Particle Engine

[zero-impact]

This is a revamped version of a particle engine I made last year.
It now runs much much faster.

The controls are as follows:

Hold space bar to attract the particles to the mouse.

Hold Control to repulse the particles away from the mouse.

Click and hold the mouse to spawn particles.


Any tips, comments or criticism are greatly appreciated


Note: Try playing around with some of the constants for different effects. Also if it is running too slowly for you just change the MAXPART constant. As well as in the graphics procedure you can uncomment the drawfillbox for a neat effect

code:

%%particlesim%% setscreen ("graphics:max;max;nobuttonbar;offscreenonly") type particle :     record         x : int         y : int         xvel : real         yvel : real         col : int     end record const GRAV : real := 0.9 const AIR : real := 0.99 const TRANSFER : real := 0.5 const FRIC := 0.8 const NULL := 9876543 const BACKCOL : int := black var mousex, mousey, mouseClick : int var spawnRate := 10 const MAXPART := 2000 var part : array 1 .. MAXPART of particle var mouseAngle : real var chars : array char of boolean for i : 1 .. MAXPART     part (i).x := NULL     part (i).y := NULL     part (i).xvel := 0     part (i).yvel := 0     part (i).col := 0 end for var currentPart : int := 0 proc spawnParticle (particlex : int, particley : int)     for k : 1 .. spawnRate         if currentPart = MAXPART then             currentPart := 0         end if         currentPart += 1         part (currentPart).x := particlex + k         part (currentPart).y := particley         %part (currentPart).xvel := Rand.Int (-10, 10)         %part (currentPart).yvel := Rand.Int (1, 4)         part (currentPart).xvel := cosd (Rand.Int (0,360)) * 10 %Help from http://compsci.ca/v3/viewtopic.php?t=17607         part (currentPart).yvel := sind (Rand.Int (0,360)) * 10 % help from http://compsci.ca/v3/viewtopic.php?t=17607                 part (currentPart).col := Rand.Int (0, 15)         if part (currentPart).col = black then             part (currentPart).col += 1         end if     end for end spawnParticle function getMouseAngle (x, y : real) : real %Help from compsci.ca    http://compsci.ca/v3/viewtopic.php?t=17607     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 270     elsif y = 0 and x > 0 then         result 0     elsif y = 0 and x < 0 then         result 180     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 360 + arctand (y / x)     elsif x < 0 and y < 0 then         result 180 + arctand (y / x)     else         result 0     end if end getMouseAngle proc getInput         Mouse.Where (mousex, mousey, mouseClick)         if mouseClick = 1 then             spawnParticle (mousex, mousey)         end if end getInput proc physics     for i : 1 .. upper (part)         Input.KeyDown (chars)         if chars (' ') then             mouseAngle := getMouseAngle (mousex - part (i).x, mousey - part (i).y)  %%Help from compsci.ca             part (i).xvel += cosd (mouseAngle) * 2 %Help from http://compsci.ca/v3/viewtopic.php?t=17607             part (i).yvel += sind (mouseAngle) * 2 % help from http://compsci.ca/v3/viewtopic.php?t=17607         elsif chars (KEY_CTRL) then             mouseAngle := getMouseAngle (mousex - part (i).x, mousey - part (i).y)          %%Help from compsci.ca             part (i).xvel += -round (cosd (mouseAngle) * 2) %Help from http://compsci.ca/v3/viewtopic.php?t=17607             part (i).yvel += -round (sind (mouseAngle) * 2) % help from http://compsci.ca/v3/viewtopic.php?t=17607         end if         if part (i).x = NULL & part (i).y = NULL then             %do nothing         else             if part (i).y > 0 then                 part (i).yvel -= GRAV   %gravity             end if             if part (i).y < 0 then                 part (i).y := 0                 part (i).yvel := -part (i).yvel * TRANSFER             end if             if part (i).x >= maxx then                 part (i).x := 1                 %part (i).xvel := -part (i).xvel * TRANSFER  %bounce off right wall                 %part (i).on := false             end if             if part (i).x <= 0 then                 part (i).x := maxx - 1                 %part (i).xvel := -part (i).xvel * TRANSFER  %bounce off left wall                 %part (i).x := 0             end if         end if         part (i).xvel *= AIR         part (i).x += round (part (i).xvel)     %adding the x and y vel to the a and y position         part (i).y += round (part (i).yvel)     end for end physics proc gfx     drawfillbox (0, 0, maxx, maxy, BACKCOL)     %background     for i : 1 .. upper (part)         %drawfillbox (part (i).x, part (i).y, part (i).x + 5, part (i).y + 5, part (i).col) %particle         drawdot (part (i).x, part (i).y, part (i).col)     %particle     end for     View.Update end gfx loop     getInput     physics     gfx     Time.DelaySinceLast (30) end loop

