build.zig

const std = @import("std");

const platform_wasm4_pkg = make_pkg("platform", "src/platform_wasm4.zig", &[_]std.build.Pkg{});
const platform_null_pkg = make_pkg("platform", "src/platform_null.zig", &[_]std.build.Pkg{});

const gfx_pkg = make_pkg("gfx", "src/gfx.zig", ([_]std.build.Pkg{platform_wasm4_pkg})[0..]);

const sfx_pkg = make_pkg("sfx", "src/sfx.zig", ([_]std.build.Pkg{platform_wasm4_pkg})[0..]);

pub fn build(b: *std.build.Builder) !void {
    const tests = b.addTest("src/tests.zig");
    tests.setBuildMode(b.standardReleaseOptions());

    tests.addPackage(platform_null_pkg);
    tests.addPackage(gfx_pkg);
    tests.addPackage(sfx_pkg);

    const test_step = b.step("test", "Run all tests");
    test_step.dependOn(&tests.step);

    try build_wasm4(b);
}

fn build_wasm4(b: *std.build.Builder) !void {
    const cart = b.addSharedLibrary("cart", "src/main_wasm4.zig", .unversioned);
    cart.setBuildMode(b.standardReleaseOptions());
    cart.setTarget(.{ .cpu_arch = .wasm32, .os_tag = .freestanding });
    cart.import_memory = true;
    cart.initial_memory = 65536;
    cart.max_memory = 65536;
    cart.stack_size = 14752;
    cart.export_symbol_names = &[_][]const u8{ "start", "update" };
    cart.install();

    cart.addPackage(platform_wasm4_pkg);
    cart.addPackage(gfx_pkg);
    cart.addPackage(sfx_pkg);

    cart.addPackage(.{
        .name = "data",
        .source = .{ .path = this_dir() ++ "/src/data.zig" },
    });

    const prefix = b.getInstallPath(.lib, "");
    const cart_opt = b.addSystemCommand(&[_][]const u8{
        "wasm-opt",
        "-Oz",
        "--strip-debug",
        "--strip-producers",
        "--zero-filled-memory",
    });

    cart_opt.addArtifactArg(cart);
    const wasmopt_out = try std.fs.path.join(b.allocator, &.{ prefix, "cart_opt.wasm" });
    defer b.allocator.free(wasmopt_out);
    cart_opt.addArgs(&.{ "--output", wasmopt_out });

    const release_build = b.step("release", "Run wasm-opt on cart.wasm, producing opt.wasm");
    release_build.dependOn(&cart.step);
    release_build.dependOn(&cart_opt.step);
}

inline fn make_pkg(
    name: []const u8,
    src_path: []const u8,
    dependencies: anytype,
) std.build.Pkg {
    return .{
        .name = name,
        .source = .{ .path = this_dir() ++ "/" ++ src_path },
        .dependencies = dependencies,
    };
}

inline fn this_dir() []const u8 {
    return comptime std.fs.path.dirname(@src().file) orelse ".";
}