I need to determine the color palette depth a display is running when my
program starts up. Does anyone know how this is done?

Thanks.

John Russell

Give this routine a try ....

      'determine number of color bits supported.
        BitsPerPixel = GetDeviceCaps(frmIn.hDC, BITSPIXEL)
        NbrPlanes = GetDeviceCaps(frmIn.hDC, PLANES)
        ColorBits = (BitsPerPixel * NbrPlanes)

      Select Case ColorBits
        Case 32:   RgnCnt = 256    '16M colors:  8 bits for blue
        Case 24:   RgnCnt = 256    '16M colors:  8 bits for blue
        Case 16:   RgnCnt = 256    '64K colors:  5 bits for blue
        Case 15:   RgnCnt = 32     '32K colors:  5 bits for blue
        Case 8:    RgnCnt = 64     '256 colors:  64 dithered blues
        Case 4:    RgnCnt = 64     '16 colors :  64 dithered blues
        Case Else: ColorBits = 4
                   RgnCnt = 64     '16 colors assumed: 64 dithered blues
      End Select

Print ColorBits, RgnCnt
---

Public Const PLANES = 14       '  Number of planes
Public Const BITSPIXEL = 12    '  Number of bits per pixel

Declare Function GetDeviceCaps Lib "gdi32" (ByVal hDC As Long, ByVal nIndex
As Long) As Long

--
Randy Birch, MVP Visual Basic

Moderator, Fidonet Visual Basic Programmer's Conference
VBnet, The Visual Basic Developers Resource Centre
http://home.sprynet.com/sprynet/rasanen/

: I need to determine the color palette depth a display is running when my
: program starts up. Does anyone know how this is done?
:
: Thanks.
:
: John Russell
:
:

Randy --

FYI, AFAIK, GetDeviceCaps will never return 15 bitspixel: it is unable to
distinguish between 32K and 64K colors (and frankly, so am I <g>).

Jim Deutch
MS Dev MVP

You can use the API call GetDeviceCaps(Form1.hDC, BITSPIXEL) and
GetDeviceCaps(Form1.hDC, PLANES) to get the bits/per plane and planes
values. If you multiply these values you should get the display depth.
If you find a way to distinguish 15-bit from 16-bit displays drop me
a line because these calls always give 16!

Probably quite right. :)

 This was a routine I found somewhere, so included all for completeness.

--
Randy Birch, MVP Visual Basic

Moderator, Fidonet Visual Basic Programmer's Conference
VBnet, The Visual Basic Developers Resource Centre
http://home.sprynet.com/sprynet/rasanen/

: Randy --
:
: FYI, AFAIK, GetDeviceCaps will never return 15 bitspixel: it is unable to
: distinguish between 32K and 64K colors (and frankly, so am I <g>).
:
: Jim Deutch
: MS Dev MVP
:


: > Give this routine a try ....
: >
: >       'determine number of color bits supported.
: >         BitsPerPixel = GetDeviceCaps(frmIn.hDC, BITSPIXEL)
: >         NbrPlanes = GetDeviceCaps(frmIn.hDC, PLANES)
: >         ColorBits = (BitsPerPixel * NbrPlanes)
: >    
: >       Select Case ColorBits
: >         Case 32:   RgnCnt = 256    '16M colors:  8 bits for blue
: >         Case 24:   RgnCnt = 256    '16M colors:  8 bits for blue
: >         Case 16:   RgnCnt = 256    '64K colors:  5 bits for blue
: >         Case 15:   RgnCnt = 32     '32K colors:  5 bits for blue
: >         Case 8:    RgnCnt = 64     '256 colors:  64 dithered blues
: >         Case 4:    RgnCnt = 64     '16 colors :  64 dithered blues
: >         Case Else: ColorBits = 4
: >                    RgnCnt = 64     '16 colors assumed: 64 dithered
blues
: >       End Select
:
:

Tim Roberts slapped me silly once for including the "15", and he writes
video drivers, so he should know <g>.

The really funny thing was, a week later, someone from NetQuest (currently
known as Aditi) posted a cut-and-paste of my (since corrected) reply,
including the "15".  Guess he missed the correction.

Jim Deutch

Sorry, I don't know how to tell 15- from 16-bit video.

Jim Deutch
MS Dev MVP