refactor(dsp): restructure oscillators, fft, window, update gen-diagrams

packages/dsp/src/fft.ts → packages/dsp/src/fft/fft.ts

@@ -1,7 +1,7 @@
 import { NumericArray } from "@thi.ng/api";
 import { isNumber } from "@thi.ng/checks";
-import { ComplexArray } from "./api";
-import { magDb } from "./util/convert";
+import { ComplexArray } from "../api";
+import { magDb } from "../util/convert";
 
 const PI = Math.PI;
 

packages/dsp/src/index.ts

@@ -1,5 +1,4 @@
 export * from "./api";
-export * from "./fft";
 
 export * from "./comp/addg";
 export * from "./comp/compp";
@@ -31,7 +30,7 @@ export * from "./gen/white-noise";
 export * from "./proc/allpass";
 export * from "./proc/aproc";
 export * from "./proc/biquad";
-export * from "./proc/dcblocker";
+export * from "./proc/dcblock";
 export * from "./proc/delay";
 export * from "./proc/feedback-delay";
 export * from "./proc/foldback";
@@ -41,17 +40,19 @@ export * from "./proc/onepole";
 export * from "./proc/svf";
 export * from "./proc/waveshaper";
 
-export * from "./stateless/additive";
-export * from "./stateless/dsf";
-export * from "./stateless/mix";
-export * from "./stateless/parabolic";
-export * from "./stateless/rect";
-export * from "./stateless/saw";
-export * from "./stateless/sin";
-export * from "./stateless/tri";
-export * from "./stateless/wavetable";
+export * from "./osc/additive";
+export * from "./osc/dsf";
+export * from "./osc/mix";
+export * from "./osc/parabolic";
+export * from "./osc/rect";
+export * from "./osc/saw";
+export * from "./osc/sin";
+export * from "./osc/tri";
+export * from "./osc/wavetable";
+
+export * from "./fft/fft";
+export * from "./fft/window";
 
 export * from "./util/anti-alias";
 export * from "./util/convert";
 export * from "./util/filter-response";
-export * from "./util/window";

packages/dsp/src/proc/dcblocker.ts → packages/dsp/src/proc/dcblock.ts

@@ -6,9 +6,9 @@ import { OnePole } from "./onepole";
  *
  * @param freq
  */
-export const dcblocker = (freq: number) => new DCBlocker(FilterType.LP, freq);
+export const dcBlock = (freq: number) => new DCBlock(FilterType.LP, freq);
 
-export class DCBlocker extends OnePole {
+export class DCBlock extends OnePole {
     next(x: number) {
         return x - super.next(x);
     }

packages/dsp/src/proc/foldback.ts

@@ -5,6 +5,10 @@ import { AProc } from "./aproc";
  * Recursively folds input into `[-thresh .. +thresh]` interval and
  * amplifies it with `amp` (default: 1/thresh).
  *
+ * @remarks
+ * Reference:
+ * - https://www.desmos.com/calculator/lkyf2ag3ta
+ *
  * @param thresh - fold threshold
  * @param amp - post amplifier
  */

packages/dsp/src/proc/svf.ts

@@ -27,14 +27,13 @@ export const svfAllpass = (fc: number, q?: number) =>
     new SVF(FilterType.ALL, fc, q);
 
 /**
- * State variable filter w/ trapezoidal integration, after Andrew
- * Simper.
+ * Multi-type state variable filter w/ trapezoidal integration, after
+ * Andrew Simper.
  *
  * Reference:
  *
  * - https://cytomic.com/files/dsp/SvfLinearTrapOptimised2.pdf
  * - https://en.wikipedia.org/wiki/Trapezoidal_rule
- *
  */
 export class SVF extends AProc<number, number> implements IReset {
     protected _a1!: number;
@@ -47,7 +46,7 @@ export class SVF extends AProc<number, number> implements IReset {
     constructor(
         protected _type: SVFType,
         protected _freq: number,
-        protected _q = 0
+        protected _q = 0.5
     ) {
         super(0);
         this.reset();

packages/dsp/tools/generate-diagrams.ts

@@ -26,7 +26,6 @@ import {
 import { writeFileSync } from "fs";
 import {
     allpass,
-    AllPass1,
     biquadBP,
     biquadHiShelf,
     biquadHP,
@@ -35,9 +34,10 @@ import {
     biquadNotch,
     biquadPeak,
     curve,
-    dcblocker,
+    dcBlock,
     dsfHOF,
     filterResponse,
+    foldback,
     freqMs,
     freqRange,
     IGen,
@@ -55,9 +55,12 @@ import {
     saw,
     sin,
     StatelessOscillator,
+    svfAllpass,
     svfBP,
     svfHP,
     svfLP,
+    svfNotch,
+    svfPeak,
     tri,
     wavetable,
     whiteNoise
@@ -76,7 +79,7 @@ const OSC: IObjectOf<StatelessOscillator> = {
     tri,
     parabolic,
     recttri: mixOscHOF(rect, tri),
-    dsf: dsfHOF(0.4, 3),
+    dsf: dsfHOF(0.6, 2.04),
     wt: wavetable(curve(1, -1, 127).take(128))
 };
 
@@ -245,9 +248,15 @@ withFilters((id) => `${id}-svf-hpf.svg`, svfHP);
 
 withFilters((id) => `${id}-svf-bpf.svg`, svfBP);
 
+withFilters((id) => `${id}-svf-notch.svg`, svfNotch);
+
+withFilters((id) => `${id}-svf-peak.svg`, svfPeak);
+
+withFilters((id) => `${id}-svf-all.svg`, svfAllpass);
+
 withFilters((id) => `${id}-1pole-lpf.svg`, onepoleLP);
 
-withFilters((id) => `${id}-dcblock.svg`, dcblocker);
+withFilters((id) => `${id}-dcblock.svg`, dcBlock);
 
 withFilters((id) => `${id}-bq-lpf.svg`, biquadLP);
 
@@ -263,6 +272,14 @@ withFilters((id) => `${id}-bq-lsh.svg`, biquadLoShelf);
 
 withFilters((id) => `${id}-bq-hsh.svg`, biquadHiShelf);
 
+withFilters(
+    (id) => `${id}-foldback.svg`,
+    (t) => foldback(t),
+    undefined,
+    [0.5, 0.3, 0.15],
+    ["orig", ...[0.5, 0.3, 0.15].map((t) => `t=${t}`)]
+);
+
 withFilters(
     (id) => `${id}-allpass1.svg`,
     (f) => allpass(f)
@@ -289,8 +306,8 @@ withFilters(
 withFilters(
     (id) => `${id}-allpass-high.svg`,
     (f) => {
-        let flt = new AllPass1(f);
-        return <any>{
+        let flt = allpass(f);
+        return <IGen<number>>{
             next(x: number) {
                 return flt.high(x);
             }