SKAction属性介绍
在使用动作过程当中,对于属性的设置是必不可少的,本文将说说最常用的属性,分别是速度,时间,曲线方式.下面就分模块说一下三个常用的属性.我们首先先把我们的准备工作做好,创建好背景和精灵,代码如下所示.
#import "GameScene.h"
@implementation GameScene
-(instancetype)initWithSize:(CGSize)size{
if (self = [super initWithSize:size]) {
self.backgroundColor = [SKColor whiteColor];
}
return self;
}
-(void)didMoveToView:(SKView *)view{
[super didMoveToView:view];
[self backgroundNode];
[self planeNode];
}
#pragma mark ----创建背景----
-(void)backgroundNode{
SKSpriteNode *backgroundNode = [SKSpriteNode spriteNodeWithImageNamed:@"bg_02.jpg"];
backgroundNode.position = CGPointZero;
backgroundNode.zPosition = 0;
backgroundNode.anchorPoint = CGPointZero;
backgroundNode.size = self.size;
[self addChild:backgroundNode];
}
#pragma mark ---- 创建两个飞船 ----
-(void)planeNode{
SKSpriteNode *planeNode = [SKSpriteNode spriteNodeWithImageNamed:@"飞机.png"];
planeNode.position = CGPointMake(self.size.width/2, self.size.height/2);
planeNode.anchorPoint = CGPointMake(0.5, 0.5);
planeNode.zPosition = 1;
planeNode.name = @"plane";
[self addChild:planeNode];
SKSpriteNode *planeNode1 = [SKSpriteNode spriteNodeWithImageNamed:@"飞机.png"];
planeNode1.position = CGPointMake(self.size.width/2+100, self.size.height/2);
planeNode1.anchorPoint = CGPointMake(0.5, 0.5);
planeNode1.zPosition = 1;
planeNode1.name = @"plane1";
[self addChild:planeNode1];
}
speed(速度属性)
速度因素调整动作的动画速度。例如,速度2.0倍意味着动画运行速度的两倍。速度的默认值为1.0.下面就是API文档中的SKAction的speed属性的介绍.
下面就用两个精灵说明速度属性.代码如下.
#pragma mark ---- 移动飞船 ----
-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
SKSpriteNode *planeNode = (SKSpriteNode *)[self childNodeWithName:@"plane"];
SKAction *moveAction = [SKAction moveToY:0 duration:1];
//设置速度
moveAction.speed = 0.5;
[planeNode runAction:moveAction];
SKSpriteNode *planeNode1 = (SKSpriteNode *)[self childNodeWithName:@"plane1"];
SKAction *moveAction1 = [SKAction moveToY:0 duration:1];
//设置速度
moveAction1.speed = 2;
[planeNode1 runAction:moveAction1];
}
@end
效果图如下所示.
效果图
duration(时间属性)
想要设置或者是获取动作所需要的时间,需要使用到duration这个属性.在API文章的duration属性介绍如下图所示.
API文档中duration属性介绍
在上面的速度代码中,我们直接添加上获取时间的代码.如下所示,修改duration属性也是一样,这里我们只做获取的操作.
#pragma mark ---- 移动飞船 ----
-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
SKSpriteNode *planeNode = (SKSpriteNode *)[self childNodeWithName:@"plane"];
SKAction *moveAction = [SKAction moveToY:0 duration:1];
//设置速度
moveAction.speed = 0.5;
[planeNode runAction:moveAction];
SKSpriteNode *planeNode1 = (SKSpriteNode *)[self childNodeWithName:@"plane1"];
SKAction *moveAction1 = [SKAction moveToY:0 duration:1];
//设置速度
moveAction1.speed = 2;
[planeNode1 runAction:moveAction1];
NSLog(@"动作一的所需时间:%f",moveAction.duration);
NSLog(@"动作二的所需时间:%f",moveAction1.duration);
}
@end
控制台打印信息如下.我们看到我们获得了动作的时间属性.
timingMode(曲线方式属性)
动作的曲线方式其实就是动画总体变化的时间曲线,动作的曲线方式的设置以及获取需要使用到timingMode这个一个属性,timingMode的取值一共有4个,如下表所示.
| 曲线方式 | 功能 |
|---|---|
| SKActionTimingLinear | 动画在其持续时间内平均分布 |
| SKActionTimingEaseIn | 动画在开始的时候较慢,然后渐渐加快 |
| SKActionTimingEaseOut | 动画开始的时候较快,然后渐渐变慢 |
| SKActionTimingEaseInEaseOut | 动画开始的时候慢,然后渐渐加速到中间,然后在渐渐变慢到完成 |
如果不对曲线方式属性进行设置的话,默认的是SKActionTimingLinear.下面我们就用看一下代码示例.我们在速度代码的基础上加以修改,来验证曲线方式.
#pragma mark ---- 创建两个飞船 ----
-(void)planeNode{
SKSpriteNode *planeNode = [SKSpriteNode spriteNodeWithImageNamed:@"飞机.png"];
planeNode.position = CGPointMake(self.size.width/2, self.size.height/2);
planeNode.anchorPoint = CGPointMake(0.5, 0.5);
planeNode.zPosition = 1;
planeNode.name = @"plane";
[self addChild:planeNode];
SKSpriteNode *planeNode1 = [SKSpriteNode spriteNodeWithImageNamed:@"飞机.png"];
planeNode1.position = CGPointMake(self.size.width/2+100, self.size.height/2);
planeNode1.anchorPoint = CGPointMake(0.5, 0.5);
planeNode1.zPosition = 1;
planeNode1.name = @"plane1";
[self addChild:planeNode1];
SKSpriteNode *planeNode2 = [SKSpriteNode spriteNodeWithImageNamed:@"飞机.png"];
planeNode2.position = CGPointMake(self.size.width/2-100, self.size.height/2);
planeNode2.anchorPoint = CGPointMake(0.5, 0.5);
planeNode2.zPosition = 1;
planeNode2.name = @"plane2";
[self addChild:planeNode2];
}
#pragma mark ---- 移动飞船 ----
-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
SKSpriteNode *planeNode = (SKSpriteNode *)[self childNodeWithName:@"plane"];
SKAction *moveAction = [SKAction moveToY:0 duration:2];
//设置曲线方式
moveAction.timingMode = SKActionTimingEaseIn;
[planeNode runAction:moveAction];
SKSpriteNode *planeNode1 = (SKSpriteNode *)[self childNodeWithName:@"plane1"];
SKAction *moveAction1 = [SKAction moveToY:0 duration:2];
//设置曲线方式
moveAction1.timingMode = SKActionTimingEaseOut;
[planeNode1 runAction:moveAction1];
SKSpriteNode *planeNode2 = (SKSpriteNode *)[self childNodeWithName:@"plane2"];
SKAction *moveAction2 = [SKAction moveToY:0 duration:2];
//设置曲线方式
moveAction2.timingMode = SKActionTimingEaseInEaseOut;
[planeNode2 runAction:moveAction1];
}
下面我们就看一下效果图,
各个精灵对象设置的曲线方式
效果图
总结:SKAction常用属性速度,时间,曲线方式基本就写到这了.下一篇博客,就是游戏中的重头戏:物理引擎,希望大家关注,谢谢.最后废话不多说,Demo双手奉上.
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