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Still here? Great!
This is Part 3 of the three part series on using the DAC. In here I'm
going to give you a leg-up and drop a few hints and tips that we've come
across over the years that make the VGA screen a bit more exciting.
The pointers used by PALETTE are not in any sequence so when you use
COLOR 8, x, PALETTE points to DAC register 56! This situation is difficult
to handle when you want to "do your own thing" so we need to make it a bit
more manageable. The easy way is to reset the pointers in PALETTE to be in
sequence. This is easily done:
FOR C% = 0 TO 15
PALETTE C%, C%
NEXT
This bit of code alines the 16 pointers to the first 16 DAC registers and,
consequently, lines them up with the numbers used by COLOR. The whole
thing becomes so simple that it's child's play.
This same thing could have been done using PALETTE USING. This routine
loads the values (C%) from an array:
DIM Pal%(63)
FOR V% = 0 TO 63
Pal%(V%) = V%
NEXT
PALETTE USING Pal%(0)
This bit of code would load the first 16 elements of Pal%() into the
PALETTE pointers. If you had use PALETTE USING Pal%(16) then elements
16 through 31 would have been used. So, in short, by using PALETTE USING
and a few other goodies you could pre-define all 64 DAC registers in four
sets of 16 and change the colors on your screen like this:
FOR X% = 0 TO 63 STEP 16
PALETTE USING Pal%(X%)
DELAY 2
NEXT
Down at the bottom of this file is routine called DACcolorDATA that will
return the RGB values for 92 colors. If you have a quick look you'll see
that most of these colors are in combinations of 3, normal, light and dark.
The reason for this is that it requires at least 3 shades of the same color
to create a 3D effect. Think of a simple box on SCREEN 12. You draw and
fill the box with normal, then draw a line across the top and down the left
side with light and across the bottom and down the right side with dark and
you have, what looks to be a button popping out of the screen. This is so
common place in today's GUI's I know you've seen it but it is extremely
difficult to do using the standard 16 colors that come with SCREEN 12. To
get the job done easily you need to load you own colors into the DAC. This
will could give you 5 color sets and white. If you arrange the color sets
properly you can also save yourself another headache. Consider this:
%White = 0
%Red = 1 : %LtRed = 6 : %DkRed = 11
%Green = 2 : %LtGreen = 7 : %DkGreen = 12
%Blue = 3 : %LtBlue = 8 : %DkBlue = 13
%Gold = 4 : %LtGold = 9 : %DkGold = 14
%Grey = 5 : %LtGrey = 10 : %DkGrey = 15 (black)
If you set your palette pointers to 0 through 15 then load the color
values as shown above from the list in DACcolorDATA you have 5 3D color
sets and easy access, mathematically, to the light and dark shades of the
colors. You could build and call box drawing routines with just one
color attribute and it would be able to compute the light and dark
attributes quite easily. The little function, below, is in almost every
program I've written for several years. It loads my favorite 5 colors
and returns the original DAC values so I can restore them before ending
the program.
FUNCTION fLoad3Dcolor$ () LOCAL PUBLIC
LOCAL D$, H$, P%
' WHITE RED GREEN BLUE YELLOW GREY
' 旼컴컴커 旼컴컴커 旼컴컴커 旼컴컴커 旼컴컴커 旼컴컴커
D$ = CHR$(63,63,63,55,00,00,00,42,08,00,00,56,63,47,00,36,36,36) +_
CHR$(63,30,30,15,63,15,28,28,63,63,57,21,48,48,48) +_
CHR$(42,00,00,00,24,00,00,00,36,48,30,00,08,08,08)
H$ = fDACread$(16)
CALL DACwrite( D$ )
FOR P% = 0 TO 15
PALETTE P%, P%
NEXT
fLoad3Dcolors$ = H$
END FUNCTION
This routine will get you started with 3D boxes. The border width is
determined by the parameter Depth% and you only need send one color
from the "normal" list ( 1 to 5 ).
