Touch detection on the two sides of the screen.

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Touch detection on the two sides of the screen.

(18 posts) (4 voices)

Started 2 years ago by Korki696
Latest reply from jonathan0382

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Korki696
Member

Hello everyone
First i have to say that the cocos engine is awesome. i am new to iphone game development and this has made things so much easier.

I am having a problem with touches. What i want is that the screen is split up into two sections, the left side has multiple sprites and if someone taps on one and they move their finger it follows, and on the right side it will fire a bullet to that location from the location of the selected sprite and dissappear.

Example.
if touch.location.y < 240 and on a sprite. select sprite and follow finger.
if touch.location.y > 240 and a sprite is selected fire bullet from sprite (not finger) to tap location that is greater than 240 on y.

so my question is how can i define the two spaces and then how can i make a bullet fly to a certain spot with a certain speed and dissappear once it get there.

Thanks
-Lars

Posted 2 years ago #
Kevin
Member

I recommend this article for handling touches in cocos2d-iphone.
http://lethain.com/entry/2008/oct/20/touch-detection-in-cocos2d-iphone/

Posted 2 years ago #

Korki696
Member

Hey Kevin
Thanks for that article it helped me out a lot. I managed to get it set up and working but with the code that im using the sprite will only follow if you click the sprite and drag and as long as you dont move out of its rect.

Here is the moved code im using:

-(BOOL) ccTouchesMoved:(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];

	if([PlayerSprites SomethingWasTouched:location]){
		NSArray * mySprites = [PlayerSprites allMySprites];
		NSUInteger i, count = [mySprites count];

		for (i = 0; i < count; i++) {
			PlayerSprites * obj = (PlayerSprites *)[mySprites objectAtIndex:i];

			if (CGRectContainsPoint([obj rect], location) && [obj GetCanTrack]) {
				// code here is only executed if obj has been touched

				if([obj tag] == backButton){//if the button was touched
					[obj runAction: [FadeOut actionWithDuration:1]];//lets make the button fade out
					[obj SetCanTrack:NO];//the button cant be tracked
					[obj setVisible:NO];//set the button not Visible

					/********************* Appear the 3 sprites ************************/
					[[self getChildByTag:easySprite] runAction: [FadeIn actionWithDuration:1.0]]; //easy
					[[self getChildByTag:mediumSprite] runAction: [FadeIn actionWithDuration:1.0]];//medium
					[[self getChildByTag:hardSprite] runAction: [FadeIn actionWithDuration:1.0]];//hard
					/*******************************************************************/

					/***************** Set all the sprites trackeables *****************/
					[[PlayerSprites FindByTag:easySprite] SetCanTrack:YES];
					[[PlayerSprites FindByTag:mediumSprite] SetCanTrack:YES];
					[[PlayerSprites FindByTag:hardSprite] SetCanTrack:YES];
					/*******************************************************************/
				} else {//We touched something different from the button (a character :P)
					[obj SetCanTrack:YES];//The object that we touched cant be tracked anymore.
					CocosNode *s = [self getChildByTag:easySprite];
					[s stopAllActions];
					[s runAction: [MoveTo actionWithDuration:1 position:ccp(location.x, location.y)]];
					[[self getChildByTag:backButton] setVisible:YES];
					[[self getChildByTag:backButton] runAction: [FadeIn	actionWithDuration:1.0]];
					[[PlayerSprites FindByTag:backButton] SetCanTrack:YES];//the button object can be tracked now.
				}
			} else { //Make the other objects that hasnt been touched, dissapear, except if it was the button that was touched
				if([obj tag] != backButton){
					[obj runAction: [FadeOut actionWithDuration:1.0]];
					[obj SetCanTrack:NO];
				} 

			}
		}
	}

	return kEventHandled;
}

Thanks again
-Lars

Posted 2 years ago #

jonathan0382
Member

It's way past my bedtime (:D) so this is going to be sloppy, but...

First things first, the left and right side of the screen concern the x axis. The y axis is the vertical one. So your y < 240 should be x < 240.

That said...

Make CGRect's for the sprites, then in the touchesBegan see if the touch location intersects with the rectangle for the sprite (If(CGRectIntersectsPoint(_ , _){, or something... can't remember). If so then make it do something.
If your sprites are more circlular then you might just want to use pythagorus' theorem to see if the touch location is close enough to the sprite's location.

If you touch a sprite, flag it (subclass the sprite and add a BOOL property, called "flagged", or something. Then do sprite.setFlagged:YES). Then when you touch the right side of the screen, run through an array of your sprites, and if one is flagged then put a bullet at it's location and then run an action to move it to the touch location.

HTH. If not, I apologize for my tired ramblings.

Jonathan

Posted 2 years ago #
jonathan0382
Member

Oh, bad timing. I see you just posted some code. From what you wrote, I think you need to flag your sprite, and then have it follow as long as it is flagged. When the use use lifts their finger then you can unflag it.

Posted 2 years ago #
jonathan0382
Member

Oh, and flag the sprite on ccTouchesBegan, make it go to the location in ccTouchesMoved, and then unflag it in ccTouchesEnded... I'm going to bed before I complain about no edit function.

