initial commit

libraries/FastLED/src/fl/fft_impl.h

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+#pragma once
+
+#include "fl/hash_map_lru.h"
+#include "fl/pair.h"
+#include "fl/unique_ptr.h"
+#include "fl/span.h"
+#include "fl/vector.h"
+
+namespace fl {
+
+class AudioSample;
+class FFTContext;
+struct FFT_Args;
+
+// Example:
+//   FFTImpl fft(512, 16);
+//   auto sample = SINE WAVE OF 512 SAMPLES
+//   fft.run(buffer, &out);
+//   FASTLED_WARN("FFTImpl output: " << out);  // 16 bands of output.
+class FFTImpl {
+  public:
+    // Result indicating success or failure of the FFTImpl run (in which case
+    // there will be an error message).
+    struct Result {
+        Result(bool ok, const string &error) : ok(ok), error(error) {}
+        bool ok = false;
+        fl::string error;
+    };
+    // Default values for the FFTImpl.
+    FFTImpl(const FFT_Args &args);
+    ~FFTImpl();
+
+    fl::size sampleSize() const;
+    // Note that the sample sizes MUST match the samples size passed into the
+    // constructor.
+    Result run(const AudioSample &sample, FFTBins *out);
+    Result run(span<const i16> sample, FFTBins *out);
+    // Info on what the frequency the bins represent
+    fl::string info() const;
+
+    // Detail.
+    static int DefaultSamples() { return 512; }
+    static int DefaultBands() { return 16; }
+    static float DefaultMinFrequency() { return 174.6f; }
+    static float DefaultMaxFrequency() { return 4698.3f; }
+    static int DefaultSampleRate() { return 44100; }
+
+    // Disable copy and move constructors and assignment operators
+    FFTImpl(const FFTImpl &) = delete;
+    FFTImpl &operator=(const FFTImpl &) = delete;
+    FFTImpl(FFTImpl &&) = delete;
+    FFTImpl &operator=(FFTImpl &&) = delete;
+
+  private:
+    fl::unique_ptr<FFTContext> mContext;
+};
+
+}; // namespace fl