1 files changed, 111 insertions, 0 deletions
diff --git a/libopna/opnafm.h b/libopna/opnafm.h
new file mode 100644
index 0000000..acd673f
--- /dev/null
+++ b/libopna/opnafm.h
@@ -0,0 +1,111 @@
+#ifndef LIBOPNA_OPNAFM_H_INCLUDED
+#define LIBOPNA_OPNAFM_H_INCLUDED
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+enum {
+  ENV_ATTACK,
+  ENV_DECAY,
+  ENV_SUSTAIN,
+  ENV_RELEASE,
+  ENV_OFF,
+};
+
+struct opna_fm_slot {
+  // 20bits, upper 10 bits will be the index to sine table
+  uint32_t phase;
+  // 10 bits
+  uint16_t env;
+  uint16_t env_count;
+  uint8_t env_state;
+  uint8_t rate_shifter;
+  uint8_t rate_selector;
+  uint8_t rate_mul;
+
+  uint8_t tl;
+  uint8_t sl;
+
+  uint8_t ar;
+  uint8_t dr;
+  uint8_t sr;
+  uint8_t rr;
+
+  uint8_t mul;
+  uint8_t det;
+  uint8_t ks;
+
+  uint8_t keycode;
+
+  bool keyon;
+};
+
+struct opna_fm_channel {
+  struct opna_fm_slot slot[4];
+
+  // save 2 samples for slot 1 feedback
+  uint16_t fbmem1;
+  uint16_t fbmem2;
+  // save sample for long (>2) chain of slots
+  uint16_t alg_mem;
+
+  uint8_t alg;
+  uint8_t fb;
+  uint16_t fnum;
+  uint8_t blk;
+};
+
+struct opna_fm {
+  struct opna_fm_channel channel[6];
+
+  // remember here what was written on higher byte,
+  // actually write when lower byte written
+  uint8_t blkfnum_h;
+  // channel 3 blk, fnum
+  struct {
+    uint16_t fnum[3];
+    uint8_t blk[3];
+    uint8_t mode;
+  } ch3;
+
+  // do envelope once per 3 samples
+  uint8_t env_div3;
+
+  // pan
+  bool lselect[6];
+  bool rselect[6];
+};
+
+void opna_fm_reset(struct opna_fm *fm);
+void opna_fm_mix(struct opna_fm *fm, int16_t *buf, unsigned samples);
+void opna_fm_writereg(struct opna_fm *fm, unsigned reg, unsigned val);
+
+//
+void opna_fm_chan_reset(struct opna_fm_channel *chan);
+void opna_fm_chan_phase(struct opna_fm_channel *chan);
+void opna_fm_chan_env(struct opna_fm_channel *chan);
+void opna_fm_chan_set_blkfnum(struct opna_fm_channel *chan, unsigned blk, unsigned fnum);
+int16_t opna_fm_chanout(struct opna_fm_channel *chan);
+void opna_fm_slot_key(struct opna_fm_channel *chan, int slotnum, bool keyon);
+
+void opna_fm_chan_set_alg(struct opna_fm_channel *chan, unsigned alg);
+void opna_fm_chan_set_fb(struct opna_fm_channel *chan, unsigned fb);
+void opna_fm_slot_set_ar(struct opna_fm_slot *slot, unsigned ar);
+void opna_fm_slot_set_dr(struct opna_fm_slot *slot, unsigned dr);
+void opna_fm_slot_set_sr(struct opna_fm_slot *slot, unsigned sr);
+void opna_fm_slot_set_rr(struct opna_fm_slot *slot, unsigned rr);
+void opna_fm_slot_set_sl(struct opna_fm_slot *slot, unsigned sl);
+void opna_fm_slot_set_tl(struct opna_fm_slot *slot, unsigned tl);
+void opna_fm_slot_set_ks(struct opna_fm_slot *slot, unsigned ks);
+void opna_fm_slot_set_mul(struct opna_fm_slot *slot, unsigned mul);
+void opna_fm_slot_set_det(struct opna_fm_slot *slot, unsigned det);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* LIBOPNA_OPNAFM_H_INCLUDED */