@xtor/cga.js
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Xtor Compute Geometry Algorithm Libary 计算几何算法库
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text/typescript
import { Vec3 } from '../../math/Vec3';
import { Segment } from './Segment';
import { DistanceResult } from '../../alg/result';
import { Triangle } from './Triangle';
import { Line } from './Line';
import { Rectangle } from './Rectangle';
export class Ray {
origin: Vec3;
direction: Vec3;
constructor(origin: Vec3, direction: Vec3) {
this.origin = origin;
this.direction = direction.normalize();
}
/**
* 射线到射线的距离
* @param {Ray} ray
*/
distanceRay(ray: Ray): DistanceResult {
var result: DistanceResult
= {
parameters: [],
closests: [],
};
var diff = this.origin.clone().sub(ray.origin);
var a01 = - this.direction.dot(ray.direction);
var b0 = diff.dot(this.direction), b1;
var s0, s1;
if (Math.abs(a01) < 1) {
// 射线不平行
b1 = - diff.dot(ray.direction);
s0 = a01 * b1 - b0;
s1 = a01 * b0 - b1;
if (s0 >= 0) {
if (s1 >= 0) // region 0 (interior)
{
// Minimum at two interior points of rays.
var det = 1 - a01 * a01;
s0 /= det;
s1 /= det;
}
else // region 3 (side)
{
s1 = 0;
if (b0 >= 0) {
s0 = 0;
}
else {
s0 = -b0;
}
}
}
else {
if (s1 >= 0) // region 1 (side)
{
s0 = 0;
if (b1 >= 0) {
s1 = 0;
}
else {
s1 = -b1;
}
}
else // region 2 (corner)
{
if (b0 < 0) {
s0 = -b0;
s1 = 0;
}
else {
s0 = 0;
if (b1 >= 0) {
s1 = 0;
}
else {
s1 = -b1;
}
}
}
}
}
else {
// Rays are parallel.
if (a01 > 0) {
// Opposite direction vectors.
s1 = 0;
if (b0 >= 0) {
s0 = 0;
}
else {
s0 = -b0;
}
}
else {
// Same direction vectors.
if (b0 >= 0) {
b1 = - diff.dot(ray.direction);
s0 = 0;
s1 = -b1;
}
else {
s0 = -b0;
s1 = 0;
}
}
}
result.parameters![0] = s0;
result.parameters![1] = s1;
result.closests![0] = this.direction.clone().multiplyScalar(s0).add(this.origin);
result.closests![1] = ray.direction.clone().multiplyScalar(s1).add(ray.origin);
diff = result.closests![0].clone().sub(result.closests![1]);
result.distanceSqr = diff.dot(diff);
result.distance = Math.sqrt(result.distanceSqr);
return result;
}
/**
* 射线到线段的距离
* @param segment
*/
distanceSegment(segment: Segment): DistanceResult {
const result: DistanceResult = {
parameters: [],
closests: []
};
// segment.GetCenteredForm(segCenter, segDirection, segExtent);
var segCenter = segment.center;
var segDirection = segment.direction;
var segExtent = segment.extent * 0.5;
var diff = this.origin.clone().sub(segCenter);
var a01 = - this.direction.dot(segDirection);
var b0 = diff.dot(this.direction);
var s0, s1;
if (Math.abs(a01) < 1) {
// The ray and segment are not parallel.
var det = 1 - a01 * a01;
var extDet = segExtent * det;
var b1 = - diff.dot(segDirection);
s0 = a01 * b1 - b0;
s1 = a01 * b0 - b1;
if (s0 >= 0) {
if (s1 >= -extDet) {
if (s1 <= extDet) // region 0
{
// Minimum at interior points of ray and segment.
s0 /= det;
s1 /= det;
}
else // region 1
{
s1 = segExtent;
s0 = Math.max(-(a01 * s1 + b0), 0);
}
}
else // region 5
{
s1 = -segExtent;
s0 = Math.max(-(a01 * s1 + b0), 0);
}
}
else {
if (s1 <= -extDet) // region 4
{
s0 = -(-a01 * segExtent + b0);
if (s0 > 0) {
s1 = -segExtent;
}
else {
s0 = 0;
s1 = -b1;
if (s1 < -segExtent) {
s1 = -segExtent;
}
else if (s1 > segExtent) {
s1 = segExtent;
}
}
}
else if (s1 <= extDet) // region 3
{
s0 = 0;
s1 = -b1;
if (s1 < -segExtent) {
s1 = -segExtent;
}
else if (s1 > segExtent) {
s1 = segExtent;
}
}
else // region 2
{
s0 = -(a01 * segExtent + b0);
if (s0 > 0) {
s1 = segExtent;
}
else {
s0 = 0;
s1 = -b1;
if (s1 < -segExtent) {
s1 = -segExtent;
}
else if (s1 > segExtent) {
s1 = segExtent;
}
}
}
}
}
else {
// Ray and segment are parallel.
if (a01 > 0) {
// Opposite direction vectors.
s1 = -segExtent;
}
else {
// Same direction vectors.
s1 = segExtent;
}
s0 = Math.max(-(a01 * s1 + b0), 0);
}
result.parameters![0] = s0;
result.parameters![1] = s1;
result.closests![0] = this.direction.clone().multiplyScalar(s0).add(this.origin);
result.closests![1] = segDirection.clone().multiplyScalar(s1).add(segCenter);
diff = result.closests![0].clone().sub(result.closests![1]);
result.distanceSqr = diff.dot(diff);
result.distance = Math.sqrt(result.distanceSqr);
return result;
}
distanceTriangle(triangle: Triangle): DistanceResult {
const result: DistanceResult = {
parameters: [],
closests: [],
triangleParameters: [],
};
var line = new Line(this.origin, this.origin.clone().add(this.direction));
// DCPQuery < Real, Line3 < Real >, Triangle3 < Real >> ltQuery;
var ltResult = line.distanceTriangle(triangle);
if (ltResult.lineParameter >= 0) {
//最近点在直线前半部分部分，涉嫌方向
result.distance = ltResult.distance;
result.distanceSqr = ltResult.distanceSqr;
result.rayParameter = ltResult.lineParameter;
result.triangleParameters![0] = ltResult.triangleParameters![0];
result.triangleParameters![1] = ltResult.triangleParameters![1];
result.triangleParameters![2] = ltResult.triangleParameters![2];
result.closests![0] = ltResult.closests![0];
result.closests![1] = ltResult.closests![1];
}
else {
var ptResult = this.origin.clone().distanceTriangle(triangle);
result.distance = ptResult.distance;
result.distanceSqr = ptResult.distanceSqr;
result.rayParameter = 0;
result.triangleParameters![0] = ptResult.triangleParameters![0];
result.triangleParameters![1] = ptResult.triangleParameters![1];
result.triangleParameters![2] = ptResult.triangleParameters![2];
result.closests![0] = this.origin;
result.closests![1] = ptResult.closests![1];
}
return result;
}
distancePloyline(): DistanceResult {
const result = {};
return result;
}
}