1. Graphics Problems
- Posted by euman at bellsouth.net
Apr 03, 2002
Hello all,
I have a program that uses graphics exclusivly for the GUI and I have one minor
problem. Im using DIBSections for the imagery and double buffering the images
with memory DC's so I can bitblt the images to screen when needed at certain
locations. What Ive found is in 256 color mode the screen and images retain
their respective palette until my window looses focus.
I have this short piece of code that works fine for any window that may overlap
my window but if any window is exclusive to the screen size (full screen) and
recieves focus then my window losses its palette when it regains focus.
elsif iMsg = WM_ACTIVATE then
if LOWORD(wParam) = 0 then
hdc = GetDC(hwnd)
savedDC = c_func(xSaveDC,{hdc})
ReleaseDC(hwnd, hdc)
elsif LOWORD(wParam) = 1 or LOWORD(wParam) = 2 then
if lParam = hwnd then
ShowWindow(hwnd, SW_SHOWNORMAL)
junk = c_func(xRestoreDC,{hdc, -1})
c_proc(UpdateWindow, {hwnd})
end if
any ideas?
Euman
euman at bellsouth.net
5 2 1 - 1 - n - 5 The Doors
2. Re: Graphics Problems
- Posted by euman at bellsouth.net
Apr 03, 2002
----- Original Message -----
From: "Bernie Ryan" <xotron at localnet.com>
> euman at bellsouth.net wrote:
> > Hello all,
> >
> > I have a program that uses graphics exclusivly for the GUI and I have
> > one minor
>> <snip>
> Euman:
> The -1 in RestoreDC maybe causing a problem if somewhere
> in your program or windows the device context stack has
> been disturbed.
> Bernie
Thanks Bernie for the reply.!
Here is a bit more info on my problem that might help you help me.
I also create a private DC, I use CS_OWNDC.
(eg. poke4(wndclass + style, CS_OWNDC) )
a private device context is preserved throughout the lifetime of its associated
window, you need to retrieve its handle only once.
the private device context is not retrieved from the GDI device-context cache.
This means that any attribute changes (in modes, colors, origins, and graphic
objects)
that you make to a private device context are preserved until you explicitly
modify them.
So I ask this:
If I issue SaveDC( ) when my windows is deactivated and RestoreDC( ) when
my window is re-Activated how can the DC stack become corrupt in an unactive
state?
Maybe this will help???
Euman
euman at bellsouth.net
.
3. Re: Graphics Problems
- Posted by euman at bellsouth.net
Apr 03, 2002
----- Original Message -----
From: "Chris Bensler" <bensler at mail.com>
To: "EUforum" <EUforum at topica.com>
> Have you tried resetting the palette on WM_ACTIVATE?
>
> Exotica requires you to rebuild custom graphics on WM_ACTIVATE. If not,
> the video memory buffer is corrupted from other windows, and the custom
> bitmaps are thrashed.
> I assume, it's a similar situation.
>
> Chris
>
Thanks Chris for the reply.!
I had tried resetting the palette initially and it didnt work.
I even tried using a memory DC to hold the window image
and bitblt this back to the hwndDC when the program came
back into focus. The image is there but has an awfull looking
palette (all green and red and, neither of these colors are in the
the real image).
I have a routine in the code to move the window around
the screen and noticed that when the image looks as it should (colors)
that the image does not drag smoothly but when this (Red &Green)
image comes up, the image can be dragged around smoothly as
it does in 16 bit+ modes.
Im frustrated..... Thanks again, I 'll post the code if anyone would like.
Euman
euman at bellsouth.net
5 2 1 - 1 - n - 5 The Doors
4. Re: Graphics Problems
- Posted by euman at bellsouth.net
Apr 03, 2002
>
> Euman:
> The -1 in RestoreDC maybe causing a problem if somewhere
> in your program or windows the device context stack has
> been disturbed.
