pgiline

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Find all intersections of a line, defined by two points, with a polygon.

Usage
pgiline(X, IX, PX1scalar, PY1scalar), PX2scalar, PY2scalar)
X
a closed point-list or a polygon-stream defining one or more polygons.
IX
The index of the polygon of X to be tested; 0 <= IX < pgget(X)
PX1, PY1, PX2, PY2
The points <PX1,PY1> and <PX2,PY2> defining the line to be tested.
Result 3
The result r is a Nx3 matrix. Each row of the matrix contains the coordinates of a point of the line and its state.
i r[i,0], r[i,1] r[i,2]
0 start point of the line 0 if the start point is outside XIX
1 if the start point is inside XIX
1 .. N-2 intersection point 0 if the line leaves XIX
1 if the line enters XIX
N-1 end point of the line 0 if the end point is outside XIX
1 if the end point is inside XIX
See also
pginit, pgget, pgitest, pgxgrid, pgsplit, pgtrans, pghull


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