Sprite (alpha) Particles

[kevin]

This  example uses sprites Alpha+ Circle Alpha Addition effects.    


 

 Updated Jan 2024, corrected a few small differences for modern PlayBASIC

PlayBASIC Code: [Select]

  OpenSCreen 640,480,32,1


; CReate an FX copy of the display
   FXScreen=NewFXImage(GetScreenWidth(),GetScreenHeight()) 

; Projection constants
   constant   ProjectionX#=400
   constant ProjectionY#=400

; View Z depth
   Zdepth#=1000



; Size of Alpha Texture
   Size=32

   MaxImages=64
   Dim ParticleIMage(MaxImages)

   Col=$ffffff
   For lp=0 to MaxImages
  ParticleIMage(lp)=Newimage(Size,Size)  
  rendertoimage ParticleIMage(lp)
  Preparefximage ParticleIMage(lp)
  RenderPhongImage  ParticleIMage(lp),Size/2,Size/2,col,255,260/(size/2)
  Col=rndrgb()
   next
   rendertoscreen 
   ParticleSize=GetImageWidth(ParticleIMage(0))
   
   
   NumberOfParticles=400

   acset =1
   Constant Particle_Xpos=ac(1)   
   Constant Particle_Ypos=ac(1)   
   Constant Particle_Zpos=ac(1)   
   Constant Particle_Size=ac(1)   
   Constant Particle_Sprite=ac(1)   
   Constant Particle_StructSize=ac(1)   
   
   Dim VertexList#(NumberOfParticles,Particle_StructSize)
   Dim RotatedVertexList#(NumberOfParticles,Particle_StructSize)

   Size=300
   For lp=0 to NumberOfParticles
  VertexList#(lp,Particle_Xpos)=rndrange(-size,size)    
  VertexList#(lp,Particle_Ypos)=rndrange(-size,size)    
  VertexList#(lp,Particle_Zpos)=rndrange(-size,size)    
  VertexList#(lp,Particle_Size)=rndrange(20,50)

  ThisSprite=NewSprite(0,0,ParticleIMage(rnd(MaxImages)))
  SpriteDRawmode ThisSprite,2+16
  VertexList#(lp,Particle_Sprite)=ThisSprite
   next


   RenderMode=1


   rendertoimage fxscreen   
   Createcamera 1
   cameracls 1,off
   
   RenderToSCreen

  Do

  rendertoimage fxscreen


  RotateVerts(VertexList#(),RotatedVertexList#(),NumberOFParticles,Tilt#,turn#,roll#,Zdepth#)


  if RenderMode=0
     CaptureToscene
     ClsScene

    inkmode 1+64

    For lp=0 to NumberOFParticles
       z#=RotatedVertexList#(lp,Particle_Zpos)
      if z#>1
         capturedepth z#
         Size#=(VertexList#(lp,Particle_Size)*ProjectionX#)/z#
         Circlec RotatedVertexList#(lp,Particle_Xpos),RotatedVertexList#(lp,Particle_Ypos),Size#,1,$80808
       endif
    next
     DrawCamera 1

  endif
  

  if RenderMode=1


     For lp=0 to NumberOFParticles
    z#=RotatedVertexList#(lp,Particle_Zpos)
    if z#>1
       ThisSprite=VertexList#(lp,Particle_Sprite)
       SizeX#=VertexList#(lp,Particle_Size)
       POsitionSpritexyz  ThisSprite,RotatedVertexList#(lp,Particle_Xpos),RotatedVertexList#(lp,Particle_Ypos),z#
       ScaleSprite ThisSprite,(SizeX#*ProjectionX#)/z#/ParticleSize  
    else
      POsitionSpritex  ThisSprite,-100
      
    endif
     next
     drawAllsprites

  endif


  
  inkmode 1
  rendertoscreen

  if RenderMode=1 then   BlitImageClr(FXScreen,0,0,rgb(20,30,40))
  if RenderMode=0 then BlitImageALphaSub(FXScreen,X#,y#,Rgb(23,34,22))

