[REBOL] Re: alpha image blending...
From: cyphre:seznam:cz at: 23-Jul-2003 18:20
Hi Max again,
Have a look at http://www.escribe.com/internet/rebol/m26856.html
Using this function you can draw into alphachannel using any DRAW command(so
also using a pictures) but it is not so fast as native implementation could
be (I requested possibility to draw/load images into alphachannel but this
is probably still on RTs huge todo list)
I have quickly hacked-up another way how to make alphachannel from image
fastly but this need preprocessed(in some gfx program or slowly using Rebol)
8-bit greyscale bitmap:
-------------------------start of the code(watch out line
breaks!)----------------------------------
REBOL [
title: "use 256grayscale image for alphachannel"
author: [cyphre--seznam--cz]
]
site: http://www.rebol.cz/~cyphre/
;you can write your own to-8-bit-gryscale-bitmap converter in Rebol but it
will be slow IMO
;so I exported the raw bitmap data form Photoshop for example
bay-alpha: read-thru site/bay-greyscale.raw ;this is normal raw 8-bit
grayscale bitmap
img: to-image make face [
size: 192x144 ;size of the original bay image
color: blue
edge: none
effect: [gradient -1x-1 255.0.0 0.0.255]
]
img-tmp: to-block mold img
append/only img-tmp/3 bay-alpha
img2: do bind img-tmp 'system
view layout [backcolor green image img image img2]
------------------------end of
code-------------------------------------------
regards,
Cyphre
----- Original Message -----
From: "Maxim Olivier-Adlhoch" <[maximo--meteorstudios--com]>
To: <[rebol-list--rebol--com]>
Sent: Wednesday, July 23, 2003 4:33 PM
Subject: [REBOL] Re: alpha image blending...
I was waiting for a reply from you...
thanks for the alphamul example.
can we alphamul with another image?
-max
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meteor Studios, T.D.
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Strong enough for a man, but made for a woman
