The function
shift()
adds its arguments to the corresponding
world_coordinates of a Point. In the following example,
the function show() is used to print the world_coordinates
of p0 to standard output.
Point p0(0, 0, 0);
p0.shift(1, 2, 3);
p0.show("p0:");
-| p0: (1, 2, 3)
p0.shift(10);
p0.show("p0:");
-| p0: (11, 2, 3)
p0.shift(0, 20);
p0.show("p0:");
-| p0: (11, 22, 3)
p0.shift(0, 0, 30);
p0.show("p0:");
-| p0: (11, 22, 33)
shift takes three real arguments, whereby the second and
third are optional. To shift a Point in the direction of
the positive or negative y-axis, and/or the positive or negative z-axis
only, then a 0 argument for the
x direction, and possibly one for the y direction
must be used as placeholders, as in the example above.
shift() can be invoked with a Point argument
instead of real arguments. In this case, the x, y, and
z-coordinates of the argument are used for shifting the Point:
Point a(10, 10, 10);
Point b(1, 2, 3);
a.shift(b);
a.show("a:")
-| a: (11, 12, 13)
Another way of shifting Points is to use the binary +=
operator (Point::operator+=()) with a Point
argument.
Point a0(1, 1, 1);
Point a1(2, 2, 2);
a0 += a1;
a0.show("a0:");
-| a0: (3, 3, 3)