[feat]: Filter (#18)

closes #16

Reviewed-on: #18

inc/BandPassFilter.h

@@ -0,0 +1,14 @@
+#pragma once
+#include "Filter.h"
+
+class BandPassFilter : public Filter {
+  private:
+    void CalculateCoefficients() override;
+
+  public:
+    BandPassFilter(Filter* filter);
+    BandPassFilter(float freq, float res, float q);
+    BandPassFilter(/* args */);
+    ~BandPassFilter();
+    bool IsSameFilterType(FilterType type) override { return type == BandPass; };
+};