Hey guys, i ready many many questions about that point, but i really didn't get the right one yet.
So.. this is the problem..
This is my first project with cocos2d, so sorry for that.
I have one scene called Gameplay inside that i have one Layer with the name Grid and inside of this grid, have many many Block (Layer too).
I need check when you touch one Block, i do this before with Interface Builder, so when i call touchesBegin i have the exact touch in one view. But in cocos2D, i understand you have to check the position of the objects, and not hit test then right?!
So my touchesBegin is like this:
- (void)ccTouchesBegan:(NSSet*)touches withEvent:(UIEvent*)event
{
UITouch *touch = [touches anyObject];
CGPoint location = [touch locationInView: [touch view]];
//location = [[Director sharedDirector] convertCoordinate: location];
for(int i = 0; i < [arrAllBlocks count]; i++)
{
for (int j = 0; j < [[arrAllBlocks objectAtIndex:i] count]; j++)
{
Block *tempBlock = [[arrAllBlocks objectAtIndex:i] objectAtIndex:j];
CGRect mySurface = (CGRectMake(tempBlock.position.x, tempBlock.position.y, tempBlock.contentSize.width,tempBlock.contentSize.height));
if(CGRectContainsPoint(mySurface, location))
{
NSLog(#"Hit Positions %fl:%fl",location.x,location.y);
NSLog(#"Object Positions %fl:%fl",tempBlock.position.x,tempBlock.position.y);
NSLog(#"Object Color:%# hited", tempBlock.strName);
}
}
}
}
The first Problem is: This looks upsidedown! When i click in one of this blocks at the first line! I get the block at last line!! I Really dont get that! And the hit not seens perfect to me! And when i convertCoordinate this going even worst!
Someone can help me?! And sorry for bad english =/
There are two things to remember...
Cocos2D coordinate system's origin is bottom left corner.
By default, the anchor points of display elements are their centers.
So this is how I solved this problem:
Set the anchor points of the elements to be bottom left as well.
[block setAnchorPoint:ccp(0, 0)];
Use convertCoordinate in ccTouchesBegan.
-(BOOL)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint pt = [touch locationInView:[touch view]];
CGPoint ptConv = [[Director sharedDirector] convertCoordinate:pt];
}
Calculate the rectangle of the element and compare...
CGSize size = [block contentSize];
CGPoint point = [block position];
rect = CGRectMake(point.x, point.y, size.width, size.height);
if (CGRectContainsPoint(rect, ptConv))
{
// touched
}
It looks like the only step you are missing is to change the anchor point.
If you prefer not to change the anchor point, you need to change the way rectangle is calculated; adding and subtracting the half of width and height.
Hope it helps.
Remember that the coordinate system in Cocos2D is upside down from that of Cocoa. (Really, Cocoa is upside down to me, but it's just a convention).
I forget this all the time myself!
Related
I am trying to develop a game using openGL where i have used GLTextureLoader class to load images and these sprites are moving from left to right with some calculated velocity , i need to detect touch on these images.
Since your purpose is very simple, all you have to do is draw whatever object you have twice, the visible one and another one with just color on an invisible buffer. then you check for the location where the user pressed in the invisible buffer, see what color it is and there you have your object.
http://www.lighthouse3d.com/opengl/picking/index.php3?color1
That is the basic theory.
OpenGL is a rendering API. It only draws stuff.
Techniques like lighthouse3d do work, but glReadPixels is slow.
You should check this on the CPU; that is, for each drawn sprite, test if the touch position is inside.
I found out how to do it ,as per my requirement , As i said i am not the expert in openGL but managed to do it some way around.
