How Do I Avoid Processes?

[riveryu]

How Do I Avoid Processes?
Things rather seem complicated without using processes? I tried not use processes after reading Why Avoid Process... in Tutorial section. When I programmed I tried to keep a neat time line in my head, but many times, processes seems to be a shortcut. I cant find other ways, very frustrated right now and when I'm frustrated I play guitar, which annoys neighbor annoys me back and infinite loop....

Here is a , I have an actual problem with trying to draw smoke and then let them "fade" or rather disappear in this example code...
To me this looks to be the most inefficient way to draw smoke b/c I dont know any other...

Turing:

var cx, cy : int var cx1, cy1 : int var cxx, cyy : int var cx11, cy11 : int process smoke for decreasing i :  200 .. 10 by 10     cx:=maxx div 2     cy:=i     for i2 : 1 .. 40         randint (cx1, 0 + cx, 100 + cx) %random ovals forming realistic clouds, and every time different shape         randint (cy1, 0 + cy, 10 + cy)         if i2 mod 2 = 0                 then             drawfilloval (cx1, cy1, 10, 10, 29)         else             drawfilloval (cx1, cy1, 10, 10, 30)         end if         delay (5)     end for end for end smoke process fade for decreasing i :  200 .. 10 by 10     cxx:=maxx div 2     cyy:=i     for i2 : 1 .. 40         randint (cx11, 0 + cxx, 100 + cxx)         randint (cy11, 0 + cyy, 10 + cyy)                      drawfilloval (cx11, cy11, 15, 15, white)         delay (5)     end for end for end fade fork smoke delay (2000) fork fade

If you have any better way please enlighten me, and also if I were to make them actually fade than disappear, do I have to store each oval's location in an array then redraw ovals on top of each with fading color values? This would be complicated since the smoke is basically overlapped ovals. How do I specifically identify the top most ovals without reducing amount of ovals and risk white space?
This seems complicated to me, how do I make them fade?? ARRGHH....

[Saad]

What you want to do is update everything in one big loop frame by frame

The code structure would go along the lines of

Turing:

loop     %% Draw some smoke     if (waitedEnoughTime) then         %% Erase some smoke     end if end loop

[riveryu]

So, in this case. I should get rid of the for loop, put in a counter manually, use a loop and exit when then...

if Time.Elapsed = whatever
then blow smoke away + keep on drawing new smoke
end if

Does Time.Elapsed end up differently on different computers? How can I record time from a specific point of the program other than using process?
I know the other way may be counting how many time it looped and start erasing smoke at a specific loop approximating the time (I think), but anyways plz answer question above.

I have a nearly unrelated question, do you think a grade 10 half way through a semester expects his students to acheive this? (serious question)

[CodeMonkey2000]

You could have a finite amount of smoke that you keep drawing. That way you could move those points and cls the screen.

[riveryu]

Can you be a little more clearer CodeMonkey? Did you mean, I keep drawing the smoke in one place for a while, and then moving the whole thing in one direction with the smoek actually keep drawing in one place in that picture, instead of keep on drawing in one direction like what I did earlier?

[CodeMonkey2000]

Each smoke particle has a set amount of "life" or amount of time it is on screen. Once this time is up, it start over.

[riveryu]

Firstly, thx CodeMonkey for ur help...

Sry, I would like make it clear that I'm Ultra N00b. I dont know how to do that CodeMonkey... but here is a wild guess does the solution involve using variables/array to store each smoke particle location and drawing over them each time with lighter color until transparency?

can you show me some code example?

Im trying to be courteous and perhaps overly demanding at the same time hmmm...
Is it unethnical....

[CodeMonkey2000]

This is a test of my old particle engine. I don't expect you to understand this, but observe what's happening. There are at most
5 particles on screen. My program process each one, and if I reach the end of my array, I start look at the first particle and restart it. Each particles is only allowed to live for 100 milliseconds. If it lives longer, I send it back to the start. This gives you the illusion of infinate particles.

