rtti2pnm.cpp

// Simple rtti2pnm converter
// Assumes little endian rtti and binary i/o from stdin/stdout (Posix)

#include <iostream>
#include <string>

int main(int argc, char** argv)
{
	enum State {
		TYPE,
		WIDTH,
		HEIGHT,
		IMAGE8R,
		IMAGE8G,
		IMAGE8B,
		IMAGE16R,
		IMAGE16G,
		IMAGE16B,
		IMAGEFLOATR,
		IMAGEFLOATG,
		IMAGEFLOATB,
		SUCCESS,
		FAILURE
	} state = TYPE;

	unsigned int counter = 0;
	unsigned char c = 0;
	std::string type;
	unsigned int width = 0;
	unsigned int height = 0;
	std::basic_string<unsigned char> r;
	std::basic_string<unsigned char> g;
	std::basic_string<unsigned char> b;
	union {
		unsigned int raw;
		float cooked;
	} f;

	while (
		std::cin.get(reinterpret_cast<char&>(c))
		&& state != SUCCESS
		&& state != FAILURE
	) {
		switch (state) {
			case TYPE: {
				switch (c) {
					case '\n': {
						state = WIDTH;
						break;
					}

					default: {
						type += c;
						break;
					}
				}
				break;
			}

			case WIDTH: {
				width |= c << (8 * counter);
				++counter;
				if (counter == 4) {
					counter = 0;
					state = HEIGHT;
				}
				break;
			}

			case HEIGHT: {
				height |= c << (8 * counter);
				++counter;
				if (counter == 4) {
					r.reserve(width * height);
					g.reserve(width * height);
					b.reserve(width * height);
					counter = 0;
					if (type == "Image8") {
						state = IMAGE8R;
					}
					else if (type == "Image16") {
						state = IMAGE16R;
					}
					else if (type == "Imagefloat") {
						state = IMAGEFLOATR;
						f.raw = 0;
					}
					else {
						state = FAILURE;
					}
				}
				break;
			}

			case IMAGE8R: {
				r.push_back(c);
				state = IMAGE8G;
				break;
			}

			case IMAGE8G: {
				g.push_back(c);
				state = IMAGE8B;
				break;
			}

			case IMAGE8B: {
				b.push_back(c);
				++counter;
				if (counter == width * height) {
					state = SUCCESS;
				} else {
					state = IMAGE8R;
				}
				break;
			}

			case IMAGE16R: {
				if (counter % 2) {
					r.push_back(c);
				}
				++counter;
				if (counter == width * height * 2) {
					counter = 0;
					state = IMAGE16G;
				}
				break;
			}

			case IMAGE16G: {
				if (counter % 2) {
					g.push_back(c);
				}
				++counter;
				if (counter == width * height * 2) {
					counter = 0;
					state = IMAGE16B;
				}
				break;
			}

			case IMAGE16B: {
				if (counter % 2) {
					b.push_back(c);
				}
				++counter;
				if (counter == width * height * 2) {
					state = SUCCESS;
				}
				break;
			}

			case IMAGEFLOATR: {
				switch (counter % 4) {
					default: {
						f.raw |= c << (8 * (counter % 4));
						break;
					}

					case 3: {
						f.raw |= c << 24;
						r.push_back(f.cooked / 256.f);
						f.raw = 0;
						break;
					}
				}
				++counter;
				if (counter == width * height * 4) {
					counter = 0;
					state = IMAGEFLOATG;
				}
				break;
			}

			case IMAGEFLOATG: {
				switch (counter % 4) {
					default: {
						f.raw |= c << (8 * (counter % 4));
						break;
					}

					case 3: {
						f.raw |= c << 24;
						g.push_back(f.cooked / 256.f);
						f.raw = 0;
						break;
					}
				}
				++counter;
				if (counter == width * height * 4) {
					counter = 0;
					state = IMAGEFLOATB;
				}
				break;
			}

			case IMAGEFLOATB: {
				switch (counter % 4) {
					default: {
						f.raw |= c << (8 * (counter % 4));
						break;
					}

					case 3: {
						f.raw |= c << 24;
						b.push_back(f.cooked / 256.f);
						f.raw = 0;
						break;
					}
				}
				++counter;
				if (counter == width * height * 4) {
					state = SUCCESS;
				}
				break;
			}

			case SUCCESS:
			case FAILURE: {
				break;
			}
		}
	}

	if (state == SUCCESS) {
		std::cout << "P6\n";
		std::cout << "# Created by rtti2pnm\n";
		std::cout << width << " " << height << "\n";
		std::cout << "255\n";
		for (unsigned int i = 0; i < width * height; ++i) {
			std::cout.put(r[i]);
			std::cout.put(g[i]);
			std::cout.put(b[i]);
		}
	} else {
		std::cerr << "Could not convert input RTTI." << std::endl;
		return 1;
	}

	return 0;
}

I hate to ask, but I haven't been able to figure out how to use this. I've got it compiled, but my knowledge of cpp is so old and foggy (and frankly rudimentary) that absent any prompts, I can't get it to do right.

I know this is a long shot since this was posted so long ago, but I'm with the last guy who commented, I've got it compiled but I'm lost from there, any chance you can help a guy out with some step-by-step instructions? I lost a ton of pics awhile back and I've been holding on to the thumbnail cache files for years hoping I'd eventually find a way to use them.