three
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JavaScript 3D library
241 lines (150 loc) • 4.62 kB
JavaScript
import CANNON from "../libs/cannon.module.min.js";
function compose( position, quaternion, array, index ) {
var x = quaternion.x, y = quaternion.y, z = quaternion.z, w = quaternion.w;
var x2 = x + x, y2 = y + y, z2 = z + z;
var xx = x * x2, xy = x * y2, xz = x * z2;
var yy = y * y2, yz = y * z2, zz = z * z2;
var wx = w * x2, wy = w * y2, wz = w * z2;
array[ index + 0 ] = ( 1 - ( yy + zz ) );
array[ index + 1 ] = ( xy + wz );
array[ index + 2 ] = ( xz - wy );
array[ index + 3 ] = 0;
array[ index + 4 ] = ( xy - wz );
array[ index + 5 ] = ( 1 - ( xx + zz ) );
array[ index + 6 ] = ( yz + wx );
array[ index + 7 ] = 0;
array[ index + 8 ] = ( xz + wy );
array[ index + 9 ] = ( yz - wx );
array[ index + 10 ] = ( 1 - ( xx + yy ) );
array[ index + 11 ] = 0;
array[ index + 12 ] = position.x;
array[ index + 13 ] = position.y;
array[ index + 14 ] = position.z;
array[ index + 15 ] = 1;
}
function CannonPhysics() {
var frameRate = 60;
var frameTime = 1 / frameRate;
var world = new CANNON.World();
world.gravity.set( 0, - 9.8, 0 );
world.broadphase = new CANNON.SAPBroadphase( world );
// world.solver.iterations = 20;
// world.solver.tolerance = 0.001;
// world.allowSleep = true;
//
function getShape( geometry ) {
var parameters = geometry.parameters;
// TODO change type to is*
switch ( geometry.type ) {
case 'BoxBufferGeometry':
var halfExtents = new CANNON.Vec3();
halfExtents.x = parameters.width !== undefined ? parameters.width / 2 : 0.5;
halfExtents.y = parameters.height !== undefined ? parameters.height / 2 : 0.5;
halfExtents.z = parameters.depth !== undefined ? parameters.depth / 2 : 0.5;
return new CANNON.Box( halfExtents );
case 'PlaneBufferGeometry':
return new CANNON.Plane();
case 'SphereBufferGeometry':
var radius = parameters.radius;
return new CANNON.Sphere( radius );
}
return null;
}
var meshes = [];
var meshMap = new WeakMap();
function addMesh( mesh, mass = 0 ) {
var shape = getShape( mesh.geometry );
if ( shape !== null ) {
if ( mesh.isInstancedMesh ) {
handleInstancedMesh( mesh, mass, shape );
} else if ( mesh.isMesh ) {
handleMesh( mesh, mass, shape );
}
}
}
function handleMesh( mesh, mass, shape ) {
var position = new CANNON.Vec3();
position.copy( mesh.position );
var quaternion = new CANNON.Quaternion();
quaternion.copy( mesh.quaternion );
var body = new CANNON.Body( {
position: position,
quaternion: quaternion,
mass: mass,
shape: shape
} );
world.addBody( body );
if ( mass > 0 ) {
meshes.push( mesh );
meshMap.set( mesh, body );
}
}
function handleInstancedMesh( mesh, mass, shape ) {
var array = mesh.instanceMatrix.array;
var bodies = [];
for ( var i = 0; i < mesh.count; i ++ ) {
var index = i * 16;
var position = new CANNON.Vec3();
position.set( array[ index + 12 ], array[ index + 13 ], array[ index + 14 ] );
var body = new CANNON.Body( {
position: position,
mass: mass,
shape: shape
} );
world.addBody( body );
bodies.push( body );
}
if ( mass > 0 ) {
mesh.instanceMatrix.setUsage( 35048 ); // THREE.DynamicDrawUsage = 35048
meshes.push( mesh );
meshMap.set( mesh, bodies );
}
}
//
function setMeshPosition( mesh, position, index = 0 ) {
if ( mesh.isInstancedMesh ) {
var bodies = meshMap.get( mesh );
bodies[ index ].position.copy( position );
} else if ( mesh.isMesh ) {
var body = meshMap.get( mesh );
body.position.copy( position );
}
}
//
var lastTime = 0;
function step() {
var time = performance.now();
if ( lastTime > 0 ) {
var delta = ( time - lastTime ) / 1000;
// console.time( 'world.step' );
world.step( frameTime, delta, frameRate );
// console.timeEnd( 'world.step' );
}
lastTime = time;
//
for ( var i = 0, l = meshes.length; i < l; i ++ ) {
var mesh = meshes[ i ];
if ( mesh.isInstancedMesh ) {
var array = mesh.instanceMatrix.array;
var bodies = meshMap.get( mesh );
for ( var j = 0; j < bodies.length; j ++ ) {
var body = bodies[ j ];
compose( body.position, body.quaternion, array, j * 16 );
}
mesh.instanceMatrix.needsUpdate = true;
} else if ( mesh.isMesh ) {
var body = meshMap.get( mesh );
mesh.position.copy( body.position );
mesh.quaternion.copy( body.quaternion );
}
}
}
// animate
setInterval( step, 1000 / frameRate );
return {
addMesh: addMesh,
setMeshPosition: setMeshPosition
// addCompoundMesh
};
}
export { CannonPhysics };