Question

我正在寻找一些关于如何使用Cocos2d，我可以拥有一个以恒定速度持续运动的物体（让他们说火箭）的指导，我只有两个按钮来简单改变方向。

我已经找到了一些关于如何改变火箭方向的信息，但是我只是坚持让火箭不断运动。

我后来想让火箭能够从屏幕上飞出并重新出现在屏幕的另一侧，但那是另一个问题（我发现了一些问题）已经帮助了。）

我是Cocos2d的新手并且已经搜索了几个小时，但我们还没有找到我之后的内容。

能否让我的火箭不断移动，并对方向的变化作出反应，有人能指出我正确的方向吗？

Answer 1

所以，这是第一步，你可以做些什么：

// ProjectileTest拥有一个只知道如何操作的射弹类   移动自己

// WrapBoundaryTest是显示潜在用法的示例场景   ProjectileTest

<强> ProjectileTest.h

#import "cocos2d.h"

@interface ProjectileTest : CCNode
{
    CCSprite *sprite;
    CGPoint velocity;
    CGRect bounds;
    BOOL isActive;
    float steerAmount;
}

@property CCSprite *sprite;
@property CGPoint velocity;
@property CGRect bounds;
@property BOOL isActive;
@property float steerAmount;

+(id) projectileWithBounds:(CGRect) boundary
               andVelocity:(CGPoint) v
         andSteeringAmount:(float) steeringAmount;

-(void) step:(CCTime) dt;
-(void) steerLeft;
-(void) steerRight;
@end

<强> ProjectileTest.m

#import "ProjectileTest.h"

@implementation ProjectileTest

@synthesize sprite, velocity, bounds, isActive, steerAmount;

+(id) projectileWithBounds:(CGRect) boundary andVelocity:(CGPoint) v andSteeringAmount:(float) steeringAmount
{
    ProjectileTest *proj = [[self alloc] init];
    proj.bounds = boundary;
    proj.velocity = v;
    proj.steerAmount = steeringAmount;
    proj.isActive = YES;
    [proj calculateAngleForVelocity: v];
    return proj;
}

-(id) init
{
    if(( self = [super init]))
    {
        sprite = [CCSprite spriteWithImageNamed:@"Icon.png"];
        [self addChild:sprite];

        [sprite setScale:0.50f];
        bounds = CGRectZero;
        velocity = CGPointZero;
        isActive = NO;
        steerAmount = 1.0f;
    }
    return self;
}

-(void) calculateAngleForVelocity:(CGPoint) v
{
    float rads = ccpToAngle(v);
    float degs = -CC_RADIANS_TO_DEGREES(rads);
    sprite.rotation = degs + 90.0f;
}

-(void) steerLeft
{
    [self steer: YES];
}

-(void) steerRight
{
    [self steer: NO];
}

-(void) steer:(BOOL) left
{
    if(left)
    {
        velocity = ccpRotateByAngle(velocity, CGPointZero, -CC_DEGREES_TO_RADIANS(-steerAmount));
    }
    else // right
    {
        velocity = ccpRotateByAngle(velocity, CGPointZero, -CC_DEGREES_TO_RADIANS(steerAmount));
    }
}

-(void) step:(CCTime)dt
{
    if(isActive)
    {
        if(CGRectContainsPoint(bounds, self.position))
        {
            self.position = ccpAdd(self.position, velocity);
            [self calculateAngleForVelocity: velocity];
        }
        else
        {
            float nudge = 0.5f;
            if(self.position.x >= bounds.size.width && velocity.x > 0.0f)
            {
                self.position = ccp(bounds.origin.x + nudge, self.position.y);
            }
            else if(self.position.x <= bounds.origin.x && velocity.x < 0.0f)
            {
                self.position = ccp(bounds.size.width - nudge, self.position.y);
            }

            if(self.position.y >= bounds.size.height && velocity.y > 0.0f)
            {
                self.position = ccp(self.position.x, bounds.origin.y + nudge);
            }
            else if(self.position.y <= bounds.origin.y && velocity.y < 0.0f)
            {
                self.position = ccp(self.position.x, bounds.size.height - nudge);
            }
        }
    }
}

@end

<强> WrapBoundaryTest.h

#import "cocos2d.h"
#import "cocos2d-ui.h"

@interface WrapBoundaryTest : CCScene
{
    NSMutableArray *projectiles;
    CCButton *left;
    CCButton *right;
}

@property __strong NSMutableArray *projectiles;
+(id) scene;
@end

<强> WrapBoundaryTest.m

#import "WrapBoundaryTest.h"
#import "ProjectileTest.h"

@implementation WrapBoundaryTest

@synthesize projectiles;

+(id) scene
{
    return [[self alloc] init];
}

-(id) init
{
    if(( self = [super init]))
    {
        projectiles = [NSMutableArray array];
        CGRect projectileBounds = CGRectMake(
                                             0.0f,
                                             0.0f,
                                             [CCDirector sharedDirector].designSize.width,
                                             [CCDirector sharedDirector].designSize.height
                                             );

        CGPoint origin = ccp(200.0f, 150.0f);
        [self addProjectileWithBoundsRect:projectileBounds andVelocity:ccp( 1.0f,  5.0f) andSteeringAmount:2.0f atStartingPosition:origin];
        [self addProjectileWithBoundsRect:projectileBounds andVelocity:ccp(-1.0f, -5.0f) andSteeringAmount:1.0f atStartingPosition:origin];
        [self addProjectileWithBoundsRect:projectileBounds andVelocity:ccp(-1.0f,  1.0f) andSteeringAmount:0.5f atStartingPosition:origin];
        [self addProjectileWithBoundsRect:projectileBounds andVelocity:ccp( 8.0f,  1.0f) andSteeringAmount:7.5f atStartingPosition:origin];

        left = [CCButton buttonWithTitle:@"Left" fontName:@"Arial" fontSize:16.0f];
        left.positionType = CCPositionTypeNormalized;
        left.position = ccp(0.1f, 0.1f);

        [self addChild:left];

        right = [CCButton buttonWithTitle:@"Right" fontName:@"Arial" fontSize:16.0f];
        right.positionType = CCPositionTypeNormalized;
        right.position = ccp(0.9f, 0.1f);
        [self addChild:right];
    }
    return self;
}

-(void) addProjectileWithBoundsRect:(CGRect) boundsRect
                        andVelocity:(CGPoint) velocity
                  andSteeringAmount:(float) steeringAmount
                 atStartingPosition:(CGPoint) startingPosition
{
    ProjectileTest *proj = [ProjectileTest projectileWithBounds: boundsRect
                                                    andVelocity: velocity
                                              andSteeringAmount: steeringAmount
                            ];
    proj.position = startingPosition;
    [self addChild:proj];
    [projectiles addObject:proj];
}

-(void) update:(CCTime)delta
{
    for(ProjectileTest *p in projectiles)
    {
        if(left.touchInside)
        {
            [p steerLeft];
        }

        if(right.touchInside)
        {
            [p steerRight];
        }

        [p step:delta];
    }
}

@end

// HTH

用Cocos2d不断移动物体

1 个答案: