Lighting system

common/everything_registry.ts

@@ -98,6 +98,16 @@ interface BlockStateVariant {
 export const RENDER_LAYERS = ["solid", "cutout", "translucent"] as const;
 export type RenderLayer = typeof RENDER_LAYERS[number];
 
+// like minecraft: solid blocks stop light, everything else lets it through unless it says otherwise
+export function block_light_opacity(block: BlockRegistry | undefined): number {
+	if (!block) return 0;
+	return block.light_opacity ?? ((block.render_layer ?? "solid") === "solid" ? 15 : 0);
+}
+
+export function block_light_emission(block: BlockRegistry | undefined): number {
+	return block?.light_emission ?? 0;
+}
+
 export interface BlockRegistry {
 	id: string;
 	textures: string | TextureSideTopBottom | TextureFront;
@@ -105,6 +115,10 @@ export interface BlockRegistry {
 	render_layer?: RenderLayer;
 	// hide faces between two of this block, like glass and water. defaults to true for translucent blocks
 	cull_same?: boolean;
+	// light level 0-15 it gives off
+	light_emission?: number;
+	// how much light going through it loses, 0-15. see block_light_opacity for the default
+	light_opacity?: number;
 	alpha?: number;
 
 	has_collision: boolean;

common/mod_data.ts

@@ -33,6 +33,8 @@ export interface BlockJson {
 	textures: BlockTextures;
 	render_layer?: RenderLayer;
 	cull_same?: boolean;
+	light_emission?: number;
+	light_opacity?: number;
 	// replaced by render_layer, true means translucent
 	transparent?: boolean;
 	alpha?: number;
@@ -89,6 +91,8 @@ export function block_to_json(block: BlockRegistry, has_item: boolean): BlockJso
 	const json: BlockJson = { id: block.id, textures: block.textures };
 	if (block.render_layer && block.render_layer !== "solid") json.render_layer = block.render_layer;
 	if (block.cull_same !== undefined) json.cull_same = block.cull_same;
+	if (block.light_emission !== undefined) json.light_emission = block.light_emission;
+	if (block.light_opacity !== undefined) json.light_opacity = block.light_opacity;
 	if (block.alpha !== undefined) json.alpha = block.alpha;
 	if (!block.has_collision) json.collision = false;
 	if (block.toughness !== undefined) {
@@ -114,6 +118,8 @@ export function block_from_json(json: BlockJson): { block: BlockRegistry; has_it
 	const render_layer = json.render_layer ?? (json.transparent ? "translucent" : undefined);
 	if (render_layer && render_layer !== "solid") block.render_layer = render_layer;
 	if (json.cull_same !== undefined) block.cull_same = json.cull_same;
+	if (json.light_emission !== undefined) block.light_emission = json.light_emission;
+	if (json.light_opacity !== undefined) block.light_opacity = json.light_opacity;
 	if (json.alpha !== undefined) block.alpha = json.alpha;
 	if (json.mining) {
 		block.toughness = json.mining.toughness;
@@ -258,6 +264,12 @@ export function validate_block(json: unknown): Problems {
 	if (json.render_layer !== undefined && !RENDER_LAYERS.includes(json.render_layer as RenderLayer)) {
 		problems.push(`render_layer must be one of ${RENDER_LAYERS.join(", ")}`);
 	}
+	for (const key of ["light_emission", "light_opacity"]) {
+		const value = json[key];
+		if (value !== undefined && (!Number.isInteger(value) || (value as number) < 0 || (value as number) > 15)) {
+			problems.push(`${key} must be a whole number from 0 to 15`);
+		}
+	}
 	for (const key of ["cull_same", "transparent", "collision", "item", "interactive", "replaceable"]) {
 		if (json[key] !== undefined && typeof json[key] !== "boolean") problems.push(`${key} must be true or false`);
 	}