@thi.ng/shader-ast-stdlib/math/osc.js

Function collection for modular GPGPU / shader programming with @thi.ng/shader-ast

import {
  float,
  FLOAT0,
  FLOAT05,
  FLOAT1,
  FLOAT2,
  TAU
} from "@thi.ng/shader-ast/ast/lit";
import { madd, mul, sub } from "@thi.ng/shader-ast/ast/ops";
import { abs, fract, sin, step } from "@thi.ng/shader-ast/builtin/math";
const __defOsc = (fn) => (phase, freq, amp = FLOAT1, dc = FLOAT0) => madd(fn(mul(float(phase), float(freq))), amp, dc);
const sinOsc = __defOsc((phase) => sin(mul(phase, TAU)));
const sawOsc = __defOsc(
  (phase) => sub(FLOAT1, mul(fract(phase), FLOAT2))
);
const triOsc = __defOsc(
  (phase) => sub(abs(madd(fract(phase), 4, float(-2))), FLOAT1)
);
const rectOsc = (phase, freq, amp = FLOAT1, dc = FLOAT0, duty = FLOAT05) => madd(
  madd(
    step(float(duty), fract(mul(float(phase), float(freq)))),
    FLOAT2,
    float(-1)
  ),
  amp,
  dc
);
export {
  rectOsc,
  sawOsc,
  sinOsc,
  triOsc
};