Re: Display problem with 16Bpp TFT

From: dan (user100_at_bluewin.ch)
Date: 06/29/04


Date: 29 Jun 2004 04:57:01 -0700


"Dan" <user100@bluewin.ch> wrote in message news:<40e07cca$1_1@news.bluewin.ch>...
> Hello everybody,
>
> Finally I'v got my QVGA TFT working with Windows CE on the Accelent IDP
> board. The graphic seems Ok. All colors
> are correct. But it still has problem in text mode(see attached photo). It
> looks to me that the gray level of the letters are not correctly shown. Some
> gray becomes black and some becomes white. That's why the text on the
> desktop looks very strange and the text on the console window has irregular
> width. I'm using EngCreatePalette(PAL_BITFIELDS, NULL, NULL, 0xF800, 0x07E0,
> 0x001F) to create the default color palette for the 16Bpp display.
> The problem with text dispears if I use an 8Bpp PSTN display(rebuild the
> image with 8Bpp configuration).
>
> My questions are:
> Does text mode using a different color palette from the graphic mode with
> 16Bpp display?
> How can I change the default color palette?
>
> Thanks a lot in advance for any hints and tips.
>
> Dan

It is not possible to attach the picture. So I try TO illustrate the
effect in text:
(Backslash) (seen on my 16 Bpp TFT) (Display memory
contents)
                                           FFFF FFFF FFFF FFFF FFFF
FFFF FFFF
  \\ ** FFFF 0001 0000 FFFF FFFF
FFFF FFFF
    \\ ** FFFF FFFF 0000 0000 FFFF
FFFF FFFF
      \\ ** FFFF FFFF 0001 0000 FFFF
FFFF FFFF
        \\ ** FFFF FFFF FFFF 0000 0000
FFFF FFFF
          \\ *** FFFF FFFF FFFF 0003 0000
0002 FFFF
            \\ ** FFFF FFFF FFFF FFFF 0000
0000 FFFF

It seems that the display driver uses a 2 or 4 bits monochrome palette
to
produce the gray level for the characters. The color values 0001,
0002, 0003(a little bit blue) are practically black for my 16Bpp
display. A gray level in
16Bpp display would be something like 0x39C3(00111 001110 00111). Why
my
display driver produce the gray levels simply as 0x0001, 0x0002,
0x0003 etc.?

Thanks

Dan



Relevant Pages

  • Re: Display problem with 16Bpp TFT
    ... > Finally I'v got my QVGA TFT working with Windows CE on the Accelent IDP ... > looks to me that the gray level of the letters are not correctly shown. ... > How can I change the default color palette? ... It seems that the display driver uses a 2 or 4 bits monochrome palette ...
    (microsoft.public.windowsce.embedded)
  • Re: Display problem with 16Bpp TFT(better readable)
    ... > Finally I'v got my QVGA TFT working with Windows CE on the Accelent IDP ... > looks to me that the gray level of the letters are not correctly shown. ... > How can I change the default color palette? ... It seems that the display driver uses a 2 or 4 bits monochrome palette ...
    (microsoft.public.windowsce.platbuilder)
  • Re: Display problem with 16Bpp TFT(better readable)
    ... > Finally I'v got my QVGA TFT working with Windows CE on the Accelent IDP ... > looks to me that the gray level of the letters are not correctly shown. ... > How can I change the default color palette? ... It seems that the display driver uses a 2 or 4 bits monochrome palette ...
    (microsoft.public.windowsce.embedded)