向量几何在游戏编程中的使用:https://blog.csdn.net/gaojinjingg/article/details/53159187
游戏制作中常用的数据结构与算法:https://blog.csdn.net/Loving_Forever_/article/details/52419198
随机、追踪、闪避算法:http://www.cnblogs.com/ccsccs/articles/4137725.html
追踪算法:
function(targetPosition){
// 让物体朝目标移动的速率
let speed = 4;
// 当前对象和目标相撞的最短距离
let minDistance = 100;
//求两点的差值向量(两点的座标相减)
let vectorX = targetPosition.x - this.x;
let vectorY = targetPosition.y - this.y;
// 求当前对象和目标两点间的距离
let distance = Math.sqrt(vectorX * vectorX + vectorY * vectorY);
//判断是否相撞
if(distance <= minDistance){
return true;
}
// 记录当前对象x和y座标
let oldX = this.x;
let oldY = this.y;
// 求两点的差值的单位向量
let singleVectorX = vectorX / distance;
let singleVectorY = vectorY / distance;
// 设置当前对象运动后的x和y座标
this.x += speed * singleVectorX;
this.y += speed * singleVectorY;
// 旋转相应的角度
let deltaRotation= 90 - Math.atan2(this.y - oldY, this.x - oldX) * 180 / Math.PI;
this.rotation = deltaRotation;
//返回不相撞
return false;
}