Gravity Wells (highly customizable)

[Cezna]

This is my gravity wells program. It's just a gravity simulator, using a warped version of the real formula for the force of gravity (assuming mass of 1 for the balls, which is why only one mass variable appears in the equation).
The controls are:

Left click: create a ball (they get pulled around by gravity)
Right click: create a gravity well (these exert gravity on the balls)
Scroll click on a well: this changes it's colour and it's mass, toggling through:
red = positive mass (attracts balls)
green = 0 mass (does nothing to balls)
blue = negative mass (this repels the balls)
Space bar: toggles background between black and white
1, 2 and 3: toggles the 'zoom' (I put that in quotes because it just changes the radius and mass of everything, as I couldn't figure out a simple way to simulate zooming in and out)
Arrow keys: toggle the respective boundaries between bouncing the balls back when they hit them (represented by a blue line along the boundary) and sending them to the opposite side of the screen if they go out of bounds (represented by a red line along the boundary)

Fell free to play with it, tear it apart, use any of the code in it, and post ideas, suggestions, etc.
There is also some cool music, which is why it is a zip.

[Insectoid]

Methinks you're missing something.

[Carey]

I would be happy to take a look at it and give you feedback but for that I would need to see your code

[Cezna]

I can't figure out how to attach a file....
It just waits like 10 minutes while saying 'Sending request to compsci.ca...' at the bottom of my browser, then gives an error, and it's well under the max size for .zip files

So until I figure it out, or someone explains it to me, here is the code (but obviously not the song):

code:

