diff options
Diffstat (limited to 'gfx/wr/webrender/build.rs')
| -rw-r--r-- | gfx/wr/webrender/build.rs | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/gfx/wr/webrender/build.rs b/gfx/wr/webrender/build.rs new file mode 100644 index 0000000000..783f8cd5ca --- /dev/null +++ b/gfx/wr/webrender/build.rs @@ -0,0 +1,352 @@ +/* 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 std::collections::hash_map::DefaultHasher; +use std::hash::Hasher; +use webrender_build::shader::*; +use webrender_build::shader_features::{ShaderFeatureFlags, get_shader_features}; + +// glsopt is known to leak, but we don't particularly care. +#[no_mangle] +pub extern "C" fn __lsan_default_options() -> *const u8 { + b"detect_leaks=0\0".as_ptr() +} + +/// 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. +fn escape_include_path(path: &Path) -> String { + let full_path = canonicalize(path).unwrap(); + let full_name = full_path.as_os_str().to_str().unwrap(); + let full_name = full_name.replace("\\\\?\\", ""); + let full_name = full_name.replace("\\", "/"); + + full_name +} + +fn write_unoptimized_shaders( + mut glsl_files: Vec<PathBuf>, + shader_file: &mut File, +) -> Result<(), std::io::Error> { + writeln!( + shader_file, + " pub static ref UNOPTIMIZED_SHADERS: HashMap<&'static str, SourceWithDigest> = {{" + )?; + writeln!(shader_file, " let mut shaders = HashMap::new();")?; + + // 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())); + + 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 = DefaultHasher::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.write(s.as_bytes()), + ); + let digest: ProgramSourceDigest = hasher.into(); + + writeln!( + shader_file, + " shaders.insert(\"{}\", SourceWithDigest {{ source: include_str!(\"{}\"), digest: \"{}\"}});", + shader_name, + escape_include_path(&glsl), + digest, + )?; + } + writeln!(shader_file, " shaders")?; + writeln!(shader_file, " }};")?; + + Ok(()) +} + +#[derive(Clone, Debug)] +struct ShaderOptimizationInput { + shader_name: &'static str, + config: String, + gl_version: ShaderVersion, +} + +#[derive(Debug)] +struct ShaderOptimizationOutput { + full_shader_name: String, + gl_version: ShaderVersion, + vert_file_path: PathBuf, + frag_file_path: PathBuf, + digest: ProgramSourceDigest, +} + +#[derive(Debug)] +struct ShaderOptimizationError { + shader: ShaderOptimizationInput, + message: String, +} + +/// Prepends the line number to each line of a shader source. +fn enumerate_shader_source_lines(shader_src: &str) -> String { + // For some reason the glsl-opt errors are offset by 1 compared + // to the provided shader source string. + let mut out = format!("0\t|"); + for (n, line) in shader_src.split('\n').enumerate() { + let line_number = n + 1; + out.push_str(&format!("{}\t|{}\n", line_number, line)); + } + out +} + +fn write_optimized_shaders( + shader_dir: &Path, + shader_file: &mut File, + out_dir: &str, +) -> Result<(), std::io::Error> { + writeln!( + shader_file, + " pub static ref OPTIMIZED_SHADERS: HashMap<(ShaderVersion, &'static str), OptimizedSourceWithDigest> = {{" + )?; + writeln!(shader_file, " let mut shaders = HashMap::new();")?; + + // The full set of optimized shaders can be quite large, so only optimize + // for the GL version we expect to be used on the target platform. If a different GL + // version is used we will simply fall back to the unoptimized shaders. + let shader_versions = match env::var("CARGO_CFG_TARGET_OS").as_ref().map(|s| &**s) { + Ok("android") | Ok("windows") => [ShaderVersion::Gles], + _ => [ShaderVersion::Gl], + }; + + let mut shaders = Vec::default(); + for &gl_version in &shader_versions { + let mut flags = ShaderFeatureFlags::all(); + if gl_version != ShaderVersion::Gl { + flags.remove(ShaderFeatureFlags::GL); + } + if gl_version != ShaderVersion::Gles { + flags.remove(ShaderFeatureFlags::GLES); + flags.remove(ShaderFeatureFlags::TEXTURE_EXTERNAL); + } + if !matches!( + env::var("CARGO_CFG_TARGET_OS").as_ref().map(|s| &**s), + Ok("android") + ) { + flags.remove(ShaderFeatureFlags::TEXTURE_EXTERNAL_ESSL1); + } + flags.remove(ShaderFeatureFlags::DITHERING); + + for (shader_name, configs) in get_shader_features(flags) { + for config in configs { + shaders.push(ShaderOptimizationInput { + shader_name, + config, + gl_version, + }); + } + } + } + + let outputs = build_parallel::compile_objects::<_, _, ShaderOptimizationError, _>( + &|shader: &ShaderOptimizationInput| { + println!("Optimizing shader {:?}", shader); + let target = match shader.gl_version { + ShaderVersion::Gl => glslopt::Target::OpenGl, + ShaderVersion::Gles => glslopt::Target::OpenGles30, + }; + let glslopt_ctx = glslopt::Context::new(target); + + let features = shader + .config + .split(",") + .filter(|f| !f.is_empty()) + .collect::<Vec<_>>(); + + let (vert_src, frag_src) = + build_shader_strings(shader.gl_version, &features, shader.shader_name, &|f| { + Cow::Owned(shader_source_from_file( + &shader_dir.join(&format!("{}.glsl", f)), + )) + }); + + let full_shader_name = if shader.config.is_empty() { + shader.shader_name.to_string() + } else { + format!("{}_{}", shader.shader_name, shader.config.replace(",", "_")) + }; + + // Compute a digest of the optimized shader sources. 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 = DefaultHasher::new(); + + let [vert_file_path, frag_file_path] = [ + (glslopt::ShaderType::Vertex, vert_src, "vert"), + (glslopt::ShaderType::Fragment, frag_src, "frag"), + ] + .map(|(shader_type, shader_src, extension)| { + let output = glslopt_ctx.optimize(shader_type, shader_src.clone()); + if !output.get_status() { + let source = enumerate_shader_source_lines(&shader_src); + return Err(ShaderOptimizationError { + shader: shader.clone(), + message: format!("{}\n{}", source, output.get_log()), + }); + } + + let shader_path = Path::new(out_dir).join(format!( + "{}_{:?}.{}", + full_shader_name, shader.gl_version, extension + )); + write_optimized_shader_file( + &shader_path, + output.get_output().unwrap(), + &shader.shader_name, + &features, + &mut hasher, + ); + Ok(shader_path) + }); + + let vert_file_path = vert_file_path?; + let frag_file_path = frag_file_path?; + + println!("Finished optimizing shader {:?}", shader); + + Ok(ShaderOptimizationOutput { + full_shader_name, + gl_version: shader.gl_version, + vert_file_path, + frag_file_path, + digest: hasher.into(), + }) + }, + &shaders, + ); + + match outputs { + Ok(mut outputs) => { + // Sort the shader list so that the shaders.rs file is filled + // deterministically. + outputs.sort_by(|a, b| { + (a.gl_version, a.full_shader_name.clone()) + .cmp(&(b.gl_version, b.full_shader_name.clone())) + }); + + for shader in outputs { + writeln!( + shader_file, + " shaders.insert(({}, \"{}\"), OptimizedSourceWithDigest {{", + shader.gl_version.variant_name(), + shader.full_shader_name, + )?; + writeln!( + shader_file, + " vert_source: include_str!(\"{}\"),", + escape_include_path(&shader.vert_file_path), + )?; + writeln!( + shader_file, + " frag_source: include_str!(\"{}\"),", + escape_include_path(&shader.frag_file_path), + )?; + writeln!(shader_file, " digest: \"{}\",", shader.digest)?; + writeln!(shader_file, " }});")?; + } + } + Err(err) => match err { + build_parallel::Error::BuildError(err) => { + panic!("Error optimizing shader {:?}: {}", err.shader, err.message) + } + _ => panic!("Error optimizing shaders."), + }, + } + + writeln!(shader_file, " shaders")?; + writeln!(shader_file, " }};")?; + + Ok(()) +} + +fn write_optimized_shader_file( + path: &Path, + source: &str, + shader_name: &str, + features: &[&str], + hasher: &mut DefaultHasher, +) { + let mut file = File::create(&path).unwrap(); + for (line_number, line) in source.lines().enumerate() { + // We embed the shader name and features as a comment in the + // source to make debugging easier. + // The #version directive must be on the first line so we insert + // the extra information on the next line. + if line_number == 1 { + let prelude = format!("// {}\n// features: {:?}\n\n", shader_name, features); + file.write_all(prelude.as_bytes()).unwrap(); + hasher.write(prelude.as_bytes()); + } + file.write_all(line.as_bytes()).unwrap(); + file.write_all("\n".as_bytes()).unwrap(); + hasher.write(line.as_bytes()); + hasher.write("\n".as_bytes()); + } +} + +fn main() -> Result<(), std::io::Error> { + let out_dir = env::var("OUT_DIR").unwrap_or("out".to_owned()); + + let shaders_file_path = 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)? { + let entry = entry?; + 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()); + } + } + + let mut shader_file = File::create(shaders_file_path)?; + + writeln!(shader_file, "/// AUTO GENERATED BY build.rs\n")?; + writeln!(shader_file, "use std::collections::HashMap;\n")?; + writeln!(shader_file, "use webrender_build::shader::ShaderVersion;\n")?; + writeln!(shader_file, "pub struct SourceWithDigest {{")?; + writeln!(shader_file, " pub source: &'static str,")?; + writeln!(shader_file, " pub digest: &'static str,")?; + writeln!(shader_file, "}}\n")?; + writeln!(shader_file, "pub struct OptimizedSourceWithDigest {{")?; + writeln!(shader_file, " pub vert_source: &'static str,")?; + writeln!(shader_file, " pub frag_source: &'static str,")?; + writeln!(shader_file, " pub digest: &'static str,")?; + writeln!(shader_file, "}}\n")?; + writeln!(shader_file, "lazy_static! {{")?; + + write_unoptimized_shaders(glsl_files, &mut shader_file)?; + writeln!(shader_file, "")?; + write_optimized_shaders(&res_dir, &mut shader_file, &out_dir)?; + writeln!(shader_file, "}}")?; + + Ok(()) +} |