> Bernie
>
Bernie you helpfull freind!
you indirectly (possibly) solved the whole mess.
you pointed right at the answer:
RestoreDC( ) -1 look at the DC it should be "savedDC"
if lParam = hwnd then
ShowWindow(hwnd, SW_SHOWNORMAL)
junk = c_func(xRestoreDC,{hdc, -1})
c_proc(UpdateWindow, {hwnd})
end if
Thanks, I'll get back to you if this doesnt work!
Euman
euman at bellsouth.net
5. Re: Graphics Problems
- Posted by euman at bellsouth.net
Apr 04, 2002
Hello,
I think this should be book marked as one of the best sites that
explains palettes in Windows. (interested parties ofcourse)
http://www.compuphase.com/palette.htm
Euman
euman at bellsouth.net
6. Re: Graphics Problems
- Posted by euman at bellsouth.net
Apr 04, 2002
Hello all,
I hope I write this right!
See if you can wrap your brain around this....
My Graphics problem is not really an issue of my DC being corrupt
but instead a palette issue after all.
I downloaded this utility that allows you to snoop the palette across
the system and running apps. http://www.compuphase.com/palspy.zip
I opened Jasc PSP 7.0 and the palette the image I am displaying doesnt match
the palette from my program when I have SaveDC( ), RestoreDC and then
RealizePalette( ). The problem is that there are 20 colors that Windows uses
for a "system palette" and my "logical palette" contains (3) colors that are
system
colors, these make my logical palette become unorginized.
I read that using PC_NOCOLLAPSE would eliminate this problem but it doesnt
seem to be working as advertised on Win 98 SE. What I am going to do is take
the (3) colors and slightly change these in the image to different RGB values so
they no longer are mapped to the system colors to see if this works.
I'll get back to you all to let you know my findings.
Euman
7. Re: Graphics Problems
- Posted by euman at bellsouth.net
Apr 04, 2002
Hello all,
Here is my updated Palette code!
I initialize the palette when I create my first DDB (DIB)
my DibSection code is not included here for size purposes.
This code originated with Win32lib but has evolved into
this much faster piece (maybe the Win32lib guys will like this?)
Keep in mind that when you use hDIB = c_func( xCreateDIBitmap
that this only creates a bitmap thats Device-Dependant and will
default to using the system palette (I really should change this for
less confusion, maybe later) Dib-Sections are not Dependant and
can render using a logical palette which this code in
global function createDIB presents "palette routine".
There is a way to convert DDB bitmaps to DibSections but I havent
included this code either. (READ MORE BELOW CODE)
-- (highly modified!)Code from win32lib development
-- "contains palette code and optimizations"
-- Euman 2002
global atom newpal, palinfo
newpal = 0
-----------------------------------------------------------------------------
function packScanLine( sequence pixels )
-- convert a scanline of data into a packed scanline
integer fill
sequence packed
packed = pixels
fill = and_bits( length( packed ), 4 - 1 )
if fill then
packed = packed & repeat( 0, 4-fill )
end if
return packed
end function
global atom ple
ple = myalloc(1028)
constant --CBM_CREATEDIB = #2,
CBM_INIT = #4
atom memBitmapInfo
integer pal_exist
pal_exist = 0
global atom hPal --hpal = 0
global sequence spal
global function createDIB(atom hdc, sequence pal, sequence pixels)
integer palSize, headerSize, bitsPer, h, w, at
atom memBits, hDIB, onine, lnine
sequence ret
palSize = length(pal)
bitsPer = 8
-- size of bitmap
w = length( pixels[1] )
h = length( pixels )
-- calculate the size of the BITMAPINFO header
headerSize = 40 + (4 * palSize )
-- Allocate memory for DIB
memBitmapInfo = myalloc(headerSize)
-- build the bitmap info header
mypoke4( memBitmapInfo + 0, 40 )
mypoke4( memBitmapInfo + 4, w ) -- Width in pixels.
mypoke4( memBitmapInfo + 8, -h ) -- Height in pixels.
mypoke ( memBitmapInfo + 12, {1,0} ) -- 1 color plane.
mypoke ( memBitmapInfo + 14, {8,0} ) -- bits per pixel.
mypoke4( memBitmapInfo + 32, 256 ) -- Colors used.
