我一直在尝试在Xcode上用鼠标事件在sprite之间绘制两个点之间的精灵线。
我一直在关注此链接中论坛上给出的步骤： cocos2d forums
但是当我运行代码时，我会让线路一直走向模拟器。就像这样。
该行应该由第二个鼠标精灵生成的代码停止，但它不会并且一直向前移动。
我的场景是这样的。
我的.h班
#import <Foundation/Foundation.h>
#import "cocos2d.h"
#import "Constants.h"
#import "SceneManager.h"
@interface EscenaInfo : CCLayer{
CGPoint lastTouchPoint;
CCSprite * background;
}
@property (nonatomic, assign) BOOL iPad;
@end
我的.mm
#import "EscenaInfo.h"
@implementation EscenaInfo
@synthesize iPad;
- (void)onBack: (id) sender {
/*
This is where you choose where clicking 'back' sends you.
*/
[SceneManager goMenuPrincipal];
}
- (void)addBackButton {
if (self.iPad) {
// Create a menu image button for iPad
CCMenuItemImage *goBack = [CCMenuItemImage itemFromNormalImage:@"Arrow-Normal-iPad.png"
selectedImage:@"Arrow-Selected-iPad.png"
target:self
selector:@selector(onBack:)];
// Add menu image to menu
CCMenu *back = [CCMenu menuWithItems: goBack, nil];
// position menu in the bottom left of the screen (0,0 starts bottom left)
back.position = ccp(64, 64);
// Add menu to this scene
[self addChild: back];
}
else {
// Create a menu image button for iPhone / iPod Touch
CCMenuItemImage *goBack = [CCMenuItemImage itemFromNormalImage:@"Arrow-Normal-iPhone.png"
selectedImage:@"Arrow-Selected-iPhone.png"
target:self
selector:@selector(onBack:)];
// Add menu image to menu
CCMenu *back = [CCMenu menuWithItems: goBack, nil];
// position menu in the bottom left of the screen (0,0 starts bottom left)
back.position = ccp(32, 32);
// Add menu to this scene
[self addChild: back];
}
}
- (id)init {
if( (self=[super init])) {
// Determine Screen Size
CGSize screenSize = [CCDirector sharedDirector].winSize;
//Boton en la Interfaz del iPad
self.iPad = UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad;
// Put a 'back' button in the scene
[self addBackButton];
///
self.isTouchEnabled = YES;
lastTouchPoint = ccp(-1.0f,-1.0f);
///
[CCTexture2D setDefaultAlphaPixelFormat:kCCTexture2DPixelFormat_RGB565];
background = [CCSprite spriteWithFile:@"background.png"];
background.anchorPoint = ccp(0,0);
[self addChild:background z:-1];
[CCTexture2D setDefaultAlphaPixelFormat:kCCTexture2DPixelFormat_Default];
}
return self;
}
- (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];
}
- (void)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
if( touch ) {
CGPoint location = [touch locationInView: [touch view]];
location = [[CCDirector sharedDirector] convertToGL:location];
CCLOG(@"location(%f,%f)", location.x, location.y);
if( CGPointEqualToPoint(lastTouchPoint, ccp(-1.0f,-1.0f) ) )
{
lastTouchPoint = ccp(location.x, location.y);
CCSprite *circle = [CCSprite spriteWithFile:@"circle.png"];
[circle setPosition:lastTouchPoint];
[self addChild:circle];
CCLOG(@"initial touchpoint set. to (%f,%f)", lastTouchPoint.x, lastTouchPoint.y);
}
else {
CCLOG(@"lastTouchPoint is now(%f,%f), location is (%f,%f)", lastTouchPoint.x, lastTouchPoint.y, location.x, location.y);
CGPoint diff = ccpSub(location, lastTouchPoint);
float rads = atan2f( diff.y, diff.x);
float degs = -CC_RADIANS_TO_DEGREES(rads);
float dist = ccpDistance(lastTouchPoint, location);
CCSprite *line = [CCSprite spriteWithFile:@"line.png"];
[line setAnchorPoint:ccp(0.0f, 0.5f)];
[line setPosition:lastTouchPoint];
[line setScaleX:dist];
[line setRotation: degs];
[self addChild:line];
CCSprite *circle = [CCSprite spriteWithFile:@"circle.png"];
[circle setPosition:location];
[self addChild:circle];
// lastTouchPoint = ccp(location.x, location.y);
lastTouchPoint = ccp(-1.0f,-1.0f);
}
}
}
@end
有谁知道如何解决这个问题？我一直在尝试很多东西，但没有什么对我有用，或者可能指出我的错误。我真的很感激。
答案 0 :(得分：3)
我没有运行代码，但看起来相当简单。问题的原因在于本节：
float dist = ccpDistance(lastTouchPoint, location);
CCSprite *line = [CCSprite spriteWithFile:@"line.png"];
[line setAnchorPoint:ccp(0.0f, 0.5f)];
[line setPosition:lastTouchPoint];
[line setScaleX:dist];
此代码以点（像素）计算两个触摸点之间的距离，创建一个新的精灵（将成为线）并将锚点设置到右侧，垂直居中。它将其定位在最后一次触摸的位置，然后根据之前计算的距离设置精灵宽度的比例。这个比例因子将确保精灵“足够长”以达到两点之间。
您的问题：
这不考虑您要加载的图像的初始尺寸（ line.png ）。如果这不是1x1维度png，那么setScale将导致生成的精灵过大 - 您遇到的溢出。
解决方案
使 line.png 成为1 x 1像素的图像。你的代码将完美地运行，尽管你会有一条非常细的线条，这在美学上并不令人愉悦。
或者，为了获得最佳效果，请考虑 line.png 的宽度来计算精灵的比例。这样精灵可以更加详细，不会溢出。
将setScaleX行更改为：
[line setScaleX:dist / line.boundingBox.size.width];
答案 1 :(得分：0)
使用Cocos2D v3.x，这有效：
在-(void)update:(CCTime)delta{}中执行此操作：
[self.drawnode drawSegmentFrom:ccp(50,100) to:ccp(75, 25) radius:3 color:self.colorDraw];
self.drawnode和self.colorDraw属性初始化如下，可能在-(void)onEnter{} :
self.drawnode = [CCDrawNode node];
self.colorDraw = [CCColor colorWithCcColor3b:ccRED];
[self addChild:self.drawnode];
答案 2 :(得分：-1)
我认为你可以在这里使用核心图形：
- (void)drawRect:(CGRect)rect {
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetLineWidth(context,4);
CGContextSetStrokeColorWithColor(context, [UIColor redColor].CGColor);
CGContextMoveToPoint(context,startPoint.x , startPoint.y);
CGContextAddLineToPoint(context, endPoint.x, endPoint.y);
CGContextStrokePath(context);
}
- (void) touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event
{
UITouch* touchPoint = [touches anyObject];
startPoint = [touchPoint locationInView:self];
endPoint = [touchPoint locationInView:self];
[self setNeedsDisplay];
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch* touch = [touches anyObject];
endPoint=[touch locationInView:self];
[self setNeedsDisplay];
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch* touch = [touches anyObject];
endPoint = [touch locationInView:self];
[self setNeedsDisplay];
}
我认为这会对你有帮助。