@thi.ng/shader-ast-optimize

[!NOTE] This is one of 199 standalone projects, maintained as part of the @thi.ng/umbrella monorepo and anti-framework.

🚀 Please help me to work full-time on these projects by sponsoring me on GitHub. Thank you! ❤️

About
- defOptimized()
- Tree optimizations
  - Constant folding
Status
Installation
Dependencies
Usage examples
API
Authors
License

About

Shader AST code optimization passes/strategies. This is a support package for @thi.ng/shader-ast.

defOptimized()

The function defOptimize() can be used as direct replacement for thi.ng/shader-ast's defMain() to define automatically optimized shader main() functions.

Tree optimizations

Currently, only the following operations are supported/considered:

Constant folding

scalar math operators (incl. some vector versions)
scalar math built-in functions (incl. some vector versions)
scalar comparisons
single component vector swizzling
literal hoisting

(See tests for some more examples, non-exhaustive...)

Note: The static optimizer throws an error if it detects a division-by-zero...

import {
  add, defn, float, mul, neg, ret, scope, vec2, $x, $y
} from "@thi.ng/shader-ast";
import { targetGLSL } from "@thi.ng/shader-ast-glsl";
import { constantFolding } from "@thi.ng/shader-ast-optimize";

// function def
const foo = defn("float", "foo", ["float"], (x) => [
  ret(mul(x, add(neg(float(10)), 42)))
]);

const bar = vec2(100, 200);

// program def
const prog = scope([
  foo,
  foo(add(float(1), float(2))),
  foo(add($x(bar), $y(bar)))
], true);

// GLSL codegen
const glsl = targetGLSL();

// unoptimized AST as GLSL (see section above)
console.log(glsl(prog));
// #version 300 es
// float foo(in float _s0) {
// return (_s0 * ((-10.0) + 42.0));
// }
// foo((1.0 + 2.0));
// foo((vec2(100.0, 200.0).x + vec2(100.0, 200.0).y));

// with constant folding
console.log(glsl(constantFolding(prog)))
// #version 300 es
// float foo(in float _s0) {
// return (_s0 * 32.0);
// }
// foo(3.0);
// foo(300.0);

const expr = mul(float(4), $x(vec2(2)))

console.log(glsl(expr))
// (4.0 * vec2(2.0).x)

// optimize single expression
console.log(glsl(constantFolding(expr)))
// 8.0

Status

STABLE - used in production

Search or submit any issues for this package

Installation

yarn add @thi.ng/shader-ast-optimize

ESM import:

import * as opt from "@thi.ng/shader-ast-optimize";

Browser ESM import:

<script type="module" src="https://esm.run/@thi.ng/shader-ast-optimize"></script>

JSDelivr documentation

For Node.js REPL:

const opt = await import("@thi.ng/shader-ast-optimize");

Package sizes (brotli'd, pre-treeshake): ESM: 1.26 KB

Dependencies

Note: @thi.ng/api is in most cases a type-only import (not used at runtime)

Usage examples

One project in this repo's /examples directory is using this package:

Screenshot	Description	Live demo	Source
	Evolutionary shader generation using genetic programming	Demo	Source

API

Generated API docs

TODO

Authors

Karsten Schmidt

If this project contributes to an academic publication, please cite it as:

@misc{thing-shader-ast-optimize,
  title = "@thi.ng/shader-ast-optimize",
  author = "Karsten Schmidt",
  note = "https://thi.ng/shader-ast-optimize",
  year = 2019
}