Tom Boullay
65 lines
1.7 KiB
TypeScript
65 lines
1.7 KiB
TypeScript
import { useMemo } from "react";
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import { useGLTF } from "@react-three/drei";
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import * as THREE from "three";
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import type { Vector3Tuple } from "@/types/three/three";
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const TERRAIN_MODEL_PATH = "/models/terrain/model.gltf";
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const RAYCAST_Y = 500;
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const RAYCAST_FAR = 1000;
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const DOWN = new THREE.Vector3(0, -1, 0);
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interface TerrainHeightSampler {
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getHeight: (x: number, z: number) => number | null;
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}
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function createTerrainHeightSampler(
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scene: THREE.Object3D,
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): TerrainHeightSampler {
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const meshes: THREE.Mesh[] = [];
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const raycaster = new THREE.Raycaster(
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new THREE.Vector3(),
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DOWN,
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0,
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RAYCAST_FAR,
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);
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scene.updateMatrixWorld(true);
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scene.traverse((child) => {
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if (child instanceof THREE.Mesh) {
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meshes.push(child);
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}
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});
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return {
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getHeight: (x, z) => {
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raycaster.set(new THREE.Vector3(x, RAYCAST_Y, z), DOWN);
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const hit = raycaster.intersectObjects(meshes, false)[0];
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return hit?.point.y ?? null;
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},
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};
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}
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export function useTerrainHeightSampler(): TerrainHeightSampler {
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const { scene } = useGLTF(TERRAIN_MODEL_PATH);
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return useMemo(() => createTerrainHeightSampler(scene), [scene]);
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}
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export function useTerrainSnappedPosition(
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position: Vector3Tuple,
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): Vector3Tuple {
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const terrainHeight = useTerrainHeightSampler();
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return useMemo(() => {
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const [x, y, z] = position;
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const height = terrainHeight.getHeight(x, z);
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return [x, height ?? y, z];
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}, [position, terrainHeight]);
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}
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export function normalizeMapScale(scale: Vector3Tuple): Vector3Tuple {
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const [x, y, z] = scale;
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const isUniform = Math.abs(x - y) < 0.001 && Math.abs(x - z) < 0.001;
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return isUniform ? scale : [x, x, x];
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}
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