setscreen ("offscreenonly, nobuttonbar, graphics:max;max") Mouse.ButtonChoose ("multibutton") Music.PlayFileLoop ("Osmos.mp3") var wells, maxballs, balls, maxwells, backclr, mx, my, b, ballradius : int var angle, wellmass, grav : real var click1, click100, spacepress, uppress, downpress, leftpress, rightpress, mid, large, pageuppress, pagedownpress     : boolean := false var topbound, bottombound, leftbound, rightbound, small : boolean := true var keys : array char of boolean maxballs := 200 maxwells := 100 var ballx, bally, ballvx, ballvy : array 1 .. maxballs of real var ballclr : array 1 .. maxballs of int var d, wellmassmem : array 1 .. maxballs of real var click10 : array 1 .. maxwells of boolean balls := 0 wells := 0 backclr := white ballradius := 8 grav := 1 /* CONTROLS */ /* LEFT CLICK : spawn a ball at the mouse*/ /* RIGHT CLICK : spawn a gravity well at the mouse*/ /* SCROLL CLICK : change the mass (between positive, zero, and negative) of a gravity well*/ /* red wells : poisitve mass (attract balls)  green wells : zero mass (don't effect balls)  blue wells : negative mass (repel balls)*/ /* SPACE BAR : toggle background colour between white and black*/ /* UP ARROW : toggle top boundary*/ /* DOWN ARROW : toggle bottom boundary*/ /* LEFT ARROW : toggle left boundary*/ /* RIGHT ARROW : toggle right boundary*/ /* CTRL (CONTROL) : change between large, medium and small wells and balls  this will effect only wells and balls drawn after the change is made*/ /* PAGE UP : increase strength of gravity (multiply by 10)*/ /* PAGE DOWN : decrease strength of gravity (divide by 10)*/ type gravwell :     record         x : real         y : real         mass : real         radius : int         clr : int     end record var well : array 1 .. 100 of gravwell function getAngle (x, y : real) : real     if x = 0 and y = 0 then         result 0     elsif x = 0 and y > 0 then         result 90     elsif x < 0 and y = 0 then         result 180     elsif x = 0 and y < 0 then         result 270     elsif x > 0 and y > 0 then         result arctand (y / x)     elsif x < 0 and y > 0 then         result 180 + arctand (y / x)     elsif x < 0 and y < 0 then         result 180 + arctand (y / x)     elsif x > 0 and y < 0 then         result 360 + arctand (y / x)     else         result 0     end if end getAngle function getDistance (x1, y1, x2, y2 : real) : real     if sqrt ((x2 - x1) ** 2 + (y2 - y1) ** 2) = 0 then         result .001     else         result sqrt ((x2 - x1) ** 2 + (y2 - y1) ** 2)     end if end getDistance proc Boundaries     for count : 1 .. balls         % left bound         if leftbound = true then             if ballx (count) + ballvx (count) - 8 <= 0 then                 ballvx (count) *= -.5             end if             if ballx (count) < 0 then                 ballx (count) := 1             end if         elsif leftbound = false then             if ballx (count) < 0 then                 ballx (count) := maxx             end if         end if         % right bound         if rightbound = true then             if ballx (count) + ballvx (count) + 8 >= maxx then                 ballvx (count) *= -.5             end if             if ballx (count) > maxx then                 ballx (count) := maxx - 1             end if         elsif rightbound = false then             if ballx (count) > maxx then                 ballx (count) := 0             end if         end if         % bottom bound         if bottombound = true then             if bally (count) + ballvy (count) - 8 <= 0 then                 ballvy (count) *= -.5             end if             if bally (count) < 0 then                 bally (count) := 1             end if         elsif bottombound = false then             if bally (count) < 0 then                 bally (count) := maxy             end if         end if         % top bound         if topbound = true then             if bally (count) + ballvy (count) + 8 >= maxy then                 ballvy (count) *= -.5             end if             if bally (count) > maxy then                 bally (count) := maxy - 1             end if         elsif topbound = false then             if bally (count) > maxy then                 bally (count) := 0             end if         end if     end for end Boundaries proc Moving     for count : 1 .. balls         for count2 : 1 .. wells             angle := getAngle (well (count2).x - ballx (count), well (count2).y - bally (count))             d (count2) := getDistance (well (count2).x, well (count2).y, ballx (count), bally (count))             ballvx (count) += (cosd (angle) * well (count2).mass) / (d (count2) ** 2) * grav             ballvy (count) += (sind (angle) * well (count2).mass) / (d (count2) ** 2) * grav         end for         ballx (count) += ballvx (count)         bally (count) += ballvy (count)     end for     % spawning balls     if b = 1 and balls < maxballs and mx >= 0 and mx <= maxx and my >= 0 and my <= maxy then         if click1 = false then             balls += 1             ballx (balls) := mx             bally (balls) := my             ballvx (balls) := 0             ballvy (balls) := 0             ballclr (balls) := Rand.Int (0, 255)         end if         click1 := true     else         click1 := false     end if     for count : 1 .. wells         if well (count).clr not= green then             wellmass := well (count).mass         else             wellmass := 0         end if         % changing mass of wells         if b = 10 and (well (count).x - mx) ** 2 + (well (count).y - my) ** 2 < well (count).radius ** 2 then             if click10 (count) = false then                 if wellmass > 0 then                     wellmassmem (count) := well (count).mass                     well (count).mass := 0                     well (count).clr := green                 elsif wellmass = 0 then                     well (count).mass := wellmassmem (count)                     well (count).mass *= -1                     well (count).clr := blue                 elsif wellmass < 0 then                     well (count).mass *= -1                     well (count).clr := red                 end if             end if             click10 (count) := true         else             click10 (count) := false         end if     end for     % spawning wells     if b = 100 and wells < maxwells and mx >= 0 and mx <= maxx and my >= 0 and my <= maxy then         if click100 = false then             wells += 1             well (wells).x := mx             well (wells).y := my             if small then                 well (wells).radius := 50                 wellmassmem (wells) := 5000             elsif mid then                 well (wells).radius := 20                 wellmassmem (wells) := 2000             elsif large then                 well (wells).radius := 10                 wellmassmem (wells) := 1000             end if             well (wells).mass := 0             well (wells).clr := green         end if         click100 := true     else         click100 := false     end if     Input.KeyDown (keys)     if keys (' ') then         if spacepress = false then             if backclr = black then                 backclr := white             elsif backclr = white then                 backclr := black             end if         end if         spacepress := true     else         spacepress := false     end if     if keys (KEY_UP_ARROW) then         if uppress = false then             if topbound = true then                 topbound := false             elsif topbound = false then                 topbound := true             end if         end if         uppress := true     else         uppress := false     end if     if keys (KEY_DOWN_ARROW) then         if downpress = false then             if bottombound = true then                 bottombound := false             elsif bottombound = false then                 bottombound := true             end if         end if         downpress := true     else         downpress := false     end if     if keys (KEY_LEFT_ARROW) then         if leftpress = false then             if leftbound = true then                 leftbound := false             elsif leftbound = false then                 leftbound := true             end if         end if         leftpress := true     else         leftpress := false     end if     if keys (KEY_RIGHT_ARROW) then         if rightpress = false then             if rightbound = true then                 rightbound := false             elsif rightbound = false then                 rightbound := true             end if         end if         rightpress := true     else         rightpress := false     end if     if keys ('1') then         small := true         mid := false         large := false         ballradius := 8         for count : 1 .. wells             well (count).radius := 50             if well (count).mass < 0 then                 well (count).mass := -5000             elsif well (count).mass = 0 then                 wellmassmem (count) := 5000             elsif well (count).mass > 0 then                 well (count).mass := 5000             end if         end for     end if     if keys ('2') then         small := false         mid := true         large := false         ballradius := 3         for count : 1 .. wells             well (count).radius := 20             if well (count).mass < 0 then                 well (count).mass := -2000             elsif well (count).mass = 0 then                 wellmassmem (count) := 2000             elsif well (count).mass > 0 then                 well (count).mass := 2000             end if         end for     end if     if keys ('3') then         small := false         mid := false         large := true         ballradius := 1         for count : 1 .. wells             well (count).radius := 10             if well (count).mass < 0 then                 well (count).mass := -1000             elsif well (count).mass = 0 then                 wellmassmem (count) := 1000             elsif well (count).mass > 0 then                 well (count).mass := 1000             end if         end for     end if     if keys ('r') then         small := true         mid := false         large := false         ballradius := 8         balls := 0         wells := 0         grav := 1         cls     end if     if keys (chr (201)) /* PAGE UP */ and grav <= 100 then         if pageuppress = false then             grav *= 10         end if         pageuppress := true     else         pageuppress := false     end if     if keys (chr (209)) /* PAGE DOWN */ and grav >= .001 then         if pagedownpress = false then             grav /= 10         end if         pagedownpress := true     else         pagedownpress := false     end if end Moving loop     colourback (backclr)     cls     Mouse.Where (mx, my, b)     Boundaries     Moving     for count : 1 .. wells         drawfilloval (round (well (count).x), round (well (count).y), well (count).radius, well (count).radius, well (count).clr)     end for     for count : 1 .. balls         drawfilloval (round (ballx (count)), round (bally (count)), ballradius, ballradius, ballclr (count))     end for     % border indicators     if topbound then         drawline (0, maxy, maxx, maxy, blue)     elsif not topbound then         drawline (0, maxy, maxx, maxy, red)     end if     if leftbound then         drawline (0, 0, 0, maxy, blue)     elsif not leftbound then         drawline (0, 0, 0, maxy, red)     end if     if bottombound then         drawline (0, 0, maxx, 0, blue)     elsif not bottombound then         drawline (0, 0, maxx, 0, red)     end if     if rightbound then         drawline (maxx, 0, maxx, maxy, blue)     elsif not rightbound then         drawline (maxx, 0, maxx, maxy, red)     end if     Time.DelaySinceLast (30)     View.Update end loop

