Added an audio FFT view in Wideband FM receive

Tried speeding up fill_rectangle for clearing the waveform widget

firmware/common/message.hpp

@@ -106,6 +106,7 @@ public:
 		
 		AudioLevelReport = 51,
 		CodedSquelch = 52,
+		AudioSpectrumConfig = 53,
 		MAX
 	};
 
@@ -273,6 +274,27 @@ public:
 	size_t trigger { 0 };
 };
 
+struct AudioSpectrum {
+	std::array<uint8_t, 128> db { { 0 } };
+	//uint32_t sampling_rate { 0 };
+};
+
+using AudioSpectrumFIFO = FIFO<AudioSpectrum>;
+
+class AudioSpectrumConfigMessage : public Message {
+public:
+	static constexpr size_t fifo_k = 2;
+	
+	constexpr AudioSpectrumConfigMessage(
+		AudioSpectrumFIFO* fifo
+	) : Message { ID::AudioSpectrumConfig },
+		fifo { fifo }
+	{
+	}
+
+	AudioSpectrumFIFO* fifo { nullptr };
+};
+
 struct ChannelSpectrum {
 	std::array<uint8_t, 256> db { { 0 } };
 	uint32_t sampling_rate { 0 };