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"drawImageAlpha V1.1 (Added clipping, lut)", by ashcroftman

Mimics the original draw image command, except it now has alpha blending. Looks just about right..

V1.1 Should be alot faster now on a good cpu.

Code

Dim aLut(600,3) ;3X higher than color that could be request...pre-done clamping :)
Function initAlphaLut()
local r
;---
     Dim aLut(600,3)
     For r=1 To 600
          c=r
          If c>255 c=255
          aLut(r,1) = (c And 255) Shl 16 
          aLut(r,2) = (c And 255) Shl 8 
          aLut(r,3) = (c And 255) 
     Next
;---
End Function

Function drawImageAlpha2(image,x,y,a#) ;V2.0 Faster/Safer. 
Local drgb,srgb,dX,dY,w,h,na#,nX,nY
;--
LockBuffer
LockBuffer ImageBuffer(image)
If x<1 x=1 
If y<1 y=1
w=ImageWidth(image)
h=ImageHeight(image)
If x+w>GraphicsWidth() w=w-(x+w-GraphicsWidth())
If y+h>GraphicsHeight() h=h-(y+h-GraphicsHeight())
If a>1 a=1
If a<0 a=0
nA# = 1 - a;
     For dY= 1 To h 
          For dX = 1 To w
                    nX=dX+x
                    nY=dY+y
                    drgb = ReadPixelFast(dX,dY,ImageBuffer(image))
                    srgb = ReadPixelFast(nX,nY)
                    WritePixelFast nX,nY,$ff000000 Or aLut(  ((srgb Shr 16) And 255) * nA + (((dRgb Shr 16) And 255) * a),1)Or aLut( ((sRgb Shr 8) And 255) * nA + (((dRgb Shr 8) And 255) * a),2 ) Or aLut( (sRgb And 255) * nA + ((dRgb And 255) * a) ,3)
          Next
     Next
UnlockBuffer ImageBuffer(image)
UnlockBuffer
;--
End Function

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