127 lines
4.1 KiB
C++
127 lines
4.1 KiB
C++
/*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* Copyright 2011-2015 Danny Robson <danny@nerdcruft.net>
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*/
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#include "netpbm.hpp"
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#include "io.hpp"
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#include "except.hpp"
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#include <fstream>
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///////////////////////////////////////////////////////////////////////////////
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// HACK: This does not support the full header structure with any robustness.
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// In particular it will abort when it sees a comment. If you want better
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// support use waif, or port its implementation.
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util::image::buffer<uint8_t>
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util::pgm::read (const boost::filesystem::path &path)
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{
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util::mapped_file raw (path);
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std::ifstream cooked (path.string (), std::ios::binary);
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char magic[2];
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size_t width, height, scale;
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char space;
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cooked >> magic[0] >> magic[1] >> width >> height >> scale >> space;
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if (magic[0] != 'P' && magic[1] != '5')
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throw std::runtime_error ("invalid header magic");
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if (width == 0 || height == 0 || scale == 0)
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throw std::runtime_error ("zero width, height, or scale");
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size_t expected = width * height;
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size_t remain = raw.size () - cooked.tellg ();
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if (expected != remain)
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throw std::runtime_error ("expected data size mismatch");
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util::image::buffer<uint8_t> out (width, height);
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CHECK_EQ (out.w, out.s);
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std::copy (raw.begin () + cooked.tellg () - 1, raw.end (), out.begin ());
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return out;
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}
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//-----------------------------------------------------------------------------
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static void
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write_netpbm (const uint8_t *restrict pixels,
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size_t components,
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size_t width,
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size_t height,
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size_t stride,
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const boost::filesystem::path &path,
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const char* MAGIC) {
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CHECK (pixels);
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CHECK_GT (components, 0);
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CHECK_GT (width, 0);
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CHECK_GE (stride, width);
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CHECK_GT (height, 0);
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// Establish an output stream
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std::ofstream output (path.string ());
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if (!output.good ())
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throw util::output_error ("Unable to open output file");
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// Write the PPM header.
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output << MAGIC << "\n"
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<< width << "\n"
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<< height << "\n"
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<< (size_t)std::numeric_limits<uint8_t>::max () << "\n";
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// Write the data rows
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for (size_t y = 0; y < height; ++y) {
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for (size_t x = 0; x < width; ++x)
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for (size_t c = 0; c < components; ++c)
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output << pixels[y * stride + x * components + c];
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}
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}
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//-----------------------------------------------------------------------------
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void
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util::pgm::write (const util::image::buffer<uint8_t> &src,
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const boost::filesystem::path &path)
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{
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write (src.begin (), src.w, src.h, src.s, path);
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}
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//-----------------------------------------------------------------------------
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void
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util::pgm::write (const uint8_t *restrict pixels,
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size_t width,
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size_t height,
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size_t stride,
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const boost::filesystem::path &path) {
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// TODO: We should switch between P2 (ascii) and P5 (binary)
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static const char MAGIC[] = "P5";
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write_netpbm (pixels, 1, width, height, stride, path, MAGIC);
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}
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//-----------------------------------------------------------------------------
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void
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util::ppm::write (const uint8_t *restrict pixels,
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size_t width,
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size_t height,
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size_t stride,
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const boost::filesystem::path &path) {
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// TODO: We should switch between P3 (ascii) and P6 (binary)
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static const char MAGIC[] = "P6";
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write_netpbm (pixels, 3, width, height, stride, path, MAGIC);
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}
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