为什么 CATransform3DMakeRotation 不将 (0,0,1) 视为绕 Z 轴旋转? [英] Why does a CATransform3DMakeRotation not take (0,0,1) as rotating around the Z-axis?
问题描述
如果我在 Cocoa 的应用程序中转换为 NSView
:
If I do a transform to an NSView
in Cocoa's app:
self.view.layer.transform = CATransform3DMakeRotation(30 * M_PI / 180, 0, 0, 1);
我看到正方形没有围绕 Z 轴旋转,而是旋转了,就好像该矢量指向下方和向外一样.我需要成功
I see the square not rotated around the Z-axis, but rotated as if that vector is pointing downward and outward. I need to make it
self.view.layer.transform = CATransform3DMakeRotation(30 * M_PI / 180, 1, 1, 1);
使其绕Z轴旋转,如图这个问题.
to make it rotate around the Z-axis, as shown in the picture on this question.
但是,如果我设置一个 NSTimer
然后在 update
方法中更新 transform
,然后使用
However, if I set an NSTimer
and then update the transform
in the update
method, then using
-(void) update:(id) info {
self.view.layer.transform =
CATransform3DMakeRotation(self.degree * M_PI / 180, 0, 0, 1);
self.degree += 10;
}
(这次,使用 (0, 0, 1)
)会起作用:它绕 Z 轴旋转.我想知道为什么 (1, 1, 1)
需要在 applicationDidFinishLaunching
内部,但是 (0, 0, 1)
可以在更新
方法?
(this time, using (0, 0, 1)
) will work: it rotates around the Z-axis. I wonder why (1, 1, 1)
is needed inside of applicationDidFinishLaunching
, but (0, 0, 1)
can be used in the update
method?
推荐答案
原来需要先将视图添加到window.contentView
:
It turns out the view needs to be added to window.contentView
first:
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
self.view = [[NSView alloc] initWithFrame:NSMakeRect(100, 100, 200, 200)];
[self.window.contentView addSubview:self.view];
self.view.wantsLayer = YES;
self.view.layer = [CALayer layer];
self.view.layer.backgroundColor = [[NSColor yellowColor] CGColor];
self.view.layer.anchorPoint = CGPointMake(0.5, 0.5);
self.view.layer.transform = CATransform3DMakeRotation(30 * M_PI / 180, 0, 0, 1);
}
此外,self.view.layer = [CALayer layer];
行需要在 self.view.wantsLayer = YES;
行之后.为什么这些顺序,我不确定,但它按预期工作.我还找不到提到此订单要求的文档,但上面的代码有效.当我找到更多关于为什么需要订单的信息时,我会更新答案.
also, the line self.view.layer = [CALayer layer];
needs to be after the line self.view.wantsLayer = YES;
. Why these order, I am not sure, but it works as it is supposed to. I can't find the docs that mentions the requirement for this order yet, but the code above works. I will update the answer when I find more info about why the order is needed.
这篇关于为什么 CATransform3DMakeRotation 不将 (0,0,1) 视为绕 Z 轴旋转?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!