2 files changed, 90 insertions, 0 deletions
diff --git a/apps/web/src/params/index.ts b/apps/web/src/params/index.ts
new file mode 100644
index 00000000..633bfbd0
--- /dev/null
+++ b/apps/web/src/params/index.ts
@@ -0,0 +1,50 @@
+export type ParamValues = Record<string, number | string | boolean>;
+
+export type ParamGroup = "stroke";
+
+interface BaseParamDefinition<TKey extends string = string> {
+	key: TKey;
+	label: string;
+	group?: ParamGroup;
+}
+
+export interface NumberParamDefinition<TKey extends string = string>
+	extends BaseParamDefinition<TKey> {
+	type: "number";
+	default: number;
+	min: number;
+	max?: number;
+	step: number;
+	/** When set, min/max/step are in display space. display = stored * displayMultiplier. */
+	displayMultiplier?: number;
+	/** Show as percentage of max. min/max/step/default stay in stored space. */
+	unit?: "percent";
+	/** Short label shown as the scrub handle icon in the number field (e.g. "W", "R"). */
+	shortLabel?: string;
+}
+
+export interface BooleanParamDefinition<TKey extends string = string>
+	extends BaseParamDefinition<TKey> {
+	type: "boolean";
+	default: boolean;
+}
+
+export interface ColorParamDefinition<TKey extends string = string>
+	extends BaseParamDefinition<TKey> {
+	type: "color";
+	default: string;
+}
+
+export interface SelectParamDefinition<TKey extends string = string>
+	extends BaseParamDefinition<TKey> {
+	type: "select";
+	default: string;
+	options: Array<{ value: string; label: string }>;
+}
+
+export type ParamDefinition<TKey extends string = string> =
+	| NumberParamDefinition<TKey>
+	| BooleanParamDefinition<TKey>
+	| ColorParamDefinition<TKey>
+	| SelectParamDefinition<TKey>;
+
diff --git a/apps/web/src/params/registry.ts b/apps/web/src/params/registry.ts
new file mode 100644
index 00000000..d9fcc266
--- /dev/null
+++ b/apps/web/src/params/registry.ts
@@ -0,0 +1,40 @@
+import type { ParamDefinition, ParamValues } from "@/params";
+
+export function buildDefaultParamValues(
+	params: ParamDefinition[],
+): ParamValues {
+	const values: ParamValues = {};
+	for (const param of params) {
+		values[param.key] = param.default;
+	}
+	return values;
+}
+
+export class DefinitionRegistry<TKey extends string, TDefinition> {
+	private definitions = new Map<TKey, TDefinition>();
+	private entityName: string;
+
+	constructor(entityName: string) {
+		this.entityName = entityName;
+	}
+
+	register(key: TKey, definition: TDefinition): void {
+		this.definitions.set(key, definition);
+	}
+
+	has(key: TKey): boolean {
+		return this.definitions.has(key);
+	}
+
+	get(key: TKey): TDefinition {
+		const def = this.definitions.get(key);
+		if (!def) {
+			throw new Error(`Unknown ${this.entityName}: ${key}`);
+		}
+		return def;
+	}
+
+	getAll(): TDefinition[] {
+		return Array.from(this.definitions.values());
+	}
+}