Board index » cppbuilder » DirectDraw Palette error

2005-08-09 06:09:10 PM
cppbuilder70
Hi all,
I'm writing a direct draw app, using 256 color mode, since I needed some
color animation.
however, when I used the following code to get the palette:
lpddpal = DDLoadPalette(lpdd, "Houses.bmp");
lpddsfront->SetPalette(lpddpal);
The palette will be wrong - the color became all purple-ish. It used to work
correctly back when I first created the code (on the same machine) a year
ago (it had been put aside due to work schedule, and I now have time to
resume the app). The color animation effect is working correctly. (with
wrong coloring though)
So I changed to the following code to get the correct palette. The graphics
look exactly how it should - with the correct palette.
BMP *pal = new BMP;
pal->LoadFromFile("Houses.bmp");
lpdd->CreatePalette(DDPCAPS_8BIT, (PALET{*word*249}TRY *)pal->Palette, &lpddpal,
NULL);
lpddsfront->SetPalette(lpddpal);
delete pal;
but I'm having problem with this palette when I try to access the palette
entries via lpddpal->GetEntries() and SetEntries(). It generated some sort
of Exceptions when executed. The Set/GetEntries are not giving any problem
if I used the first method (DDLoadPalette()) which is from the ddutil.c in
the samples come with C++Builder 6. I've checked, the flags used to create
the palette is exactly the same. I've also tried to include the
DDPCAPS_ALLOW256 | DDPCAPS_INITIALIZE
flags and they are not helping.
I have no idea what exception was generated, since I'm running in full
screen, exclusive mode. It is pointless to convert the app to windowed mode
since it have to be 256 color mode, or I'll have to chang quite a bit of the
code - and eliminating 256 color mode along the change. Can anyone help me
here? Why is the palette color suddenly changed? it used to be perfectly
okay one year ago when I used the same hardware (but I may be using
C++Builder 3 back then, I can't remember quite clear). Thanks in advance.
Regards.
 

"Choykw" < XXXX@XXXXX.COM >wrote in message
should be able to find out what exceptions are thrown via Builder's debug
log. In BCB4, it is under the View menu, then Debug Windows, and is called
Event Log.
Jonathan
 

thanks for your informatoin, I managed to track down the problem. It appears
to be some typo in my code (but it get through the compiler...)
"Jonathan Benedicto" < XXXX@XXXXX.COM >wrote in message

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