做了点儿格式上的小改动,写了一个小用例,逻辑还是原作的逻辑~
原文链接:http://www.cocoachina.com/bbs/simple/?t40047.html
让 ccsprite 围绕一个点做旋转运动,cocos2d 本身的 setAnchorPoint 虽然可以,
但是 sprite 本身也在自转着,有时后我们不需要 sprite 自转,这时候下面的扩展便能派上用场了~
BYRoundBy.h
// // BYRoundBy.h // Oh my fish! // // Created by Bruce Yang on 12-8-9. // Copyright (c) 2012年 EricGameStudio. All rights reserved. // /** * 参考链接: * http://www.cocoachina.com/bbs/simple/?t40047.html */ #import "cocos2d.h" /** * Round circle a CCNode object clockwise a number of degrees by modiying it's rotation attribute. */ @interface BYRoundBy : CCActionInterval <NSCopying> { // Forward or Reverse round BOOL turn; // default float startAngle; // Round circle radius float radius; // Round circle center point CGPoint center; } /** * creates the action~ */ +(id) actionWithDuration:(ccTime)duration turn:(BOOL)a center:(CGPoint)point radius:(float)r; /** * initializes the action~ */ -(id) initWithDuration:(ccTime)duration turn:(BOOL)a center:(CGPoint)point radius:(float)r; @end
// // BYRoundBy.mm // Oh my fish! // // Created by Bruce Yang on 12-8-9. // Copyright (c) 2012年 EricGameStudio. All rights reserved. // #import "BYRoundBy.h" // // CCRoundBy // #pragma mark - #pragma mark BYRoundBy @implementation BYRoundBy +(id) actionWithDuration:(ccTime)t turn:(BOOL)a center:(CGPoint)point radius:(float)r { return [[[self alloc] initWithDuration:t turn:a center:point radius:r] autorelease]; } -(id) initWithDuration:(ccTime)t turn:(BOOL)a center:(CGPoint)point radius:(float)r { if((self = [super initWithDuration:t])) { turn = a; center = point; radius = r; } return self; } -(id) copyWithZone:(NSZone*)zone { CCAction* copy = [[[self class] allocWithZone: zone] initWithDuration: [self duration] turn:turn center:center radius:radius]; return copy; } -(void) startWithTarget:(id)aTarget { [super startWithTarget:aTarget]; startAngle = [target_ rotation]; if(turn) { ((CCNode*)target_).position = ccpAdd(center, ccp(-radius, 0)); } else { ((CCNode*)target_).position = ccpAdd(center, ccp(radius, 0)); } } -(void) update:(ccTime)t { // XXX: shall I add % 360 float rotate = (startAngle + 360.0f * t ); if (turn) { rotate *= -1; } [target_ setRotation:rotate]; float fradian = rotate * M_PI / 180.0f; CGPoint pos = ccp(center.x + radius * sinf(fradian), center.y + radius * cosf(fradian)); [target_ setPosition: pos]; } -(CCActionInterval*) reverse { BOOL result = !turn; return [[self class] actionWithDuration:duration_ turn:result center:center radius:radius]; } @end
-(void) testRotateEx { CGSize winSize = [[CCDirector sharedDirector] winSize]; CGPoint pntAnchor = ccp(winSize.width / 2.0f, 0); // 锚点精灵~ CCSprite* spAnchor = [CCSprite spriteWithFile:@"blackCircle.png"]; [spAnchor setPosition:pntAnchor]; [self addChild:spAnchor z:0 tag:TAG_SPRITE_ANCHOR]; // 旋转体精灵~ CCSprite* spTree = [CCSprite spriteWithFile:@"tree.png"]; id rotate = [BYRoundBy actionWithDuration:3.0f turn:YES center:pntAnchor radius:winSize.height/2.0f]; id action = [CCRepeatForever actionWithAction:rotate]; [spTree runAction:action]; [self addChild:spTree z:0 tag:TAG_SPRITE_TREE]; }