新增Physics.linecast/linecastAll方法

source/src/Physics/Physics.ts

@@ -1,3 +1,4 @@
+///<reference path="./RaycastHit.ts" />
 module es {
     export class Physics {
         /** 调用reset并创建一个新的SpatialHash时使用的单元格大小 */
@@ -13,6 +14,12 @@ module es {
          * 在碰撞器中开始的射线/直线是否强制转换检测到那些碰撞器
          */
         public static raycastsStartInColliders = false;
+        /**
+         * 我们保留它以避免在每次raycast发生时分配它
+         */
+        public static _hitArray: RaycastHit[] = [
+            new RaycastHit()
+        ];
 
         public static reset() {
             this._spatialHash = new SpatialHash(this.spatialHashCellSize);
@@ -85,6 +92,34 @@ module es {
             this._spatialHash.register(collider);
         }
 
+        /**
+         * 返回与layerMask匹配的碰撞器的第一次命中
+         * @param start
+         * @param end
+         * @param layerMask
+         */
+        public static linecast(start: Vector2, end: Vector2, layerMask: number = Physics.allLayers): RaycastHit{
+            this._hitArray[0].reset();
+            this.linecastAll(start, end, this._hitArray, layerMask);
+            return this._hitArray[0];
+        }
+
+        /**
+         * 通过空间散列强制执行一行，并用该行命中的任何碰撞器填充hits数组
+         * @param start
+         * @param end
+         * @param hits
+         * @param layerMask
+         */
+        public static linecastAll(start: Vector2, end: Vector2, hits: RaycastHit[], layerMask: number = Physics.allLayers){
+            if (hits.length == 0){
+                console.warn("传入了一个空的hits数组。没有点击会被返回");
+                return 0;
+            }
+
+            return this._spatialHash.linecast(start, end, hits, layerMask);
+        }
+
         /**
          * debug绘制空间散列的内容
          * @param secondsToDisplay

source/src/Physics/RaycastHit.ts

@@ -30,7 +30,7 @@ module es {
          */
         public centroid: Vector2;
 
-        constructor(collider: Collider, fraction: number, distance: number, point: Vector2, normal: Vector2){
+        constructor(collider?: Collider, fraction?: number, distance?: number, point?: Vector2, normal?: Vector2){
             this.collider = collider;
             this.fraction = fraction;
             this.distance = distance;

source/src/Physics/Verlet/SpatialHash.ts

@@ -144,6 +144,73 @@ module es {
             return this._tempHashSet;
         }
 
+        /**
+         * 通过空间散列强制执行一行，并用该行命中的任何碰撞器填充hits数组。
+         * @param start
+         * @param end
+         * @param hits
+         * @param layerMask
+         */
+        public linecast(start: Vector2, end: Vector2, hits: RaycastHit[], layerMask: number){
+            let ray = new Ray2D(start, end);
+            this._raycastParser.start(ray, hits, layerMask);
+
+            // 在与网格相同的空间中获取起始/结束位置
+            let currentCell = this.cellCoords(start.x, start.y);
+            let lastCell = this.cellCoords(end.x, end.y);
+
+            let stepX = Math.sign(ray.direction.x);
+            let stepY = Math.sign(ray.direction.y);
+
+            // 我们要确保，如果我们在同一行或同一行，我们不会步进不必要的方向
+            if (currentCell.x == lastCell.x) stepX = 0;
+            if (currentCell.y == lastCell.y) stepY = 0;
+
+            // 计算单元边界。当这一步是正的，下一个单元格在这一步之后意味着我们加1。
+            // 如果为负，则单元格在此之前，这种情况下不添加边界
+            let xStep = stepX < 0 ? 0 : stepX;
+            let yStep = stepY < 0 ? 0 : stepY;
+            let nextBoundaryX = (currentCell.x + xStep) * this._cellSize;
+            let nextBoundaryY = (currentCell.y + yStep) * this._cellSize;
+
+            // 确定射线穿过第一个垂直体素边界时的t值。y/horizontal。
+            // 这两个值的最小值将表明我们可以沿着射线走多少，而仍然保持在当前体素中，对于接近vertical/horizontal的射线来说可能是无限的
+            let tMaxX = ray.direction.x != 0 ? (nextBoundaryX - ray.start.x) / ray.direction.x : Number.MAX_VALUE;
+            let tMaxY = ray.direction.y != 0 ? (nextBoundaryY - ray.start.y) / ray.direction.y : Number.MAX_VALUE;
+
+            let tDeltaX = ray.direction.x != 0 ? this._cellSize / (ray.direction.x * stepX) : Number.MAX_VALUE;
+            let tDeltaY = ray.direction.y != 0 ? this._cellSize / (ray.direction.y * stepY) : Number.MAX_VALUE;
+
+            // 开始遍历并返回交叉单元格。
+            let cell = this.cellAtPosition(currentCell.x, currentCell.y);
+
+            if (cell && this._raycastParser.checkRayIntersection(currentCell.x, currentCell.y, cell)){
+                this._raycastParser.reset();
+                return this._raycastParser.hitCounter;
+            }
+
+            while (currentCell.x != lastCell.x || currentCell.y != lastCell.y){
+                if (tMaxX < tMaxY){
+                    currentCell.x = MathHelper.approach(currentCell.x, lastCell.x, Math.abs(stepX));
+
+                    tMaxX += tDeltaX;
+                }else{
+                    currentCell.y = MathHelper.approach(currentCell.y, lastCell.y, Math.abs(stepY));
+
+                    tMaxY += tDeltaY;
+                }
+
+                cell = this.cellAtPosition(currentCell.x, currentCell.y);
+                if (cell && this._raycastParser.checkRayIntersection(currentCell.x, currentCell.y, cell)){
+                    this._raycastParser.reset();
+                    return this._raycastParser.hitCounter;
+                }
+            }
+
+            this._raycastParser.reset();
+            return this._raycastParser.hitCounter;
+        }
+
         /**
          * 获取位于指定圆内的所有碰撞器
          * @param circleCenter
@@ -268,7 +335,7 @@ module es {
         };
 
         public _hits: RaycastHit[];
-        public _tempHit: RaycastHit;
+        public _tempHit: RaycastHit = new RaycastHit();
         public _checkedColliders: Collider[] = [];
         public _cellHits: RaycastHit[] = [];
         public _ray: Ray2D;