Raytracer copied from the TS homepage
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Ben
307
TypeScript/RayTracerExample/example.ts
Normal file
307
TypeScript/RayTracerExample/example.ts
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class Vector {
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constructor(public x: number, public y: number, public z: number) { }
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static times(k: number, v: Vector) {
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return new Vector(k * v.x, k * v.y, k * v.z);
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}
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static minus(v1: Vector, v2: Vector) {
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return new Vector(v1.x - v2.x, v1.y - v2.y, v1.z - v2.z);
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}
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static plus(v1: Vector, v2: Vector) {
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return new Vector(v1.x + v2.x, v1.y + v2.y, v1.z + v2.z);
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}
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static dot(v1: Vector, v2: Vector) {
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return v1.x * v2.x + v1.y * v2.y + v1.z * v2.z;
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}
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static mag(v: Vector) {
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return Math.sqrt(v.x * v.x + v.y * v.y + v.z * v.z);
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}
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static norm(v: Vector) {
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let mag = Vector.mag(v);
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let div = (mag === 0) ? Infinity : 1.0 / mag;
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return Vector.times(div, v);
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}
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static cross(v1: Vector, v2: Vector) {
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return new Vector(v1.y * v2.z - v1.z * v2.y,
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v1.z * v2.x - v1.x * v2.z,
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v1.x * v2.y - v1.y * v2.x);
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}
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}
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class Color {
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constructor(public r: number, public g: number, public b: number) { }
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static scale(k: number, v: Color) {
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return new Color(k * v.r, k * v.g, k * v.b);
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}
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static plus(v1: Color, v2: Color) {
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return new Color(v1.r + v2.r, v1.g + v2.g, v1.b + v2.b);
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}
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static times(v1: Color, v2: Color) {
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return new Color(v1.r * v2.r, v1.g * v2.g, v1.b * v2.b);
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}
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static white = new Color(1.0, 1.0, 1.0);
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static grey = new Color(0.5, 0.5, 0.5);
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static black = new Color(0.0, 0.0, 0.0);
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static background = Color.black;
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static defaultColor = Color.black;
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static toDrawingColor(c: Color) {
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let legalize = d => d > 1 ? 1 : d;
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return {
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r: Math.floor(legalize(c.r) * 255),
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g: Math.floor(legalize(c.g) * 255),
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b: Math.floor(legalize(c.b) * 255)
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}
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}
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}
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class Camera {
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forward: Vector;
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right: Vector;
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up: Vector;
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constructor(public pos: Vector, lookAt: Vector) {
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let down = new Vector(0.0, -1.0, 0.0);
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this.forward = Vector.norm(Vector.minus(lookAt, this.pos));
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this.right = Vector.times(1.5, Vector.norm(Vector.cross(this.forward, down)));
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this.up = Vector.times(1.5, Vector.norm(Vector.cross(this.forward, this.right)));
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}
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}
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interface Ray {
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start: Vector;
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dir: Vector;
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}
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interface Intersection {
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thing: Thing;
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ray: Ray;
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dist: number;
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}
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interface Surface {
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diffuse: (pos: Vector) => Color;
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specular: (pos: Vector) => Color;
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reflect: (pos: Vector) => number;
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roughness: number;
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}
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interface Thing {
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intersect: (ray: Ray) => Intersection;
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normal: (pos: Vector) => Vector;
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surface: Surface;
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}
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interface Light {
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pos: Vector;
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color: Color;
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}
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interface Scene {
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things: Thing[];
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lights: Light[];
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camera: Camera;
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}
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class Sphere implements Thing {
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radius2: number;
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constructor(public center: Vector, radius: number, public surface: Surface) {
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this.radius2 = radius * radius;
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}
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normal(pos: Vector): Vector {
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return Vector.norm(Vector.minus(pos, this.center));
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}
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intersect(ray: Ray) {
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let eo = Vector.minus(this.center, ray.start);
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let v = Vector.dot(eo, ray.dir);
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let dist = 0;
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if (v >= 0) {
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let disc = this.radius2 - (Vector.dot(eo, eo) - v * v);
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if (disc >= 0) {
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dist = v - Math.sqrt(disc);
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}
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}
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if (dist === 0) {
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return null;
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} else {
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return { thing: this, ray: ray, dist: dist };
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}
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}
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}
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class Plane implements Thing {
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normal: (pos: Vector) => Vector;
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intersect: (ray: Ray) => Intersection;
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constructor(norm: Vector, offset: number, public surface: Surface) {
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this.normal = function(pos: Vector) { return norm; }
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this.intersect = function(ray: Ray): Intersection {
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let denom = Vector.dot(norm, ray.dir);
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if (denom > 0) {
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return null;
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} else {
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let dist = (Vector.dot(norm, ray.start) + offset) / (-denom);
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return { thing: this, ray: ray, dist: dist };
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}
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}
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}
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}
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namespace Surfaces {
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export let shiny: Surface = {
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diffuse: function(pos) { return Color.white; },
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specular: function(pos) { return Color.grey; },
