blending images?

Blitz3D Forums/Blitz3D Programming/blending images?

Stevie G
 #1
This should work .... As you can see ... it's dog slow. The percent param should be between 0 and 1.0.

Stevie

Graphics 800,600,16,1

;load starting image
Global Image1 = LoadImage( "Screenshot003.bmp")
;load ending image
Global Image2 = LoadImage( "Screenshot006.bmp")
;create image to be displayed same size as other 2
Global Image3 = CreateImage( ImageWidth( Image1), ImageHeight( Image1) )

Dir = 10
Cur = 0

While Not KeyDown(1)

	Cur = Cur + Dir : If Cur = 0 Or Cur = 100 Dir = - Dir
	IMAGEblend( Image1, Image2 , Image3 , Floor(Cur) / 100.0 )
	DrawImage Image3, 0,0
	Flip
	
Wend

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Function IMAGEblend( Image1, Image2 , Image3 , Percent# )

	IW = ImageWidth( Image1 )
	IH = ImageHeight( Image1 )

	LockBuffer ImageBuffer( Image1 )
	LockBuffer ImageBuffer( Image2 )
	LockBuffer ImageBuffer( Image3 )
		
	For j = 0 To IH- 1
		For i = 0 To IW - 1
		
			;get colour info from image 1
			argb1 = ReadPixelFast( i,j, ImageBuffer( image1 ) )
			r1 = ( argb1 And $FF0000) Shr 16
			g1 = ( argb1 And $FF00 ) Shr 8  
			b1 = ( argb1 And $FF )  
			a1 = ( argb1 And $FF000000 ) Shr 24
			
			;get colour info from image 2
			argb2 = ReadPixelFast( i,j, ImageBuffer( image2 ) )
			r2 = ( argb2 And $FF0000) Shr 16
			g2 = ( argb2 And $FF00 ) Shr 8  
			b2 = ( argb2 And $FF )  
			a2 = ( argb2 And $FF000000 ) Shr 24

			;interpolate colours from image 1 to image 2			
			r = r1 + ( r2 - r1 ) * Percent
			g = g1 + ( g2 - g1 ) * Percent
			b = b1 + ( b2 - b1 ) * Percent
			a = a1 + ( a2 - a1 ) * Percent
			
			argb = ( a Shl 24 ) Or ( r Shl 16 ) Or ( g Shl 8 ) Or b	
			WritePixelFast i , j , argb, ImageBuffer( Image3 )
		Next
	Next			

	UnlockBuffer ImageBuffer( Image1 )
	UnlockBuffer ImageBuffer( Image2 )
	UnlockBuffer ImageBuffer( Image3 )
	SetBuffer BackBuffer()
	
End Function

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