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [[touches allObjects] objectAtIndex:0];
CGPoint touchLocation = [touch locationInView:self.view];
touchLocation = touchLocation = CGPointMake(touchLocation.x, 320 - touchLocation.y);
//self.player.moveVelocity = GLKVector2Make(50, 50);
//NSLog(#"Location in view %#", NSStringFromCGPoint(touchLocation));
//NSLog(#"bounding box is %#",NSStringFromCGRect([self.player boundingBox]));
GameSprite *temp;
for (GameSprite *tempSprite in self.children) {
if (CGRectContainsPoint([tempSprite boundingBox], touchLocation)) {
NSLog(#"touched the player");
temp =tempSprite;
}
}
[self.children removeObject:temp];
}
- (CGRect)boundingBox {
CGRect rect = CGRectMake(self.position.x, self.position.y, self.contentSize.width, self.contentSize.height);
return rect;
}
I am rather new to using Cocos2d for iPhone and I am having an issue with touch locations. At the moment I am simply trying to touch and move a sprite on the screen, this works fine when the layer is unmoved as well as when I translate the layer (changing self.position in X direction in my case) however, when I scale my layer (example: self.scale = .5) the touch no longer moves the sprite. I have done a lot of forum searching/google searching and I think my issue has to do with my coordinate transforms (node space/world space etc.) But I am not 100% sure. I did notice that when I scale, if I click the location where the sprite would be without the scale, then I could move the sprite. This leads me to believe that my transforms are not taking the scale into account.
Here is the coordinate transform code I am currently using to get touch locations:
- (void)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *myTouch = [touches anyObject];
CGPoint location = [myTouch locationInView:[myTouch view]];
location = [self convertToNodeSpace:location];
location = [[CCDirector sharedDirector] convertToGL:location];
}
Here is the code that is checking if the location (same location variable as above) is touching a sprite, although I feel much more confident that this code is correct, who knows!
for (CCSprite *sprite in movableSprites) {
if (CGRectContainsPoint(sprite.boundingBox, touchLocation)) {
NSLog(#"Woohoo, you touched a sprite!");
break;
}
}
Let me know if you need anymore information and thanks for reading!
I think you should double the bounding box with the scale
for (CCSprite *sprite in movableSprites) {
if (CGRectContainsPoint(sprite.boundingBox*sprite.scale, touchLocation)) {
//touch sprite action
}
}
About converting the point, if I need an absolut screen point I always use:
convertToWorldSpace:CGPointZero.
I'm not really sure why you need this on your touch location, I would usually do this on sprites when I need to disregard their position in a parent node.
Other then that, If your game is not real multi-touch game you better use ccTouchBegan and not ccTouchesBegan.
Use this function to get sprite rect.
-(CGRect)getSpriteRect:(CCNode *)inSprite
{
CGRect sprRect = CGRectMake(
inSprite.position.x - inSprite.contentSize.width*inSprite.anchorPoint.x,
inSprite.position.y - inSprite.contentSize.height*inSprite.anchorPoint.y,
inSprite.contentSize.width,
inSprite.contentSize.height
);
return sprRect;
}
- (void)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *myTouch = [touches anyObject];
CGPoint location = [myTouch locationInView:[myTouch view]];
location = [[CCDirector sharedDirector] convertToGL:location];
for (CCSprite *sprite in movableSprites)
{
CGRect rect = [self getSpriteRect:sprite];
if (CGRectContainsPoint(rect, location))
{
NSLog(#"Woohoo, you touched a sprite!");
break;
}
}
}
I have a view control and inside I plan to place some controls like buttons textbox etc... I can drag my view along the x axis like:
1)
2)
with the following code:
-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [[event allTouches] anyObject];
if( [touch view] == ViewMain)
{
CGPoint location = [touch locationInView:self.view];
displaceX = location.x - ViewMain.center.x;
displaceY = ViewMain.center.y;
startPosX = location.x - displaceX;
}
CurrentTime = [[NSDate date] timeIntervalSince1970];
}
- (void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [[event allTouches] anyObject];
if( [touch view] == ViewMain)
{
CGPoint location = [touch locationInView:self.view];
location.x =location.x - displaceX;
location.y = displaceY;
ViewMain.center = location;
}
}
-(void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
double time = [[NSDate date] timeIntervalSince1970]-CurrentTime;
UITouch *touch = [[event allTouches] anyObject];
if( [touch view] == ViewMain)
{
CGPoint location = [touch locationInView:self.view];
location.x =location.x - displaceX;
location.y = displaceY;
ViewMain.center = location;
double speed = (ViewMain.center.x-startPosX)/(time*2);
NSLog(#"speed: %f", speed);
}
}
not that I have to add the global variables:
float displaceX = 0;
float displaceY = 0;
float startPosX = 0;
float startPosY = 0;
double CurrentTime;
the reason why I created those variables is so that when I start dragging the view the view moves from the point where I touch it instead of from the middle.
