BBOURBIN@UMDD.BITNET (Brett S Bourbin) (05/16/88)
I am trying to write a color fade routine for a double ViewPort screen and
my first attempt was to do it the legal, "correct" way by creating a second
task to control the fade ins and outs. The second task was to receice messages
from the controlling task and handle the LoadRGB4(), MakeVPort(), MrgCop() and
LoadView() calls since I wanted to fade the colors every 5 vertical blanks.
Creating the second task places a lot of overhead in terms of both memory and
time, which I REALLY need for a double-buffered 3-D perspective top ViewPort
so I must go to the Copper list directly during the VBLANK period to gain some
speed.
Here are my questions:
o Does MakeVPort() and LoadRGB4() create a Copper list for the color
registers for ALL the colors in the ColorMap (ie. a 5 bitplane ViewPort
has 32 colors, so will there be 32 'move #rgbval,colorregs?) or does
only the color registers that are different from the previous ViewPort?
o To find the start of the executing Copper list, can I do a:
lea view,a0
move.l v_LOFCprList(a0),a0
move.l crl_start(a0),a1
and to get the number of entries:
move crl_MaxCount(a0),d0 ?
o Will all of the color register Copper intructions be continuous in
memory? (ie.:
dc.w $0180,xxxx ; color register 00
dc.w $0182,xxxx ; color register 01
dc.w $0184,xxxx ; color register 02
etc.
or could they be spread out in RAM?)
_-_-_-_-_-_
- Brett S Bourbin
- Instructional Computer Programs, University of Maryland
- College Park, MD 20742
- {bbourbin@umdd.BITNET | brett@rover.umd.edu}