Question

我正在尝试制作像飞行控制这样的游戏，其中有数量的汽车，每个都有自己的路径。我的想法是制作一个汽车类的子类型SKNode，并为每个对象都有一个CGMutablePathRef实例变量。我可以使用touchsBegins，touchsMoved和touchesEnded创建CGMutablePathRef，然后我可以让每个对象跟随SKAction followPath的特定路径。这是一个好方法吗？如果不是，你会怎么做？这就是我目前为Vehicle类所做的：

Vehicle.h

@interface Vehicle: SKNode

@property (nonatomic, assign) CGMutablePathRef pathToFollow;
@property (nonatomic) CGFloat speed;
@property (nonatomic) int direction;

- (instancetype)initWith:(CGMutablePathRef)pathPassed;

@end

Vehicle.m

@implementation Vehicle : SKNode

@synthesize pathToFollow;
@synthesize speed;
@synthesize direction;


- (id)init
{
    self = [super init];
    if (self) {
        SKSpriteNode *vehicle = [SKSpriteNode spriteNodeWithImageNamed:@"Spaceship"];
        [self addChild:vehicle];
        [self setDirection:4];
        [vehicle setName:@"car"];
        [self setScale:.5];
    }
    return self;
}
- (id)initWith:(CGMutablePathRef)pathPassed {

    self = [super init];
    if (self) {
        SKSpriteNode *vehicle = [SKSpriteNode spriteNodeWithImageNamed:@"Spaceship"];
        [self addChild:vehicle];
        [self setPathToFollow:pathPassed];
        [self setDirection:4];
        [vehicle setName:@"car"];
        [self setScale:.1];
    }

    return self;
}

@end

编辑：添加GameScene希望它会有所帮助。我现在的实现有一个问题，其中Vehicle对象跟随路径，但只有在它跳到第一个点的坐标+场景上的节点位置之后（例如：position =（200,200），第一个点） =（123,456）它将转到（323,656）然后按照路径）。它绘制了我想要它的行，但随后它从这个坐标开始。再次感谢您的帮助！

GameScene.m

-(void)didMoveToView:(SKView *)view {
    _car = [[Vehicle new] init]; // init the Vehicle object then set position
    [_car setPosition:CGPointMake(self.scene.size.width/2, self.scene.size.height/2)];
    [self addChild_car]; // add the child to the scene
}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

    // get the node that was touched
    UITouch* touch = [touches anyObject];
    CGPoint positionInScene = [touch locationInNode:self];
    _nodeTouchedFirst = [self nodeAtPoint:positionInScene];

    if ([_nodeTouchedFirst.name isEqualToString:@"car"]) {
        if (lineNode != NULL) { // remove the previous path
            [lineNode removeFromParent];
            [CGPathRelease(pathToDraw);
        }

        //Start a new path and display it on the screen
        pathToDraw = CGPathCreateMutable();
        CGPathMoveToPoint(pathToDraw, NULL, positionInScene.x, positionInScene.y);
        lineNode = [SKShapeNode];
        lineNode.path = pathToDraw;
        lineNode.strokeColor = [SKColor redColor];
        [self addChild:lineNode];


    }
} // touchesBegan

- (void)touchesMoved:(NSSet*)touches withEvent:(UIEvent*)event
{
    if ([_nodeTouchedFirst.name isEqualToString:@"car"]) {
        UITouch* touch = [touches anyObject];
        CGPoint positionInScene = [touch locationInNode:self];

        CGPathAddLineToPoint(pathToDraw, NULL, positionInScene.x, positionInScene.y);
        lineNode.path = pathToDraw;
    }
} // touchesMoved

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    if ([_nodeTouchedFirst.name isEqualToString:@"car"]) {
        SKAction *followPath = [SKAction followPath:pathToDraw asOffset:YES orientToPath:NO duration:2];
        [_nodeTouchedFirst runAction:followPath];
        lineNode.strokeColor = [SKColor grayColor];
    }

}

Answer 1

一些可能有帮助或可能没有帮助的观察结果：

您正在设置_car的位置并将其添加到场景中，然后再为其指定路径。
您引用了_nodeTouchedFirst和nodeTouchedFirst，"car"和"car1"。
您正在使用asOffset:YES, orientToPath:NO, duration:2（而不是asOffset:NO, orientToPath:YES, speed:2）跟踪路径。
direction与SKNode zRotation属性不对应。

如何制作几个精灵节点，每个节点都有一个特殊的路径可供遵循

1 个答案: