1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
|
/// <reference path="vec2.js" />
/// <reference path="mat4.js" />
/// <reference path="circle.js" />
/// <reference path="line2.js" />
/// <reference path="collision.js" />
const GRAVITY = 9.8;
const BYTES_PER_FLOAT = 4;
/**
*
* @param {Shape} pObject a 2D shape like a circle, rectangle, or line
* @param {Object} pData initial data for the rigidboy
*/
function makeRigidBody2(pObject, pData) {
pObject.velocity = vec2();
pObject.prevVelocity = pObject.velocity;
pObject.position = pData.position || vec2();
pObject.prevPosition = pObject.position;
pObject.force = vec2();
pObject.rotationVelocity = 0;
pObject.rotationRadians = 0;
pObject.torque = 0;
pObject.mass = pData.mass !== undefined ? pData.mass : 1.0;
pObject.getMomentOfInertia = pData.getMomentOfInertia;
return pObject;
}
function updateRigidBody2(pRigidbody, pDeltaTimeSeconds) {
applyForceRigidbody2(pRigidbody, vec2(0, -1.0 * (pRigidbody.mass * GRAVITY)));
const lCurrentAcceleration = scaleVec2(pRigidbody.force, 1.0 / pRigidbody.mass);
pRigidbody.prevVelocity = pRigidbody.velocity;
pRigidbody.velocity = addVec2(pRigidbody.velocity, scaleVec2(lCurrentAcceleration, pDeltaTimeSeconds));
pRigidbody.prevPos = { ...pRigidbody.position };
pRigidbody.position = addVec2(pRigidbody.position, scaleVec2(pRigidbody.velocity, pDeltaTimeSeconds));
pRigidbody.force = vec2();
const lMomentOfInertia = pRigidbody.getMomentOfInertia(pRigidbody);
const lAngularAcceleration = pRigidbody.torque / lMomentOfInertia;
pRigidbody.rotationVelocity += lAngularAcceleration * pDeltaTimeSeconds;
pRigidbody.rotationRadians += pRigidbody.rotationVelocity * pDeltaTimeSeconds;
pRigidbody.torque = 0;
pRigidbody.model = rotateMatrix2d(translateMatrix(mat4(), pRigidbody.position.x, pRigidbody.position.y, 0), pRigidbody.rotationRadians);
}
function applyForceRigidbody2(pRigidbody, pForceVector, pPointOfApplication) {
if (pPointOfApplication !== undefined) {
const lOriginToPointOfApp = subVec2(vec2(), pPointOfApplication),
lPerpVec = vec2(-lOriginToPointOfApp.y, lOriginToPointOfApp.x);
pRigidbody.torque += TORQUE_MULTIPLIER * dot2(lPerpVec, pForceVector);
}
pRigidbody.force = addVec2(pRigidbody.force, pForceVector);
}
|
