linear_interpolation.hh

#ifndef VTESTBED_GEOMETRY_LINEAR_INTERPOLATION_HH
#define VTESTBED_GEOMETRY_LINEAR_INTERPOLATION_HH

#include <vector>

#include <vtestbed/geometry/curve_segments.hh>
#include <vtestbed/geometry/math.hh>

namespace vtb {

    namespace geometry {

        template <class T,int N=3>
        class Linear_interpolation {

        public:
            using value_type = Vertex<T,N>;
            using reference = value_type&;
            using const_reference = const value_type&;
            using vertex_array = std::vector<value_type>;
            using size_type = size_t;
            using segments_type = Curve_segments<T,N>;

        private:
            vertex_array _points;
            segments_type _segments;

        public:
            inline explicit
            Linear_interpolation(const vertex_array& values):
            _points(values),
            _segments(values) {
                this->_segments.normalise();
            }

            inline value_type
            operator()(T t) const {
                const auto& segments = this->_segments;
                const auto& points = this->_points;
                size_type i = 0;
                segments.locate(t, i);
                if (i == segments.size()) {
                    return points.back();
                }
                const auto& a = points[i];
                const auto& b = points[i+1];
                return a + t*(b - a);
            }

            inline const_reference
            front() const noexcept {
                return this->_points.front();
            }

            inline const_reference
            back() const noexcept {
                return this->_points.back();
            }

            inline size_type
            size() const {
                return this->_points.size();
            }

            inline const segments_type&
            segments() const {
                return this->_segments;
            }

            inline segments_type&
            segments() {
                return this->_segments;
            }

            inline void
            range(T min, T max) {
                this->_segments.range(min, max);
            }

        };

    }

}

#endif // vim:filetype=cpp