;   BlitImageALphaAdd(FXScreen,X#,y#,Rgb(11,11,11))
;   BlitImageALphaSub(FXScreen,X#,y#,Rgb(13,14,12))

;  drawimage FXScreen,0,0,0
  

  Rem animate the tilt, turn And roll values
   tilt# = tilt#+1.31
   turn# = turn#+0.42   
   roll# = roll#+0.53



   ShowSubDivides   = enterkey()
     
  if upkey() and zdepth#>400 then Zdepth#=Zdepth#-20
  if downkey() then Zdepth#=Zdepth#+20

   
  If SpaceKey() and Released=false
     RenderMode=1-rendermode  
     released=true
  endif

  if Scancode()=0
     released=false

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Original Code:

PlayBASIC Code: [Select]

; PROJECT : AlphaParticles
; AUTHOR  : Kevin Picone (c) Underware Design 2005
; CREATED : 13/08/2004
; EDITED  : 8/01/2006


  OpenSCreen 640,480,16,2


; CReate an FX copy of the display
   FXScreen=NewImage(GetScreenWidth(),GetScreenHeight()) 
   PrepareFXimage FXscreen

; Projection constants
   constant   ProjectionX#=400
   constant ProjectionY#=400

; View Z depth
   Zdepth#=1000



; Size of Alpha Texture
   Size=32

   MaxImages=64
   Dim ParticleIMage(MaxImages)

   Col=$ffffff
   For lp=0 to MaxImages
  ParticleIMage(lp)=Newimage(Size,Size)  
  rendertoimage ParticleIMage(lp)
  Preparefximage ParticleIMage(lp)
  RenderPhongImage  ParticleIMage(lp),Size/2,Size/2,col,255,260/(size/2)
  Col=rndrgb()
   next
   rendertoscreen 
   ParticleSize=GetImageWidth(ParticleIMage(0))
   
   
   NumberOfParticles=400

   acset =1
   Constant Particle_Xpos=ac(1)   
   Constant Particle_Ypos=ac(1)   
   Constant Particle_Zpos=ac(1)   
   Constant Particle_Size=ac(1)   
   Constant Particle_Sprite=ac(1)   
   Constant Particle_StructSize=ac(1)   
   
   Dim VertexList#(NumberOfParticles,Particle_StructSize)
   Dim RotatedVertexList#(NumberOfParticles,Particle_StructSize)

   Size=300
   For lp=0 to NumberOfParticles
  VertexList#(lp,Particle_Xpos)=rndrange(-size,size)    
  VertexList#(lp,Particle_Ypos)=rndrange(-size,size)    
  VertexList#(lp,Particle_Zpos)=rndrange(-size,size)    
  VertexList#(lp,Particle_Size)=rndrange(20,50)

  ThisSprite=NewSprite(0,0,ParticleIMage(rnd(MaxImages)))
  SpriteDRawmode ThisSprite,2+16
  VertexList#(lp,Particle_Sprite)=ThisSprite
   next


   RenderMode=1


   rendertoimage fxscreen   
   Createcamera 1
   cameracls 1,off
   
   RenderToSCreen

  Do

  rendertoimage fxscreen


  RotateVerts(VertexList#(),RotatedVertexList#(),NumberOFParticles,Tilt#,turn#,roll#,Zdepth#)


  if RenderMode=0
     CaptureToscene
     ClsScene

    inkmode 1+64

    For lp=0 to NumberOFParticles
       z#=RotatedVertexList#(lp,Particle_Zpos)
      if z#>1
         capturedepth z#
         Size#=(VertexList#(lp,Particle_Size)*ProjectionX#)/z#
         Circlec RotatedVertexList#(lp,Particle_Xpos),RotatedVertexList#(lp,Particle_Ypos),Size#,1,$80808
       endif
    next
     DrawCamera 1