Turing:

%saurabh %unit class particleSystem     export execute, RunParticle, atributes     type vector :         record             x : real             y : real             vY : real             vX : real             duration : int             clr : int         end record     var maxDuration : int := 2500     var pullY : real := -.98     var pullX : real := 0     var pClr : int := white     var spitOut : int := 10     var maxParticle : int := 2000     var CurrentParticle : int := 0     var particles : flexible array 0 .. 0 of vector     proc DrawParticle (current : int)         drawfilloval (round (particles (current).x), round (particles (current).y), 5, 5, particles (current).clr)     end DrawParticle     fcn onScreen (x, y : real) : boolean         result x >= 0 and x <= maxx and y >= 0 and y <= maxy     end onScreen     procedure RunParticle         for x : 1 .. upper (particles)             if particles (x).duration < maxDuration then                 particles (x).duration += 1                 particles (x).vY := particles (x).vY + pullY                 particles (x).vX := particles (x).vX + pullX                 particles (x).y := (particles (x).y + particles (x).vY)                 particles (x).x := (particles (x).x + particles (x).vX)                 if not onScreen (particles (x).x, particles (x).y) then                     particles (x).duration := maxDuration                 end if                 if particles (x).duration < maxDuration then                     DrawParticle (x)                 end if             end if         end for     end RunParticle     procedure CreateParticle (x, y : real)         var angle : real         var radii : real         if CurrentParticle > maxParticle then             CurrentParticle := 1         end if         if CurrentParticle + 1 > upper (particles) then             new particles, upper (particles) + 1         end if         CurrentParticle += 1         particles (CurrentParticle).duration := 1         particles (CurrentParticle).clr := pClr         particles (CurrentParticle).duration := 1         particles (CurrentParticle).x := x         particles (CurrentParticle).y := y         angle := Rand.Int (1, 360)         radii := Rand.Int (1, 12)         particles (CurrentParticle).vX := radii * cosd (angle)         particles (CurrentParticle).vY := radii * sind (angle)         DrawParticle (CurrentParticle)     end CreateParticle     proc execute (times, x, y : int)         for b : 1 .. times             for k : 1 .. spitOut                 CreateParticle (x, y)             end for         end for     end execute     proc atributes (pX, pY : real, colour, duration, out, maxP : int)         pullX := pX         pullY := pY         pClr := colour         maxDuration := duration         spitOut := out         maxParticle := maxP     end atributes end particleSystem View.Set ("offscreenonly") var myParticle : ^particleSystem var x, y, b : int new particleSystem, myParticle colourback (black) loop     Mouse.Where (x, y, b)     if b > 0 then         particleSystem (myParticle).atributes (0, -.6, grey, 100, 1, 5) %112         particleSystem (myParticle).execute (1, x, y)     end if     particleSystem (myParticle).RunParticle     View.Update     Time.DelaySinceLast (round (1000 / 30))     cls end loop

[riveryu]

thanks a lot CodeMonkey2000

I dont understand:
- the math involved moving the particles
- how classes work
- how you set the duration to be exactly 100 millisec, all i' m seeing is...
I understand:
-you reset the varibles when they reach the limit
-each time it loops duration is added 1 if it does not reach the limits, when it does, you stop drawing then reset the variable and loops it again, you did similarly with the number of particles limit

tell me if my assumptions are correct...

[CodeMonkey2000]

Your assumptions are somewhat correct. You don't need to understand how classes work, it's not important. For your program, just pick a maximum amount of smoke. Declare an array that will hold all the points from 1 to the maximum. You also need to memorize the current particle you are on. Now make a main loop. In this main loop process the current particle (send it to where ever you want on the screen). Next clear the screen and draw all the particles from 1 to the current particle (you have the coordinates stored in an array). Then look at the next particle, if there is no next particle, then current particle should equal 1. Hope that helps!

[riveryu]

Thank you, my problem is solved. I learned a lot from this.