Player: volume depend of frequency

higher the note is, lower is the volume.

src/audio/FreqPlayer.cpp

@@ -21,6 +21,14 @@
 
 #include "FreqPlayer.hpp"
 
+#ifndef min
+#define min(a,b) (a<b?a:b)
+#endif
+
+#ifndef max
+#define max(a,b) (a>b?a:b)
+#endif
+
 template<typename sample_t> FreqPlayer<sample_t>::FreqPlayer(int _rate):
 	rate(_rate),
 	n_frame(0)
@@ -28,6 +36,7 @@ template<typename sample_t> FreqPlayer<sample_t>::FreqPlayer(int _rate):
 	k = K();
 	k_update = -1; // invalid: don't update
 	max_harmonic_freq = rate / 2;
+	freq2volume();
 }
 
 template<typename sample_t> void FreqPlayer<sample_t>::Reset()
@@ -37,6 +46,7 @@ template<typename sample_t> void FreqPlayer<sample_t>::Reset()
 	if (k_update != -1) {
 		k = k_update;
 		k_update = -1;
+		freq2volume();
 	}
 }
 
@@ -62,8 +72,11 @@ template<typename sample_t> void FreqPlayer<sample_t>::SetWaveform(WAVEFORM form
 	waveform = form;
 }
 
-template<> int16_t FreqPlayer<int16_t>::max() { return INT16_MAX; }
+template<> int16_t FreqPlayer<int16_t>::sample_min() { return INT16_MIN; }
-template<> double FreqPlayer<double>::max() { return 1; }
+template<> double FreqPlayer<double>::sample_min() { return -1; }
+
+template<> int16_t FreqPlayer<int16_t>::sample_max() { return INT16_MAX; }
+template<> double FreqPlayer<double>::sample_max() { return 1; }
 
 template<typename sample_t> double FreqPlayer<sample_t>::radius()
 {
@@ -102,7 +115,13 @@ template<typename sample_t> sample_t FreqPlayer<sample_t>::AudioFrame()
 		break;
 	}
 
-	return v * max() * volume;
+	return max(min(v * sample_max() * volume, sample_max()), sample_min());
+}
+
+template<typename sample_t> void FreqPlayer<sample_t>::freq2volume()
+{
+	if (volume_adaptative) volume = min(volume_max, max(volume_min, (freq_volume_min - freq) / (freq_volume_min - freq_volume_max) * (volume_max - volume_min) + volume_min));
+	std::cerr << "volume " << volume << std::endl;
 }
 
 template<typename sample_t> void FreqPlayer<sample_t>::WriteAudio(sample_t *out, int nb_frame, bool stop)
@@ -119,6 +138,7 @@ template<typename sample_t> void FreqPlayer<sample_t>::WriteAudio(sample_t *out,
 				n_frame = 0;
 				k = k_update;
 				k_update = -1;
+				freq2volume();
 				v = AudioFrame();
 			}
 			else if (stop) {

src/audio/FreqPlayer.hpp

@@ -30,10 +30,19 @@ template<typename sample_t> class FreqPlayer {
 	enum WAVEFORM { W_SINUS, W_TRIANGLE, W_HARMONIC };
 
 	private:
+	/// frequencies for min and max volumes
+	static constexpr double freq_volume_min = 1200;
+	static constexpr double freq_volume_max = 120;
+
 	/// current frequency
 	double freq = 440;
 	/// current volume (linear)
 	double volume = 0.5;
+	/// volume min and max
+	double volume_min = 0.5;
+	double volume_max = 1;
+	/// if volume is adaptative to freq (lower -> volume higher)
+	bool volume_adaptative = true;
 	/// audio rate
 	int rate;
 	/// current frame nb
@@ -52,9 +61,13 @@ template<typename sample_t> class FreqPlayer {
 	/// return k computed
 	double K() const;
 	/// return the max sample_t
-	sample_t max();
+	sample_t sample_min();
+	/// return the max sample_t
+	sample_t sample_max();
 	/// return the current radius
 	double radius();
+	/// return volume if adaptative
+	void freq2volume();
 
 	public:
 	FreqPlayer(int rate);