gr_vect.gml

来自「开放源码的编译器open watcom 1.6.0版的源代码」· GML 代码 · 共 16 行

The arc is a segment of the ellipse drawn within this bounding
rectangle.
The arc starts at the point on this ellipse that intersects the vector
from the centre of the ellipse to the point
.coord x3 y3 .
The arc ends at the point on this ellipse that intersects the vector
from the centre of the ellipse to the point
.coord x4 y4 .
The arc is drawn in a counter-clockwise direction
with the current plot action
using the current color and the current line style.
.pp
The following picture illustrates the way in which the bounding
rectangle and the vectors specifying the start and end points are
defined.