[M3devel] pixmap problem

[Jay]

Randy, I'm pretty clueless here.
I don't do gui or graphics.
If anyone has a clue, please stand up.
If you can get us code to run, please do.
But I think I need multiple particularly configured machines too.

I'm curious what this code prints on the systems:

#include
#include

int main()
{
int pix_ver = { 0 };
int pix_hor = { 0 };
int mm_hor = { 0 };
int mm_ver = { 0 };
HWND hwnd = { 0 };
HDC hdc = { 0 };

hwnd = GetDesktopWindow();
hdc = GetDC(hwnd);
mm_hor = GetDeviceCaps(hdc, HORZSIZE);
mm_ver = GetDeviceCaps(hdc, VERTSIZE);
pix_hor = GetSystemMetrics(SM_CXSCREEN);
pix_ver = GetSystemMetrics(SM_CYSCREEN);

printf("horizonal pixels %d\n", pix_hor);
printf("veritical pixels SM_CYSCREEN %d\n", pix_ver);
printf("horizontal millimeters %d\n", mm_hor);
printf("veritical millimeters %d\n", mm_ver);

printf("horizontal pixels per millimeter %f\n", (((float) pix_hor) / ((float) mm_hor)));
printf("vertical pixels per millimeter %f\n", (((float) pix_ver) / ((float) mm_ver)));

printf("horizontal pixels per inch %f\n", (((float) pix_hor) / ((float) mm_hor) * 10.0 * 2.54));
printf("vertical pixels per inch %f\n", (((float) pix_ver) / ((float) mm_ver) * 10.0 * 2.54));

return 0;
}


for me:

$ gcc dpi.c -luser32 -lgdi32

jay at jay-win9 /dev2/j/dpi
$ ./a
horizonal pixels 1280
veritical pixels SM_CYSCREEN 800
horizontal millimeters 384
veritical millimeters 240
horizontal pixels per millimeter 3.333333
vertical pixels per millimeter 3.333333
horizontal pixels per inch 84.666667
vertical pixels per inch 84.666667

(Visual C++ is fine:
cl dpi.c user32.lib gdi32.lib
.\dpi
)

I wonder if lying in this code:

Searching for 'GetDeviceCaps'...
D:\dev2\cm3.2\m3-ui\ui\src\winvbt\WinScreenType.m3(25): VAR res := NEW(T); n_colors := GetDeviceCaps (WinGDI.NUMCOLORS);
D:\dev2\cm3.2\m3-ui\ui\src\winvbt\WinScreenType.m3(32): res.depth := GetDeviceCaps(WinGDI.BITSPIXEL); (* John Karnak 8/3/98 *)
D:\dev2\cm3.2\m3-ui\ui\src\winvbt\WinScreenType.m3(68): mm_hor = GetDeviceCaps (WinGDI.HORZSIZE),
D:\dev2\cm3.2\m3-ui\ui\src\winvbt\WinScreenType.m3(69): mm_ver = GetDeviceCaps (WinGDI.VERTSIZE) DO

Searching for 'res.res[Axis.T.'...
D:\dev2\cm3.2\m3-ui\ui\src\winvbt\WinScreenType.m3(71): res.res[Axis.T.Hor] := FLOAT(pix_hor) / FLOAT(mm_hor);
D:\dev2\cm3.2\m3-ui\ui\src\winvbt\WinScreenType.m3(72): res.res[Axis.T.Ver] := FLOAT(pix_ver) / FLOAT(mm_ver);


D:\dev2\cm3.2\m3-ui\ui\src\winvbt\WinScreenType.m3(89):PROCEDURE GetDeviceCaps (cap: Ctypes.int): INTEGER =
D:\dev2\cm3.2\m3-ui\ui\src\winvbt\WinScreenType.m3(93): res := WinGDI.GetDeviceCaps (hdc, cap);
D:\dev2\cm3.2\m3-ui\ui\src\winvbt\WinScreenType.m3(98): END GetDeviceCaps;
D:\dev2\cm3.2\m3-ui\ui\src\winvbt\WinScrnColorMap.m3(268): cnt := WinGDI.GetDeviceCaps (hdc, WinGDI.NUMCOLORS);
D:\dev2\cm3.2\m3-ui\ui\src\winvbt\WinScrnFont.m3(316): LogicalPixelsPerVertInch := WinGDI.GetDeviceCaps(er.hdc, WinGDI.LOGPIXELSY);
9 occurrence(s) have been found.


Searching for '1000.0'...
D:\dev2\cm3.2\m3-ui\ui\src\winvbt\WinScrnPixmap.m3(463): bmih.biXPelsPerMeter := ROUND (st.res[Axis.T.Hor] * 1000.0);
D:\dev2\cm3.2\m3-ui\ui\src\winvbt\WinScrnPixmap.m3(464): bmih.biYPelsPerMeter := ROUND (st.res[Axis.T.Ver] * 1000.0);


and just claiming 96dpi is the way to go.
Can you try that??


Specifically try setting res.res[Axis.T.Hor] and .Ver to 3.779527559055118.
Or heck to 3.3333 like my laptop has.


Or maybe claiming ignorance and setting biXPelsPerMeter and biYPelsPerMeter to 0???
Claiming ignorance feels better than lying of course. :)

Hm, so throw in also:

printf("LogicalPixelsX %u\n", GetDeviceCaps(hdc, LOGPIXELSX));
printf("LogicalPixelsY %u\n", GetDeviceCaps(hdc, LOGPIXELSY));

I get the magic number 96.

- Jay
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