When I say it looks garbled, I think it is trying to draw the bitmap as if
it were drawing it into a 4-bit (the native depth, it's a Zire 21) window.
It's like it thinks it has to convert the bitmap to 4-bit and then blit it
to the window. But, it's not a 4-bit window, I created the offscreen window
with a 1-bit bitmap.

The reason I suspect this is because it draws stretched out with banding
wherever there should be black pixels. It's fuzzed horizontally a few
pixels.

Also, if I ever try to set the foreground color for this bitmap window, the
bitmap does not draw on a 4-bit device, or it draws pink on an 8-bit device.

Terry



I wrote:
> I'm creating a window with WinCreateBitmapWindow and a 1-bit bitmap created
> with BmpCreate and a nil colortable. Then I draw a 1-bit bitmap read from a
> database into that offscreen window. Later I transfer the offscreen window
> to the display.
> 
> This works fine on devices that are black and white. It does not work fine
> on devices that are natively gray or color. It will: (1) Draw garbled
> looking bitmaps -- you can see a resemblance, it's not just noise, but is
> garbled. (2) If I call WinDrawRectangle, nothing draws after that -- or at
> least, nothing transfers back to the display window. (3) Sometimes, not
> always, I get a crash during WinCopyRectangle in a function named (something
> sort of like) PrvMisalignBlt....
> 
> If I make the window's bitmap 2 or more bits deep, everything works fine.
> Or, like I said, if it's on a device with a native 1-bit display, it works.
> 
> Does anyone know what the problem is?
> 
> Is there a rule like: never make a window with a 1-bit bitmap on a device
> with greater than 1-bit display? Or what's the rule I'm breaking? I'm
> doing lots of other bitmap manipulations and I want to know so I don't break
> the rule somewhere else.


-- 
For information on using the Palm Developer Forums, or to unsubscribe, please see 
http://www.palmos.com/dev/support/forums/

Reply via email to