Fit type of polyline | Home |

A "Fit type" parameter determines how a polyline's curve fits to a polyline's vertices. In the examples below you see polylines with the same vertices coordinates but with different fit types.

Fit type:

Description: Direct lines or arcs between vertices.

Curve between vertices is defined by LC_PROP_VER_BULGE property, called "Bulge coefficient". It is calculated as CD/AD (see picture below), where A and B are consequtive vertices of a polyline. Value

Bulge in vertex 0=-0.5, 1=-0.77, 4=0.2, others=0.0

Fit type:

Description: Quadratic B-spline.

Fit type:

Description: Cubic B-spline.

Fit type:

Description: Cubic spline goes through vertices. Spline direction at start point is controlled by the LC_PROP_PLINE_ANG0 and LC_PROP_PLINE_HASANG0 properties, direction at end point - by the LC_PROP_PLINE_ANG2 and LC_PROP_PLINE_HASANG2 properties.

Fit type:

Description: Polyline with rounded vertices.

The radius of vertex arc is defined by the LC_PROP_VER_RADIUS property.

Fit type:

Description: Combination of linear segments and quadratic B-spline segments. These kinds of curves are used to code Windows TTF characters.

LC_PROP_VER_FIX property defines vertex behaviour: "False" means polyline goes offside of vertex, "True" means curve is fixed to vertex. Between offside vertices, LiteCAD generates spline segment.

lcBlockAddPolyline