135 lines
4 KiB
C++
135 lines
4 KiB
C++
#include "lily_png.h"
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std::vector<color> palette;
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bool palette_found = false;
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static void read_raw_data(const std::string &file_path, buffer_unsigned &data, metadata &meta)
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{
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std::println("Zlib version is {}", zlibVersion());
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unsigned char magic[9] = {137, 80, 78, 71, 13, 10, 26, 10};
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file_reader reader(file_path);
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char file_magic[9] = {0};
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reader.read_buffer(file_magic, 8);
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if (memcmp(magic, file_magic, 8) != 0)
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{
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std::println("File is not a png!");
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return ;
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}
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buffer_unsigned raw_dat{};
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while (true)
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{
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std::tuple<unsigned int, buffer> chunk_header;
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std::get<1>(chunk_header).size = 4;
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auto ret = reader.read_from_tuple(chunk_header);
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if (ret.second == READ_FILE_ENDED || ret.second == READ_INCOMPLETE)
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{
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std::println("Chunk incomplete!");
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return ;
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}
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unsigned int size = std::get<0>(chunk_header);
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//std::println("Chunk type {} Size {}", std::get<1>(chunk_header).data, std::get<0>(chunk_header));
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buffer_unsigned raw_data{};
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raw_data.size = std::get<0>(chunk_header);
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std::tuple<buffer, unsigned> dat;
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std::get<0>(dat).size = std::get<0>(chunk_header);
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ret = reader.read_from_tuple(dat);
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if (ret.second == READ_FILE_ENDED || ret.second == READ_INCOMPLETE)
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{
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std::println("Chunk incomplete!");
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return ;
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}
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unsigned long crc = crc32(0, reinterpret_cast<unsigned char *>(std::get<1>(chunk_header).data), 4);
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crc = crc32(crc, reinterpret_cast<unsigned char *>(std::get<0>(dat).data), std::get<0>(chunk_header));
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if (crc != std::get<1>(dat))
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throw std::runtime_error("Crc check failed");
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if (strncmp(std::get<1>(chunk_header).data, "IDAT", 4) == 0)
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{
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raw_dat.write(reinterpret_cast<unsigned char *>(std::get<0>(dat).data), std::get<0>(chunk_header));
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}
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else if (strncmp(std::get<1>(chunk_header).data, "IHDR", 4) == 0)
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{
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meta = parse_metadata(std::get<0>(dat));
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}
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else if (strncmp(std::get<1>(chunk_header).data, "PLTE", 4) == 0)
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{
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palette_found = true;
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if (size%3 != 0)
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{
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std::println("Palette size is not divisible by 3");
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return ;
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}
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for (int i = 0; i < size; i += 3)
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{
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color tmp_color;
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tmp_color.r = std::get<0>(dat).data[i];
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tmp_color.g = std::get<0>(dat).data[i + 1];
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tmp_color.b = std::get<0>(dat).data[i + 2];
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palette.push_back(tmp_color);
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}
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}
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else if (strncmp(std::get<1>(chunk_header).data, "IEND", 4) == 0)
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break;
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}
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data.allocate(get_uncompressed_size(meta));
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size_t prev_allocated = data.allocated;
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int r = uncompress(data.data, &prev_allocated, raw_dat.data, raw_dat.allocated);
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if (r != Z_OK)
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{
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std::println("Uncompress failed {}", r);
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throw std::runtime_error("Uncompress fail");
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}
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}
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static void apply_palette_scanline(unsigned char *scanline, unsigned char *dest, metadata &meta)
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{
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size_t pixel_size = get_pixel_bit_size(meta);
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size_t pixel_size_bytes = (pixel_size + 7)/8;
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size_t scanline_size = (meta.width * pixel_size + 7)/8;
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unsigned long dest_index = 0;
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for (int i = 0; i < scanline_size; i++)
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{
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color tmp_color = palette[scanline[i]];
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dest[dest_index] = tmp_color.r;
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dest[dest_index++] = tmp_color.g;
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dest[dest_index++] = tmp_color.b;
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}
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}
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static void apply_palette(buffer_unsigned &data, buffer_unsigned &dest, metadata &meta)
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{
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unsigned long index = 0;
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unsigned long index_dest = 0;
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size_t pixel_size = get_pixel_bit_size(meta);
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size_t pixel_size_bytes = (pixel_size + 7)/8;
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size_t scanline_size = (meta.width * pixel_size + 7)/8;
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unsigned long scanlines = 0;
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dest.allocate(get_uncompressed_size(meta) * 3);
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while (scanlines < meta.height)
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{
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unsigned char filter = data.data[index];
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std::println("Filter {}", filter);
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apply_palette_scanline(&data.data[index + 1], &dest.data[index_dest], meta);
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index += scanline_size + 1;
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index_dest += scanline_size;
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scanlines++;
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}
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}
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void read_png(const std::string &file_path, buffer_unsigned &data)
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{
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buffer_unsigned tmp_data{};
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metadata meta{0};
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read_raw_data(file_path, tmp_data, meta);
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if (palette_found == true)
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{
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buffer_unsigned dest_palette{};
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apply_palette(tmp_data, dest_palette, meta);
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tmp_data = dest_palette;
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}
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filter(tmp_data, data, meta);
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}
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