@awayjs/core
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AwayJS core classes
202 lines (148 loc) • 4.75 kB
text/typescript
import { PlaneClassification } from './PlaneClassification';
import { Vector3D } from './Vector3D';
export class Plane3D {
/**
* The A coefficient of this plane. (Also the x dimension of the plane normal)
*/
public a: number;
/**
* The B coefficient of this plane. (Also the y dimension of the plane normal)
*/
public b: number;
/**
* The C coefficient of this plane. (Also the z dimension of the plane normal)
*/
public c: number;
/**
* The D coefficient of this plane. (Also the inverse dot product between normal and point)
*/
public d: number;
public _iAlignment: number;
// indicates the alignment of the plane
public static ALIGN_ANY: number = 0;
public static ALIGN_XY_AXIS: number = 1;
public static ALIGN_YZ_AXIS: number = 2;
public static ALIGN_XZ_AXIS: number = 3;
/**
* Create a Plane3D with ABCD coefficients
*/
constructor(a: number = 0, b: number = 0, c: number = 0, d: number = 0) {
this.a = a;
this.b = b;
this.c = c;
this.d = d;
if (a == 0 && b == 0) {
this._iAlignment = Plane3D.ALIGN_XY_AXIS;
} else if (b == 0 && c == 0) {
this._iAlignment = Plane3D.ALIGN_YZ_AXIS;
} else if (a == 0 && c == 0) {
this._iAlignment = Plane3D.ALIGN_XZ_AXIS;
} else {
this._iAlignment = Plane3D.ALIGN_ANY;
}
}
/**
* Fills this Plane3D with the coefficients from 3 points in 3d space.
* @param p0 Vector3D
* @param p1 Vector3D
* @param p2 Vector3D
*/
public fromPoints(p0: Vector3D, p1: Vector3D, p2: Vector3D): void {
const d1x: number = p1.x - p0.x;
const d1y: number = p1.y - p0.y;
const d1z: number = p1.z - p0.z;
const d2x: number = p2.x - p0.x;
const d2y: number = p2.y - p0.y;
const d2z: number = p2.z - p0.z;
this.a = d1y * d2z - d1z * d2y;
this.b = d1z * d2x - d1x * d2z;
this.c = d1x * d2y - d1y * d2x;
this.d = this.a * p0.x + this.b * p0.y + this.c * p0.z;
// not using epsilon, since a plane is infinite and a small incorrection can grow very large
if (this.a == 0 && this.b == 0) {
this._iAlignment = Plane3D.ALIGN_XY_AXIS;
} else if (this.b == 0 && this.c == 0) {
this._iAlignment = Plane3D.ALIGN_YZ_AXIS;
} else if (this.a == 0 && this.c == 0) {
this._iAlignment = Plane3D.ALIGN_XZ_AXIS;
} else {
this._iAlignment = Plane3D.ALIGN_ANY;
}
}
/**
* Fills this Plane3D with the coefficients from the plane's normal and a point in 3d space.
* @param normal Vector3D
* @param point Vector3D
*/
public fromNormalAndPoint(normal: Vector3D, point: Vector3D): void {
this.a = normal.x;
this.b = normal.y;
this.c = normal.z;
this.d = this.a * point.x + this.b * point.y + this.c * point.z;
if (this.a == 0 && this.b == 0) {
this._iAlignment = Plane3D.ALIGN_XY_AXIS;
} else if (this.b == 0 && this.c == 0) {
this._iAlignment = Plane3D.ALIGN_YZ_AXIS;
} else if (this.a == 0 && this.c == 0) {
this._iAlignment = Plane3D.ALIGN_XZ_AXIS;
} else {
this._iAlignment = Plane3D.ALIGN_ANY;
}
}
/**
* Normalize this Plane3D
* @return Plane3D This Plane3D.
*/
public normalize(): Plane3D {
const len: number = 1 / Math.sqrt(this.a * this.a + this.b * this.b + this.c * this.c);
this.a *= len;
this.b *= len;
this.c *= len;
this.d *= len;
return this;
}
/**
* Returns the signed distance between this Plane3D and the point p.
* @param p Vector3D
* @returns Number
*/
public distance(p: Vector3D): number {
if (this._iAlignment == Plane3D.ALIGN_YZ_AXIS) {
return this.a * p.x - this.d;
} else if (this._iAlignment == Plane3D.ALIGN_XZ_AXIS) {
return this.b * p.y - this.d;
} else if (this._iAlignment == Plane3D.ALIGN_XY_AXIS) {
return this.c * p.z - this.d;
} else {
return this.a * p.x + this.b * p.y + this.c * p.z - this.d;
}
}
/**
* Classify a point against this Plane3D. (in front, back or intersecting)
* @param p Vector3D
* @return int Plane3.FRONT or Plane3D.BACK or Plane3D.INTERSECT
*/
public classifyPoint(p: Vector3D, epsilon: number = 0.01): number {
// check NaN
if (this.d != this.d)
return PlaneClassification.FRONT;
let len: number;
if (this._iAlignment == Plane3D.ALIGN_YZ_AXIS)
len = this.a * p.x - this.d;
else if (this._iAlignment == Plane3D.ALIGN_XZ_AXIS)
len = this.b * p.y - this.d;
else if (this._iAlignment == Plane3D.ALIGN_XY_AXIS)
len = this.c * p.z - this.d;
else
len = this.a * p.x + this.b * p.y + this.c * p.z - this.d;
if (len < -epsilon)
return PlaneClassification.BACK;
else if (len > epsilon)
return PlaneClassification.FRONT;
else
return PlaneClassification.INTERSECT;
}
public toString(): string {
return 'Plane3D [a:' + this.a + ', b:' + this.b + ', c:' + this.c + ', d:' + this.d + ']';
}
}