移动精灵会导致运动不平稳
我的精灵动作有些不稳定。
基本上，当用户触摸屏幕上的某个点时，精灵应该移动到该点。这基本上工作得很好......它甚至考虑到了增量 - 因为帧速率可能不一致。
然而，我注意到 y 运动通常在 x 运动之前完成（即使行进距离相同），因此看起来精灵正在以“L”形状而不是平滑的对角线移动。
垂直和水平速度（vx、vy）都设置为 300。有什么问题吗？我怎样才能让我的精灵沿着平滑的对角线移动？
- (void)update:(ccTime)dt
{
int x = self.position.x;
int y = self.position.y;
//if ball is to the left of target point
if (x<targetx)
{
//if movement of the ball won't take it to it's target position
if (x+(vx *dt) < targetx)
{
x += vx * dt;
}
else {
x = targetx;
}
} else if (x>targetx) //same with x being too far to the right
{
if (x-(vx *dt) > targetx)
{
x -= vx * dt;
}
else {
x = targetx;
}
}
if (y<targety)
{
if (y+(vy*dt)<targety)
{
y += vy * dt;
}
else {
y = targety;
}
} else if (y>targety)
{
if (y-(vy*dt)>targety)
{
y -= vy * dt;
}
else {
y = targety;
}
}
self.position = ccp(x,y);
}
I've got some jerky movement of my sprite.
Basically, when the user touches a point on the screen, the sprite should move to that point. This is working mostly fine... it's even taking into account a delta - because frame rate may not be consistant.
However, I notice that the y movement usually finishes before the x movement (even when the distances to travel are the same), so it appears like the sprite is moving in an 'L' shape rather than a smooth diagonal line.
Vertical and horizontal velocity (vx, vy) are both set to 300. Any ideas what's wrong? How can I go about getting my sprite to move in a smooth diagonal line?
- (void)update:(ccTime)dt
{
int x = self.position.x;
int y = self.position.y;
//if ball is to the left of target point
if (x<targetx)
{
//if movement of the ball won't take it to it's target position
if (x+(vx *dt) < targetx)
{
x += vx * dt;
}
else {
x = targetx;
}
} else if (x>targetx) //same with x being too far to the right
{
if (x-(vx *dt) > targetx)
{
x -= vx * dt;
}
else {
x = targetx;
}
}
if (y<targety)
{
if (y+(vy*dt)<targety)
{
y += vy * dt;
}
else {
y = targety;
}
} else if (y>targety)
{
if (y-(vy*dt)>targety)
{
y -= vy * dt;
}
else {
y = targety;
}
}
self.position = ccp(x,y);
}
如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。
绑定邮箱获取回复消息
由于您还没有绑定你的真实邮箱，如果其他用户或者作者回复了您的评论，将不能在第一时间通知您！
发布评论
评论（1）
您想要从任意 (x,y) 移动到 (targetx, targety) 并同时到达两个坐标（以避免“狗腿”）。因此，假设 x 速度为 vx 并且您在 t 秒内到达那里。这意味着 vx = (targetx - x)/t。如果您希望同时平滑地移动到同一点，则 t 的 y 坐标必须相同，这意味着 t = (targetx - x)/vx 且 vy 实际上必须为 (targety - y)*vx/(targetx - x）。
也就是说，你无法分别设置vx和vy并得到你想要的结果。
You want to move to (targetx, targety) from any (x,y) and arrive at both coordinates at the same time (to avoid the "dogleg"). So, suppose the x velocity is vx and you get there in t seconds. That means vx = (targetx - x)/t. t must be the same for the y coordinate if you want smooth movement to the same point at the same time, so that means t = (targetx - x)/vx and vy must actually be (targety - y)*vx/(targetx - x).
In other words, you can't set vx and vy separately and get the result you want.