gecko-dev/gfx/wr/webrender/build.rs

93 строки
3.5 KiB
Rust

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
extern crate webrender_build;
use std::borrow::Cow;
use std::env;
use std::fs::{canonicalize, read_dir, File};
use std::io::prelude::*;
use std::path::{Path, PathBuf};
use webrender_build::shader::*;
fn write_shaders(glsl_files: Vec<PathBuf>, shader_file_path: &Path) {
let mut shader_file = File::create(shader_file_path).unwrap();
write!(shader_file, "/// AUTO GENERATED BY build.rs\n\n").unwrap();
write!(shader_file, "use std::collections::HashMap;\n\n").unwrap();
write!(shader_file, "pub struct SourceWithDigest {{ pub source: &'static str, pub digest: &'static str }}\n\n")
.unwrap();
write!(shader_file, "lazy_static! {{\n").unwrap();
write!(
shader_file,
" pub static ref SHADERS: HashMap<&'static str, SourceWithDigest> = {{\n"
).unwrap();
write!(shader_file, " let mut h = HashMap::new();\n").unwrap();
for glsl in glsl_files {
// Compute the shader name.
assert!(glsl.is_file());
let shader_name = glsl.file_name().unwrap().to_str().unwrap();
let shader_name = shader_name.replace(".glsl", "");
// Compute a digest of the #include-expanded shader source. We store
// this as a literal alongside the source string so that we don't need
// to hash large strings at runtime.
let mut hasher = Sha256::new();
let base = glsl.parent().unwrap();
assert!(base.is_dir());
ShaderSourceParser::new().parse(
Cow::Owned(shader_source_from_file(&glsl)),
&|f| Cow::Owned(shader_source_from_file(&base.join(&format!("{}.glsl", f)))),
&mut |s| hasher.input(s.as_bytes()),
);
let digest: ProgramSourceDigest = hasher.into();
// Compute the shader path for insertion into the include_str!() macro.
// This makes for more compact generated code than inserting the literal
// shader source into the generated file.
//
// If someone is building on a network share, I'm sorry.
let full_path = canonicalize(&glsl).unwrap();
let full_name = full_path.as_os_str().to_str().unwrap();
let full_name = full_name.replace("\\\\?\\", "");
let full_name = full_name.replace("\\", "/");
write!(
shader_file,
" h.insert(\"{}\", SourceWithDigest {{ source: include_str!(\"{}\"), digest: \"{}\"}});\n",
shader_name,
full_name,
digest,
).unwrap();
}
write!(shader_file, " h\n").unwrap();
write!(shader_file, " }};\n").unwrap();
write!(shader_file, "}}\n").unwrap();
}
fn main() {
let out_dir = env::var("OUT_DIR").unwrap_or("out".to_owned());
let shaders_file = Path::new(&out_dir).join("shaders.rs");
let mut glsl_files = vec![];
println!("cargo:rerun-if-changed=res");
let res_dir = Path::new("res");
for entry in read_dir(res_dir).unwrap() {
let entry = entry.unwrap();
let path = entry.path();
if entry.file_name().to_str().unwrap().ends_with(".glsl") {
println!("cargo:rerun-if-changed={}", path.display());
glsl_files.push(path.to_owned());
}
}
// Sort the file list so that the shaders.rs file is filled
// deterministically.
glsl_files.sort_by(|a, b| a.file_name().cmp(&b.file_name()));
write_shaders(glsl_files, &shaders_file);
}