1. Windows - DEVMODE
The following bit of code is supposed to set the screen resolution to
640X480 but it doesn't change. (I have my screen set to 1024X768)
This works when I code it in C. Therefor, I believe I may have the
wrong offsets for the structure members, but I'm not sure.
dmScreenSettings = allocate(148) --DEVMODE structure
mem_set(dmScreenSettings,0,148) --clear smScreenSettings
poke(dmScreenSettings + 36,148) --dmSize
poke4(dmScreenSettings +
40,or_all({DM_BITSPERPEL,DM_PELSWIDTH,DM_PELSHEIGHT})) -- dmFields
poke4(dmScreenSettings + 91, 24) -- dmBitsPerPel
poke4(dmScreenSettings + 95, 640) --dmPelWidth
poke4(dmScreenSettings + 99, 480) --dmPelHeight
if c_func(ChangeDisplaySettingsA,{dmScreenSettings,CDS_FULLSCREEN}) !=
DISP_CHANGE_SUCCESSFUL then
retval = message_box("The requested fullscreen mode is not
supported by\nyour video card. ", "Error", or_bits(MB_OK,MB_ICONSTOP))
end if
2. Re: Windows - DEVMODE
----- Original Message -----
From: "Evan Marshall" <1evan at sbcglobal.net>
To: <EUforum at topica.com>
Subject: Windows - DEVMODE
>
>
> The following bit of code is supposed to set the screen resolution to
> 640X480 but it doesn't change. (I have my screen set to 1024X768)
> This works when I code it in C. Therefor, I believe I may have the
> wrong offsets for the structure members, but I'm not sure.
>
> dmScreenSettings = allocate(148) --DEVMODE structure
> mem_set(dmScreenSettings,0,148) --clear smScreenSettings
> poke(dmScreenSettings + 36,148) --dmSize
> poke4(dmScreenSettings +
> 40,or_all({DM_BITSPERPEL,DM_PELSWIDTH,DM_PELSHEIGHT})) -- dmFields
> poke4(dmScreenSettings + 91, 24) -- dmBitsPerPel
> poke4(dmScreenSettings + 95, 640) --dmPelWidth
> poke4(dmScreenSettings + 99, 480) --dmPelHeight
> if c_func(ChangeDisplaySettingsA,{dmScreenSettings,CDS_FULLSCREEN}) !=
> DISP_CHANGE_SUCCESSFUL then
> retval = message_box("The requested fullscreen mode is not
> supported by\nyour video card. ", "Error", or_bits(MB_OK,MB_ICONSTOP))
> end if
Maybe you do have the offsets incorrect. Here is wha I make them to be...
typedef struct _devicemode { /* dvmd */
0 TCHAR dmDeviceName[32];
32 WORD dmSpecVersion;
34 WORD dmDriverVersion;
36 WORD dmSize;
38 WORD dmDriverExtra;
40 DWORD dmFields;
44 short dmOrientation;
46 short dmPaperSize;
48 short dmPaperLength;
50 short dmPaperWidth;
52 short dmScale;
54 short dmCopies;
56 short dmDefaultSource;
58 short dmPrintQuality;
60 short dmColor;
62 short dmDuplex;
64 short dmYResolution;
66 short dmTTOption;
68 short dmCollate;
70 TCHAR dmFormName[32];
102 WORD dmUnusedPadding;
104 USHORT dmBitsPerPel;
106 DWORD dmPelsWidth;
110 DWORD dmPelsHeight;
114 DWORD dmDisplayFlags;
118 DWORD dmDisplayFrequency;
122 (sizeof)
} DEVMODE
This is why I use the allot(), fetch() and store() routines in win32lib. These
do the math for me.
--
Derek
3. Re: Windows - DEVMODE
Derek Parnell wrote:
>Maybe you do have the offsets incorrect. Here is wha I make them to be...
>
Thanks, but that didn't work either, my numbers returned a
DISP_CHANGE_SUCCESSFUL and yours
returned DISP_CHANGE_BADMODE.
Here's what the Microsoft SDK reads,
typedef struct _devicemode {
BCHAR dmDeviceName[CCHDEVICENAME];
WORD dmSpecVersion;
WORD dmDriverVersion;
WORD dmSize;
WORD dmDriverExtra;
DWORD dmFields;
union {
struct {
short dmOrientation;
short dmPaperSize;
short dmPaperLength;
short dmPaperWidth;
short dmScale;
short dmCopies;
short dmDefaultSource;
short dmPrintQuality; };
POINTL dmPosition;
DWORD dmDisplayOrientation;
DWORD dmDisplayFixedOutput; };
short dmColor;
short dmDuplex;
short dmYResolution;
short dmTTOption;
short dmCollate;
BYTE dmFormName[CCHFORMNAME];
WORD dmLogPixels;
DWORD dmBitsPerPel;
DWORD dmPelsWidth;
DWORD dmPelsHeight;
union {
DWORD dmDisplayFlags;
DWORD dmNup; }
DWORD dmDisplayFrequency;
#if(WINVER >= 0x0400)
DWORD dmICMMethod;
DWORD dmICMIntent;
DWORD dmMediaType;
DWORD dmDitherType;
DWORD dmReserved1;
DWORD dmReserved2;
#if (WINVER >= 0x0500) || (_WIN32_WINNT >= 0x0400)
DWORD dmPanningWidth;
DWORD dmPanningHeight;
#endif
#endif /* WINVER >= 0x0400 */ } DEVMODE;
4. Re: Windows - DEVMODE
> > dmScreenSettings = allocate(148) --DEVMODE structure
> > mem_set(dmScreenSettings,0,148) --clear smScreenSettings
I'm not sure setting up a DEVMODE structure this way is ideal ?
The MS docs state that one should use EnumDisplaySettings() to fill in your
DEVMODE structure completely with *valid* values first, and use this
structure when calling ChangeDisplaySettings().
... as it is, you've got a lot of invalid zeroes ( garbage ), in this struc{
Apparently, looping thru EnumDisplaySetting() by incrementing iModeNum, and
checking for 24,640,480... will give you the complete structure you need to
pass (to change), assuming it's a valid mode, without poking...
5. Re: Windows - DEVMODE
Wolf wrote:
> <SNIP>
>
>I'm not sure setting up a DEVMODE structure this way is ideal ?
>The MS docs state that one should use EnumDisplaySettings() to fill in your
>DEVMODE structure completely with *valid* values first, and use this
>structure when calling ChangeDisplaySettings().
>... as it is, you've got a lot of invalid zeroes ( garbage ), in this struc{
>Apparently, looping thru EnumDisplaySetting() by incrementing iModeNum, and
>checking for 24,640,480... will give you the complete structure you need to
>pass (to change), assuming it's a valid mode, without poking...
>
>
Thanks.
You could be right, but like I said previously, it works when I do it
this way in C. I'll try this and see if it helps.