[Cezna]

What does it mean if I try to attach a file, and after like 10 minutes of loading, it goes to an error page saying "No post mode specified"?

[Zren]

After I saw what this could do, I could hardly stop myself from making this. Add it before the main loop:

Turing:

for i : 0 .. 359 by 4     wells += 1     well (wells).x := round (maxx div 2 + i  * cosd (i * 3))     well (wells).y := round (maxy div 2 + i  * sind (i * 3))     well (wells).radius := 10     wellmassmem (wells) := 500     well (wells).mass := -10-i*1.5     well (wells).clr := blue end for

[Cezna]

I had never even thought of that, but it looks amazing.
If anyone else has any cool ideas, post 'em here.

If I get enough responses in the same format as Zren's, I'll make them into modules that can be called from the main program, so you can run any of them from the same program.

[Cezna]

Here's another version, this one traces the orbits of the balls
I recommend using size 2 or 3 (press 2 or 3 when you start), with gravity 10 times normal (press page up when you start).
You have to allow the balls to settle into orbit so that they aren't going to hit the centre and go flying off the screen, but once they have settled down, you can turn the boundaries off by pressing the arrow keys, and allow them to go off the screen during their orbit.

You can get some really cool designs with this one. (Finally got it to attach files, sort of, I just stopped trying to post the .zip)

I also attached the original program, the one posted above. (I can't get the song to upload, however)