pgiline

Find all intersections of a line, defined by the starting and the ending point, with the polygon x.

Usage

pgiline(X, IX, PX1scalar, PY1scalar), PX2scalar, PY2scalar)

PX1, PY1, PX2, PY2

The start point <PX1,PY1> and the end point <PX2,PY2> of the line P to be tested.

Result 3

The result r is a scalar.

r=0	... the line P is outside the polygon XIX
r=1	... the line P is inside the polygon XIX
r=2	... the line P intersects the polygon XIX

---

Usage 4

pgitest(X, IX, P, IP)

P

a closed point-list or a polygon-stream defining one or more polygons.

IP

The index of the polygon of P to be tested; 0 <= IP < pgget(P))

Result 4

The result r is a scalar.

r=0	... the polygon PIP is outside the polygon XIX
r=1	... the polygon PIP is included in the polygon XIX
r=2	... the polygons PIP and XIX are partly overlapping
r=3	... the polygon XIX is included in the polygon PIP

---

See also

pginit, pgget, pgiline, pgxgrid, pgsplit, pgtrans, pghull

<function list>

X2, Y2

The x/y coordinate of the last point in the line.

Result:

Detect intersections of the line <X1,Y1>..<X2,Y2> and the polygon XS[IX].

The result IS is an "N x 3" matrix:

row 0: col0,col1 x and y of start-point

col2 0 if start-point outside and 1 if start-point inside the polygon

...

row i: col0,col1 x and y of intersection point i (i = 1 .. N-2)

col2 0 if the line leaves and 1 if the line enters the polygon

...

row N-1: col0,col1 x and y of end-point

col2 0 if end-point outside and 1 if end-point inside the polygon