[/code][/syntax]

[saltpro15]

cool, great job lawson

[Amit]

Very impressive, this is one of the better particle engines I've seen. Just one thing I saw, you wrote

Turing:

if part (i).x = NULL & part (i).y = NULL then             %do nothing         else             *physics code*

Another way to do this would be

Turing:

if not(part (i).x = NULL & part (i).y = NULL) then             *physics code*

It does that same thing, but it gets rid of the unnecessary else statement.

[zero-impact]

Hey uhm saltpro I dont believe I know who you are?

and thanks Amit, I'm glad you caught that

[Amit]

No problem, glad to help. One other thing, there is a constant FRIC that never seems to get used. Something you were going to include?

[zero-impact]

Oh yea it was just to stop the particles from sliding along the floor but the air friction works fine.

[saltpro15]

drew

[zero-impact]

oooh hey

[SNIPERDUDE]

This is a great improvement from last years, I remember it quite well. I'm very surprised at the speed it's running, much faster than mine or any other I've seen, kudos. One thing that should be done I think is make the particles go invisible when the particles stop moving or have a constant altitude (stop moving vertically).

Awesome job 8)

[zero-impact]

Thanks a lot SNIPERDUDE. I'm very surprised that you actually remembered that from the first version I posted.

This is just a small modification I did to show my teacher some things you could do with it.

code:

