[bmx] Desaturation Fader by xlsior [ 1+ years ago ]

[BlitzBot]

Title : Desaturation Fader
Author : xlsior
Posted : 1+ years ago

Description : Fade a screen from color to Black-and-white, and back again

Code :

Code (blitzmax) Select Expand

' BlitzMax Color-to-B&W Fade Routine
' Takes a full screen image, and smoothly desaturates it.
'
' *Great* for using when pausing a game!
'
' Freeware, (C) 2005 by xlsior/Marc van den Dikkenberg
'
' - Press any key to start the fade effect.
' - Press Escape to exit.

Strict

Graphics 800,600,0

Local pixcolor:Long ' Pixel colors as read from the pixmap
Local pixred:Int
Local pixgreen:Int
Local pixblue:Int    
Local pixavg:Int      ' Averaged RGB values
Local orgformat:Int   ' Keep track of the original PixelMap format, for conversion
Local monopix:Int     ' Colors in ARGB format
Local workimg:timage
Local workpix:tpixmap
Local bwimg:timage
Local sourceimg:timage

sourceimg:timage=LoadImage("d:/working/background3.jpg",DYNAMICIMAGE)
workimg:timage=CreateImage (GraphicsWidth(),GraphicsHeight(),1,DYNAMICIMAGE)

DrawImage sourceimg,0,0
'
' blah blah blah, run a program, draw things to the backbuffer, until
' you want to invoke the effect:
'

GrabImage (workimg:timage,0,0)
Flip

workpix:tpixmap=LockImage(workimg:timage)

orgformat=PixmapFormat(workpix)
If orgformat<>PF_RGB888 Then
' if the Pixmap in a different format than these routined expect, then convert:
workpix:tpixmap=ConvertPixmap:tpixmap(workpix,PF_RGB888)
End If

For Local xx=0 To GraphicsWidth()-1
For Local yy=0 To GraphicsHeight()-1
pixcolor=ReadPixel(workpix,xx,yy)
pixred=(pixcolor & $00FF0000) Shr 16
pixgreen=(pixcolor & $FF00) Shr 8
pixblue=(pixcolor & $FF)
pixavg=(pixred*0.299)+(pixgreen*0.587)+(pixblue*0.114)
pixred=pixavg Shl 16
pixgreen=pixavg Shl 8
pixblue=pixavg
monopix=pixred | pixgreen | pixblue
WritePixel(workpix,xx,yy,monopix)
Next
Next

If orgformat<>PF_RGB888 Then
' The pixmap was converted to a different format originally.
' Now convert it back to what it was.
workpix:tpixmap=ConvertPixmap:tpixmap(workpix,orgformat)
End If

bwimg:timage=LoadImage(workpix:tpixmap)
UnlockImage(workimg:timage)

' At this point we have the following:
' workpix     - A pixmap containing a black-and-white version
' bwimg       - An image containing a black-and-white version
' workimg     - The screen grabbed full-color version
' sourceimg   - The original image loaded from disk

WaitKey()

For Local counter=0 To 100 Step 2
crossfade(workimg:timage,bwimg:timage,counter)
Flip
If KeyDown (key_Escape) Then Exit
Next

WaitKey()

For Local counter=0 To 100 Step 2
crossfade(bwimg:timage,workimg:timage,counter)
Flip
If KeyDown (key_Escape) Then Exit
Next

WaitKey()

Function CrossFade(pic1:timage,pic2:timage,perc:Float)
' Generic Crossfade routine, to fade between the full color and
' Black-and-white versions of the image.
' Parameters: sourcepic, destination pic, percentage faded
If perc<1 Then
perc=1
ElseIf perc>100 Then
perc=100
End If
SetBlend (SolidBlend)
SetColor 255,255,255
DrawImage (pic1,0,0)
SetBlend (Alphablend)
SetAlpha (perc/100)
DrawImage (pic2,0,0)
End Function

Comments :


dmaz(Posted 1+ years ago)

 very nice.