fix: broken log scaling

Author: eye-wave

package.json

@@ -1,7 +1,7 @@
 {
 	"name": "svelte-knobs",
 	"description": "Svelte component library for building customizable knob controls.",
-	"version": "0.1.0",
+	"version": "0.1.1",
 	"repository": {
 		"url": "https://github.com/eye-wave/svelte-knobs"
 	},

src/lib/params/float-param.ts

@@ -45,10 +45,8 @@ export function unnormalize(value: number, param: FloatParam): number {
 	}
 }
 
-function log(value: number, base = 10): number {
-	if (value === 0) return 0;
-
-	const x = value < 0 ? -value : value;
+export function log(value: number, base = 10): number {
+	const x = Math.abs(value) + 1;
 	const sign = Math.sign(value);
 
 	if (base === 10) return sign * Math.log10(x);
@@ -58,8 +56,13 @@ function log(value: number, base = 10): number {
 	return sign * (Math.log(x) / Math.log(base));
 }
 
-function exp(value: number, base = 10): number {
-	const x = value < 0 ? -value : value;
+export function exp(value: number, base = 10): number {
+	const sign = Math.sign(value);
+	const expValue = Math.abs(value);
+
+	if (base === 10) return sign * (Math.pow(10, expValue) - 1);
+	if (base === 2) return sign * (Math.pow(2, expValue) - 1);
+	if (base === Math.E) return sign * (Math.exp(expValue) - 1);
 
-	return Math.pow(base, x) * Math.sign(value);
+	return sign * (Math.pow(base, expValue) - 1);
 }

src/routes/+page.svelte

@@ -12,6 +12,7 @@
 	const basicParam = createFloatParam(createRange('lin', 0, 100));
 	const freqParam = createFloatParam(createRange('log', 20, 20_000));
 	const gainParam = createFloatParam(createRange('log', -30, 30, Math.E));
+	const qParam = createFloatParam(createRange('log', 0.01, 30, 2));
 	const smoothParam = createFloatParam(createRange('lin', 0, 100));
 	const snapParam = createFloatParam(createRange('lin', 0, 2000));
 	const enumParam = createEnumParam(['🍍', '🍉', '🍌', '🍎', '🥭', '🍇', '🥝', '🍋'] as const);
@@ -23,6 +24,7 @@
 	let basicValue = 0;
 	let freqValue = 20;
 	let gainValue = 20;
+	let qValue = 0;
 	let smoothValue = 0;
 	let snapValue = 0;
 	let enumValue: Variant<typeof enumParam> = '🍎';
@@ -44,6 +46,7 @@
 		<h2>Logarithmic</h2>
 		<Knob param={freqParam} bind:value={freqValue} label="Frequency" unit="hz" />
 		<Knob param={gainParam} bind:value={gainValue} label="Gain" unit="dB" />
+		<Knob param={qParam} bind:value={qValue} label="Q" unit="dB" decimalDigits={2} />
 
 		<p>A knob with logarithmic scaling (default base is 10).</p>
 	</div>