Processing 1.0 - Processing Discourse - segment and circle don't intersect....

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segment and circle don't intersect.... (Read 1692 times)

bo YaBB Newbies Offline Posts: 8	segment and circle don't intersect.... Apr 19^th, 2010, 6:34pm I've created a snake game, and trying to get the snake to grow every time it "hits" or intersects with the flashing circles (food) that pop up, but the intersection isn't working. you can view the game and download the code here: http://www.imagearts.ryerson.ca/lbonsell/snake/snakegame.html THANKS!

blindfish

Re: segment and circle don't intersect....
Reply #1 - Apr 20^th, 2010, 5:57am

bo wrote on Apr 19^th, 2010, 6:34pm:

I've created a snake game, and trying to get the snake to grow every time it "hits" or intersects with the flashing circles (food) that pop up, but the intersection isn't working.

you can view the game and download the code here: http://www.imagearts.ryerson.ca/lbonsell/snake/snakegame.html

THANKS!

Funny - someone posted with a very similar problem the other day.
Question: What do you pass to your intersect() function
Answer:

Quote:

if (intersect(snake.headx, snake.heady, snake.headsize,
food.x, food.y, food.diameter) == true) {
food.activate();
}

Question: Where are these properties defined
Answer: In the Snake constructor which gets called only once - when the snake is first created:

Code:

Snake() {
    headx = mouseX;
    heady = mouseY;
    headsize = 20;
  }

Solution: assign mouseX/Y to headx/y properties on each frame - perhaps in the Snake display method...

Where is the what if the what is in why?

Re: segment and circle don't intersect....
Reply #2 - Apr 20^th, 2010, 9:58am

okay, I tried moving
Code:

 headx = mouseX;
    heady = mouseY;
    headsize = 20;

into the snake display code and the intersection seemed to work, but instead of following the append to increase the array (snake) by one segment it made the snake get off the screen huge. Shocked

It added A LOT more segments then just one like I wanted

Re: segment and circle don't intersect....
Reply #3 - Apr 20^th, 2010, 12:30pm

Okay, I fixed the intersection, now my problem is the append.
When the snake collects the food (flashing circle) I want it to just increase the segment size by 1, but for some reason it gets extremely large (off the screen large) when it hits the food and I have no idea why!!
Please help!
I've updated the code here: http://www.imagearts.ryerson.ca/lbonsell/snake/snakegame.html

PhiLho YaBB Moderator Offline Posts: 4190 Near Paris (France)	Re: segment and circle don't intersect.... Reply #4 - Apr 20^th, 2010, 2:39pm Perhaps you should set a flag to test head/food collision only once (per food lifetime): I bet you check this collision on each frame and increase the size each time, thus the quick growth.

bo YaBB Newbies Offline Posts: 8	Re: segment and circle don't intersect.... Reply #5 - Apr 20^th, 2010, 8:53pm what is a flag and how do I set it??

PhiLho YaBB Moderator Offline Posts: 4190 Near Paris (France)	Re: segment and circle don't intersect.... Reply #6 - Apr 20^th, 2010, 11:09pm A flag is just a boolean (true/false, flag raised or lowered...). A signaling variable...

bo YaBB Newbies Offline Posts: 8	Re: segment and circle don't intersect.... Reply #7 - Apr 20^th, 2010, 11:11pm I tried using a boolean but it still didn't work.... maybe I coded the boolean incorrectly?? please help!!

PhiLho

Re: segment and circle don't intersect....
Reply #8 - Apr 20^th, 2010, 11:31pm

Show the logic you used to manage that.

The idea is: set the variable bHeadHit to false (name is just an example...)
Check the hit on each frame. If hitting and bHeadHit is false, set it to true and do the related action (grow snake). If hitting and bHeadHit is true, just ignore the event, it is already processed. If not hitting and bHeadHit is true, set it to false to manage a new hit.

bo YaBB Newbies Offline Posts: 8	Re: segment and circle don't intersect.... Reply #9 - Apr 21^st, 2010, 8:25am http://www.imagearts.ryerson.ca/lbonsell/snake/boolean/ that is the new link to what I have attempted. I have the keyPressed as a tester for if the growing work and it does, but still, for some reason, when the snake intersects with the food the snake grows constantly.

PhiLho YaBB Moderator Offline Posts: 4190 Near Paris (France)	Re: segment and circle don't intersect.... Reply #10 - Apr 21^st, 2010, 10:08am I fail to see where is your boolean (probably scanning code too fast). I suggest to try my algorithm.

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