BBS: Inland Empire Archive
Date: 11-14-92 (12:24) Number: 345
From: HARRY GISH Refer#: NONE
To: DEREK BELL Recvd: NO
Subj: FADE.OBJE Conf: (2) Quik_Bas
DB> Hey! Could you possibly post FADE.OBJ after you
DB> find out how to use it so that you could give
DB> instructions to use it too? I've been looking for
DB> a way to fade a screen for a while.
Fading (or reverse fading) a 256 color screen (it's vaguely
possible in 16 color screens, though the results are not
likely to be acceptable) is really quite simple, and it
works in text color modes as well.
What happens is this, you simply take the palette colors and decrement them
all to zero. Technically the way it works is this:
Each of the 256 colors has values between 0 and 63 stored in 3 registers
(called DAC or Digital To Analog Conversion registers) ...
in the 32K color / 24 BIT color schemes it's 0 to 255 ...
They describe the Red, Green and Blue components of the
given color. It's probably easiest for you to visualize
this with the DEF COLOR statement in ZBasic. Let's say we
want to "define" COLOR 42 to be Red level 10, Green level
31 and Blue level to 63. Simply issue DEF COLOR
42,10,31,63. Thus to execute a fade (let's say you have an
image with something in COLOR 42, with those definitions,
into a background which is set to 0,0,0) simply enter
FOR X = 63 TO 0 STEP-1
DEFCOLOR 42,,,X
NEXT
FOR X = 31 TO 0 STEP-1
DEFCOLOR 42,,X,
NEXT
FOR X = 10 TO 0 STEP-1
DEFCOLOR 42,X,,
NEXT
--- Maximus/2 2.01wb
* Origin: ACCESS BBS (1:124/2122)
