Super Sampling (In Software)

[kevin]

  Super Sampling (In Software)
 
    Super sampling is type of full screen anti aliasing found in modern 3d hardware.  It works by up scaling the render surface by 2 or more,  then filtering the larger version down into the original screen size.  Bellow we're using the built in the features of PlayBasic to emulate this, just slowly :).

    To emulate the sampling, we first render the screen to a double sized surface (so we scaled everything up by 2), then we blur this surface to smudge the pixels together. For output, we can use the bi-linear filtering when scaling it down by 50%.   Which gives an interesting approximation.  

 
   Bellow are a couple of demos using this effect.


    Tunnel

PlayBASIC Code: [Select]

  Screen=NewFxImage(1600,1200)   
   
  
  
  Do
  
        rendertoimage Screen
      if Spacekey()
           Cls $000000
      else
          inkmode 1+2048
          boxc 0,0,GetImageWidth(Screen),GetImageHeight(screen),true,$f8e8a8
           inkmode 1
        endif
           
      x=mousex()*2
      y=mousey()*2


      Offset=MOd(Offset+10,80)
      inkmode 1+64

      for lp=0 to 100

         Depth=100+(lp*80)+Offset
         size=(500*500)/Depth
          Ring(Angle#+lp,x,y,size)
      next

      angle#=wrapangle(angle#,2)

      inkmode 1
      Blurimage Screen,9.1
      rendertoscreen
      drawrotatedimage screen,0,0,0,0.50,0.50,0,0,false+8
      
        Sync
  loop     



Function Ring(Angle#,x,y,size)

      StepValue=10
      
      For lp=0 to 359 step StepValue
         angle2#=wrapangle(angle#,lp)
         x2=x+cos(angle2#)*size
         y2=y+sin(angle2#)*size

         angle2#=wrapangle(angle#,lp+StepValue)
         x3=x+cos(angle2#)*size
         y3=y+sin(angle2#)*size
         linec x2,y2,x3,y3,$446688
         
      next

EndFunction

    Flower

PlayBASIC Code: [Select]

  Screen=NewFxImage(1600,1200)   
   
  
  
  Do
  
        rendertoimage Screen
      if Spacekey()
           Cls $000000
      else
          inkmode 1+2048
          boxc 0,0,GetImageWidth(Screen),GetImageHeight(screen),true,$f8e8a8
           inkmode 1
        endif
           
      x=mousex()*2
      y=mousey()*2


      Offset=MOd(Offset+10,80)
      inkmode 1+64


       Ring(Angle#+lp,x,y,1000)

      angle#=wrapangle(angle#,2)

      inkmode 1
      Blurimage Screen,9.1
      rendertoscreen
      drawrotatedimage screen,0,0,0,0.50,0.50,0,0,false+8
      
        Sync
  loop     




Function Ring(Angle#,x,y,size)

      StepValue=8
      
      For lp=0 to 359 step StepValue
         angle2#=wrapangle(angle#,lp)
         x2=x+cos(angle2#)*size
         y2=y+sin(angle2#)*size

         angle2#=wrapangle(angle#,lp+StepValue)
         x3=x+cos(angle2#)*(size/2)
         y3=y+sin(angle2#)*(size/2)

         if Toggle
            Toggle=0
            tric x,y,x2,y2,x3,y3,$999999
         else
            tric x,y,x2,y2,x3,y3,$110041
            Toggle=1
         endif      

      next

EndFunction

[ATLUS]

amazing  :o

[monkeybot]

nice...very nice

[kevin]

  Super Sampled (Anti Aliased) Filled Circle

   Here's a function that will render a circle to a temp image,  super sample it (blur and scaling it down) and render the result. There's a bit of bug in the blurimage routine in V1.64M (and bellow) which doesn't take the alpha channel into account, so the result image has the wrong alpha level, but you the get the idea.

PlayBASIC Code: [Select]

   Loadfont "Verdana",1,32
   makebitmapfont 1,$ffffffff,8
   FontDrawMode 1,1 

   screen=newimage(800,600,2)
   
   do
      RenderToIMage Screen
      cls $00304060
      centertext 400,10,"Super Sampled (Anti Aliased) Filled Circle"

      x=mousex()
      y=mousey()
      radius=100
      ; super sampled circle
      DrawAliasedCircle(x,y,RAdius,$ffffffff)

      ; normal circle
      circlec x,y+Radius*2,radius,true,$ffffffff

      rendertoscreen
      drawimage screen,0,0,false

      sync
   loop


Function DrawAliasedCircle(x,y,radius,colour)
   surface=getsurface()
   
   w=Radius*4
   h=Radius*4
   tempimage=newfximage(w,h,true)
   rendertoimage tempimage
   circlec radius*2,radius*2,Radius*2,true,Colour
   blurimage tempimage,9.1
   rendertoimage surface
   scaleimage tempimage,radius*2,radius*2,1   
   drawimage tempimage,x-radius,y-radius,true
   deleteimage tempimage

EndFUnction   
   

[ATLUS]

and video
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