SUB BevelBox( BYVAL X1%, BYVAL Y1%, BYVAL X2%, BYVAL Y2%, _
BYVAL Colour%, BYVAL Depth% ) LOCAL PUBLIC
LOCAL D%
LINE ( X1%, Y1% ) - ( X2%, Y2% ), Colour%, BF ' fill the inside
FOR D% = 0 TO ( Depth% -1 )
LINE (X1%, Y1% ) - ( X2%, Y1% ), Colour% + 5 ' top row
LINE (X1%, Y1% ) - ( X1%, Y2% ), Colour% + 5 ' left side
LINE (X1%, Y2% ) - ( X2%, Y2% ), Colour% +10 ' bottom row
LINE (X2%, Y1%+1 ) - ( X2%, Y2% ), Colour% +10 ' right side
X1% = X1% + 1 : X2% = X2% - 1 ' decrease size
Y1% = Y1% + 1 : Y2% = Y2% - 1 ' of the box
NEXT
END SUB
Well, that's about it. You should now be able to take this info and
start punching up your VGA screen. Throughout these three tutorials I've
concentrated on graphics mode but remember the DAC controls the colors
in text mode as well so, have at it! It is against my better judgement
but I'm going to mention it anyhow; If you like what you've seen here
then I would invite you do d/load my library "Nuts 'n Bolts". The 3D
color system is supported by this library and there are some rather
good (even if I say so myself;) box drawing routines and a host of ASM
routines specifically built for the 386 and SCREEN 12 that will make
life a bit easier. As long as you use the routines in the library for
yourself it is a freebie.
Have fun,
Don
' 컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴�
SUB DACcolorDATA ( BYVAL Colour$, SEG Red%, SEG Green%, SEG Blue% ) LOCAL PUBLIC
SELECT CASE UCASE$( Colour$ )
CASE "PURPLE" : Red% = 42 : Green% = 24 : Blue% = 47
CASE "PURPLEL" : Red% = 57 : Green% = 18 : Blue% = 63
CASE "PURPLED" : Red% = 23 : Green% = 00 : Blue% = 26
CASE "FUCHSIA" : Red% = 63 : Green% = 00 : Blue% = 49
CASE "FUCHSIAL" : Red% = 63 : Green% = 24 : Blue% = 49
CASE "FUCHSIAD" : Red% = 42 : Green% = 00 : Blue% = 36
CASE "PINK" : Red% = 63 : Green% = 33 : Blue% = 49
CASE "PINKL" : Red% = 63 : Green% = 38 : Blue% = 49
CASE "PINKD" : Red% = 60 : Green% = 22 : Blue% = 38
CASE "LAVENDER" : Red% = 63 : Green% = 21 : Blue% = 63
CASE "LAVENDERL" : Red% = 63 : Green% = 33 : Blue% = 63
CASE "LAVENDERD" : Red% = 31 : Green% = 00 : Blue% = 31
CASE "DASRED" : Red% = 55 : Green% = 00 : Blue% = 00
CASE "DASREDL" : Red% = 63 : Green% = 30 : Blue% = 30
CASE "DASREDD" : Red% = 42 : Green% = 00 : Blue% = 00
CASE "DASGREEN" : Red% = 00 : Green% = 42 : Blue% = 08
CASE "DASGREENL" : Red% = 15 : Green% = 63 : Blue% = 15
CASE "DASGREEND" : Red% = 00 : Green% = 24 : Blue% = 00
CASE "DASBLUE" : Red% = 00 : Green% = 00 : Blue% = 56
CASE "DASBLUEL" : Red% = 28 : Green% = 28 : Blue% = 63
CASE "DASBLUED" : Red% = 00 : Green% = 00 : Blue% = 36
CASE "DASGOLD" : Red% = 63 : Green% = 47 : Blue% = 00
CASE "DASGOLDL" : Red% = 63 : Green% = 57 : Blue% = 21
CASE "DASGOLDD" : Red% = 48 : Green% = 30 : Blue% = 00
CASE "DASGREY" : Red% = 36 : Green% = 36 : Blue% = 36
CASE "DASGREYL" : Red% = 48 : Green% = 48 : Blue% = 48
CASE "DASGREYD" : Red% = 08 : Green% = 08 : Blue% = 08
CASE "GREY" : Red% = 36 : Green% = 36 : Blue% = 36
CASE "GREYL" : Red% = 48 : Green% = 48 : Blue% = 48
CASE "GREYD" : Red% = 08 : Green% = 08 : Blue% = 08
CASE "BLUE" : Red% = 00 : Green% = 00 : Blue% = 42
CASE "BLUEL" : Red% = 15 : Green% = 63 : Blue% = 42
