example/mod: add frequency to cent conversion

example/mod.cpp

@@ -7,6 +7,82 @@
 #include "mod/mod.hpp"
 #include "mod/getfunk/getfunk.mod.h"
 
+/*
+
+
+Octave 1: 856, C
+ */
+
+struct oct_fns
+{
+  int oct;
+  int fns;
+};
+
+struct oct_fns oct_fns(int x)
+{
+  const uint16_t _cent[] = {
+    0x0,
+    0x3d,
+    0x7d,
+    0xc2,
+    0x10a,
+    0x157,
+    0x1a8,
+    0x1fe,
+    0x25a,
+    0x2ba,
+    0x321,
+    0x38d,
+  };
+
+  switch (x) {
+  case 856: return {2, _cent[0]}; // C
+
+  case 808: return {1, _cent[11]}; // C#
+  case 762: return {1, _cent[10]}; // D
+  case 720: return {1, _cent[9]}; // D#
+  case 678: return {1, _cent[8]}; // E
+  case 640: return {1, _cent[7]}; // F
+  case 604: return {1, _cent[6]}; // F#
+  case 570: return {1, _cent[5]}; // G
+  case 538: return {1, _cent[4]}; // G#
+  case 508: return {1, _cent[3]}; // A
+  case 480: return {1, _cent[2]}; // A#
+  case 453: return {1, _cent[1]}; // B
+  case 428: return {1, _cent[0]}; // C
+
+  case 404: return {0, _cent[11]}; // D#
+  case 381: return {0, _cent[10]}; // D
+  case 360: return {0, _cent[9]}; // D#
+  case 339: return {0, _cent[8]}; // E
+  case 320: return {0, _cent[7]}; // F
+  case 302: return {0, _cent[6]}; // F#
+  case 285: return {0, _cent[5]}; // G
+  case 269: return {0, _cent[4]}; // G#
+  case 254: return {0, _cent[3]}; // A
+  case 240: return {0, _cent[2]}; // A#
+  case 226: return {0, _cent[1]}; // B
+  case 214: return {0, _cent[0]}; // C
+
+  case 202: return {-1, _cent[11]}; // D#
+  case 190: return {-1, _cent[10]}; // D
+  case 180: return {-1, _cent[9]}; // D#
+  case 170: return {-1, _cent[8]}; // E
+  case 160: return {-1, _cent[7]}; // F
+  case 151: return {-1, _cent[6]}; // F#
+  case 143: return {-1, _cent[5]}; // G
+  case 135: return {-1, _cent[4]}; // G#
+  case 127: return {-1, _cent[3]}; // A
+  case 120: return {-1, _cent[2]}; // A#
+  case 113: return {-1, _cent[1]}; // B
+  case 107: return {-1, _cent[0]}; // C
+
+  default:
+    return {-1, -1};
+  }
+}
+
 void wait()
 {
   uint32_t ffst = system.FFST;
@@ -70,7 +146,7 @@ void main()
   wait(); aica_sound.common.dmea0_mrwinh = aica::dmea0_mrwinh::MRWINH(0b1101);
 
   wait(); aica_sound.channel[0].KYONB(1);
-  wait(); aica_sound.channel[0].LPCTL(1);
+  wait(); aica_sound.channel[0].LPCTL(0);
   wait(); aica_sound.channel[0].PCMS(1); // 8-bit pcm
   wait(); aica_sound.channel[0].LSA(0);
   wait(); aica_sound.channel[0].LEA(sample_bytes);
@@ -80,7 +156,7 @@ void main()
   wait(); aica_sound.channel[0].AR(0x1f);
 
   wait(); aica_sound.channel[0].OCT(-2);
-  wait(); aica_sound.channel[0].FNS(0);
+  wait(); aica_sound.channel[0].FNS(0x1a8);
   wait(); aica_sound.channel[0].DISDL(0xf);
   wait(); aica_sound.channel[0].DIPAN(0x0);
 
@@ -97,5 +173,41 @@ void main()
 
   wait(); aica_sound.channel[0].KYONEX(1);
 
-  while (1);
+  int division = 0;
+  struct pattern * pattern = &mod.patterns[3];
+
+  constexpr uint32_t timer_a_interrupt = (1 << 6);
+  int started = 0;
+  while (1) {
+    wait();
+    if (!started || (aica_sound.common.SCIPD() & timer_a_interrupt)) {
+      started = 1;
+      aica_sound.common.scire = timer_a_interrupt;
+      aica_sound.common.tactl_tima =
+          aica::tactl_tima::TACTL(6)  // increment once every 128 samples
+        | aica::tactl_tima::TIMA(256 - 128) // interrupt after 128 counts
+        ;
+
+
+      struct channel * c = &pattern->division[division][0];
+      if (c->parameter != 0) {
+        struct oct_fns of = oct_fns(c->parameter);
+        wait(); aica_sound.channel[0].KYONB(0);
+        wait(); aica_sound.channel[0].KYONEX(1);
+
+        wait(); aica_sound.channel[0].OCT(of.oct - 1);
+        wait(); aica_sound.channel[0].FNS(of.fns);
+
+        wait(); aica_sound.channel[0].KYONB(1);
+        wait(); aica_sound.channel[0].KYONEX(1);
+      }
+
+
+      division += 1;
+      if (division >= 64) {
+        break;
+        division = 0;
+      }
+    }
+  }
 }