I think that when you're working with PF_A8 pixmaps (only alpha channel) the ReadPixel function should return only the alpha channel with zeros for RGB.
I can mask the returned value with $FF000000, but I think it should return only the alpha value.
Local pixmap:TPixmap=CreatePixmap(1,1,PF_A8)
pixmap.WritePixel(0,0,$FF000000)
Print Hex$(pixmap.ReadPixel(0,0))
If pixmap.ReadPixel(0,0) Then Print "alpha on" Else Print "alpha off"
Print
pixmap.WritePixel(0,0,$00000000)
Print Hex$(pixmap.ReadPixel(0,0))
If pixmap.ReadPixel(0,0) Then Print "alpha on" Else Print "alpha off"
'Module BRL.Pixmap
'
' Method ReadPixel( x,y )
' Assert x>=0 And x<width And y>=0 And y<height Else "Pixmap coordinates out of bounds"
' Local p:Byte Ptr=PixelPtr(x,y)
' Select format
' Case PF_A8
' Return p[0] Shl 24 | $00ffffff <--------------------
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