Diff: player.h

Revision:

0:6679ec22f0e5

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/player.h	Sun Nov 10 23:19:38 2019 +0000
@@ -0,0 +1,60 @@
+#ifndef PLAYER_H
+#define PLAYER_H
+
+#include <stdint.h>
+#include <stdio.h>
+
+// Midi player for tesla coils
+// - adjusts duty cycle to prevent coil from exploding when many notes play simultaneously
+// - messes with phase offset to work around 1-bit output resolution of tesla coil when possible
+
+// set this to audio sample frequency
+#define SAMPLE_FREQEUENCY 48000
+
+#define CHEATER_FREQUENCY_MULT_POWER 9
+
+// maximum number of notes that can be played
+// if this is too large, the code will be slow
+// it this is too small, notes might be left out
+#define MAX_NOTES 10
+
+// 64-bit struct representing a single note to be played
+// each tick is 1/sample_frequency long
+// notes contain:
+// - starting time (up to 2^32 ticks, ~1 day at 50 kHz)
+// - duration (up to 2^24 ticks, ~6 minutes at 50 kHz)
+//   * the lower 16 bits of duration are stored in _duration
+// - note (midi notes are 0-255, this is looked up in the frequency table)
+struct Note {
+    Note(uint32_t start, uint32_t duration, uint8_t note) :
+        _note(note) {
+        if(start >= (1 << 16))
+            printf("! start tick %d is too long\n", start);
+        _start_tick = start & 0xffff;
+        if(duration >= (1 << 8))
+            printf("! Duration %d is too long\n", duration);
+        _duration = duration & 0xff;
+    }
+    uint16_t _start_tick;
+    uint8_t _duration;
+    uint8_t  _note;
+};
+
+
+// set this to the Note array for the song
+extern Note* song;
+
+// set this to the length of the Note array
+extern uint32_t songLength;
+
+// this becomes true when the song is done playing
+extern bool songDone;
+
+
+// call this at SAMPLE_FREQUENCY to determine if the output should be enabled or not
+uint16_t play();
+
+// call this once BEFORE calling play the first time and every time after switching songs
+void initialize_play();
+
+#endif // PLAYER_H
\ No newline at end of file