Changes the method used by the font mapper when it converts a logical font to a physical font.
An application can use SetMapperFlags to cause the font mapper to attempt to choose only a physical font that exactly matches the aspect ratio of the specified device.
An application that uses only raster fonts can use the SetMapperFlags function to ensure that the font selected by the font mapper is attractive and readable on the specified device. Applications that use scalable (TrueType) fonts typically do not use SetMapperFlags.
If no physical font has an aspect ratio that matches the specification in the logical font, GDI chooses a new aspect ratio and selects a font that matches this new aspect ratio.