0]));
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else
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fail("P3 format is not supported");
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if (!is)
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fail("stream error");
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return pixmap;
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}
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void write_pgm(pixmap_monochrome const & p, std::ostream & os)
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{
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os << "P5\n" << p.width() << " " << p.height() << "\n255\n";
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os.write(reinterpret_cast<char const *>(p.data()), p.width() * p.height() * sizeof(p.data()[0]));
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}
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void write_ppm(pixmap_rgb const & p, std::ostream & os)
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{
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os << "P6\n" << p.width() << " " << p.height() << "\n255\n";
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os.write(reinterpret_cast<char const *>(p.data()), p.width() * p.height() * sizeof(p.data()[0]));
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}
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}
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