iPad App设置:SceneA包含layerA - 1024x768。按下layerA中的按钮,使用CCMoveTo操作将layerB下降到顶部。 LayerB只有800x600,所以你可以看到它背后的layerA(想想一个重叠的暂停屏幕类型效果)。 LayerB包含一个800x600精灵,用户可以通过按下按钮放大。缩放效果只是CCScaleTo和CCMoveTo的组合,使其以放大的部分为中心。但是,当精灵缩放时,layerB的layerB也是如此。有没有办法在包含的窗口内缩放精灵?
答案 0 :(得分:1)
LayerB应该使用GL_SCISSOR_TEST
修剪自身的外部。您可以轻松地谷歌搜索有关它的更多信息,它基本上定义了rect
,然后使用glScissor
删除外部。当我需要这样做时,我有一个课程,如下所示:
//
// CCNodeClip.h
//
// Created by Ignacio Orlandoni on 7/29/11.
//
#import <Foundation/Foundation.h>
#import "cocos2d.h"
@interface CCNodeClip : CCLayer {
}
-(void)preVisit;
-(void)postVisit;
@end
-
//
// CCNodeClip.m
//
// Created by Ignacio Orlandoni on 7/29/11.
//
#import "CCNodeClip.h"
@implementation CCNodeClip
-(void)visit {
[self preVisit];
[super visit];
[self postVisit];
}
-(void)preVisit {
if (!self.visible)
return;
glEnable(GL_SCISSOR_TEST);
CGPoint position = [self position];
//I don't remember if this rect really serves for both orientations, so you may need to change the order of the values here.
CGRect scissorRect = CGRectMake(position.x, position.y, [self contentSize].width, [self contentSize].height);
// CCLOG(@"Scrissor Rect: X: %02f, Y:%02f, W: %02f, H: %02f", scissorRect.origin.x, scissorRect.origin.y, scissorRect.size.width, scissorRect.size.height);
// Handle Retina
scissorRect = CC_RECT_POINTS_TO_PIXELS(scissorRect);
glScissor((GLint) scissorRect.origin.x, (GLint) scissorRect.origin.y,
(GLint) scissorRect.size.width, (GLint) scissorRect.size.height);
}
-(void)postVisit {
glDisable(GL_SCISSOR_TEST);
}
@end
将其导入LayerB
后,您现在可以将其定义为CCNodeClip
而不是CCLayer
。
有些链接......
Circle shape clipping with opengl-es in cocos2d << StackOverflow
Cocos2d iPhone - Sprite cliping/mask/frame << StackOverflow
Another Cocos2D gem: ClippingNode << Learn-Cocos2d.com
作为旁注......
如果精灵的锚点居中,则可以避免CCScaleTo + CCMoveTo,因此图像在缩放时保持在容器的中心位置。 (.anchorPoint = ccp(0.5, 0.5);
)