build.rs

  1#![cfg_attr(any(not(target_os = "macos"), feature = "macos-blade"), allow(unused))]
  2
  3//TODO: consider generating shader code for WGSL
  4//TODO: deprecate "runtime-shaders" and "macos-blade"
  5
  6fn main() {
  7    #[cfg(target_os = "macos")]
  8    macos::build();
  9}
 10
 11#[cfg(target_os = "macos")]
 12mod macos {
 13    use std::{
 14        env,
 15        path::{Path, PathBuf},
 16    };
 17
 18    use cbindgen::Config;
 19
 20    pub(super) fn build() {
 21        generate_dispatch_bindings();
 22        #[cfg(not(feature = "macos-blade"))]
 23        {
 24            let header_path = generate_shader_bindings();
 25
 26            #[cfg(feature = "runtime_shaders")]
 27            emit_stitched_shaders(&header_path);
 28            #[cfg(not(feature = "runtime_shaders"))]
 29            compile_metal_shaders(&header_path);
 30        }
 31    }
 32
 33    fn generate_dispatch_bindings() {
 34        println!("cargo:rustc-link-lib=framework=System");
 35        println!("cargo:rerun-if-changed=src/platform/mac/dispatch.h");
 36
 37        let bindings = bindgen::Builder::default()
 38            .header("src/platform/mac/dispatch.h")
 39            .allowlist_var("_dispatch_main_q")
 40            .allowlist_var("_dispatch_source_type_data_add")
 41            .allowlist_var("DISPATCH_QUEUE_PRIORITY_HIGH")
 42            .allowlist_var("DISPATCH_TIME_NOW")
 43            .allowlist_function("dispatch_get_global_queue")
 44            .allowlist_function("dispatch_async_f")
 45            .allowlist_function("dispatch_after_f")
 46            .allowlist_function("dispatch_time")
 47            .allowlist_function("dispatch_source_merge_data")
 48            .allowlist_function("dispatch_source_create")
 49            .allowlist_function("dispatch_source_set_event_handler_f")
 50            .allowlist_function("dispatch_resume")
 51            .allowlist_function("dispatch_suspend")
 52            .allowlist_function("dispatch_source_cancel")
 53            .allowlist_function("dispatch_set_context")
 54            .parse_callbacks(Box::new(bindgen::CargoCallbacks))
 55            .layout_tests(false)
 56            .generate()
 57            .expect("unable to generate bindings");
 58
 59        let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
 60        bindings
 61            .write_to_file(out_path.join("dispatch_sys.rs"))
 62            .expect("couldn't write dispatch bindings");
 63    }
 64
 65    fn generate_shader_bindings() -> PathBuf {
 66        let output_path = PathBuf::from(env::var("OUT_DIR").unwrap()).join("scene.h");
 67        let crate_dir = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
 68        let mut config = Config::default();
 69        config.include_guard = Some("SCENE_H".into());
 70        config.language = cbindgen::Language::C;
 71        config.export.include.extend([
 72            "Bounds".into(),
 73            "Corners".into(),
 74            "Edges".into(),
 75            "Size".into(),
 76            "Pixels".into(),
 77            "PointF".into(),
 78            "Hsla".into(),
 79            "ContentMask".into(),
 80            "Uniforms".into(),
 81            "AtlasTile".into(),
 82            "PathRasterizationInputIndex".into(),
 83            "PathVertex_ScaledPixels".into(),
 84            "ShadowInputIndex".into(),
 85            "Shadow".into(),
 86            "QuadInputIndex".into(),
 87            "Underline".into(),
 88            "UnderlineInputIndex".into(),
 89            "Quad".into(),
 90            "SpriteInputIndex".into(),
 91            "MonochromeSprite".into(),
 92            "PolychromeSprite".into(),
 93            "PathSprite".into(),
 94            "SurfaceInputIndex".into(),
 95            "SurfaceBounds".into(),
 96            "TransformationMatrix".into(),
 97        ]);
 98        config.no_includes = true;
 99        config.enumeration.prefix_with_name = true;
100
101        let mut builder = cbindgen::Builder::new();
102
103        let src_paths = [
104            crate_dir.join("src/scene.rs"),
105            crate_dir.join("src/geometry.rs"),
106            crate_dir.join("src/color.rs"),
107            crate_dir.join("src/window.rs"),
108            crate_dir.join("src/platform.rs"),
109            crate_dir.join("src/platform/mac/metal_renderer.rs"),
110        ];
111        for src_path in src_paths {
112            println!("cargo:rerun-if-changed={}", src_path.display());
113            builder = builder.with_src(src_path);
114        }
115
116        builder
117            .with_config(config)
118            .generate()
119            .expect("Unable to generate bindings")
120            .write_to_file(&output_path);
121
122        output_path
123    }
124
125    /// To enable runtime compilation, we need to "stitch" the shaders file with the generated header
126    /// so that it is self-contained.
127    #[cfg(feature = "runtime_shaders")]
128    fn emit_stitched_shaders(header_path: &Path) {
129        use std::str::FromStr;
130        fn stitch_header(header: &Path, shader_path: &Path) -> std::io::Result<PathBuf> {
131            let header_contents = std::fs::read_to_string(header)?;
132            let shader_contents = std::fs::read_to_string(shader_path)?;
133            let stitched_contents = format!("{header_contents}\n{shader_contents}");
134            let out_path =
135                PathBuf::from(env::var("OUT_DIR").unwrap()).join("stitched_shaders.metal");
136            std::fs::write(&out_path, stitched_contents)?;
137            Ok(out_path)
138        }
139        let shader_source_path = "./src/platform/mac/shaders.metal";
140        let shader_path = PathBuf::from_str(shader_source_path).unwrap();
141        stitch_header(header_path, &shader_path).unwrap();
142        println!("cargo:rerun-if-changed={}", &shader_source_path);
143    }
144
145    #[cfg(not(feature = "runtime_shaders"))]
146    fn compile_metal_shaders(header_path: &Path) {
147        use std::process::{self, Command};
148        let shader_path = "./src/platform/mac/shaders.metal";
149        let air_output_path = PathBuf::from(env::var("OUT_DIR").unwrap()).join("shaders.air");
150        let metallib_output_path =
151            PathBuf::from(env::var("OUT_DIR").unwrap()).join("shaders.metallib");
152        println!("cargo:rerun-if-changed={}", shader_path);
153
154        let output = Command::new("xcrun")
155            .args([
156                "-sdk",
157                "macosx",
158                "metal",
159                "-gline-tables-only",
160                "-mmacosx-version-min=10.15.7",
161                "-MO",
162                "-c",
163                shader_path,
164                "-include",
165                &header_path.to_str().unwrap(),
166                "-o",
167            ])
168            .arg(&air_output_path)
169            .output()
170            .unwrap();
171
172        if !output.status.success() {
173            eprintln!(
174                "metal shader compilation failed:\n{}",
175                String::from_utf8_lossy(&output.stderr)
176            );
177            process::exit(1);
178        }
179
180        let output = Command::new("xcrun")
181            .args(["-sdk", "macosx", "metallib"])
182            .arg(air_output_path)
183            .arg("-o")
184            .arg(metallib_output_path)
185            .output()
186            .unwrap();
187
188        if !output.status.success() {
189            eprintln!(
190                "metallib compilation failed:\n{}",
191                String::from_utf8_lossy(&output.stderr)
192            );
193            process::exit(1);
194        }
195    }
196}