Particle Candle

[kevin]

 Particle Candle

   This example manually plots some particles (sprites) to simulate a lit candle.  

    Code attached at bottom of post with MEDIA,  written for PlayBASIC V1.63.


   
Video:

   

 


  This code is a PlayBASIC program that displays a candle on the screen and creates particle effects that simulate flames. The program uses the "blitimage" library to manipulate images and sprites.

The program starts by loading an image of a candle and blurring it slightly. It also loads an image of a flare to be used as a particle. A FX screen is created to avoid fetching pixels from the backbuffer.

The program then enters a loop that continuously updates the screen. In each iteration, the candle image is drawn on the screen, and new particles are spawned at the position of the mouse cursor when the left mouse button is pressed. The color of the particles is randomly chosen as a red/yellow tint.

The particle effects are implemented using a list of "tParticle" objects, which store information about the particle's sprite, image, color, lifetime, and other properties. The program updates the position, color, and scaling of each particle over time based on its lifetime.

The program also allows the user to change the "screen fade/tint color" by pressing the right mouse button. The screen color is changed to a random color. Additionally, the program applies a screen fade/tint effect on the screen.

Finally, the program uses the "Sync" function to synchronize the framerate of the animation to 60 FPS. The loop continues indefinitely until the program is closed.

PlayBASIC Code: [Select]

---------------------------------------------


   #Include "blitimage" 

   SetFPS 60

   Type tParticle
      Sprite
      ParticleImage   
      Colour
      LifeTime
      LifeSTartTime
      LifeEndTime
      NextRefresh
      Speed#
      Scale#
   EndType

   // Dim the particle list
   Dim Particle as tParticle List


   // Load the candle image + scale blur it a little   
   CandleImage=LoadnewFXimage("gfx/candle.jpg")
   Scaleimage CandleImage,2,2,0
   BlurImage CandleImage,8.5

   ParticleImg=LoadnewFXimage("gfx/flare.png")


   ; use a FX screen to avoid fetching pixels from backbuffer (which is in video memory)
   Screen=NewFXImage(GetScreenWidth(),GetScreenHeight())


   TimeProgramStarted=Timer()

   // SCreen Tint/Fade Colour
   ScreenFadeColour=$ffffff
   
   Do

      RenderToImage Screen
      ; Clear the screen buffer
      cls Rgb(0,0,0)

      Xpos=GetScreenWidth()/2-GetImageWidth(CandleImage)/2
      Ypos=GetScreenHeight()-GetImageHeight(CandleImage)
      DrawImage CandleImage,Xpos,Ypos,false


      // Pick a redy/yellow colour to tint each flame particle
      r=rndrange(40,120)
      g=rndrange(20,60)
      b=rndrange(0,20)
      SpawnParticle(ParticleImg,392,310,rgb(r,g,b))


      // Spawn a particle at the mouse position
       if LeftMouseButton()
         SpawnParticle(ParticleImg,Mousex(),mousey(),rndrgb())
      endif

      ; Change the 'Screen fade/Tint colour' just for something to look at :)
      if RightMousebUtton()
         ScreenFadeColour=rndrgb()         
      endif

      // Refresh the particle list
      CurrentTime=timer()
      For Each Particle()

         Spr=Particle.Sprite
         ThisImage=GetSpriteIMage(spr)         

            if CurrentTime=>particle.LifeEndTime
                  DeleteImage Thisimage
                  DeleteSprite Spr
                  Particle      =null
            else

               TimePassed#=CurrentTime-Particle.LifeStartTime

               if CurrentTime>Particle.NextRefresh
                  Particle.NextRefresh=CurrentTime+100
                  Scale#=(TimePassed#/Particle.LifeTime)*100
                  Scale#=100-ClipRange#(Scale#,0,100)
                  Colour=RgbFade(Particle.Colour,Scale#)
                  RenderToImage ThisImage   
                  BlitImageAlphaMultColour(Particle.ParticleImage,0,0,Colour)      
               endif

               Speed#=(Timepassed#/Particle.LifeTime)*Particle.Speed
               Speed#=Particle.Speed-ClipRange#(Speed#,0,Particle.Speed)
               MoveSprite Spr,0,-Speed#