Anyways if I touch a button or image the view will not drag even though the images have transparency on the background. I want to be able to still be able to drag the view regardless if there is an image on top of the view. I where thinking that maybe I need to place a large transparent view on top of everything but I need to have buttons, images etc. I want to be able to drag a view just like you can with:
note that I was able to drag the view regardless of wither I first touched an app/image or text. How could I do that?
I think your problem is that if you touch a UIButton or a UIImageView with interaction enabled, it doesn't pass the touch along.
For the images, uncheck the User Interaction Enabledproperty in IB.
For the buttons that are causing touchesBegan:withEvent:, etc. to not get called, then look at the following link: Is there a way to pass touches through on the iPhone?.
You may want to consider a different approach to this problem. Rather than trying to manually manage the content scrolling yourself you would probably be better off using a UIScrollView with the pagingEnabled property set to YES. This is the method Apple recommends (and it's probably the method used by Springboard.app in your last screenshot). If you are a member of the iOS developer program check out the WWDC 2010 session on UIScrollView for an example of this. I think they may have also posted sample code on developer.apple.com.
I am facing one problem. I have done some coding to rotate cpSegmentShapeNew but its not working . Have a look on the following code,
//**creating shape
testBody = cpBodyNew(INFINITY, INFINITY);
cpShape* testShape = cpSegmentShapeNew(testBody, cpv(230, 82), cpv(193, 46), 0.0f);
testShape->e = 0.0;
testShape->u = 0.0;
testShape->data = flipper;
testShape->collision_type = 2;
cpSpaceAddStaticShape(space, testShape);
//Body moving when user touch
-(BOOL) ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
//event that starts when a finger touchs the screen
UITouch *touch = [touches anyObject];
CGPoint tmpLoc = [touch locationInView: [touch view]];
CGPoint location = [[Director sharedDirector] convertCoordinate:tmpLoc];
ball.position = location;
ballBody->p = location;
[flipper runAction:[RotateTo actionWithDuration:0.1f angle:60]];
cpBodySetAngle(testBody, 60);
cpvrotate(testBody->rot, cpv(100000,0));
return kEventHandled;
}
Please anyone tell me that where i am wrong.
Thanks.
Greetings,
The problem is that you are rotating both objects (sprite + body) through code.
What you need is rotate one, and let the other object know it's happened so it can do it too.
For example, if you move the body, then the method that updates the sprites should look like that:
void updateShapes(void* ptr, void* unused)
{
cpShape* shape = (cpShape*)ptr;
Sprite* sprite = shape->data;
if(sprite)
{
cpBody* body = shape->body;
[sprite setPosition:cpv(body->p.x, body->p.y)];
[sprite setRotation: (float) CC_RADIANS_TO_DEGREES( -body->a )];
}
}
The last line of code updates the rotation. That's the line you are missing.
I hope that helps you or someone else in the future.
Good luck cocos2d mate !
Yohann T.
I am developing a 2d game for iPhone by using cocos2d.
I use many small sprite (image) in my game. I want to touch two similar types of sprite(image) and then both sprite(image) will be hidden.
How can I detect touch in a specific sprite(image) ?
