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Diffstat (limited to 'src/components/utility/LinearApproximation.h')
-rw-r--r-- | src/components/utility/LinearApproximation.h | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/src/components/utility/LinearApproximation.h b/src/components/utility/LinearApproximation.h new file mode 100644 index 00000000..f7104ced --- /dev/null +++ b/src/components/utility/LinearApproximation.h @@ -0,0 +1,41 @@ +#pragma once + +#include <cstddef> +#include <array> + +namespace Pinetime { + namespace Utility { + + // based on: https://github.com/SHristov92/LinearApproximation/blob/main/Linear.h + template <typename Key, typename Value, std::size_t Size> class LinearApproximation { + using Point = struct { + Key key; + Value value; + }; + + public: + LinearApproximation(const std::array<Point, Size>&& sorted_points) : points {sorted_points} { + } + + Value GetValue(Key key) const { + if (key <= points[0].key) { + return points[0].value; + } + + for (std::size_t i = 1; i < Size; i++) { + const auto& p = points[i]; + const auto& p_prev = points[i - 1]; + + if (key < p.key) { + return p_prev.value + (key - p_prev.key) * (p.value - p_prev.value) / (p.key - p_prev.key); + } + } + + return points[Size - 1].value; + } + + private: + std::array<Point, Size> points; + }; + } +} |