【问题标题】：How to implement water ripples?如何实现水波纹？
【发布时间】：2009-03-20 05:25:37
【问题描述】：

我正在开发一款 iPhone 游戏。在那我不得不产生水波纹。我不知道如何得到它。听说可以用openGL来做。我对这个概念很陌生。任何人都可以指导我吗？

【问题讨论】：

到底有没有达到效果？

标签： iphone opengl-es

【解决方案1】：

以下是我找到的一些资源：

Language Agnostic 2d Water Ripple Algorithm

_{（来源：virgin.net）}
_{（来源：virgin.net）}

OpenGL Project with Water Ripples (Source)

_{（来源：sulaco.co.za）}

您可能还想通过GameDev's FAQ 摇摆。向下滚动到“水渲染”部分。

【讨论】：

【解决方案2】：

jk:

z=sin(x)+cos(y)

更严重的是，Quartz Composer 基本上不作为效果层之一为您制作涟漪吗？还是仅针对 iPhone 3.0 SDK 发布？

【讨论】：

这是一个非常昂贵的例程。它绝对会在游戏中杀死 OpenGL。我猜他想要一个不错的水效果，这意味着老式的纹理映射技巧。
请原谅；我知道。我在开玩笑。

【解决方案3】：

我找到了水波纹效果的源代码，所以下面的代码可以实现到您的项目中并解决您的问题。

导入“HelloWorldLayer.h”

// HelloWorldLayer implementation
@implementation HelloWorldLayer

+(CCScene *) scene
{
    // 'scene' is an autorelease object.
    CCScene *scene = [CCScene node];
    
    // 'layer' is an autorelease object.
    HelloWorldLayer *layer = [HelloWorldLayer node];
    
    // add layer as a child to scene
    [scene addChild: layer];
    
    // return the scene
    return scene;
}

// on "init" you need to initialize your instance
-(id) init
{
    
    if( (self=[super init])) {

        rippleImage = [ pgeRippleSprite ripplespriteWithFile:@"image_old.png" ];
        [ self addChild:rippleImage ];
        CCLabelTTF *label = [CCLabelTTF labelWithString:@"Hello Cocos2D Forum" fontName:@"Marker Felt" fontSize:16];
        label.position = ccp( 80 , 300 );
        [self addChild: label];
        [ [ CCTouchDispatcher sharedDispatcher ] addTargetedDelegate:self priority:0 swallowsTouches:YES ]; 
        
        // schedule update
        [ self schedule:@selector( update: ) ];    
                
    }
    return self;
}

float runtime = 0;

-( BOOL )ccTouchBegan:( UITouch* )touch withEvent:( UIEvent* )event {
    runtime = 0.1f;
    [ self ccTouchMoved:touch withEvent:event ];
    return( YES );
}

-( void )ccTouchMoved:(UITouch *)touch withEvent:(UIEvent *)event {
    CGPoint pos;
    
    if ( runtime >= 0.1f ) {
        
        runtime -= 0.1f;
        
        // get touch position and convert to screen coordinates
        pos = [ touch locationInView: [ touch view ] ];
        pos = [ [ CCDirector sharedDirector ] convertToGL:pos ];
    
        // [ rippleImage addRipple:pos type:RIPPLE_TYPE_RUBBER strength:1.0f ];    
        [ rippleImage addRipple:pos type:RIPPLE_TYPE_WATER strength:2.0f ];  
        
        
    }
}

-( void )update:( ccTime )dt {
    
    runtime += dt;
    
    [ rippleImage update:dt ];
}

// on "dealloc" you need to release all your retained objects
- (void) dealloc
{
    // in case you have something to dealloc, do it in this method
    // in this particular example nothing needs to be released.
    // cocos2d will automatically release all the children (Label)
    
    // don't forget to call "super dealloc"
    [super dealloc];
}
@end

Also you can download the source code from the Git

【讨论】：