               Scale#=(Timepassed#/Particle.LifeTime)*Particle.Scale
               Scale#=Particle.Scale-ClipRange#(Scale#,0,Particle.Scale)
               ScaleSprite Spr,0.45+Scale#
            endif   
         next

         RenderToImage Screen

         // Draw this batch of sprite in one hit
         DrawAllSprites

         // Restore rendering to the back buffer
         RenderToScreen

         // Do Screen Fade/Tint 
         Ticks=Timer()-TimeProgramStarted
         Ticks=mod(Ticks,10000)
         angle#=Ticks*(360/10000.0)
         Scale#=50+Sin(angle#)*50
         Scale#=cliprange#(scale#,0,100)

         // move & colour the Screenimage to the backbuffer
         BlitImageAlphaMultColour(Screen,0,0,RgbFade(ScreenFadeColour,Scale#))      

      Sync
   loop 


 
Function SpawnParticle(ParticleImg,Xpos,Ypos,Colour)
   // Get the source images size
    Width   =GetImageWidth(ParticleIMG)
    Height   =GetImageHeight(ParticleIMG)

   // Spawn temp cache image
    ThisIMage=NewFXimage(Width,Height);
    RenderToImage ThisImage   
    result=BlitImageAlphaMultColour(ParticleImg,0,0,Colour)      
    RenderToScreen 

   // Create a sprite and assign the draw mode
    Spr=newSprite(xpos,ypos,ThisIMage)
    SpriteDrawmode spr,2+16
     ScaleSprite Spr,rndrange#(0.15,0.45)

   CenterSpriteHandle spr

   Particle = new tParticle
   Particle.sprite         =spr
   Particle.ParticleImage   =ParticleIMg
   Particle.Colour         =Colour

   Particle.LifeTime=rndrange(1000,1800)

Login required to view complete source code

Music:

     Vitality - By Benjamin Martins


 Download (attached):

[Adaz]

Superb, totally reminds me to Cadaver on Amiga :-)

[ATLUS]

 :o cool!!!!!!!!!!!!!!!!!!

[thaaks]

Yeah, looks great and pretty similar to Crystal Noir's PureBasic example.

Although I must say that using a combination of SpriteDrawModes (2+4+16 or 2+4+2048) and calling the appropriate functions SpriteAlphaLevel, SpriteFadeLevel, SpriteAlphaColour seems much more intuitive and simpler to me than using BlitImageAlphaMultColour() and storing a separate image for each particle sprite...
This is a much more low level solution if you know what I mean  :-\

But thanks for this source code, at least we now know how to deal with those blending combinations  ;)

Cheers,
Tommy

[Crystal Noir]

Great effect :)

Not a real time effect (cf thaaks) but good particle effect :)

Perhaps the solution is to "attack" the 3D sprite structures in the 1.70 version to have real time lightning effect.

this code is a good example to simulate lightning effects :)

Thx :)

[kevin]

Not a real time effect

It is real time.

[kevin]

Although I must say that using a combination of SpriteDrawModes (2+4+16 or 2+4+2048)

   Combining those modes does not give the above effect.   The so called 'lighting' effect is vertex colouring, which requires texel multiplication.  V1.63 doesn't have a mult mode in the sprite filler.

   Described  here

[thaaks]

Combining those modes does not give the above effect.   The so called 'lighting' effect is vertex colouring, which requires texel multiplication.  V1.63 doesn't have a mult mode in the sprite filler.

Oh, I thought that this SpriteAlphaColour function would give the same effect. My fault.

[Crystal Noir]

Although I must say that using a combination of SpriteDrawModes (2+4+16 or 2+4+2048)

   Combining those modes does not give the above effect.   The so called 'lighting' effect is vertex colouring, which requires texel multiplication.  V1.63 doesn't have a mult mode in the sprite filler.

   Described  here

Yes this the technic I use in Pure to have my candle effect, vertex colouring ^^

[kevin]

 Particle Candle

   This is the same example as the one above, updated for PlayBASIC V1.64/ V1.65 editions.     (Learning Edition and Retail)

  The main difference is the use of the SpriteTint function to colour the sprite pixels in so called 'real time' whatever that is.