ios - 使用cocos2d定位

Question

Here is the source

问题是我的射弹的起始位置和结束位置相差很大。我有NSLog全部CGPoints从我可以看到的点被输入 CCSequence是正确的。但我在屏幕上看到的情况却有所不同。

我认为问题的一个重要线索是，如果创建一个新的 CCSprite 并像我处理射弹一样使用它，路径就会起作用。

这是游戏关卡图层上的 addProjectile 方法(GameLevels:Level1Layer)

-(void)addProjectile:(Projectiles*)projectile
{
    NSLog(@"projectile position %@",NSStringFromCGPoint(projectile.position));
    NSLog(@"wizard position %@",NSStringFromCGPoint(self.wizardHero.position));
    NSLog(@"wizard position worldspace %@",NSStringFromCGPoint([self convertToWorldSpace:self.wizardHero.position]));
    NSLog(@"destination position %@",NSStringFromCGPoint(projectile.destination.position));

    [self addChild:projectile];

    // Determine where we wish to shoot the projectile to
    int realX;

    CGPoint diff = ccpSub(projectile.destination.position,projectile.position);
    if (diff.x > 0)
    {
        realX = (self.tileMap.mapSize.width * self.tileMap.tileSize.width) +
        (projectile.contentSize.width/2);
    } else {
        realX = -(self.tileMap.mapSize.width * self.tileMap.tileSize.width) -
        (projectile.contentSize.width/2);
    }
    float ratio = (float) diff.y / (float) diff.x;
    int realY = ((realX - projectile.position.x) * ratio) + projectile.position.y;
    CGPoint realDest = ccp(realX, realY);

    // Determine the length of how far we're shooting
    int offRealX = realX - projectile.position.x;
    int offRealY = realY - projectile.position.y;
    float length = sqrtf((offRealX*offRealX) + (offRealY*offRealY));
    float velocity = 280/1; // 280pixels/1sec
    float realMoveDuration = length/velocity;

    // Move projectile to actual endpoint
    id actionMoveDone = [CCCallFuncN actionWithTarget:self
                                             selector:@selector(projectileMoveFinished:)];
    [projectile runAction:
     [CCSequence actionOne:
      [CCMoveTo actionWithDuration: realMoveDuration
                          position: realDest]
                       two: actionMoveDone]];

    [self.projectiles addObject:projectile];
}

以及 NSLog 的输出语句将是(仅供引用:射弹是从 self.wizardHero 添加的，因此这是它的起始位置；目的地将是 self.redEnemy ):

2013-03-27 10:41:57.295 GridWars[13025:c07] projectile position {105, 178}

2013-03-27 10:41:57.296 GridWars[13025:c07] wizard position {105, 178}

2013-03-27 10:41:57.297 GridWars[13025:c07] wizard position worldspace {105, 178}

2013-03-27 10:41:57.298 GridWars[13025:c07] destination position {299, 174}

2013-03-27 11:34:46.608 GridWars[13344:c07] realDest {650, 166}

2013-03-27 11:34:46.608 GridWars[13344:c07] length 545.132080

2013-03-27 11:34:46.610 GridWars[13344:c07] realMoveDuration 1.946900

我意识到，对于 super 类，我有点难以判断发生了什么(这就是为什么我包含源代码)。基本上，我有三个主要的 super 类，它们是 CCNode 的子类。

Projectiles : CCNode
        sprite : CCSprite
        destination : GameCharacters
        damage : int


GameLevels : CCNode
        hud : HudLayer
        tileMap : CCTMXTiledMap
        enemies : NSMutablArray
        projectiles : NSMutablArray

GameCharacters : CCNode
        hp : int
        juice : int
        sprite : CCSprite
        selectedTargets : NSMutablArray
        hostLayer : GameLevels

然后是实际实现这些的三个类

        BasicProjectile : Projectiles
        Level1Layer : GameLevels
        WizardHero : GameCharacter
        RedEnemy : GameCharacter

虽然问题略有进展，但我已将其发布在 cocos2d forums 上并得到了一些帮助，这让我走到了这一步(看到射弹，但路径错误与根本看不到它们)。但已经过去几天了，希望获得更多帮助。

游戏转换物:CCNode

#import "CCNode.h"

//forward declaration because we just need to hold a reference
@class GameCharacters;

@interface GameProjectiles : CCNode

@property(nonatomic, strong) CCSprite * sprite;
@property(nonatomic,strong) GameCharacters * destination;
@property(nonatomic) int damage;
-(id)initWithDestination:(GameCharacters*)Destination;
-(CGSize)contentSize;

@end


#import "GameProjectiles.h"

@implementation GameProjectiles

-(id)initWithDestination:(GameCharacters*)Destination
{

    if (self = [super init]) {
        _damage = 0;
        _destination = Destination;
    }
    return self;
}

-(CGSize)contentSize{
    return self.sprite.contentSize;
}

-(void)setPosition:(CGPoint)position
{
    [super setPosition:position];
    self.sprite.position = position;
}
@end

基本转换物

#import "GameProjectiles.h"

@interface BasicProjectile : GameProjectiles

@end


#import "BasicProjectile.h"

@implementation BasicProjectile

-(id)initWithDestination:(GameCharacters*)Destination
{
    if (self = [super init]) {
        self.damage = 25;
        self.sprite = [CCSprite spriteWithFile:@"Projectile.png"];
        [self addChild:self.sprite z:1000 ];
        self.destination = Destination;
    }
    return self;
}

@end

Answer 1

由于您的射弹和目标位于单独的 CCNode 内，因此它们的边界框返回其父级内的位置，而不是实际的屏幕坐标(在您的情况下是您想要的)。

要转换 pos，你可以这样做

    CGPoint targetPos = [basicProjectile.destination.sprite.parent convertToWorldSpace:basicProjectile.destination.sprite.position];
    NSLog(@"targetPos  %@",NSStringFromCGPoint(targetPos));
    CGRect targetRect = [self boundingRectForSprite:basicProjectile.destination.sprite andPos:targetPos];

    CGPoint projectilePos = [basicProjectile.sprite.parent convertToWorldSpace:basicProjectile.sprite.position];
    NSLog(@"projectilePos  %@",NSStringFromCGPoint(projectilePos));
    CGRect projectileRect = [self boundingRectForSprite:basicProjectile.destination.sprite andPos:projectilePos];

boundingRectForSprite方法使用 Sprite 边界框和位置，然后计算出最终的矩形，其 anchor 为(0.5,0.5)。

现在 targetRect 和 projectileRect 是实际的屏幕坐标。