Is there API to know screen ratio?

[tropicchs2]

Is there API or MFC function to know screen ratio(4:3, 16:10, 16:9)?
Isthere API or MFC function to know if it is wide monitor or normal monitor?

Thank you.

[GCDEF]

GetSystemMetrics

[Marc G]

Retrieve the width and height of the screen, divide them to get the aspect ratio.

[bderagon]

That'll only work if the screen is set to the proper resolution, it won't actually tell you the dimensions of the monitor itself?

You need to use the monitors built-in interface, or the video card driver to do that I thought?

[GCDEF]

That'll only work if the screen is set to the proper resolution, it won't actually tell you the dimensions of the monitor itself?

You need to use the monitors built-in interface, or the video card driver to do that I thought?

He didn't ask for the monitor size, only the ratio.

[bderagon]

Sorry, I responded too quick, he actually did request both.

[Pravin Kumar]

Hello,

Best way may be to get the screen DC and use GetDeviceCaps to find the pixels (VERTRES, HORZRES) and pixels per inch (LOGPIXELSX, LOGPIXELSY) of X and Y direction. From these data, it is easy to calculate the aspect ratio.

Better still, GetDeviceCaps, when called with parameter HORZSIZE / VERTSIZE returns the entire width / height of physical screen.

HDC hDC = ::GetDC(NULL);
int nWidth = GetDeviceCaps(hDC, HORZSIZE);
int nHeight = GetDeviceCaps(hDC, VERTSIZE);
CString sRatio;
sRatio.Format("Width to Height ratio is %d:%d", nWidth, nHeight);
pDC->TextOut(0, 0, sRatio);
::ReleaseDC(NULL, hDC);

Regards,
Pravin.

[tropicchs2]

Unexpectedly, GetDeviceCaps returns value which depends on resolution.
When I set resolution as 1920x1200 for my 24 inch wide monitor, it returns
520 mm x 325 mm. This value is actual size of 24 inch wide monitor.
But, when I set resolution as 1280x1024, it returns 412 mm x 330 mm.
Is MSDN wrong?
Is there any way to know physical size of monitor in mm or ratio, regardless of resolution?

[Pravin Kumar]

Hello,

I have checked with various resolution settings. All the time, monitor aspect ratio was returned as 320:240. Are you sure that your monitor installation settings are correct?

I must admit that I have checked with the code snippet I had earlier posted and not using (VERTRES, HORZRES) and (LOGPIXELSX, LOGPIXELSY). But that also can be easily checked. I do not feel that it will yield a different answer.

Regards,
Pravin.

[tropicchs2]

I used GetDeviceCaps(hDC, HORZSIZE) and I am sure it's return value depends on resolution.
Anyway thank you. I decided to use different method.