%%particleSim%% %Lawson Fulton% %%%12/19/09%%%% %Controls: %Spacebar - attract %Control - repulse %Left/Right Mouse - Spawn particles %Note: Change MAXPART for more or less particles %      Change SPAWNRATE to change the speed the particles spawn at. setscreen ("graphics:max;max;nobuttonbar;offscreenonly") type particle :     record         x : int         y : int         xvel : real         yvel : real         col : int         prevSize : int         size : int         gettingSmaller : boolean         shape : int %1 box   2 oval     end record const MAXPART := 2000 const SPAWNRATE := 10 const GRAV : real := 0 const AIR : real := 0.99 const TRANSFER : real := 0.5 const FRIC := 0.8 const NULL := 9876543 const BACKCOL : int := black const MAXSIZE := 20 var mousex, mousey, mouseClick : int var part : array 1 .. MAXPART of particle var mouseAngle : real var chars : array char of boolean for i : 1 .. MAXPART     part (i).x := NULL     part (i).y := NULL     part (i).xvel := 0     part (i).yvel := 0     part (i).col := 0     part (i).prevSize := -1     part (i).size := 0     part (i).gettingSmaller := true     part (i).shape := 0 end for var currentPart : int := 0 proc spawnParticle (particlex : int, particley : int)     for k : 1 .. SPAWNRATE         if currentPart = MAXPART then             currentPart := 0         end if         currentPart += 1         part (currentPart).x := particlex % + k         part (currentPart).y := particley         %part (currentPart).xvel := Rand.Int (-10, 10)         %part (currentPart).yvel := Rand.Int (1, 4)         part (currentPart).xvel := cosd (Rand.Int (0, 360)) * 10 %Help from http://compsci.ca/v3/viewtopic.php?t=17607         part (currentPart).yvel := sind (Rand.Int (0, 360)) * 10 % help from http://compsci.ca/v3/viewtopic.php?t=17607         part (currentPart).col := Rand.Int (0, 15)         part (currentPart).size := Rand.Int (1, MAXSIZE - 1)         part (currentPart).shape := Rand.Int (1, 6)         if part (currentPart).col = black then             part (currentPart).col += 1         end if     end for end spawnParticle function getMouseAngle (x, y : real) : real %Help from compsci.ca    http://compsci.ca/v3/viewtopic.php?t=17607     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 270     elsif y = 0 and x > 0 then         result 0     elsif y = 0 and x < 0 then         result 180     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 360 + arctand (y / x)     elsif x < 0 and y < 0 then         result 180 + arctand (y / x)     else         result 0     end if end getMouseAngle proc getInput     Mouse.Where (mousex, mousey, mouseClick)     if mouseClick = 1 then         spawnParticle (mousex, mousey)     end if end getInput proc physics     for i : 1 .. upper (part)         Input.KeyDown (chars)         if chars (' ') then             mouseAngle := getMouseAngle (mousex - part (i).x, mousey - part (i).y)  %%Help from compsci.ca             part (i).xvel += cosd (mouseAngle) * 2 %Help from http://compsci.ca/v3/viewtopic.php?t=17607             part (i).yvel += sind (mouseAngle) * 2 % help from http://compsci.ca/v3/viewtopic.php?t=17607         elsif chars (KEY_CTRL) then             mouseAngle := getMouseAngle (mousex - part (i).x, mousey - part (i).y)          %%Help from compsci.ca             part (i).xvel += -cosd (mouseAngle) * 2 %Help from http://compsci.ca/v3/viewtopic.php?t=17607             part (i).yvel += -sind (mouseAngle) * 2 % help from http://compsci.ca/v3/viewtopic.php?t=17607         end if         part (i).prevSize := part (i).size         if part (i).gettingSmaller then             part (i).size -= 1         elsif ~part (i).gettingSmaller then             part (i).size += 1         end if         if part (i).size >= MAXSIZE or part (i).size <= 0 then             if part (i).prevSize < part (i).size then                 part (i).gettingSmaller := true             else                 part (i).gettingSmaller := false             end if         end if         if part (i).x = NULL & part (i).y = NULL then             %do nothing         else             if part (i).y > 0 then                 part (i).yvel -= GRAV   %gravity             end if            /* if part (i).y < 0 then              part (i).y := 0              part (i).yvel := -part (i).yvel * TRANSFER              end if              if part (i).x >= maxx then              part (i).x := 1 %infinite walls              %part (i).xvel := -part (i).xvel * TRANSFER  %bounce off right wall              %part (i).on := false              end if              if part (i).x <= 0 then              part (i).x := maxx - 1 %infinite walls              %part (i).xvel := -part (i).xvel * TRANSFER  %bounce off left wall              %part (i).x := 0              end if*/         end if         part (i).xvel *= AIR         part (i).yvel *= AIR         part (i).x += round (part (i).xvel)     %adding the x and y vel to the a and y position         part (i).y += round (part (i).yvel)     end for end physics proc gfx     drawfillbox (0, 0, maxx, maxy, BACKCOL)     %background     for i : 1 .. upper (part)         %drawoval (part (i).x, part (i).y, part (i).size, part (i).size, part (i).col) %particle         if part (i).shape = 1 then             drawfillbox (part (i).x, part (i).y, part (i).x + part (i).size, part (i).y + part (i).size, part (i).col)         elsif part (i).shape = 2 then             drawfilloval (part (i).x, part (i).y, part (i).size, part (i).size, part (i).col)         elsif part (i).shape = 3 then             drawbox (part (i).x, part (i).y, part (i).x + part (i).size, part (i).y + part (i).size, part (i).col)         elsif part (i).shape = 4 then             drawoval (part (i).x, part (i).y, part (i).size, part (i).size, part (i).col)         elsif part (i).shape = 5 then             drawstar (part (i).x, part (i).y, part (i).x + part (i).size, part (i).y + part (i).size, part (i).col)         elsif part (i).shape = 6 then             drawfillstar (part (i).x, part (i).y, part (i).x + part (i).size, part (i).y + part (i).size, part (i).col)         end if         %drawdot (part (i).x, part (i).y, part (i).col)     %particle     end for     View.Update end gfx loop     getInput     physics     gfx     Time.DelaySinceLast (30) end loop

[saltpro15]

oh lawson, just had to one-up paul's particle engine eh? xD

[A.J]

congrats

you really outdone yourslef (200 lines....wow)

instead of the stars and the constantly shrinking/growing ovals, why not actually have particles instead ? (like dots, for instance)

but u did a really good job

well done!

[zero-impact]

Drew- lol not really. Just seeing his inspired me to improve mine a bit.

A.J. - You can very easily change it back to particles if you look at the gfx procedure. You just have to take out the if statements and replace it with drawdot (part (i).x, part (i).y, part (i).col) The stars and such were just to spruce it up a little :p


This is a miniputt game a friend of mine did for his final assignment. It uses the particle engine for the stars.

[saltpro15]

well now you and paul have me interested in making a particle engine... oh + bits btw

[zero-impact]

Haha ok well if you make one make sure it is better than both of ours combined :p