Making a cricle follow the x and y of another

[Raknarg]

Sure. Have you tried to solve it yet?

[ThatGuyYouLove]

Insectoid @ Sat Dec 24, 2011 10:40 am wrote:

You got that backwards bro. That code will make the red ball run away.

LOL thanks bro that's actually kinda funny.

For collision detection there are a few ways I can think of off the top of my head.

Spoiler:

the simplest version of detection is just to detect for the center of one object to anywhere on another... i.e code: %Collision detection %Paste this within your loop to check every time the balls move if x2 <= (x +RadiusofBlue) and x2 >= (x - RadiusofBlue) then  %broke these up for ease of reading, can be done in one if if y2 <= (y + RadiusofBlue) and y2 >= (y - RadiusofBlue) then Collision := true end if end if there must be a more accurate version but the only one I can think of off the top of my head is... code: for radiuscount : -RadiusofRed .. RadiusofRed if (x2 + radiuscount) <= (x +RadiusofBlue) and (x2 + radiuscount) >= (x - RadiusofBlue) then  %broke these up for ease of reading, can be done in one if statement if (y2 + radiuscount) <= (y + RadiusofBlue) and (y2 + radiuscount) >= (y - RadiusofBlue) then Collision := true end if end if end for Checks for if anything on either axis touches.

[Velocity]

That seems about, right, ddi you get the answer to your question yet? cause i managed to get another solution.

[Velocity]

@ insectoid that wasnt a protip (dont mean to judge your all holy and honorable proness) that was just standard procedure or another take of it, or less time consuming, or ... ugh this list can go on forever.

[Aange10]

Velocity @ 27/12/2011, 8:44 pm wrote:

@ insectoid that wasnt a protip (dont mean to judge your all holy and honorable proness) that was just standard procedure or another take of it, or less time consuming, or ... ugh this list can go on forever.

Actually, it's an operator. Not a procedure. Secondly, if you were smart you'd realize he was being facetious. So,

@Velocity Cool story bro, you mad?

[Insectoid]

Thanks for having my back Aange10. *brofist*

Line shamelessly stolen from Tony. I think.

[chipanpriest]

Turing:

if x2 < x then     x2 += 1 elsif x2 > x then     x2 -= 1 end if if y2 < y then     y2 += 1 elsif y2 > y then     y2 -= 1 end if

this is literally all you need inside your code somewhere for the enemy to follow your guy

the collision code could be something like:

Turing:

if x2 + x2radius >= x - xradius and y2 + y2radius = y - yradius          and x2 - x2radius <= x + xradius and y2 - y2radius <= y + yradius then     exit end if

[Dreadnought]

Most of what is posted above seems to be for rectangles (x+radius > x2-radius stuff). (perhaps with the exception of ThatGuyYouLove's second piece of code).

If we want to check for collision between two circles (which I think you are) there is an easy and "perfect" way to do it. Basically, check the distance between the centers (this is good since we already know where those are). Think of it like drawing a right angled triangle with the hypotenuse being the line between the centers and the other two sides being along the x and y axes. Since we are dealing with circles, we know that the maximum distance that the two centers can be from each other without the circles overlapping is the sum of the radii. Since the distance between the centers is the hypotenuse of our triangle, we just need to check if the hypotenuse is shorter than the sum of the radii. GOGO PYTHAGOREAN THEOREM! (or just use Math.Distance... same thing)

It could look something like this:

Turing:

var x1, y1, rad1 : int % First circle var x2, y2, rad2 : int % Second circle % Check for collision if Math.Distance (x1, y1, x2, y2) < rad1 + rad2 then % This could be <= depending on preference     put "OMG A COLLISION!" end if

That's all you need to check collision between circles.

[chipanpriest]

Dreadnought @ Thu Dec 29, 2011 5:12 pm wrote:

GOGO PYTHAGOREAN THEOREM!

lol nice inspector gadget reference

[mobin12]

Alright guys if you are wondering what all this is for i will show you the other (big piece) of code for my final game:

code:

%Set the screen size setscreen ("graphics:900;550") %Anti-flicker command View.Set ("offscreenonly") var chars : array char of boolean var enemy : array 1 .. 3 of int enemy (1) := 7 enemy (2) := 7 enemy (3) := 1 var mx, my, b : int var shockwaveValue, player : array 1 .. 4 of int player (1) := 450 player (2) := 275 player (3) := 54 player (4) := 1 shockwaveValue (3) := 1 shockwaveValue (4) := 0 var space : int := 0 var count : int := 3 loop     %Draw the player     if player (4) = 1 then         drawfilloval (player (1), player (2), 10, 10, player (3))         drawfilloval (player (1), player (2), 8, 8, player (3) + 1)     end if     if enemy (3) = 1 then         drawfilloval (enemy (1), enemy (2), 7, 7, 41)     end if     Input.KeyDown (chars)     %Player controls     if chars ('a') and player (1) > 12 then         player (1) := player (1) - 2     end if     if chars ('d') and player (1) < 886 then         player (1) := player (1) + 2     end if     if chars ('w') and player (2) < 514 then         player (2) := player (2) + 2     end if     if chars ('s') and player (2) > 13 then         player (2) := player (2) - 2     end if     % Attempt on enemy follow     if player (1) > enemy (1) then         enemy (1) := enemy (1) + 1     end if     if player (1) < enemy (1) then         enemy (1) := enemy (1) - 1     end if     if player (2) > enemy (2) then         enemy (2) := enemy (2) + 1     end if     if player (2) < enemy (2) then         enemy (2) := enemy (2) - 1     end if     %Shockwave     if chars (' ') and count > 0 and space = 0 then         shockwaveValue (1) := player (1)         shockwaveValue (2) := player (2)         shockwaveValue (3) := 1         shockwaveValue (4) := 1         count := count - 1         space := 1     end if     if not chars (' ') then         space := 0     end if     %Display amount of shockwaves that are left     if count = 3 then         put "Shockwaves:"         drawoval (133, 538, 7, 7, 39)         drawoval (133, 538, 8, 8, 39)         drawoval (154, 538, 7, 7, 39)         drawoval (154, 538, 8, 8, 39)         drawoval (175, 538, 7, 7, 39)         drawoval (175, 538, 8, 8, 39)     end if     if count = 2 then         put "Shockwaves:"         drawoval (133, 538, 7, 7, 39)         drawoval (133, 538, 8, 8, 39)         drawoval (154, 538, 7, 7, 39)         drawoval (154, 538, 8, 8, 39)     end if     if count = 1 then         put "Shockwaves:"         drawoval (133, 538, 7, 7, 39)         drawoval (133, 538, 8, 8, 39)     end if     if count = 0 then         put "Shockwaves:"     end if     %Firing the bullets     mousewhere (mx, my, b)     if b = 1 then         drawline (player (1), player (2), mx, my, 43)     end if     %Enemy collision with shockwave     if enemy (1) <= shockwaveValue (3) then         enemy (3) := 0     end if     if enemy (2) <= shockwaveValue (3) then         enemy (3) := 0     end if     %Enemy collision with bullet     if enemy (1) = mx and b = 1 then         enemy (3) := 0     end if     if enemy (2) = my and b = 1 then         enemy (3) := 0     end if     %Enemy collision with player     if enemy (1) + 7 <= (player (1) + 12) and enemy (1) + 7 >= (player (1) - 12) and enemy (2) + 7 <= (player (2) + 12) and enemy (2) + 7 >= (player (2) - 12) then         player (3) := 45     end if     %Draw the shockwaves     if shockwaveValue (4) = 1 then         drawoval (shockwaveValue (1), shockwaveValue (2), shockwaveValue (3), shockwaveValue (3), 41)         shockwaveValue (3) := shockwaveValue (3) + 7         drawoval (shockwaveValue (1), shockwaveValue (2), shockwaveValue (3), shockwaveValue (3), 40)         shockwaveValue (3) := shockwaveValue (3) + 7         drawoval (shockwaveValue (1), shockwaveValue (2), shockwaveValue (3), shockwaveValue (3), 39)         shockwaveValue (3) := shockwaveValue (3) + 7         if shockwaveValue (3) >= 1000 + 5 then             shockwaveValue (4) := 0         end if     end if     %Anti-flicker command     View.Update     %Slow the program down     delay (15)     %Clear the screen for the next loop     cls end loop

[mobin12]

all i need now is a health kind of thing for the player, a background, and maybe some gun sounds

[evildaddy911]

health bars are very easy, i usually just write

Turing:

drawfillbox(0,0,health,5,red)

right before the end loop

also, where you display the number of shockwaves left, you output "shockwaves" in every scenario, just write

Turing:

if count>=0 and count<=3 then put"Shockwaves:" end if

right before the draw commands

Also, you can save a few lines there by using "elsif" instead of
"end if
if", because the if statements are dealing with a single value being a specific number

[mobin12]

is 'health' another variable

[Dreadnought]

Yes, in his case health would be an integer variable representing both health and length (in pixels) of the health bar.

[evildaddy911]

if your health variable is too large, the you can shrink the bar by using div,

Turing:

drawfillbox(0, 0, health div 10, 5, red)

div just means divide with out remainder ( mod ) or decimals ( / ), mostly used when you need an integer

if you want it to look a bit better, then use

Turing:

drawbox(0, 0, max_health div 10, 5 red) drawfillbox(0, 0, health div 10, 5, red)

max_health is another variable too.

backgrounds aren't too difficult, use Photoshop, fireworks, Google images, paint etc. to generate an image (make sure to save it as .jpg or .bmp), then,

Turing:

var background : int := Pic.FileNew ("[file name and extension]") Pic.Draw (background, 0, 0, picMerge)

which draws your picture with the bottom left corner at (0,0)