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reflect: function(pos) { return 0.7; },
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roughness: 250
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}
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export let checkerboard: Surface = {
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diffuse: function(pos) {
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if ((Math.floor(pos.z) + Math.floor(pos.x)) % 2 !== 0) {
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return Color.white;
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} else {
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return Color.black;
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}
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},
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specular: function(pos) { return Color.white; },
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reflect: function(pos) {
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if ((Math.floor(pos.z) + Math.floor(pos.x)) % 2 !== 0) {
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return 0.1;
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} else {
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return 0.7;
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}
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},
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roughness: 150
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}
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}
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class RayTracer {
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private maxDepth = 5;
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private intersections(ray: Ray, scene: Scene) {
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let closest = +Infinity;
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let closestInter: Intersection = undefined;
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for (let i in scene.things) {
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let inter = scene.things[i].intersect(ray);
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if (inter != null && inter.dist < closest) {
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closestInter = inter;
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closest = inter.dist;
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}
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}
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return closestInter;
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}
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private testRay(ray: Ray, scene: Scene) {
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let isect = this.intersections(ray, scene);
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if (isect != null) {
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return isect.dist;
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} else {
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return undefined;
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}
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}
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private traceRay(ray: Ray, scene: Scene, depth: number): Color {
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let isect = this.intersections(ray, scene);
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if (isect === undefined) {
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return Color.background;
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} else {
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return this.shade(isect, scene, depth);
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}
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}
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private shade(isect: Intersection, scene: Scene, depth: number) {
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let d = isect.ray.dir;
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let pos = Vector.plus(Vector.times(isect.dist, d), isect.ray.start);
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let normal = isect.thing.normal(pos);
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let reflectDir = Vector.minus(d, Vector.times(2, Vector.times(Vector.dot(normal, d), normal)));
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let naturalColor = Color.plus(Color.background,
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this.getNaturalColor(isect.thing, pos, normal, reflectDir, scene));
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let reflectedColor = (depth >= this.maxDepth) ? Color.grey : this.getReflectionColor(isect.thing, pos, normal, reflectDir, scene, depth);
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return Color.plus(naturalColor, reflectedColor);
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}
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private getReflectionColor(thing: Thing, pos: Vector, normal: Vector, rd: Vector, scene: Scene, depth: number) {
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return Color.scale(thing.surface.reflect(pos), this.traceRay({ start: pos, dir: rd }, scene, depth + 1));
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}
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private getNaturalColor(thing: Thing, pos: Vector, norm: Vector, rd: Vector, scene: Scene) {
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let addLight = (col, light) => {
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let ldis = Vector.minus(light.pos, pos);
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let livec = Vector.norm(ldis);
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let neatIsect = this.testRay({ start: pos, dir: livec }, scene);
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let isInShadow = (neatIsect === undefined) ? false : (neatIsect <= Vector.mag(ldis));
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if (isInShadow) {
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return col;
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} else {
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let illum = Vector.dot(livec, norm);
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let lcolor = (illum > 0) ? Color.scale(illum, light.color)
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: Color.defaultColor;
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let specular = Vector.dot(livec, Vector.norm(rd));
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let scolor = (specular > 0) ? Color.scale(Math.pow(specular, thing.surface.roughness), light.color)
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: Color.defaultColor;
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return Color.plus(col, Color.plus(Color.times(thing.surface.diffuse(pos), lcolor),
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Color.times(thing.surface.specular(pos), scolor)));
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}
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}
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return scene.lights.reduce(addLight, Color.defaultColor);
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}
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render(scene, ctx, screenWidth, screenHeight) {
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let getPoint = (x, y, camera) => {
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let recenterX = x => (x - (screenWidth / 2.0)) / 2.0 / screenWidth;
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let recenterY = y => -(y - (screenHeight / 2.0)) / 2.0 / screenHeight;
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return Vector.norm(Vector.plus(camera.forward, Vector.plus(Vector.times(recenterX(x), camera.right), Vector.times(recenterY(y), camera.up))));
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}
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for (let y = 0; y < screenHeight; y++) {
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for (let x = 0; x < screenWidth; x++) {
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let color = this.traceRay({ start: scene.camera.pos, dir: getPoint(x, y, scene.camera) }, scene, 0);
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let c = Color.toDrawingColor(color);
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ctx.fillStyle = "rgb(" + String(c.r) + ", " + String(c.g) + ", " + String(c.b) + ")";
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ctx.fillRect(x, y, x + 1, y + 1);
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}
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}
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}
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}
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function defaultScene(): Scene {
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return {
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things: [new Plane(new Vector(0.0, 1.0, 0.0), 0.0, Surfaces.checkerboard),
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new Sphere(new Vector(0.0, 1.0, -0.25), 1.0, Surfaces.shiny),
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new Sphere(new Vector(-1.0, 0.5, 1.5), 0.5, Surfaces.shiny)],
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lights: [{ pos: new Vector(-2.0, 2.5, 0.0), color: new Color(0.49, 0.07, 0.07) },
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{ pos: new Vector(1.5, 2.5, 1.5), color: new Color(0.07, 0.07, 0.49) },
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{ pos: new Vector(1.5, 2.5, -1.5), color: new Color(0.07, 0.49, 0.071) },
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{ pos: new Vector(0.0, 3.5, 0.0), color: new Color(0.21, 0.21, 0.35) }],
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camera: new Camera(new Vector(3.0, 2.0, 4.0), new Vector(-1.0, 0.5, 0.0))
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};
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}
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function exec() {
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let canv = document.createElement("canvas");
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canv.width = 1000;
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canv.height = 1000;
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document.body.appendChild(canv);
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let ctx = canv.getContext("2d");
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let rayTracer = new RayTracer();
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return rayTracer.render(defaultScene(), ctx, 1000, 1000);
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}
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exec();
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