Draw a Line Sprite between two dots made by Sprites in Cocos2d
I was trying to draw a sprite line between two points made by mouse event sprites in Xcode.
I followed the steps given on the forum in this link: cocos2d forums
But when I run the code, I get a line going all the way through the simulator. similar.
The line should be stopped with a second sprite-generated code with sprite, but it doesn't and continues to the end.
My scene is something like this.
My .h class
#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
My .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
Does anyone know how to do this? i tried a lot of things but nothing worked for me, or maybe point out my mistake. I would really appreciate that.
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I am not running the code, but it looks pretty simple. The cause of the problem lies in this section:
float dist = ccpDistance(lastTouchPoint, location);
CCSprite *line = [CCSprite spriteWithFile:@"line.png"];
[line setAnchorPoint:ccp(0.0f, 0.5f)];
[line setPosition:lastTouchPoint];
[line setScaleX:dist];
This code calculates the distance between two touchpoints in points (pixels), creates a new sprite (which will become a line), and sets the anchor point to the right, centered vertically. It positions this at the point of the last touch and then sets the scale of the sprite's width based on the previously calculated distance. This scaling factor ensures that the sprite is long enough to reach between two points.
Your problem:
This does not take into account the initial dimensions of the loaded image ( line.png ). If it is not a png 1x1 size, it setScale
will make the help result too big - the overflow you are experiencing.
Decision
Make line.png a 1 x 1 pixel image. Your code will work fine, although you will have a very thin line that is not aesthetically pleasing.
Or, for best results, calculate the scale of the sprite given the width of the line.png . This way the sprite can be more detailed and won't exceed.
Change the line setScaleX
as follows:
[line setScaleX:dist / line.boundingBox.size.width];
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Using Cocos2D v3.x this works:
in -(void)update:(CCTime)delta{}
you do this:
[self.drawnode drawSegmentFrom:ccp(50,100) to:ccp(75, 25) radius:3 color:self.colorDraw];
The self.drawnode and self.colorDraw properties are initialized like this: perhaps inside -(void)onEnter{} :
self.drawnode = [CCDrawNode node];
self.colorDraw = [CCColor colorWithCcColor3b:ccRED];
[self addChild:self.drawnode];
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I think you can use the basic graphics here:
- (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];
}
I think this will help you.
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