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2.1.21 MapMode Enumeration

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The MapMode enumeration is used to define the unit of measure for transforming page space units into device space units and for defining the orientation of the drawing axes.

 typedef  enum 
 {
   MM_TEXT = 0x01,
   MM_LOMETRIC = 0x02,
   MM_HIMETRIC = 0x03,
   MM_LOENGLISH = 0x04,
   MM_HIENGLISH = 0x05,
   MM_TWIPS = 0x06,
   MM_ISOTROPIC = 0x07,
   MM_ANISOTROPIC = 0x08
 } MapMode;

MM_TEXT: Each logical unit is mapped to one device pixel. Positive x is to the right; positive y is down.

MM_LOMETRIC: Each logical unit is mapped to 0.1 millimeter. Positive x is to the right; positive y is up.

MM_HIMETRIC: Each logical unit is mapped to 0.01 millimeter. Positive x is to the right; positive y is up.

MM_LOENGLISH: Each logical unit is mapped to 0.01 inch. Positive x is to the right; positive y is up.

MM_HIENGLISH: Each logical unit is mapped to 0.001 inch. Positive x is to the right; positive y is up.

MM_TWIPS: Each logical unit is mapped to one-twentieth of a printer's point (1/1440 inch, also called a "twip"). Positive x is to the right; positive y is up.

MM_ISOTROPIC: Logical units are isotropic; that is, they are mapped to arbitrary units with equally scaled axes. Thus, one unit along the x-axis is equal to one unit along the y-axis. The EMR_SETWINDOWEXTEX (section 2.3.11.30) and EMR_SETVIEWPORTEXTEX (section 2.3.11.28) records are used to specify the units and the orientation of the axes.

Adjustments MUST be made as necessary to ensure that the x and y units remain the same size. For example, when the window extent is set, the viewport MUST be adjusted to keep the units isotropic.

MM_ANISOTROPIC: Logical units are anisotropic; that is, they are mapped to arbitrary units with arbitrarily scaled axes. The EMR_SETWINDOWEXTEX and EMR_SETVIEWPORTEXTEX records are used to specify the units, orientation, and scaling of the axes.