Simple transparency

common/everything_registry.ts

@@ -53,6 +53,7 @@ export class EverythingRegistry {
 export interface TileRegistry<T = unknown | undefined> {
 	texture_id: string | ((tile: Block<T>) => string);
 	has_collision: boolean;
+	transparent?: boolean;
 
 	on_create?(world: ClientWorld, tile: Block<T>): void;
 	on_click?(world: ClientWorld, tile: Block<T>): void;

common/utils.ts

@@ -36,3 +36,10 @@ export function distance_point_rectangle(px: number, py: number, sqx: number, sq
 
 	return Math.sqrt(dx * dx + dy * dy);
 }
+
+export function distance_point_point(ax: number, ay: number, az: number, bx: number, by: number, bz: number) {
+	const dx = ax - bx;
+	const dy = ay - by;
+	const dz = az - bz;
+	return dx * dx + dy * dy + dz * dz;
+}