winapi - Improper width and height for second monitor from GetMonitorInfo and GetDeviceCaps -

i trying top left x,y , bottom right x,y. , calculat width , height of displays.

my secondary monitor 1920x1080 seen in display settings screenshot:

i getting monitor dimensions in 2 ways. code below js-ctypes simplified out error checking , other ctypes stuff , tried make c. winapi issue not ctypes hence didn't tag topic it.

first approach:

cpoint = point(); getcursorpos(&cpoint);   cmon = monitorfrompoint(cpoint, monitor_defaulttonearest);   cmoninfo = monitorinfoex(); cmoninfo.cbsize = monitorinfoex.size; getmonitorinfo(cmon, &cmoninfo);  lpszdriver = null; lpszdevice = cmoninfo.szdevice;  xtopleft = cmoninfo.rcmonitor.left; ytopleft = cmoninfo.rcmonitor.top; nwidth = cmoninfo.rcmonitor.right - xtopleft; nheight = cmoninfo.rcmonitor.bottom - ytopleft; 

this giving me rect of following:

_rect(-1920, -1080, -640, -360) 

doing right - left gives 1280 doing bottom - top gives 720

the dimensions wrong. should have been width of 1920 , height of 1080.

i try second method:

hdcscreen = createdc(lpszdriver, lpszdevice, null, null); nwidth = getdevicecaps(hdcscreen, horzres); nheight = getdevicecaps(hdcscreen, vertres); 

this gives me same thing, width of 1280 , height of 720. mind boggled! please me 1920x1080.

this same method gives me correct dimensions primary monitor, confused.

edit

i tried third method, , still same issues:

var jsmonitorenumproc = function(hmonitor, hdcmonitor, lprcmonitor, dwdata) {     xtopleft = lprcmonitor.contents.left;     ytopleft = lprcmonitor.contents.top;     nwidth = lprcmonitor.contents.right - xtopleft;     nheight = lprcmonitor.contents.bottom - ytopleft;      return true; } enumdisplaymonitors(null, null, jsmonitorenumproc, 0); 

this gives me rects of following:

_rect(0, 0, 1280, 1024) _rect(-1920, -1080, -640, -360) 

the first 1 primary monitor , see doing bottom - top gives 1280 , right - left gives 1024 correct primary monitor 1280 x 1024.

but second monitor again -360 - -1080 720 height , -640 - -1920 1280 width. please me figure out what's here. using take screenshots of monitors , second ones coming out clipped.

in non-dpi aware app 32bit firefox on win8.1 64bit) able proper dimensions using enumdisplaysettings using display_device struct of size 220.

js-ctypes:

            // start - monitor resolutions             var idevnum = -1;             while (true) {                 idevnum++;                 var lpdisplaydevice = ostypes.type.display_device();                 lpdisplaydevice.cb = ostypes.type.display_device.size;                 var rez_enumdisplaydevices = ostypes.api('enumdisplaydevices')(null, idevnum, lpdisplaydevice.address(), 0);                 //console.info('rez_enumdisplaydevices:', rez_enumdisplaydevices.tostring(), uneval(rez_enumdisplaydevices), cutils.jscgetdeepest(rez_enumdisplaydevices));                  if (cutils.jscequal(rez_enumdisplaydevices, 0)) { // ctypes.winlasterror != 0                     // idevnum greater largest device index.                     break;                 }                  console.info('lpdisplaydevice.devicename:', lpdisplaydevice.devicename.readstring()); // "\\.\display1" till "\\.\display4"                  if (lpdisplaydevice.stateflags & ostypes.const.display_device_attached_to_desktop) {                     console.log('is monitor');                      var dm = ostypes.type.devmode(); // sizeof_devmode = 148                     console.info('dm.size:', ostypes.type.devmode.size);                     //dm.dmfields = ostypes.const.dm_pelswidth;                     //dm.dmsize = ostypes.type.devmode.size;                      console.log('idevnum:', idevnum, lpdisplaydevice.devicename.readstring());                     var rez_enumdisplaysettings = ostypes.api('enumdisplaysettings')(lpdisplaydevice.devicename, ostypes.const.enum_current_settings, dm.address());                     //console.info('rez_enumdisplaysettings:', rez_enumdisplaysettings.tostring(), uneval(rez_enumdisplaysettings), cutils.jscgetdeepest(rez_enumdisplaysettings));                     //console.info('dm:', dm.tostring());                      collmoninfos.push({                         x: parseint(cutils.jscgetdeepest(dm.u.dmposition.x)),                         y: parseint(cutils.jscgetdeepest(dm.u.dmposition.y)),                         w: parseint(cutils.jscgetdeepest(dm.dmpelswidth)),                         h: parseint(cutils.jscgetdeepest(dm.dmpelsheight)),                         screenshot: null, // winnt, each collmoninfos entry has screenshot data                         otherinfo: {                             nbpp: parseint(cutils.jscgetdeepest(dm.dmbitsperpel)),                             lpszdriver: null,                             lpszdevice: lpdisplaydevice.devicename                         }                     });                 }             }             // end - monitor resolutions