build.zig

const std = @import("std");
const builtin = @import("builtin");

// Although this function looks imperative, note that its job is to
// declaratively construct a build graph that will be executed by an external
// runner.
pub fn build(b: *std.Build) void {
    // Standard target options allows the person running `zig build` to choose
    // what target to build for. Here we do not override the defaults, which
    // means any target is allowed, and the default is native. Other options
    // for restricting supported target set are available.
    const target = b.standardTargetOptions(.{});
    
    // Standard optimization options allow the person running `zig build` to select
    // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall. Here we do not
    // set a preferred release mode, allowing the user to decide how to optimize.
    const optimize = b.standardOptimizeOption(.{});
    
    const exe = b.addExecutable(.{
        .name = "game",
        // In this case the main source file is merely a path, however, in more
        // complicated build scripts, this could be a generated file.
        .root_source_file = b.path("src/main.zig"),
        .target = target,
        .optimize = optimize
    });
    exe.linkLibC();
    
    if (target.result.os.tag == .linux) {
        // Linking at runtime
    } else if (target.result.os.tag == .windows) {
        exe.addIncludePath(b.path("lib/SDL2/include"));
        exe.addIncludePath(b.path("lib/SDL2_image/include"));
        
        exe.addLibraryPath(b.path("lib/SDL2/lib/x64"));
        exe.addLibraryPath(b.path("lib/SDL2_image/lib/x64"));
        
        exe.linkSystemLibrary("SDL2");
        exe.linkSystemLibrary("SDL2_image");
    } else if (target.result.os.tag == .macos) {
        exe.addIncludePath(.{ .cwd_relative = "/opt/homebrew/include" });
        
        exe.linkSystemLibrary("SDL2");
        exe.linkSystemLibrary("SDL2_image");
    }
    exe.addIncludePath(b.path("lib/glad/include"));
    exe.addCSourceFile(.{
        .file = b.path("lib/glad/src/glad.c"),
        .flags = &.{}
    });
    // exe.strip = true;
    
    // This declares intent for the executable to be installed into the
    // standard location when the user invokes the "install" step (the default
    // step when running `zig build`).
    b.installArtifact(exe);
    
    // This *creates* a Run step in the build graph, to be executed when another
    // step is evaluated that depends on it. The next line below will establish
    // such a dependency.
    const run_cmd = b.addRunArtifact(exe);
    
    // By making the run step depend on the install step, it will be run from the
    // installation directory rather than directly from within the cache directory.
    // This is not necessary, however, if the application depends on other installed
    // files, this ensures they will be present and in the expected location.
    run_cmd.step.dependOn(b.getInstallStep());
    
    // This allows the user to pass arguments to the application in the build
    // command itself, like this: `zig build run -- arg1 arg2 etc`
    if (b.args) |args| {
        run_cmd.addArgs(args);
    }
    
    // This creates a build step. It will be visible in the `zig build --help` menu,
    // and can be selected like this: `zig build run`
    // This will evaluate the `run` step rather than the default, which is "install".
    const run_step = b.step("run", "Run the app");
    run_step.dependOn(&run_cmd.step);
    
    // Creates a step for unit testing. This only builds the test executable
    // but does not run it.
    const unit_tests = b.addTest(.{
        .root_source_file = b.path("src/main.zig"),
        .target = target,
        .optimize = optimize,
    });
    
    const run_unit_tests = b.addRunArtifact(unit_tests);
    
    // Similar to creating the run step earlier, this exposes a `test` step to
    // the `zig build --help` menu, providing a way for the user to request
    // running the unit tests.
    const test_step = b.step("test", "Run unit tests");
    test_step.dependOn(&run_unit_tests.step);
}