新增shapecollision 用于计算多边形碰撞

source/src/Physics/Shapes/Circle.ts

@@ -8,4 +8,16 @@ class Circle extends Shape {
         this.radius = radius;
         this._originalRadius = radius;
     }
+
+    public pointCollidesWithShape(point: Vector2): CollisionResult {
+        return ShapeCollisions.pointToCicle(point, this);
+    }
+
+    public collidesWithShape(other: Shape): CollisionResult{
+        if (other instanceof Rect && (other as Rect).isUnrotated){
+            return ShapeCollisions.circleToRect(this, other as Rect);
+        }
+
+        throw new Error(`Collisions of Circle to ${other} are not supported`);
+    }
 }

source/src/Physics/Shapes/CollisionResult.ts

@@ -0,0 +1,5 @@
+class CollisionResult {
+    public minimumTranslationVector: Vector2;
+    public normal: Vector2;
+    public point: Vector2;
+}

source/src/Physics/Shapes/Polygon.ts

@@ -1,25 +1,33 @@
 ///<reference path="./Shape.ts" />
 class Polygon extends Shape {
     public points: Vector2[];
+    public isUnrotated: boolean = true;
+    private _polygonCenter: Vector2;
+    private _areEdgeNormalsDirty = true;
+    private _originalPoint: Vector2[]
 
-    constructor(vertCount: number, radius: number){
+    constructor(vertCount: number, radius: number) {
         super();
         this.setPoints(Polygon.buildSymmertricalPolygon(vertCount, radius));
     }
 
-    public setPoints(points: Vector2[]){
+    public setPoints(points: Vector2[]) {
         this.points = points;
         this.recalculateCenterAndEdgeNormals();
+
+        this._originalPoint = new Vector2[points.length];
+        this._originalPoint = points;
     }
 
-    public recalculateCenterAndEdgeNormals(){
-
+    public recalculateCenterAndEdgeNormals() {
+        this._polygonCenter = Polygon.findPolygonCenter(this.points);
+        this._areEdgeNormalsDirty = true;
     }
 
-    public static findPolygonCenter(points: Vector2[]){
+    public static findPolygonCenter(points: Vector2[]) {
         let x = 0, y = 0;
 
-        for (let i = 0; i < points.length; i++){
+        for (let i = 0; i < points.length; i++) {
             x += points[i].x;
             y += points[i].y;
         }
@@ -27,10 +35,58 @@ class Polygon extends Shape {
         return new Vector2(x / points.length, y / points.length);
     }
 
-    public static buildSymmertricalPolygon(vertCount: number, radius: number){
+    public static getClosestPointOnPolygonToPoint(points: Vector2[], point: Vector2): { closestPoint, distanceSquared, edgeNormal } {
+        let distanceSquared = Number.MAX_VALUE;
+        let edgeNormal = new Vector2(0, 0);
+        let closestPoint = new Vector2(0, 0);
+
+        let tempDistanceSquared;
+        for (let i = 0; i < points.length; i++) {
+            let j = i + 1;
+            if (j == points.length)
+                j = 0;
+
+            let closest = ShapeCollisions.closestPointOnLine(points[i], points[j], point);
+            tempDistanceSquared = Vector2.distanceSquared(point, closest);
+
+            if (tempDistanceSquared < distanceSquared) {
+                distanceSquared = tempDistanceSquared;
+                closestPoint = closest;
+
+                let line = Vector2.subtract(points[j], points[i]);
+                edgeNormal.x = -line.y;
+                edgeNormal.y = line.x;
+            }
+        }
+
+        edgeNormal = Vector2.normalize(edgeNormal);
+
+        return { closestPoint: closestPoint, distanceSquared: distanceSquared, edgeNormal: edgeNormal };
+    }
+
+    public pointCollidesWithShape(point: Vector2): CollisionResult {
+        return ShapeCollisions.pointToPoly(point, this);
+    }
+
+    public containsPoint(point: Vector2) {
+        point = Vector2.subtract(point, this.position);
+
+        let isInside = false;
+        for (let i = 0, j = this.points.length - 1; i < this.points.length; j = i++) {
+            if (((this.points[i].y > point.y) != (this.points[j].y > point.y)) &&
+                (point.x < (this.points[j].x - this.points[i].x) * (point.y - this.points[i].y) / (this.points[j].y - this.points[i].y) +
+                    this.points[i].x)) {
+                isInside = !isInside;
+            }
+        }
+
+        return isInside;
+    }
+
+    public static buildSymmertricalPolygon(vertCount: number, radius: number) {
         let verts = new Vector2[vertCount];
 
