115 lines
2.9 KiB
C++
115 lines
2.9 KiB
C++
#include "utils.h"
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#include <fstream>
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struct __attribute__((__packed__)) tga_header_t {
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int8_t idlength;
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int8_t colormaptype;
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int8_t imagetype;
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int16_t colormaporigin;
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int16_t colormaplength;
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int8_t colormapdepth;
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int16_t xoffset;
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int16_t yoffset;
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int16_t width;
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int16_t height;
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int8_t bitsperpixel;
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int8_t imagedescriptor;
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};
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int LoadTGA(const char *filename,
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std::vector<uint8_t> &pixels,
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uint32_t *width,
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uint32_t *height,
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uint32_t *bpp) {
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std::ifstream ifs(filename, std::ios::in | std::ios::binary);
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if (!ifs.is_open()) {
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std::cerr << "couldn't open file: " << filename << "!" << std::endl;
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return -1;
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}
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tga_header_t header;
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ifs.read(reinterpret_cast<char *>(&header), sizeof(tga_header_t));
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if (ifs.fail()) {
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std::cerr << "invalid TGA file header!" << std::endl;
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return -1;
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}
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if (header.imagetype != 2) {
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std::cerr << "unsupported TGA encoding format!" << std::endl;
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return -1;
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}
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ifs.seekg(header.idlength, std::ios::cur); // skip string
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if (ifs.fail()) {
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std::cerr << "invalid TGA file!" << std::endl;
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return -1;
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}
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switch (header.bitsperpixel) {
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case 24:
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case 32: {
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auto stride = header.bitsperpixel / 8;
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auto pitch = header.width * stride;
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pixels.resize(header.height * pitch);
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// we are going to load the pixel data line by line
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for (int y = 0; y < header.height; ++y) {
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// Read current line of pixels
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auto line = pixels.data() + y * pitch;
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ifs.read(reinterpret_cast<char *>(line), pitch);
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if (ifs.fail()) {
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std::cerr << "invalid TGA file!" << std::endl;
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return -1;
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}
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// Because the TGA is BGR instead of RGB, we must swap RG components
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for (int i = 0; i < pitch; i += stride) {
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auto tmp = line[i];
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line[i] = line[i + 2];
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line[i + 2] = tmp;
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}
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}
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break;
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}
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default:
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std::cerr << "unsupported TGA bitsperpixel!" << std::endl;
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return -1;
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}
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*width = header.width;
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*height = header.height;
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*bpp = header.bitsperpixel / 8;
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return 0;
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}
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int SaveTGA(const char *filename,
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const std::vector<uint8_t> &pixels,
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uint32_t width,
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uint32_t height,
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uint32_t bpp) {
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std::ofstream ofs(filename, std::ios::out | std::ios::binary);
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if (!ofs.is_open()) {
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std::cerr << "couldn't create file: " << filename << "!" << std::endl;
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return -1;
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}
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tga_header_t header;
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header.idlength = 0;
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header.colormaptype = 0; // no palette
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header.imagetype = 2; // color mapped data
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header.colormaporigin = 0;
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header.colormaplength = 0;
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header.colormapdepth = 0;
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header.xoffset = 0;
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header.yoffset = 0;
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header.width = width;
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header.height = height;
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header.bitsperpixel = bpp * 8;
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header.imagedescriptor = 0;
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ofs.write(reinterpret_cast<char *>(&header), sizeof(tga_header_t));
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ofs.write((const char*)pixels.data(), pixels.size());
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return 0;
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} |