CASE "BLUED" : Red% = 00 : Green% = 00 : Blue% = 32
CASE "PSBLUE" : Red% = 21 : Green% = 42 : Blue% = 63
CASE "PSBLUEL" : Red% = 33 : Green% = 49 : Blue% = 63
CASE "PSBLUED" : Red% = 28 : Green% = 28 : Blue% = 63
CASE "POWDER" : Red% = 00 : Green% = 23 : Blue% = 63
CASE "POWDERL" : Red% = 00 : Green% = 35 : Blue% = 63
CASE "POWDERD" : Red% = 00 : Green% = 00 : Blue% = 56
CASE "GREEN" : Red% = 00 : Green% = 42 : Blue% = 00
CASE "GREENL" : Red% = 15 : Green% = 63 : Blue% = 15
CASE "GREEND" : Red% = 00 : Green% = 32 : Blue% = 00
CASE "BRGREEN" : Red% = 00 : Green% = 52 : Blue% = 00
CASE "BRGREENL" : Red% = 00 : Green% = 63 : Blue% = 00
CASE "BRGREEND" : Red% = 00 : Green% = 37 : Blue% = 00
CASE "PSGREEN" : Red% = 00 : Green% = 63 : Blue% = 42
CASE "PSGREENL" : Red% = 46 : Green% = 63 : Blue% = 23
CASE "PSGREEND" : Red% = 00 : Green% = 48 : Blue% = 26
CASE "CYAN" : Red% = 00 : Green% = 42 : Blue% = 42
CASE "CYANL" : Red% = 00 : Green% = 52 : Blue% = 52
CASE "CYAND" : Red% = 00 : Green% = 32 : Blue% = 32
CASE "BRCYAN" : Red% = 00 : Green% = 52 : Blue% = 52
CASE "BRCYANL" : Red% = 23 : Green% = 63 : Blue% = 63
CASE "BRCYAND" : Red% = 00 : Green% = 36 : Blue% = 36
CASE "RED" : Red% = 42 : Green% = 00 : Blue% = 00
CASE "REDL" : Red% = 63 : Green% = 30 : Blue% = 30
CASE "REDD" : Red% = 32 : Green% = 00 : Blue% = 00
CASE "BRRED" : Red% = 63 : Green% = 00 : Blue% = 00
CASE "BRREDL" : Red% = 63 : Green% = 30 : Blue% = 30
CASE "BRREDD" : Red% = 42 : Green% = 00 : Blue% = 00
CASE "DKRED" : Red% = 36 : Green% = 00 : Blue% = 00
CASE "DKREDL" : Red% = 46 : Green% = 00 : Blue% = 00
CASE "DKREDD" : Red% = 24 : Green% = 00 : Blue% = 00
CASE "MAGENTA" : Red% = 42 : Green% = 00 : Blue% = 42
CASE "MAGENTAL" : Red% = 54 : Green% = 00 : Blue% = 54
CASE "MAGENTAD" : Red% = 32 : Green% = 00 : Blue% = 32
CASE "BROWN" : Red% = 42 : Green% = 21 : Blue% = 11
CASE "BROWNL" : Red% = 53 : Green% = 32 : Blue% = 22
CASE "BROWND" : Red% = 32 : Green% = 11 : Blue% = 00
CASE "DKGREY" : Red% = 21 : Green% = 21 : Blue% = 21
CASE "LTBLUE" : Red% = 21 : Green% = 21 : Blue% = 63
CASE "LTGREEN" : Red% = 21 : Green% = 63 : Blue% = 21
CASE "LTCYAN" : Red% = 21 : Green% = 63 : Blue% = 63
CASE "LTRED" : Red% = 63 : Green% = 21 : Blue% = 21
CASE "LTMAGENTA" : Red% = 63 : Green% = 21 : Blue% = 63
CASE "WHITE" : Red% = 63 : Green% = 63 : Blue% = 63
CASE "YELLOW" : Red% = 63 : Green% = 63 : Blue% = 00
CASE "YELLOWL" : Red% = 63 : Green% = 63 : Blue% = 32
CASE "YELLOWD" : Red% = 48 : Green% = 46 : Blue% = 00
CASE "GOLD" : Red% = 57 : Green% = 44 : Blue% = 00
CASE "GOLDL" : Red% = 63 : Green% = 50 : Blue% = 23
CASE "GOLDD" : Red% = 47 : Green% = 34 : Blue% = 00
CASE "COPPER" : Red% = 63 : Green% = 44 : Blue% = 00
CASE "COPPERL" : Red% = 63 : Green% = 49 : Blue% = 12
CASE "COPPERD" : Red% = 50 : Green% = 30 : Blue% = 00
CASE "DKGOLD" : Red% = 56 : Green% = 42 : Blue% = 00
CASE "DKGOLDL" : Red% = 63 : Green% = 49 : Blue% = 12
CASE "DKGOLDD" : Red% = 44 : Green% = 30 : Blue% = 00
CASE "ORANGE" : Red% = 63 : Green% = 24 : Blue% = 00
CASE "ORANGEL" : Red% = 63 : Green% = 35 : Blue% = 10
CASE "ORANGED" : Red% = 45 : Green% = 16 : Blue% = 00
CASE ELSE : Red% = 00 : Green% = 00 : Blue% = 00 ' BLACK
END SELECT
END SUB