-        for (let i = 0; i < vertCount; i ++){
+        for (let i = 0; i < vertCount; i++) {
             let a = 2 * Math.PI * (i / vertCount);
             verts[i] = new Vector2(Math.cos(a), Math.sign(a) * radius);
         }

source/src/Physics/Shapes/Rect.ts

@@ -0,0 +1,8 @@
+class Rect extends Polygon {
+    public containsPoint(point: Vector2){
+        if (this.isUnrotated)
+            return this.bounds.contains(point);
+
+        return super.containsPoint(point);
+    }
+}

source/src/Physics/Shapes/Shape.ts

@@ -1,4 +1,6 @@
 abstract class Shape {
     public bounds: Rectangle;
     public position: Vector2;
+
+    public abstract pointCollidesWithShape(point: Vector2): CollisionResult;
 }

source/src/Physics/Shapes/ShapeCollisions/ShapeCollisions.ts

@@ -0,0 +1,60 @@
+class ShapeCollisions {
+    public static circleToRect(circle: Circle, box: Rect): CollisionResult{
+        let result = new CollisionResult();
+        let closestPointOnBounds = box.bounds.getClosestPointOnRectangleBorderToPoint(circle.position).res;
+
+        if (box.containsPoint(circle.position)){
+            result.point = closestPointOnBounds;
+
+            let safePlace = Vector2.add(closestPointOnBounds, Vector2.subtract(result.normal, new Vector2(circle.radius, circle.radius)));
+        }
+
+        return result;
+    }
+
+    public static pointToCicle(point: Vector2, circle: Circle){
+        let result = new CollisionResult();
+
+        let distanceSquared = Vector2.distanceSquared(point, circle.position);
+        let sumOfRadii = 1 + circle.radius;
+        let collided = distanceSquared < sumOfRadii * sumOfRadii;
+        if (collided){
+            result.normal = Vector2.normalize(Vector2.subtract(point, circle.position));
+            let depth = sumOfRadii - Math.sqrt(distanceSquared);
+            result.minimumTranslationVector = Vector2.multiply(new Vector2(-depth, -depth), result.normal);
+            result.point = Vector2.add(circle.position, Vector2.multiply(result.normal, new Vector2(circle.radius, circle.radius)));
+
+            return result;
+        }
+
+        return result;
+    }
+
+    public static closestPointOnLine(lineA: Vector2, lineB: Vector2, closestTo: Vector2){
+        let v = Vector2.subtract(lineB, lineA);
+        let w = Vector2.subtract(closestTo, lineA);
+        let t = Vector2.dot(w, v) / Vector2.dot(v, v);
+        t = MathHelper.clamp(t, 0, 1);
+
+        return Vector2.add(lineA, Vector2.multiply(v, new Vector2(t, t)));
+    }
+
+    public static pointToPoly(point: Vector2, poly: Polygon){
+        let result = new CollisionResult();
+
+        if (poly.containsPoint(point)){
+            let distanceSquared: number;
+            let gpp = Polygon.getClosestPointOnPolygonToPoint(poly.points, Vector2.subtract(point, poly.position));
+            let closestPoint = gpp.closestPoint;
+            distanceSquared = gpp.distanceSquared;
+            result.normal = gpp.edgeNormal;
+
+            result.minimumTranslationVector = Vector2.multiply(result.normal, new Vector2(Math.sqrt(distanceSquared), Math.sqrt(distanceSquared)));
+            result.point = Vector2.add(closestPoint, poly.position);
+
+            return result;
+        }
+
+        return result;
+    }
+}