Print Page - Applying a Classic Sine wave effect to an image

Title: Applying a Classic Sine wave effect to an image
Post by: kevin on July 02, 2004, 08:18:23 AM

[pbcode]
;---------------------------------------------------------------------; Sine Wave Image..;---------------------------------------------------------------------

   OpenScreen 640,480,16,2

   W=GetScreenWidth()
   H=GetScreenHeight()

   Global TempStripImage=2
   CreateImage 1,w,h
   CreateImage TempStripImage,w,1

   CreateConvexShape 1,100,5

   Do
RenderToImage 1     ;     Cls 0

    bw=32
    bh=32
    Ypos=ScrollY
    Ypos2=Ypos+bh
    For ylp=0 To h Step bh
Xpos=ScrollX
Xpos2=Xpos+bw
Toggle=Ylp And 1
For xlp=0 To w Step bw
    If Toggle
BoxC Xpos,Ypos,Xpos2,Ypos2,RGB(255,0,0)
    Else
BoxC Xpos,Ypos,Xpos2,Ypos2,RGB(155,0,255)
    EndIf
    toggle=1-toggle
    Xpos=Xpos2
    Xpos2=Xpos2+bw
Next
Ypos=Ypos2
Ypos2=Ypos2+bh
    next

    Angle#=WrapAngle(angle#,1)
    RotateShape 1,angle#,1
    Ink RGBFade($223344,70+Cos(angle)*30)
    DrawShape 1,w/2,h/2,3

    Ink RGBFade($223344,70+Sin(angle)*30)
    DrawShape 1,w/2,h/2,1

    Ink $ffffff
    CenterText w/2,h/2-50,"Sine Wave Screen "+Str$(w)+"*"+Str$(h)

    SineCopyImageToScreen(1,15)

Sync
   Loop

Function SineCopyImageToScreen(SrcImage,wavesize#)
   Static WaveAngle#
   w=GetImageWidth(SrcImage)
   Angle#=WaveAngle#
For Ylp=0 To GetImageHeight(srcImage)
    RenderToImage SrcImage
    GetImage TempStripImage,0,ylp,w,ylp+1
    RenderToScreen
    DrawImage TempStripIMage,SinRadius(Angle#,WaveSize#),ylp,0
    INC Angle#
Next
   WaveAngle#=WrapAngle(WaveAngle#,2)
EndFunction

[/pbcode]

Title: Applying a Classic Sine wave effect to an image
Post by: Draco9898 on July 02, 2004, 09:09:25 AM

VERY COOL :blink:

I just shoved it into my game and made it move with the mouse!
:rolleyes:
Looks even cooler when you move it around and distort stuff

Title: Applying a Classic Sine wave effect to an image
Post by: Draco9898 on July 02, 2004, 09:32:54 AM

Looks even stranger if you make the
For Ylp=0 To GetImageHeight(srcImage)

go in Steps of 2......... :ph34r:
But I suppose thats because every other pixel is getting missed

I think I get how this works.....you capturing the screen as an image THEN your using Static WaveAngle# and I'm not sure what the static commands does, but then you rip the image into Xwidth by 1 pixel height strips, then you paste enough of these on top of each other to get the original image back, but you've moved all the 'strips' with SinRange? and this causes the caustic effect?

ALSO: Changing the code by taking out the Static takes away all the movement and just leaves you with a trick mirror like image and changing INC angle to DEC angle causes the effect to 'run' in the other direction...

I don't think I can think of a faster way to do this effect... :huh:

I have now also altered the code to so whatever is under or near the image 'waves' get affected as well

The only idea I have for making it faster is direct pixel access? Not sure.

Also one question: ARRAYS arn't globial by defult? :unsure:

Title: Applying a Classic Sine wave effect to an image
Post by: kevin on July 03, 2004, 11:21:01 AM

The Static commands allows a variable within a function to keep it's value between calls. Normally these variables are local and thus the values/data are destroyed each time the function call has ended.

Dim's are global by default...

However, if you Dim an Array inside a function, then it's LOCAL (only visible) to the function within which it appears..

UnderwareDESIGN

PlayBASIC => Resources => Source Codes => Topic started by: kevin on July 02, 2004, 08:18:23 AM