First Light

#include "prism/renderer.hpp"
#include <exception>
#include <iostream>
#include <string_view>

int main(int argc, char* argv[]) {
    if (argc == 2 && std::string_view{argv[1]} == "--help") {
        std::cout << "Parallax CPU renderer\nUsage: prism-render <output.ppm>\n";
        return 0;
    }
    if (argc != 2) {
        std::cerr << "Usage: prism-render <output.ppm>\n";
        return 1;
    }
    try {
        const auto scene = prism::demo_scene();
        auto image = prism::render(scene);
        if (!image) { std::cerr << image.error().message << '\n'; return 1; }
        if (auto written = prism::write_ppm(std::filesystem::path{argv[1]}, *image); !written) {
            std::cerr << written.error().message << '\n';
            return 1;
        }
        std::cout << "Rendered " << image->width << " × " << image->height << " pixels.\n";
        return 0;
    } catch (const std::exception&) {
        // The CLI is the final exception boundary. Never print arbitrary input.
        std::cerr << "The render could not complete.\n";
        return 1;
    }
}