Collision Detection Help

[ajones88]

What is it you are trying to achieve?
I am creatign a tag game involving 2 ovals, when one oval touches another, the other person should become it.


What is the problem you are having?
Turing is not detecting a collision


Describe what you have tried to solve this problem
Tried whatdotcolor, didnt work because the red ovalw as always on top so it couldnt detect when the blue one collided, so i am trying with a simple collision detection.


Post any relevant code (You may choose to attach the file instead of posting the code if it is too long)

Turing:

setscreen ("graphics") var x := 150 var y := 100 var x1 := 450 var y1 := 300 var keys, key : array char of boolean var Red := 1 var Blue := 0 var r := 10 var distance := ((x1 - x) * (x1 - x)) + ((y1 - y) * (y1 - y)) ** 0.5 colorback (black) color (brightred) cls loop     if Red = 1 then         put "Red is It"     else         color (brightblue)         put "Blue is It"         color (brightred)     end if     Input.KeyDown (keys)     drawfilloval (x, y, 10, 10, brightred)     if keys (KEY_UP_ARROW) and y + 10 < maxy then         y += 1     end if     if keys (KEY_DOWN_ARROW) and y - 10 > 0 then         y -= 1     end if     if keys (KEY_LEFT_ARROW) and x - 10 > 0 then         x -= 1     end if     if keys (KEY_RIGHT_ARROW) and x + 10 < maxx then         x += 1     end if     drawfilloval (x, y, r, r, brightred)     Input.KeyDown (key)     drawfilloval (x1, y1, r, r, brightblue)     if key ('w') and y1 + 10 < maxy then         y1 += 1     end if     if key ('s') and y1 - 10 > 0 then         y1 -= 1     end if     if key ('a') and x1 + 10 > 0 then         x1 -= 1     end if     if key ('d') and x1 - 10 < maxx then         x1 += 1     end if     drawfilloval (x1, y1, 10, 10, brightblue)     View.Update     delay (5)     cls     if distance < r + r and Red = 1 then         Red := 0     elsif distance < r + r and Red = 0 then         Red := 1     end if end loop

Please specify what version of Turing you are using
Turing V. 4.1.1

[Tony]

You've got the right idea, but try running this code

code:

put "distance is: ", distance if distance < r + r and Red = 1 then         Red := 0     elsif distance < r + r and Red = 0 then         Red := 1     end if

[ajones88]

Got it Had to put the equation for distance after the movement.

Turing:

setscreen ("graphics") var x := 150 var y := 100 var x1 := 400 var y1 := 300 var keys, key : array char of boolean var Red := 1 var Blue := 0 var r := 10 colorback (black) color (brightred) cls loop     if Red = 1 then         put "Red is It"     else         color (brightblue)         put "Blue is It"         color (brightred)     end if     Input.KeyDown (keys)     drawfilloval (x, y, 10, 10, brightred)     if keys (KEY_UP_ARROW) and y + 10 < maxy then         y += 1     end if     if keys (KEY_DOWN_ARROW) and y - 10 > 0 then         y -= 1     end if     if keys (KEY_LEFT_ARROW) and x - 10 > 0 then         x -= 1     end if     if keys (KEY_RIGHT_ARROW) and x + 10 < maxx then         x += 1     end if     drawfilloval (x, y, r, r, brightred)     Input.KeyDown (key)     drawfilloval (x1, y1, r, r, brightblue)     if key ('w') and y1 + 10 < maxy then         y1 += 1     end if     if key ('s') and y1 - 10 > 0 then         y1 -= 1     end if     if key ('a') and x1 + 10 > 0 then         x1 -= 1     end if     if key ('d') and x1 - 10 < maxx then         x1 += 1     end if     drawfilloval (x1, y1, 10, 10, brightblue)     View.Update     delay (5)     cls var distance := ((x1 - x) * (x1 - x)) + ((y1 - y) * (y1 - y)) ** 0.5 put "distance is: ",distance     if distance < r + r and Red = 1 then         Red := 0     elsif distance < r + r and Red = 0 then         Red := 1     end if end loop

[ajones88]

Also any help with a better detection for the diagonal radius would be apreciated.

[Tony]

code:

loop var distance := ... end loop

You are creating a new variable in every iteration of the loop.

Also, it your ovals are circles, then the sum of their radii will always be the same, regardless of the angle.

[ajones88]

Tony @ Mon Nov 23, 2009 8:09 pm wrote:

code:

loop var distance := ... end loop

You are creating a new variable in every iteration of the loop.

Also, it your ovals are circles, then the sum of their radii will always be the same, regardless of the angle.

but if 2 "corner" edges are touching, the origin of the circles are farther apart

[Tony]

If I'm guessing at what you are talking about correctly, then you are talking about the case when distance equals to the sum of radii. In such a case, you should adjust your if conditions accordingly.

[ajones88]

Tony @ Mon Nov 23, 2009 8:31 pm wrote:

If I'm guessing at what you are talking about correctly, then you are talking about the case when distance equals to the sum of radii. In such a case, you should adjust your if conditions accordingly.

how would i go about adjusting that. Ive played with it for a bit, but i cant seem to get it. Also, is there some sort of delay i can put in so it wont keep switching who is it while they are touching, as sometimes the same person emerges it.

[Tony]

how would you check if one number is less than or equals to another number?

As for delays -- yes. You might want to wait for some time, see -- timemodule.

[ajones88]

I want to be able to move, but dont want the value of red to change for ex. 1 second since it last changed. Correct me if i am wrong, but as far as i can tell, none of those do that.

Thanks

[Tony]

The only methods that are blocking are delay and DelaySinceLast. The rest return a value to you right away.

[ajones88]

Got it had to add a check that is reset when the distance is greater than the 2 radii

Turing:

setscreen ("graphics") var x := 150 var y := 100 var x1 := 400 var y1 := 300 var keys, key : array char of boolean var Red := 1 var Blue := 0 var r := 10 var check := 0 colorback (black) color (brightred) cls loop     if Red = 1 then         put "Red is It"     else         color (brightblue)         put "Blue is It"         color (brightred)     end if     Input.KeyDown (keys)     drawfilloval (x, y, 10, 10, brightred)     if keys (KEY_UP_ARROW) and y + 10 < maxy then         y += 1     end if     if keys (KEY_DOWN_ARROW) and y - 10 > 0 then         y -= 1     end if     if keys (KEY_LEFT_ARROW) and x - 10 > 0 then         x -= 1     end if     if keys (KEY_RIGHT_ARROW) and x + 10 < maxx then         x += 1     end if     if Red = 1 then         drawfilloval (x, y, 11, 11, yellow)     end if     drawfilloval (x, y, r, r, brightred)     Input.KeyDown (key)     drawfilloval (x1, y1, r, r, brightblue)     if key ('w') and y1 + 10 < maxy then         y1 += 1     end if     if key ('s') and y1 - 10 > 0 then         y1 -= 1     end if     if key ('a') and x1 + 10 > 0 then         x1 -= 1     end if     if key ('d') and x1 - 10 < maxx then         x1 += 1     end if     if Red = 0 then         drawfilloval (x1, y1, 12, 12, yellow)     end if     drawfilloval (x1, y1, 10, 10, brightblue)     View.Update     delay (5)     cls     var distance := ((x1 - x) * (x1 - x)) + ((y1 - y) * (y1 - y)) ** 0.5     if distance < 11 + 11 and Red = 1 and check = 0 then         Red := 0         check := 1     elsif distance < 11 + 11 and Red = 0 and check = 0 then         Red := 1         check := 1     end if     if distance > 11+11 then     check:=0     end if end loop