psxrecomp/runtime/include/spu.h

#ifndef PSXRECOMP_SPU_H
#define PSXRECOMP_SPU_H

#include <stdint.h>

#ifdef __cplusplus
extern "C" {
#endif

void spu_init(void);
void spu_render(int16_t* out_stereo, int frames);

typedef struct SpuDebugInfo {
    uint32_t ctrl;
    uint32_t active_mask;
    int16_t main_l;
    int16_t main_r;
    int16_t cd_l;
    int16_t cd_r;
    uint32_t key_on_count;
    uint64_t render_frames;
    uint64_t nonzero_frames;
    int32_t last_peak;
    int32_t peak;
    uint32_t cd_frames;
    uint64_t cd_push_frames;
    uint64_t cd_overflow_frames;
    uint64_t cd_underflow_frames;
} SpuDebugInfo;

void spu_debug_info(SpuDebugInfo* out);

/* ---- Per-voice register snapshot. Mirrors the fields the Beetle oracle
 * exposes via PS_SPU::GetRegister(GSREG_V0_*) so both backends produce a
 * structurally-identical spu_voices payload that diff tooling can compare. */
typedef struct SpuVoiceState {
    int      active;        /* our internal "is voicing" flag (no ADSR yet) */
    uint16_t vol_ctrl_l;    /* raw voice reg 0 */
    uint16_t vol_ctrl_r;    /* raw voice reg 1 */
    uint16_t pitch;         /* raw voice reg 2 */
    uint16_t start_lo;      /* raw voice reg 3 (start_addr >> 3) */
    uint16_t adsr_lo;       /* raw voice reg 5 */
    uint16_t adsr_hi;       /* raw voice reg 6 */
    uint16_t loop_lo;       /* raw voice reg 7 (loop_addr >> 3) */
    uint32_t cur_addr;      /* current decode pointer (byte addr in SPU RAM) */
    uint32_t repeat_addr;   /* effective loop point (byte addr in SPU RAM) */
    uint8_t  last_flags;    /* flag byte from most recently decoded block */
    uint8_t  sample_idx;    /* position inside the current 28-sample block */
    uint16_t phase;         /* sub-sample phase counter (0..0x1000) */
    uint16_t env_level;     /* live ADSR envelope level (0..0x7FFF) */
    uint8_t  adsr_phase;    /* 0=attack 1=decay 2=sustain 3=release */
    int16_t  vol_cur_l;     /* live effective L volume (sweep-aware, full int16) */
    int16_t  vol_cur_r;     /* live effective R volume (sweep-aware, full int16) */
} SpuVoiceState;

typedef struct SpuGlobalState {
    uint16_t ctrl;          /* SPUCONT (0x1F801DAA) */
    uint16_t main_vol_l;    /* raw 0x1F801D80 */
    uint16_t main_vol_r;    /* raw 0x1F801D82 */
    uint32_t kon_latch;     /* last 24-bit KEYON value */
    uint32_t koff_latch;    /* last 24-bit KEYOFF value */
    uint32_t pmon;          /* pitch mod (0x1F801D90/92) */
    uint32_t non;           /* noise mode (0x1F801D94/96) */
    uint32_t eon;           /* reverb mode (0x1F801D98/9A) */
    uint32_t endx;          /* end-block reached latch (0x1F801D9C/9E) */
    uint32_t active_mask;   /* recomp-local "still voicing" mask */

    /* ---- SPU DSP fidelity state (issue #103: IRQ/reverb/noise/sweeps) ---- */
    uint16_t irq_flag;      /* SPU IRQ latch (mirrors SPUSTAT bit 6) */
    uint16_t reverb_on;     /* SPUCNT bit 7 (reverb work-area write enable) */
    uint32_t irq_addr;      /* IRQ address as a BYTE address (reg 0x1F801DA4 << 3) */
    uint32_t reverb_mbase;  /* reverb work area start, byte address (mBASE << 3) */
    uint32_t reverb_cur;    /* current reverb buffer address (byte, advances @22050Hz) */
    uint32_t capture_pos;   /* capture-buffer write offset (0..0x3FE, wraps at 0x400) */
    uint16_t noise_lfsr;    /* live noise shift register value */
    uint16_t noise_pad;     /* reserved / alignment */
    uint32_t sweep_l_mask;  /* voices whose LEFT volume register is in sweep mode */
    uint32_t sweep_r_mask;  /* voices whose RIGHT volume register is in sweep mode */
    uint32_t sweep_main;    /* bit0 = main L in sweep mode, bit1 = main R */
} SpuGlobalState;

void spu_get_voice_state(int voice, SpuVoiceState* out);
void spu_get_global_state(SpuGlobalState* out);
/* SPUCNT (0x1F801DAA) alone. The sample-event scheduler gates on one ctrl bit
 * per device-service call; building the full SpuGlobalState there (register
 * sweep + three 24-voice loops) was ~40% of emu-thread time during the Capcom
 * FMV's MMIO-polling loop (gdb-sampled 2026-09-01). */
uint16_t spu_ctrl_read(void);
/* Debug peek into SPU sample RAM (spu_ram TCP command). */
uint32_t spu_ram_peek(uint32_t addr, uint8_t *out, uint32_t len);