mypoke4( memBitmapInfo + 36, 256 ) -- Colors used.
for i = 1 to h do
pixels[i] = packScanLine( pixels[i] )
end for
-- get bytes per scanline
w = length( pixels[1] )
-- Allocate storage
memBits = myalloc(h * w)
-- copy pixels to memory
at = memBits
for i = 1 to h do
mypoke( at, pixels[i] )
at = at + w
end for
at = memBitmapInfo + 40
if pal_exist = 0 then
c_proc(xSetSystemPaletteUse,{hdc, 1})
onine = myalloc(40)
lnine = myalloc(40)
junk = c_func(xGetSystemPaletteEntries,{hdc, 0, 10, onine})
junk = c_func(xGetSystemPaletteEntries,{hdc, 246, 255, lnine})
for i = 1 to palSize do
if i < 11 then
if i = 1 then
junk = c_func(xCopyMemory,{at, onine, 40})
at += 40
end if
elsif i > 246 then
if i = 247 then
junk = c_func(xCopyMemory,{at, lnine, 40})
at += 40
end if
else
mypoke(at, pal[i])
at = at + 4
end if
end for
myfree(onine)
myfree(lnine)
pokew(ple + 0, #300)
pokew(ple + 2, 256)
junk = c_func(xCopyMemory,{ple+4, at - 1024, 1024})
newpal = c_func(xCreatePalette,{ple})
junk = c_func(xSetPaletteEntries, {newpal, 0, 255, ple+4})
hPal = c_func(xSelectPalette, {hdc, newpal, 1})
junk = c_func(xRealizePalette, {hdc})
junk = c_func(xSelectPalette, {hdc, hPal, 1})
pal_exist = 1
else
junk = c_func(xCopyMemory,{at, ple+4, 1024})
end if
-- Create the DIB.
hDIB = c_func( xCreateDIBitmap, {
hdc,
memBitmapInfo,
CBM_INIT,
memBits,
memBitmapInfo,
0} )
myfree(memBits)
myfree(memBitmapInfo)
return hDIB
end function
--from windproc( )
elsif iMsg = WM_ACTIVATE then
if LOWORD(wParam) = 0 then
hPal = c_func(xSelectPalette, {hdc, newpal, 0})
junk = c_func(xRealizePalette, {hdc})
InvalidateRect(hwnd, NULL, 0)
savedDC = c_func(xSaveDC,{hdc})
--junk = 0
elsif LOWORD(wParam) = 1 or LOWORD(wParam) = 2 then
if savedDC > 0 then
junk = c_func(xRestoreDC,{hdc, -1})
hPal = c_func(xSelectPalette, {hdc, newpal, 0})
junk = c_func(xRealizePalette, {hdc})
InvalidateRect(hwnd, NULL, 0)
end if
end if
return junk -- remember to return the ret-val from RealizePalette( )
This is really all there is to palette creation and It now works to display
multiple images that looks proper on all bit levels
(assuming a palette compatible graphics card and monitor is installed.)
I can answer just about any question you might have about palettes
now that Ive spent three days researching this.
Thanks again to all the help Wolf, Bernie and Chris!
Euman
euman at bellsouth.net
5 2 1 - 1 - n - 5 The Doors
8. Re: Graphics Problems
- Posted by euman at bellsouth.net
Apr 04, 2002
Before someone gets on me about one of the routines heres
an ammended version
if pal_exist = 0 then
c_proc(xSetSystemPaletteUse,{hdc, 1})
onine = myalloc(40)
lnine = myalloc(40)
junk = c_func(xGetSystemPaletteEntries,{hdc, 0, 10, onine})
junk = c_func(xGetSystemPaletteEntries,{hdc, 246, 255, lnine})
junk = c_func(xCopyMemory,{at, onine, 40})
at += 40
for i = 10 to 245 do
mypoke(at, pal[i])
at = at + 4
end for
junk = c_func(xCopyMemory,{at, lnine, 40})
at += 40
Euman
euman at bellsouth.net
5 2 1 - 1 - n - 5 The Doors
