缓存公式
// 角度旋转 dx = mouse.x - object.x; dy = mouse.y - object.y; object.rotation = Math.atan2(dy,dx)*180/Math.PI //平滑运动 value = center + Math.sin(angle)*range; angle += speed; //正圆运动 x_position = centerX + Math.sin(angle)*radius; y_position = centerY + Math.cos(angle)*radius; angle += speed; //椭圆运动 x_position = centerX + Math.cos(angle)*radiusX; y_position = centerY + Math.sin(angle)*radiusY; angle += speed; //两点间距离 dx = x2 - x1; dy = y2 - y1; dist = Math.sqrt(dx*dx + dy*dy); //任意方向速度 vx = speed * Math.cos(angle); vy = speed * Math.sin(angle); //任意方向加速度 ax = force * Math.cos(angle); ay = force * Math.xin(angle); //改变速度 vx += ax; vx += ay; //改变位置 object.x += vx; object.y += vy;