/* ---- Always-on per-voice event ring. Records KEYON, KEYOFF, voice
 * end-flag-stop and end-flag-loop events with a frame timestamp. Allocated
 * at spu_init; never armed/disarmed. Query the window of interest. */
typedef enum {
    SPU_EV_KEYON     = 1,
    SPU_EV_KEYOFF    = 2,
    SPU_EV_END_STOP  = 3,   /* loop_end without repeat → voice silenced */
    SPU_EV_END_LOOP  = 4,   /* loop_end with repeat → cur_addr=repeat_addr */
    SPU_EV_IRQ       = 5    /* SPU RAM IRQ-address hit → I_STAT bit 9 raised;
                               voice=0xFF (not voice-attributable), addr=byte
                               address that matched */
} SpuEventKind;

typedef struct SpuEvent {
    uint64_t seq;
    uint32_t frame;
    uint8_t  kind;
    uint8_t  voice;
    uint16_t pitch;
    uint32_t addr;          /* start_addr for KEYON; cur_addr for KEYOFF/END_*; repeat_addr for END_LOOP */
    uint16_t adsr_lo;
    uint16_t adsr_hi;
    uint16_t vol_l;
    uint16_t vol_r;
} SpuEvent;

uint64_t spu_event_total(void);
uint32_t spu_event_get(SpuEvent* out, uint32_t max_count);  /* most recent up to max_count */
void     spu_event_reset(void);

/* MMIO read/write (0x1F801C00-0x1F801FFF) */
uint32_t spu_read(uint32_t addr);
void spu_write(uint32_t addr, uint32_t value);

/* DMA channel 4 interface. spu_dma_read reads one 32-bit word from SPU RAM
 * at the current transfer address, advances the address by 4, and runs the
 * SPU IRQ-address check (SPU RAM -> CPU direction, DICR direction bit 0). */
void spu_dma_write(uint32_t word);
uint32_t spu_dma_read(void);
int spu_dma_ready(void);

/* CD-ROM XA/CDDA input path. Samples are stereo 44.1 kHz PCM entering the
 * SPU CD input bus; SPU control bit 0 and CD volume registers gate output. */
void spu_cd_audio_push(const int16_t* stereo, int frames);
void spu_cd_audio_reset(void);

/* Get pointer to SPU RAM for direct access (512KB) */
const uint8_t* spu_get_ram(void);

/* ---- Verified-enhancement shadow tap (consumed by spu_shadow.c) ---------
 *
 * Present-time, opt-in float SPU re-render. When the shadow is enabled,
 * spu_render fills a per-output-frame, per-voice tap with the exact inputs the
 * canon used (the 4 decoded samples bracketing the sub-sample phase, the
 * fractional phase, envelope level, and per-voice + main volumes). The shadow
 * re-interpolates these in float. The layout MUST match spu.c's internal
 * SpuShadowVoiceTap / SpuShadowFrameTap. */
#define SPU_SHADOW_MAX_VOICES 24

typedef struct {
    int16_t  s[4];     /* decoded samples sample_idx-1 .. +2 (block-edge clamped) */
    float    frac;     /* fractional sub-sample phase in [0,1) */
    uint16_t env;      /* env_level (0..0x7FFF) */
    int16_t  vol_l;    /* per-voice L volume, 1.14 scale (effective int16 >> 1) */
    int16_t  vol_r;    /* per-voice R volume, same scale */
    uint8_t  active;
} SpuShadowVoiceTapPub;

typedef struct {
    SpuShadowVoiceTapPub voice[SPU_SHADOW_MAX_VOICES];
    int16_t main_l;
    int16_t main_r;
    int     enabled;
} SpuShadowFrameTapPub;

/* Pointer to the tap array (SpuShadowFrameTapPub[]) and the number of valid
 * frames filled by the most recent spu_render block. */
const void* spu_shadow_tap_buffer(void);
int         spu_shadow_tap_count(void);

uint32_t spu_snapshot_bytes(void);
void     spu_snapshot_write(uint8_t *p);
int      spu_snapshot_read(const uint8_t *p, uint32_t len);
uint8_t *spu_get_ram_ptr(void);
uint32_t spu_get_ram_bytes(void);

/* Split digests of the snap wire (regs / voices / DSP tail) for Win↔Linux
 * aux bisect. PSX_RB_SPU_PARTS=1 prints these on rb live dig. */
typedef struct SpuSnapPartDigests {
    uint32_t regs;
    uint32_t voices;
    uint32_t tail;
} SpuSnapPartDigests;
void spu_snapshot_part_digests(SpuSnapPartDigests *out);

#ifdef __cplusplus
}
#endif

#endif /* PSXRECOMP_SPU_H */