$if 0 旼컴컴컴컴컴컴컴컴컴컴컴컴캠 PowerBASIC v3.20 旼캑 DASoft 픔컴컴컴컴컴컴컴컴컴컴컫컴컴컴컴컴컴컴컴컴� � 쳐컴컴컴컴컴컴컴컴컴컴컴컴캘 Copyright 1995 � DATE: 1995-10-01 픔� � � FILE NAME DAC .TXT � by 突袴袴袴袴袴袴袴羔 � � � � � Don Schullian, Jr. � � � 突袴袴袴袴袴袴袴袴袴袴袴袴暠 � � � A license is hereby granted to the holder to use this source code in � � � any program, commercial or otherwise, without receiving the express � � � permission of the copyright holder and without paying any royalties, � � � as long as this code is not distributed in any compilable format. � � � IE: source code files, PowerBASIC Unit files, and printed listings � � 突佶袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴� � � .................................... � 突袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴� $endif So, you say you don't really like the 16 beautiful, hand-picked colors you find on your VGA screen! Well, let's fix that. You have 262,144 to choose from. Of course you can only access 16 at a time, but at least you now have a choice. Each color you see on your screen is a presence of or absence of one or more of the 3 colors, Red, Green, or Blue. Each RGB color value can be from 0 ( none ) to 63 ( full ). If you have a color that is made up of 63 Red, 0 Green, and 0 Blue then what you see is a very bright pure red If you have 08R, 08G, 08B then you get what you normally know as DkGrey or color 8 and, of course 0, 0, 0 is Black! So, the lower the RGB value the darker the color and the higher the RGB number the brighter it is. There are 256 colors or positions in the DAC, and each holds a RGB value. SCREEN 0 and SCREEN 12 can only access the first 64 of these and they are what need to be changed in order for PowerBASIC to display all the colors available. Now, we are going to run into some trouble with names here, so: PALETTE is PowerBASIC's palette number which holds a DAC number DAC is DOS's palette number which holds the RGB values Think of it like this: PowerBASIC has an array with 16 elements ( 0 -> 15 ) Each element holds a DAC number ( 0 -> 63 ) PALETTE sets the element(s) to the DAC number Ok, one more time....... When you use the COLOR statement it points to one of the 16 PALETTE numbers which points to one of the 64 available DAC numbers which hold the R, G, and B values. So.............. You change the DAC's RGB values in position 62 to 23,00,26 then tell PALETTE 62, 15 so when you do a COLOR 14,15 what you get are yellow letters on a purple background EXAMPLE: CALL DACset( 62, 23, 00, 26 ) PALETTE 62, 15 COLOR 14, 15 CLS PRINT "YELLOW LETTERS ON A PURPLE BACKGROUND" As the DAC is laid out in one long string of BYTE values we use STRINGs and BYTE arrays to interface with it. POSs 000 001 002 003 004 005 006 007 008 009 010 011 012 013 014 015 旼컴쩡컴쩡컴쩡컴쩡컴쩡컴쩡컴쩡컴쩡컴쩡컴쩡컴쩡컴쩡컴쩡컴쩡컴쩡컴� VALs 쿝GB쿝GB쿝GB쿝GB쿝GB쿝GB쿝GB쿝GB쿝GB쿝GB쿝GB쿝GB쿝GB쿝GB쿝GB쿝GB쿝 읕컴좔컴좔컴좔컴좔컴좔컴좔컴좔컴좔컴좔컴좔컴좔컴좔컴좔컴좔컴좔컴좔� To address the first 16 DAC positions you could dim an array in either of these 2 ways. I prefer the 1st example as it allows me to quickly access the individual RGB values "by the numbers". DIM DACvals?( 0:2, 0:15 ) is a handy way or DIM DACvals?( 1:48 ) will work just as well DIM DACvals?( 0:2, 0:255 ) will get them all!!! Everything you need to do all of this is either part of PowerBASIC or can be found in this library; there's a raft of ready-to-go colors to get you started. If you want to do 3D images then you've got to put up with a few more restrictions because you only have 16 colors to work with and to do 3D you need 3 variations of each color (except the background) so you are reduced to 5 normal colors, 5 light colors, and 5 dark colors. But you will be surprized at just how effective it is when used in graphics! As you browse through the list of ready-to-go colors in DACdata you'll notice that I have prepared color sets to get you started on your own 3D VGA screens. To draw a box who's light source is in the upper left corner of the screen you would draw the top and left borders with the light color, the bottom and right borders with the dark color and the box itself would be in the normal color. This would make the box appear to pop-out of the screen! The trick is arranging your colors as we have in the test program. Ok, just a quick art lesson here: There are 3 true colors: RED, BLUE, YELLOW There are 6 primaries : RED, PURPLE, BLUE, GREEN, YELLOW, ORANGE PURPLE = RED & BLUE GREEN = BLUE & YELLOW ORANGE = YELLOW & RED BLACK = ABSENCE OF ALL COLOR ( Night time, no sun ) WHITE = IS THE EQUAL PRESENCE OF ALL 3 GREY = PRESENCE OF ALL 3 IN UNEQUAL PROPORTIONS Each color has a "feel": BLUE = Cool, calming YELLOW = Warm, full of life RED = Hot!, danger, etc. On the computer each of the 3 colors RED, GREEN, BLUE can have a value of 0 -> 63. The higher the number the "brighter" the color. Each is effected by the other. Yellow is true color and only exists on the box as a part of GREEN so to get yellow you have to pump in the green then use RED to cancel the blue. ??? say what!? Yea, really neat, huh? Try to remember these simple rules when designing your programs as the colors you use/mix are much more important than you think! To exude calm and peace stick to blues and yellows. Go light on the reds. Colors effect each other also, don't mix purple and yellow unless you want to make someone jump out of his/her skin. Ditto with green and orange. Pastels are soft and sleepy. Premieres are REAL good for young children. Go forth, now and make Picasso jealous! That's about as far as we can carry this discussion here. Other .PBLs deal with graphic screen and we go into more detail at that time. This library is just a NUTZnBOLTS unit and not able to deal with it all! Ahhhhhhhh... just a thought.... there are 64 DAC locations and PB uses 16DAC locations at a shot and 64\16 = 4 and DIM DAC?( 3, 2, 15 ) gives a total of 64 * 3 holes..... Good luck & have some fun with these as they really perk up your programs and make them stand-out from all the rest, even in TEXT MODE!!