Posted 2 years ago #
Korki696
Member

Hey Jonathan
I am doing what you said but i was wondering is there an easy way to see which object is flagged. for example right now for ccTouchesMoved i have:

-(BOOL) ccTouchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{//event that starts when a finger moves on the screen
UITouch *touch = [touches anyObject];
CGPoint tmpLoc = [touch locationInView: [touch view]];
CGPoint location = [[Director sharedDirector] convertCoordinate:tmpLoc];
CocosNode *s = [self getChildByTag:easySprite];
CocosNode *t = [self getChildByTag:mediumSprite];
CocosNode *u = [self getChildByTag:hardSprite];
[t stopAllActions];
[u stopAllActions];
[s stopAllActions];
[s runAction: [MoveTo actionWithDuration:1 position:ccp(location.x, location.y)]];
[t runAction: [MoveTo actionWithDuration:1 position:ccp(location.x, location.y)]];
[u runAction: [MoveTo actionWithDuration:1 position:ccp(location.x, location.y)]];

}

this works great but what i want is that if only one sprite is flagged that is the only sprite that moves and if all sprites are flagged they all move.
Thanks
-Lars

Posted 2 years ago #
jonathan0382
Member

Sorry for the delay. Try this:

In your subclassed sprite add a BOOL, called "flagged", and set it to NO. Make sure is it properly synthesized, retained, etc.
In the touchesMoved, run through the sprites in turn, and use an if statement to see if it is flagged. If it is then do the action. For example:
if(s.flagged == YES){
[s runAction.... etc]
}
else if(t.flagged == YES){
[t runAction....etc[
}
else if... repeat for all sprites. If you wanted to, you could just do if statements, and then if the if statement is true you could write kEventHandled so the others are not checked. This will result in only one sprite running an action at a time (good if the two sprites overlap for some reason).

You could make this easier to use if you created and stored the sprites in an array, but what I wrote should work. Just make sure that in touchesBegan you are flagging (setting to YES), and in touchesEnded you are unflagging (setting to NO).

hth,

Jonathan

Posted 2 years ago #
jonathan0382
Member

Sorry, I misread what you wrote about wanting a sprite to move if flagged, and wanting multiple sprites to move if all flagged. What I wrote above will work, just change the "else if"'s to just "if"'s. Then, whichever sprites satisfy the if statements will run the action.

Jonathan

Posted 2 years ago #
Korki696
Member

Hey Jonathan
That method works great one thing im having a problem with tho is the moveto method works great but it is kind of slow and i need it to be different for each sprite which i can easily do with the duration but the duration only accepts ints so i can do anything faster than 1 is there another method to do this?
Thanks
-Lars

Posted 2 years ago #
Codemattic
Moderator

"the duration only accepts ints"

Korki696, the duration is a ccTime which is a float, so go ahead and make a duration a fraction if you want.

[MoveTo actionWithDuration:0.25 position:ccp(location.x, location.y)]

Posted 2 years ago #
jonathan0382
Member

^^ I agree with this guy

Posted 2 years ago #
Korki696
Member

Hey Jonathan
the sprites are in an array called allSprites. how would i do it if thats the case?
Thanks
-Lars

Posted 2 years ago #
jonathan0382
Member

Depends on how you set up the array.

Suppose you have 10 sprites in allSprites, each init'd as "sprite[n]",and the property you are checking for is called "flagged",

for(int n=0; n<10; n++){
if(sprite[n].flagged == YES){
//write code here to have flagged sprites do whatever you want them to do
}
}

The above assumes that you set up the sprites as sprite[n], where n is an integer, and is the position in the array, and sprite[n] is an instance of the the sprite subclass. If you need help setting this up let me know.

Posted 2 years ago #
Korki696
Member

OK well i ended up going with the
if (sprite1.flagged == YES){
do actions

because i needed to be able to control speed.

I do have two other questions and i dont want to make new threads.

1. i have these sprites which will all be animated. what i want to do is that if the tap location is above the sprite play up animation if it is below the sprite play down animation and same for left and right. how could i do this?

2. is there a way for example if i have a menu that displays 5 different characters and they can choose three. that those three that get chosed get displayed with their attributes such as speed?

Thanks
-Lars

Posted 2 years ago #
jonathan0382
Member

1. Once you've defined the animations, and actions to call them, compare the ending y value to with the beginning y value. If the difference is positive run the up animation. Else run the down animation. See the cocos2d sprite test (I think) on how to run actions at the same time. Should be easy enough.

2. Like a character select screen? If so it would be in a different scene, right(?), and whichever you pick gets used in the next scene? If this is it then you could set up some variable properties in the second scene that determine which sprites are used, and then in the menu scene have whatever the user picks change the variables in the second scene.

Posted 2 years ago #
Korki696
Member

Hey Jonathan,
I looked at the sprite test as well as the atlas sprite test in the cocos2d samples but i didnt find what you were talking about. As for sprite or atlas sprite iv read that atlas is much faster. Is there any source code available that uses different sprite actions like i plan on doing? I have looked all over but havent found anything.
Thanks
-Lars

Posted 2 years ago #
jonathan0382
Member

if you can't find what you're looking for then it's possible I didn't understand fully what you were trying to do.

There are examples in the tests of multiple actions being run at the same time on the same sprite. I definitely recommend looking again, and also going through all the tests, watching what happens and then looking at the code to figure out what does what. In my experience the best way to learn is to take the source and tweak it, and see what happens.

I wish you luck, & am sorry I can't help more at the moment. I'm writing this on my iPhone & am now going to bed. Sorry!

Posted 2 years ago #

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