A better way to do this is to actually use the bounding box on the sprite itself (which is a CGRect). In this sample code, I put all my sprites in a NSMutableArray and I simple check if the sprite touch is in the bounding box. Make sure you turn on touch detection in the init. If you notice I also accept/reject touches on the layer by returning YES(if I use the touch) or NO(if I don't)
- (BOOL)ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event
{
CGPoint location = [self convertTouchToNodeSpace: touch];
for (CCSprite *station in _objectList)
{
if (CGRectContainsPoint(station.boundingBox, location))
{
DLog(#"Found sprite");
return YES;
}
}
return NO;
}
Following Jonas's instructions, and adding onto it a bit more ...
- (void)ccTouchesBegan:(NSSet*)touches withEvent:(UIEvent*)event
{
UITouch* touch = [touches anyObject];
CGPoint location = [[[Director sharedDirector] convertCoordinate: touch.location];
CGRect particularSpriteRect = CGMakeRect(particularSprite.position.x, particularSprite.position.y, particularSprite.contentSize.width, particularSprite.contentSize.height);
if(CGRectContainsPoint(particularSpriteRect, location)) {
// particularSprite touched
return kEventHandled;
}
}
You may need to adjust the x/y a little to account for the 'centered positioning' in Cocos
In your layer that contains your sprite, you need to say:
self.isTouchEnabled = YES;
then you can use the same events that you would use in a UIView, but they're named a little differently:
- (void)ccTouchesBegan:(NSSet*)touches withEvent:(UIEvent*)event
{
UITouch* touch = [touches anyObject];
//in your touchesEnded event, you would want to see if you touched
//down and then up inside the same place, and do your logic there.
}
#david, your code has some typos for cocos 0.7.3 and 2.2.1, specifically CGRectMake instead of CGMakeRect and [touch location] is now [touch locationInView:touch.view].
here's what I did:
- (BOOL)ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch * touch = [touches anyObject];
CGPoint location = [[Director sharedDirector] convertCoordinate: [touch locationInView:touch.view]];
CGRect myRect = CGRectMake(sprite.position.x, sprite.position.y, sprite.contentSize.width, sprite.contentSize.height);
if(CGRectContainsPoint(myRect, location)) {
// particularSprite touched
return kEventHandled;
}
}
#Genericrich: CGRectContainsPoint works in CocosLand because of the call 2 lines above:
[[Director sharedDirector] convertCoordinate:]
The Cocos2D objects will be using the OpenGL coordinate system, where 0,0 is the lower left, and UIKit coordinates (like where the touch happened) have 0,0 is upper left. convertCoordinate: is making the flip from UIKit to OpenGL for you.
Here's how it worked for me...
Where spriteSize is obviously the sprite's size... :P
- (BOOL)ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch * touch = [touches anyObject];
CGPoint location = [[Director sharedDirector] convertCoordinate: [touch locationInView:touch.view]];
CGRect myRect = CGRectMake(sprite.position.x-spriteSize/2, sprite.position.y-spriteSize/2, spriteSize, spriteSize);
if(CGRectContainsPoint(myRect, location)) {
// particularSprite touched
return kEventHandled;
}
}
this is a good tutorial explaining the basic touch system
http://ganbarugames.com/2010/12/detecting-touch-events-in-cocos2d-iphone/
first, write
self.isTouchEnabled = YES;
then, you need to implement the functions ccTouchesEnded, ccTouchesBegan, etc
from what I understood, you want to be able to 'match' two sprites that can be on different coordinates on the screen.
a method for doing this.. : (im sure theres many other methods)
consider having 2 global variables.
so everytime a touch touches a sprite, you use the CGRectContainsPoint function that is mentioned several times to find which sprite has been touched. then, you can save the 'tag' of that sprite in one of the global variables.
You do the same for the second touch, and then you compare the 2 global variables.
you should be able to figure out the rest but comment if you have problems.