This is a small C++ library for plotting contours and/or filled contours. These are contours of the Himmelblau function.

The Contouring library draws these contours by sampling the function on a coarse grid and then solving for the function on grid lines, returning a path by callback to drawing functions. The path follows a smooth curve by calling a function for bezier splines.

The principal function in this library takes quite few arguments:

extern "C" void contour(
    double (*f)(double, double), double s,
    double x0, double y0,
    double x1, double y1,
    unsigned n, unsigned m,

    void (*move_to)(double, double),
    void (*line_to)(double, double),
    void (*curve_to)(double, double, double, double, double, double),
    void (*close_path)());

The function f is being sampled in the range [x0,x1]⨯[y0,y1] on a n⨯m grid. To draw the contour four callback functions need to be given: move_to, line_to, curve_to and close_path. These functions shoud work the same as those of the same name in the Cairo drawing library.

Just copy the relevant sources to your own project.

Contouring comes with an interface for the Guile programming language. To compile this interface you need guile 2, and guile-cairo.

A Python interface is still in the works.

This work is distributed under the Apache license v2.