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

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

const bar = vec2(100, 200);

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

const glsl = targetGLSL();

// unoptimized AST as GLSL (see section above)
glsl(prog);

// float foo(in float _sym0) {
//   return (_sym0 * (-10.0 + 42.0));
// };
// foo((1.0 + 2.0));
// foo((vec2(100.0, 200.0).x + vec2(100.0, 200.0).y));

// same tree after constant folding optimizations
glsl(constantFolding(prog))

// float foo(in float _sym0) {
//   return (_sym0 * 32.0);
// };
// foo(3.0);
// foo(300.0);

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

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

glsl(constantFolding(expr))
// 8.0