Polylines

A polyline is a collection of n lines defined by the n +1 points that define the endpoints of each line segment. The entire polyline can have a set of attributes, and each line segment in the polyline also can have a set of attributes. (In addition, each vertex can have a set of attributes.) A polyline is defined by the TQ3PolyLineData data type. See "Creating and Editing Polylines" for a description of the routines you can use to create and edit polylines. Figure 20 shows a polyline.

A polyline is not closed. The last point should not be connected to the first.

Figure 20 A polyline

typedef struct TQ3PolyLineData {
    unsigned long                       numVertices;
    TQ3Vertex3D                         *vertices;
    TQ3AttributeSet                     *segmentAttributeSet;
    TQ3AttributeSet                     polyLineAttributeSet;
} TQ3PolyLineData;


numVertices

The number of vertices in the polyline. The value of this field must be at least 2.

vertices

A pointer to an array of vertices which define the polyline.

segmentAttributeSet

A pointer to an array of segment attribute sets. If no segments in the polyline are to have attributes, this field should contain the value NULL . If any of the segments have attributes, this field should contain a pointer to an array (containing numVertices  - 1 elements) of attributes sets; the array element for segments with no attributes should be set to NULL .

polyLineAttributeSet

A set of attributes for the polyline. The value in this field is NULL if no polyline attributes are defined.

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© 1997 Apple Computer, Inc.

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