Refactor fader value conversion and default handling for Ableton export

src/lib/exporters/ableton/automation.ts

@@ -1,11 +1,17 @@
 import { FaderParam } from '../../../types/types';
 import { AblGroupPatternOccurrence, AblTrack } from '../../transformers/ableton';
+import {
+  convertGroupFaderValue,
+  getFaderDefaultValue,
+  getFaderPolicy,
+} from './faderPolicies';
 
 export type AbletonAutomationTarget = {
   arrangement?: number;
   session?: number;
   staticValue?: number;
   valueOffset?: number;
+  padTrack?: AblTrack;
 };
 
 export type AbletonAutomationTargets = Partial<Record<FaderParam, AbletonAutomationTarget[]>>;
@@ -18,21 +24,6 @@ type AutomationPoint = {
 const SENTINEL_TIME = -63072000;
 const BOUNDARY_EPSILON = 0.000001;
 
-function defaultValue(parameter: FaderParam) {
-  switch (parameter) {
-    case FaderParam.LVL:
-    case FaderParam.LPF:
-      return 1;
-    case FaderParam.PTC:
-    case FaderParam.TIM:
-    case FaderParam.PAN:
-    case FaderParam.TUNE:
-      return 0.5;
-    default:
-      return 0;
-  }
-}
-
 export function convertFaderValue(
   parameter: FaderParam,
   value: number,
@@ -40,42 +31,11 @@ export function convertFaderValue(
   groupMixer: boolean,
   target?: AbletonAutomationTarget,
 ) {
-  let convertedValue: number;
-  switch (parameter) {
-    case FaderParam.LVL:
-      if (groupMixer) {
-        convertedValue = value;
-      } else {
-        convertedValue = track.volume * value;
-      }
-      break;
-    case FaderParam.PTC:
-      convertedValue = (target?.valueOffset ?? 0) + (value - 0.5) * 10;
-      break;
-    case FaderParam.LPF:
-      convertedValue = 20 + value * 0.9 * 115;
-      break;
-    case FaderParam.HPF:
-      convertedValue = 20 + value * 0.7 * 115;
-      break;
-    case FaderParam.FX:
-      convertedValue = value;
-      break;
-    case FaderParam.PAN:
-      convertedValue = (value - 0.5) * 2;
-      break;
-    case FaderParam.TUNE:
-      convertedValue = Math.max(-0.5, Math.min(0.5, value - 0.5)) * 100;
-      break;
-    case FaderParam.MOD:
-      convertedValue = value / 20;
-      break;
-    default:
-      convertedValue = value;
-      break;
-  }
-
-  return convertedValue;
+  return convertGroupFaderValue(parameter, value, {
+    track: target?.padTrack ?? track,
+    groupMixer,
+    valueOffset: target?.valueOffset,
+  });
 }
 
 export function getFaderValueAt(
@@ -98,7 +58,7 @@ export function getFaderValueAt(
 
 function getStaticValue(pattern: AblGroupPatternOccurrence, parameter: FaderParam) {
   const value = pattern.faderParams[parameter];
-  return value === -1 ? defaultValue(parameter) : value;
+  return value === -1 ? getFaderDefaultValue(parameter) : value;
 }
 
 function getConvertedStaticValue(
@@ -141,7 +101,13 @@ function getArrangementPoints(
   const points: AutomationPoint[] = [];
   let previousValue = orderedPatterns[0]
     ? getConvertedStaticValue(orderedPatterns[0], parameter, track, groupMixer, target)
-    : convertFaderValue(parameter, defaultValue(parameter), track, groupMixer, target);
+    : convertFaderValue(
+        parameter,
+        getFaderDefaultValue(parameter),
+        track,
+        groupMixer,
+        target,
+      );
 
   orderedPatterns.forEach((pattern) => {
     const patternTicks = Math.max(1, pattern.loopDuration * 96);
@@ -193,6 +159,10 @@ function getClipPoints(
     .filter((point) => point.parameter === parameter)
     .sort((a, b) => a.position - b.position);
 
+  if (sourcePoints.length === 0) {
+    return [];
+  }
+
   const staticValue = getConvertedStaticValue(pattern, parameter, track, groupMixer, target);
   return [
     { time: SENTINEL_TIME, value: staticValue },
@@ -231,7 +201,7 @@ export function buildArrangementEnvelopes(
   const envelopes: any[] = [];
   Object.entries(targets).forEach(([parameterString, targetList]) => {
     const parameter = Number(parameterString) as FaderParam;
-    if (parameter === FaderParam.TIM || parameter === FaderParam.VEL) {
+    if (getFaderPolicy(parameter).renderStrategy !== 'target') {
       return;
     }
     targetList?.forEach((target) => {
@@ -265,7 +235,7 @@ export function buildClipEnvelopes(
   const envelopes: any[] = [];
   Object.entries(targets).forEach(([parameterString, targetList]) => {
     const parameter = Number(parameterString) as FaderParam;
-    if (parameter === FaderParam.TIM || parameter === FaderParam.VEL) {
+    if (getFaderPolicy(parameter).renderStrategy !== 'target') {
       return;
     }
     targetList?.forEach((target) => {