  endif
  

  if RenderMode=1


     For lp=0 to NumberOFParticles
    z#=RotatedVertexList#(lp,Particle_Zpos)
    if z#>1
       ThisSprite=VertexList#(lp,Particle_Sprite)
       SizeX#=VertexList#(lp,Particle_Size)
       POsitionSpritexyz  ThisSprite,RotatedVertexList#(lp,Particle_Xpos),RotatedVertexList#(lp,Particle_Ypos),z#
       ScaleSprite ThisSprite,(SizeX#*ProjectionX#)/z#/ParticleSize  
    else
      POsitionSpritex  ThisSprite,-100
      
    endif
     next
     drawAllsprites

  endif


  
  inkmode 1
  rendertoscreen

  if RenderMode=1 then   BlitImageClr(FXScreen,0,0,rgb(20,30,40))
  if RenderMode=0 then BlitImageALphaSub(FXScreen,X#,y#,Rgb(23,34,22))

;   BlitImageALphaAdd(FXScreen,X#,y#,Rgb(11,11,11))
;   BlitImageALphaSub(FXScreen,X#,y#,Rgb(13,14,12))

;  drawimage FXScreen,0,0,0
  

  Rem animate the tilt, turn And roll values
   tilt# = tilt#+1.31
   turn# = turn#+0.42   
   roll# = roll#+0.53



   ShowSubDivides   = enterkey()
     
  if upkey() and zdepth#>400 then Zdepth#=Zdepth#-20
  if downkey() then Zdepth#=Zdepth#+20

   

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[stef]

Hi!

Looks nice! :)
Edit:
No, it's looking great (must use arrow-keys and space-key!)

Can you tell something about command "blitimage" and how to use it?

Greetings
stef

[medwayman]

Wow that's very nice!

I didn't realise you'd already released PlaybasicFX ;)

[kevin]

Stef,

 Here ya go
 Blit Fx Library

[Ian Price]

Looks lovely :D

[kevin]

Medway,

 Well, this stuff has always been there, but you just have to careful about how it's used ATM.   That is to say, that performing any blend operation that reads  video memory is a no/no.  But if you do it all in fx buffers, then move it down, there's less of a drama.

 Obviously the biggest benefit of PBFX  will be that all rendering will be performed with hardware...  Fun :)

[stef]

Hi!

Thanks for info!

[thaaks]

Pretty cool! Not very fast on my machine but looks great. Will fiddle around with it  ;)

Thanks for the sample code,
Tommy

[kevin]

Yeah, I can't say i'm terribly surprised, it won't ever be 'fast'.  Whatever that means.  There's a fair slab of rotation overhead on the VM handling 400 points,  and the actual shift it's to video memory, is at the mercy of your video bus.   But none of the polygon renders (which draw sprites) are MMX optimized, which is where most of the time is spent.

  It clocks about 24/25fps in32bit and about 30fps in 16bit on my Duron 800 + GF2 combo.

[kevin]

In between baby sitting yesterday, and fixing the clipping and some render errors in Blit Image, i've been experimenting with a few other modes.   This one takes two source images and performs a 50/50 alpha blend between the two and dumps tot eh output surface.  If both surfaces are FX surfaces this avoid the reading from memory bottleneck

 The blend image is secondary though, so unfortunately you can't offset the two during the merge. And the second image can't be smaller than source. It's not express at full screen (640*480*32) on the Duron 800/gf2 combo, but should be useful when used in smaller doses.

This picture is the above demo modified to merge the sprite image with a shadebox + image on a second image.  The Blit mode doesn't effect either, it just merges them and write to where ever the current surface is.

[kevin]

This image is the product of another BlitImage combination effect.  This mode performs an alpha subtraction between two images during the output.  This means that you can use a second image as sort of light map (well subtraction map).  It's creates a pretty interest effect in the particle demo, the particles turn into these sort of  morphing blobs.  Very odd, but cool :)

 I guess should explain how it works.  

 Image A = Your normal image
 Image B = Subtraction Map

 Outputted pixels are read from Pixel A and then have the corresponding pixel from image B subtracted from it then it's drawn to the ouput surface.

  So white pixels will make an area blacked out,  and Black pixels will have no effect.   Alternatively if you fill Image  with Rgb(0,0,255)  this would screen out Blue in the render image...  You can make a flash light by using gouraud shaded triangles.  Projected from (or around) the viewer.