The Aspect* and LogPixels* Values from GetDeviceCaps()

• Microsoft Windows Device Driver Kit (DDK) for Windows versions 3.0 and 3.1

The Microsoft Windows graphical environment operates with a number of hardware devices, and therefore a Windows installation includes a collection of device drivers that provide information about the particular hardware.

Windows uses the AspectX, AspectY, and AspectXY constants returned by GetDeviceCaps() to draw dotted and dashed lines that appear the same regardless of the line's orientation. The AspectX and AspectY values are dimensionless numbers that form the legs of a right triangle on the device; the AspectXY value is the length of the hypotenuse. The ratio of AspectY to AspectX is the aspect ratio of the device. The Windows graphics device interface (GDI) uses this information to draw round circles, for example.

The AspectX, AspectY, and AspectXY values should be small (less than 100 each, for example). The size of these values impacts the length of a patterned brush provided by GDI.

The LogPixelsX and LogPixelsY values describe the actual physical resolution of the device.