MAP_POLYFILL Procedure

Fills the interior of a region of the display enclosed by an arbitrary 2D polygon.

MAP_POLYFILL, x, y

x A vector providing the longitude coordinates of the points to be connected.

y A vector providing the latitude coordinates of the points to be connected.

The MAP_POLYFILL keywords are listed below. For a description of each keyword, see Chapter 3, Graphics and Plotting Keywords.

Z-buffer Specific Keywords

These keywords allow you to warp images over 2D or 3D polygons; the keywords are valid only when the Z-buffer device is active. For more information these keywords, refer to the description of the POLYFILL procedure.

Discussion

The polygon is defined by a list of connected vertices stored in x and y. The coordinates must be given in longitude/latitude form.

MAP_POLYFILL uses various filling methods:

• solid fill

• parallel lines

• a pattern contained in an array

• hardware-dependent fill pattern

Solid Fill Method Most devices can fill with a solid color. Solid fill is performed using the line fill method for devices that don't have this hardware capability. Keywords that specify a method are not required for solid filling.

Line Fill Method Filling using parallel lines is device independent and works on all devices that can draw lines. Cross-hatching may be obtained with multiple fillings of differing orientations. The spacing, linestyle, orientation, and thickness of the filling lines may be specified using the corresponding keywords. The Line_Fill keyword selects this filling style, but is not required if either the Orientation or Spacing keywords are present.

Patterned Fill Method The method of patterned filling and the usage of various fill patterns is hardware dependent. The fill pattern array may be directly specified with the Pattern keyword for some output devices. If this keyword is omitted, the polygon is filled with the hardware-dependent pattern index specified by the Fill_Pattern keyword.

MAP, POLYFILL