🚀 go-pugleaf

In article <108350001@hplred.HP.COM>, blackwoo@hplred.HP.COM (Craig Blackwood) writes:

> Specifically, I have a VGA card and a driver which supports 16 pure
> colors;  I want to write directly to the VGA card and have it change
> one or more of the palette entries so that I have control over the
> displayed color (it is even OK if windows resets the palette when
> another application is run.)
> 
> To do this I need to know how to talk directly with the VGA card
> AND do this without windows knowing that I have done it.
> 

If you are using the standard VGA driver that comes with Win 3.0 the
only way to get all sixteen mode 12 colors is behind Windows back.  If
you ask Microsoft, the official answer is 'buy the device driver kit
for Windows and write your own VGA driver'.  I found that unacceptable.
With a little help I got around the limitation. I was able to find out 
that the standard System Palette w/20 colors maps into the 16 VGA mode 
12 palette registers (the middle four colors are combinations).  
Unfortunately they don't map directly (i.e. 1->1, ..., 16->16) but in 
the following fashion:

        /* This is really ugly.  Each of the standard VGA System Palette
         * entries don't map intuitively into the VGA palette registers.
         * Here is how they map out:
         *
         *      VGAPAL    SYSPAL          VGAPAL     SYSPAL
         *        00        00              08        07
         *        01        01              09        13
         *        02        02              10        14
         *        03        03              11        15
         *        04        04              12        16
         *        05        05              13        17
         *        06        06              14        18
         *        07        12              15        19
         */

My application just waits to get a WM_SETFOCUS event, then saves the current
state of the hardware colormap and installs the one I want.  When I get a 
WM_KILLFOCUS event I put them back. I tried installing the colormap when
the mouse enters my window/client area, and un-installing it when the mouse
leaves but I could never tell when the mouse left (WM_NCMOUSEMOVE? only
tells you when the mouse moves into YOUR non-client area, not that it just
left your window :-( ).  Windows never knows whats going on.  Don't mess 
directly with the pallette registers tho', modify the color registers that 
they point to.

Of course this will probably break under the Win 3.1?, but hey, I had
a deadline to meet :-).

-- 
Mark Horstman
mh2620@sarek.sbc.com
Southwestern Bell Telephone
St. Louis, MO