1 files changed, 65 insertions, 0 deletions
diff --git a/src/window-function.hpp b/src/window-function.hpp
new file mode 100644
index 0000000..123a17e
--- /dev/null
+++ b/src/window-function.hpp
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2020-2021 Vasile Vilvoiu <vasi.vilvoiu@gmail.com>
+ *
+ * specgram is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+#ifndef _WINDOW_FUNCTION_HPP_
+#define _WINDOW_FUNCTION_HPP_
+
+#include "input-parser.hpp"
+
+#include <vector>
+#include <complex>
+#include <memory>
+
+enum class WindowFunctionType {
+    kNone,
+    kHann,
+    kHamming,
+    kBlackman,
+    kNuttall
+};
+
+class WindowFunction {
+protected:
+    const std::size_t window_size_;
+    std::vector<double> cached_factors_;
+
+    explicit WindowFunction(std::size_t window_size);
+
+public:
+    WindowFunction() = delete;
+
+    ComplexWindow Apply(const ComplexWindow& window) const;
+
+    static std::unique_ptr<WindowFunction> FromType(WindowFunctionType type, std::size_t window_size);
+};
+
+class GeneralizedCosineWindowFunction : public WindowFunction {
+protected:
+public:
+    GeneralizedCosineWindowFunction(std::size_t window_size, const std::vector<double>& a);
+};
+
+class HannWindowFunction : public GeneralizedCosineWindowFunction {
+public:
+    explicit HannWindowFunction(std::size_t window_size);
+};
+
+class HammingWindowFunction : public GeneralizedCosineWindowFunction {
+public:
+    explicit HammingWindowFunction(std::size_t window_size);
+};
+
+class BlackmanWindowFunction : public GeneralizedCosineWindowFunction {
+public:
+    explicit BlackmanWindowFunction(std::size_t window_size);
+};
+
+class NuttallWindowFunction : public GeneralizedCosineWindowFunction {
+public:
+    explicit NuttallWindowFunction(std::size_t window_size);
+};
+
+#endif
+\ No newline at end of file