build.rs

  1#![cfg_attr(any(not(target_os = "macos"), feature = "macos-blade"), allow(unused))]
  2
  3use std::{
  4    env,
  5    path::{Path, PathBuf},
  6};
  7
  8use cbindgen::Config;
  9
 10//TODO: consider generating shader code for WGSL
 11//TODO: deprecate "runtime-shaders" and "macos-blade"
 12
 13fn main() {
 14    #[cfg(target_os = "macos")]
 15    generate_dispatch_bindings();
 16    #[cfg(all(target_os = "macos", not(feature = "macos-blade")))]
 17    let header_path = generate_shader_bindings();
 18    #[cfg(all(target_os = "macos", not(feature = "macos-blade")))]
 19    #[cfg(feature = "runtime_shaders")]
 20    emit_stitched_shaders(&header_path);
 21    #[cfg(all(target_os = "macos", not(feature = "macos-blade")))]
 22    #[cfg(not(feature = "runtime_shaders"))]
 23    compile_metal_shaders(&header_path);
 24}
 25
 26fn generate_dispatch_bindings() {
 27    println!("cargo:rustc-link-lib=framework=System");
 28    println!("cargo:rerun-if-changed=src/platform/mac/dispatch.h");
 29
 30    let bindings = bindgen::Builder::default()
 31        .header("src/platform/mac/dispatch.h")
 32        .allowlist_var("_dispatch_main_q")
 33        .allowlist_var("_dispatch_source_type_data_add")
 34        .allowlist_var("DISPATCH_QUEUE_PRIORITY_DEFAULT")
 35        .allowlist_var("DISPATCH_QUEUE_PRIORITY_HIGH")
 36        .allowlist_var("DISPATCH_TIME_NOW")
 37        .allowlist_function("dispatch_get_global_queue")
 38        .allowlist_function("dispatch_async_f")
 39        .allowlist_function("dispatch_after_f")
 40        .allowlist_function("dispatch_time")
 41        .allowlist_function("dispatch_source_merge_data")
 42        .allowlist_function("dispatch_source_create")
 43        .allowlist_function("dispatch_source_set_event_handler_f")
 44        .allowlist_function("dispatch_resume")
 45        .allowlist_function("dispatch_suspend")
 46        .allowlist_function("dispatch_source_cancel")
 47        .allowlist_function("dispatch_set_context")
 48        .parse_callbacks(Box::new(bindgen::CargoCallbacks))
 49        .layout_tests(false)
 50        .generate()
 51        .expect("unable to generate bindings");
 52
 53    let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
 54    bindings
 55        .write_to_file(out_path.join("dispatch_sys.rs"))
 56        .expect("couldn't write dispatch bindings");
 57}
 58
 59fn generate_shader_bindings() -> PathBuf {
 60    let output_path = PathBuf::from(env::var("OUT_DIR").unwrap()).join("scene.h");
 61    let crate_dir = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
 62    let mut config = Config::default();
 63    config.include_guard = Some("SCENE_H".into());
 64    config.language = cbindgen::Language::C;
 65    config.export.include.extend([
 66        "Bounds".into(),
 67        "Corners".into(),
 68        "Edges".into(),
 69        "Size".into(),
 70        "Pixels".into(),
 71        "PointF".into(),
 72        "Hsla".into(),
 73        "ContentMask".into(),
 74        "Uniforms".into(),
 75        "AtlasTile".into(),
 76        "PathRasterizationInputIndex".into(),
 77        "PathVertex_ScaledPixels".into(),
 78        "ShadowInputIndex".into(),
 79        "Shadow".into(),
 80        "QuadInputIndex".into(),
 81        "Underline".into(),
 82        "UnderlineInputIndex".into(),
 83        "Quad".into(),
 84        "SpriteInputIndex".into(),
 85        "MonochromeSprite".into(),
 86        "PolychromeSprite".into(),
 87        "PathSprite".into(),
 88        "SurfaceInputIndex".into(),
 89        "SurfaceBounds".into(),
 90        "TransformationMatrix".into(),
 91    ]);
 92    config.no_includes = true;
 93    config.enumeration.prefix_with_name = true;
 94
 95    let mut builder = cbindgen::Builder::new();
 96
 97    let src_paths = [
 98        crate_dir.join("src/scene.rs"),
 99        crate_dir.join("src/geometry.rs"),
100        crate_dir.join("src/color.rs"),
101        crate_dir.join("src/window.rs"),
102        crate_dir.join("src/platform.rs"),
103        crate_dir.join("src/platform/mac/metal_renderer.rs"),
104    ];
105    for src_path in src_paths {
106        println!("cargo:rerun-if-changed={}", src_path.display());
107        builder = builder.with_src(src_path);
108    }
109
110    builder
111        .with_config(config)
112        .generate()
113        .expect("Unable to generate bindings")
114        .write_to_file(&output_path);
115
116    output_path
117}
118
119/// To enable runtime compilation, we need to "stitch" the shaders file with the generated header
120/// so that it is self-contained.
121#[cfg(feature = "runtime_shaders")]
122fn emit_stitched_shaders(header_path: &Path) {
123    use std::str::FromStr;
124    fn stitch_header(header: &Path, shader_path: &Path) -> std::io::Result<PathBuf> {
125        let header_contents = std::fs::read_to_string(header)?;
126        let shader_contents = std::fs::read_to_string(shader_path)?;
127        let stitched_contents = format!("{header_contents}\n{shader_contents}");
128        let out_path = PathBuf::from(env::var("OUT_DIR").unwrap()).join("stitched_shaders.metal");
129        std::fs::write(&out_path, stitched_contents)?;
130        Ok(out_path)
131    }
132    let shader_source_path = "./src/platform/mac/shaders.metal";
133    let shader_path = PathBuf::from_str(shader_source_path).unwrap();
134    stitch_header(header_path, &shader_path).unwrap();
135    println!("cargo:rerun-if-changed={}", &shader_source_path);
136}
137#[cfg(not(feature = "runtime_shaders"))]
138fn compile_metal_shaders(header_path: &Path) {
139    use std::process::{self, Command};
140    let shader_path = "./src/platform/mac/shaders.metal";
141    let air_output_path = PathBuf::from(env::var("OUT_DIR").unwrap()).join("shaders.air");
142    let metallib_output_path = PathBuf::from(env::var("OUT_DIR").unwrap()).join("shaders.metallib");
143    println!("cargo:rerun-if-changed={}", shader_path);
144
145    let output = Command::new("xcrun")
146        .args([
147            "-sdk",
148            "macosx",
149            "metal",
150            "-gline-tables-only",
151            "-mmacosx-version-min=10.15.7",
152            "-MO",
153            "-c",
154            shader_path,
155            "-include",
156            &header_path.to_str().unwrap(),
157            "-o",
158        ])
159        .arg(&air_output_path)
160        .output()
161        .unwrap();
162
163    if !output.status.success() {
164        eprintln!(
165            "metal shader compilation failed:\n{}",
166            String::from_utf8_lossy(&output.stderr)
167        );
168        process::exit(1);
169    }
170
171    let output = Command::new("xcrun")
172        .args(["-sdk", "macosx", "metallib"])
173        .arg(air_output_path)
174        .arg("-o")
175        .arg(metallib_output_path)
176        .output()
177        .unwrap();
178
179    if !output.status.success() {
180        eprintln!(
181            "metallib compilation failed:\n{}",
182            String::from_utf8_lossy(&output.stderr)
183        );
184        process::exit(1);
185    }
186}