Crafter.Graphics/examples/Sponza/project.cpp

import std;
import Crafter.Build;
namespace fs = std::filesystem;
using namespace Crafter;

// Sponza geometry + albedo: CC BY 3.0, Frank Meinl (Crytek), packaged by
// Jimmie Bergmann (https://github.com/jimmiebergmann/Sponza) and Morgan
// McGuire (https://casual-effects.com/data). The full asset bundle is
// ~280 MB — too large to live in this repo. GitFetch lands it in the
// per-user crafter-build cache on first build and reuses thereafter.
constexpr std::string_view kSponzaGitUrl    = "https://github.com/jimmiebergmann/Sponza.git";
constexpr std::string_view kSponzaCommitSHA = "222338979d32f4f4818466291bdbc29f192b86ba";
// Every albedo is normalized to this size so they can live as layers of
// one texture_2d_array on the GPU (WebGPU array textures require
// identical layer dimensions). 1024 matches the majority of Sponza's
// textures; the few outliers (256×1024 chain, 512² thorn, 2048² curtains)
// get bilinear-resized via stb_image_resize2.
constexpr std::uint16_t    kAlbedoSize      = 1024u;

extern "C" Configuration CrafterBuildProject(std::span<const std::string_view> args) {
    bool isWasm = false;
    for (std::string_view a : args) {
        if (a.starts_with("--target=") && a.find("wasm") != std::string_view::npos) {
            isWasm = true;
            break;
        }
    }

    std::vector<std::string> graphicsArgs(args.begin(), args.end());
    Configuration* graphics = LocalProject({
        .projectFile = "../../project.cpp",
        .args = graphicsArgs,
    });

    Configuration cfg;
    cfg.path = "./";
    cfg.name = "Sponza";
    cfg.outputName = "Sponza";
    cfg.type = ConfigurationType::Executable;
    if (isWasm) {
        cfg.target = "wasm32-wasip1";
        cfg.defines.push_back({"CRAFTER_GRAPHICS_WINDOW_DOM", ""});
        cfg.compileFlags.push_back("-msimd128");
    }
    ApplyStandardArgs(cfg, args);
    cfg.dependencies = { graphics };

    std::array<fs::path, 0> ifaces = {};
    std::array<fs::path, 1> impls = { "main" };
    cfg.GetInterfacesAndImplementations(ifaces, impls);

    // Fetch Sponza once into the shared crafter-build cache, then process
    // it into a per-material bundle under build/sponza-bundle-<hash>/.
    // Hashing on (sha, albedoSize) so changing either invalidates the
    // bundle without touching the rest of the example's build tree.
    fs::path sponzaRoot = GitFetch({
        .url    = std::string(kSponzaGitUrl),
        .commit = std::string(kSponzaCommitSHA),
    });
    std::string bundleKey = std::format("{}|{}", kSponzaCommitSHA, kAlbedoSize);
    auto bundleHash = std::hash<std::string>{}(bundleKey);
    fs::path bundleDir = fs::path("build") / std::format("sponza-bundle-{:016x}", bundleHash);

    if (auto err = BuildOBJBundle(
            sponzaRoot / "sponza.obj",
            sponzaRoot / "sponza.mtl",
            bundleDir,
            kAlbedoSize); !err.empty()) {
        std::println(std::cerr, "Sponza bundle error: {}", err);
        std::exit(1);
    }

    // Forward every produced file (.cmesh, .ctex, scene.txt) as a
    // passthrough — they're already compressed by Crafter.Asset, no
    // further compression needed. cfg.files copies them flat into
    // the executable's bin dir.
    for (const auto& entry : fs::directory_iterator(bundleDir)) {
        if (entry.is_regular_file()) cfg.files.push_back(entry.path());
    }

    if (isWasm) {
        cfg.files.emplace_back(fs::path("raygen.wgsl"));
        cfg.files.emplace_back(fs::path("closesthit.wgsl"));
        cfg.files.emplace_back(fs::path("miss.wgsl"));
        cfg.files.emplace_back(fs::path("resolve.wgsl"));
        EnableWasiBrowserRuntime(cfg);
    } else {
        cfg.shaders.emplace_back(fs::path("raygen.glsl"),     std::string("main"), ShaderType::RayGen);
        cfg.shaders.emplace_back(fs::path("closesthit.glsl"), std::string("main"), ShaderType::ClosestHit);
        cfg.shaders.emplace_back(fs::path("miss.glsl"),       std::string("main"), ShaderType::Miss);
    }
    return cfg;
}