export const TILE_PX = 256;
export const WORLD_HALF = 16384;      // gtadb-Weltgrenze in Metern
export const CHUNK_SIZE = 250;
export const SLICE = { x0: -1000, x1: 2000, y0: -500, y1: 2500 };
export const CHUNKS_PER_SIDE = (SLICE.x1 - SLICE.x0) / CHUNK_SIZE;   // 12

export const worldToThree = (X, Y) => ({ x: X, z: -Y });
export const threeToWorld = (x, z) => ({ X: x, Y: -z });

export function tileForWorld(X, Y) {
    return {
        row: Math.floor((WORLD_HALF - Y) / TILE_PX),
        col: Math.floor((X + WORLD_HALF) / TILE_PX),
    };
}

export function chunkForWorld(X, Y) {
    return {
        i: Math.floor((X - SLICE.x0) / CHUNK_SIZE),
        j: Math.floor((SLICE.y1 - Y) / CHUNK_SIZE),
    };
}

/** Nordwest-Ecke eines Chunks in Weltkoordinaten. */
export function chunkOrigin(i, j) {
    return { X: SLICE.x0 + i * CHUNK_SIZE, Y: SLICE.y1 - j * CHUNK_SIZE };
}