psxrecomp/runtime/include/gpu.h

/* gpu.h — PS1 GPU hardware simulation (Phase 3).
 *
 * Implements GPUSTAT, GP0, GP1, and 1024x512 16-bit VRAM.
 * No rendering to screen — just correct hardware state transitions.
 */

#ifndef PSXRECOMP_GPU_H
#define PSXRECOMP_GPU_H

#include <stdint.h>

#ifdef __cplusplus
extern "C" {
#endif

void     gpu_init(void);
uint32_t gpu_read_gpustat(void);   /* 0x1F801814 read */
uint32_t gpu_read_gpuread(void);   /* 0x1F801810 read */
void     gpu_write_gp0(uint32_t val);  /* 0x1F801810 write */
void     gpu_write_gp1(uint32_t val);  /* 0x1F801814 write */
void     gpu_set_gp0_source(uint32_t addr); /* diagnostic source for next GP0 word */
void     gpu_vblank_tick(void);        /* Toggle LCF, called at each simulated vblank */

/* Display presentation accessors (Phase 3). */
const uint16_t* gpu_get_vram(void);    /* Pointer to 1024x512 16-bit VRAM */

typedef struct {
    uint32_t display_x, display_y;     /* VRAM start of display area (GP1(05h)) */
    uint32_t width, height;            /* Derived from display mode + ranges */
    int      depth24;                  /* GP1(08h) display depth flag: RGB888 scanout */
    int      disabled;                 /* GP1(03h) display disable flag */
} GpuDisplayInfo;

void gpu_get_display_info(GpuDisplayInfo* out);
void gpu_display_pixel_rgb(const GpuDisplayInfo* di, uint32_t x, uint32_t y,
                           uint8_t* r, uint8_t* g, uint8_t* b);
uint32_t gpu_display_pixel_argb(const GpuDisplayInfo* di, uint32_t x, uint32_t y);
uint64_t gpu_get_gp0_count(void);  /* Total GP0 writes since init */
void gpu_get_gp0_stats(uint64_t* nop, uint64_t* fill, uint64_t* draw, uint64_t* env, uint64_t* copy);

typedef struct {
    uint32_t left, top, right, bottom;
    int32_t offset_x, offset_y;
} GpuDrawArea;
void gpu_get_draw_area(GpuDrawArea* out);
uint16_t gpu_vram_peek(int x, int y);

/* Shaded quad vertex capture (Phase 4.5 debug). */
typedef struct {
    int32_t vx[4], vy[4];
    uint32_t color[4];
} GpuSqCapEntry;
void gpu_arm_shaded_quad_capture(void);
int  gpu_get_shaded_quad_capture(const GpuSqCapEntry** out);

/* Per-frame GP0 command ring (always-on; query via debug server).
 * Each entry records the GP0 command header + up to 6 payload words
 * (longer commands like 0x3C shaded textured quad are truncated to 6).
 * Stamped with the s_frame_count value at issue time so a debug
 * client can pull all commands for any frame in the ring window. */
#define GPU_GP0_RING_MAX_WORDS 12
typedef struct {
    uint32_t frame;
    uint32_t seq;
    uint32_t src_addr;      /* RAM/MMIO source address of command header, if known */
    uint32_t pc;            /* g_debug_last_store_pc when command completes */
    uint8_t  opcode;
    uint8_t  n_words;       /* total command length; >MAX means truncated */
    uint16_t pad;
    uint32_t cmd[GPU_GP0_RING_MAX_WORDS];
} GpuGp0RingEntry;

uint64_t gpu_gp0_ring_total(void);
uint32_t gpu_gp0_ring_capacity(void);
uint32_t gpu_gp0_ring_max_words(void);
int      gpu_gp0_ring_dump_frame(uint32_t frame, GpuGp0RingEntry *out, int max_out);
void     gpu_gp0_ring_frame_span(uint32_t *out_oldest, uint32_t *out_newest);

/* Vblank presentation callback — called from gpu_vblank_tick(). */
typedef void (*gpu_vblank_cb)(void);
void gpu_set_vblank_callback(gpu_vblank_cb cb);

/* Present-time screen-colour model (see color_lut.h ScreenKind: 0=raw,
 * 1=crt, 2=composite, 3=trinitron). Config/launcher-driven; the PSX_SCREEN
 * env var, if set, overrides this. Default 0 (raw) is byte-identical. */
void gpu_set_screen_kind(int kind);

/* Widescreen proportion correction (active only when aspect != 4:3 and the
 * game's [widescreen] block opts in — see config_loader.h). Tagged
 * character/billboard prims are re-squashed around their projected anchor;
 * untagged SPRT prims (screen-space HUD/menus) around the display centre.
 * psx_ws_sprite_tag is the per-prim callback the recompiler emits at the
 * entry of each [widescreen] sprite_tag_funcs function. */
/* mode: 0 = off (4:3 identity), 1 = squash (legacy hack), 2 = native-wide
 * (render the wider FOV into a wider frame, present 1:1; GTE not squashed). */
void gpu_ws_configure(int aspect_num, int aspect_den,
                      uint32_t sprite_anchor_addr, int hud_sprt_squash, int mode);
/* [widescreen] full_2d: opt a pure-2D sprite game into the widescreen present
 * path (treat every in-game frame as gameplay, since it never tags 3D prims). */
void gpu_ws_set_full_2d(int on);
/* [widescreen.bg2d] MMX6 background tile-loop widen — hooked at the renderer's
 * column-count / start-tile-col / start-screen-x instructions. Identity at 4:3
 * and in the engine's 512 hi-res mode. */
int psx_ws_mmx6_bg_cols(int base);
int psx_ws_mmx6_bg_startcol(int col);
int psx_ws_mmx6_bg_startx(int x);
int psx_ws_mmx6_bg_stream_left(int x);
int psx_ws_mmx6_bg_stream_right(int x);
struct CPUState;
void psx_ws_sprite_tag(struct CPUState* cpu);

/* Native-wide (mode 2) on a game frame. ws_nw_extra() is the total width the
 * frame grows by, in display pixels (the present path widens the display read
 * by this; 0 when native-wide is inactive). */
int  ws_native_wide_active(void);
int  ws_nw_extra(void);
/* True when the current frame must present at native 4:3 (FMV video or a
 * full-2D menu/title screen), so the squash is suppressed and content drawn
 * pixel-native. The present path uses the same predicate to pillarbox. */
int  gpu_ws_present_native_43(void);
/* Per-side X cull-margin (screen/world units) emitted into the game's draw-
 * cull immediates by the recompiler ([widescreen.cull]); 0 unless stretching. */
int  psx_ws_x_margin(void);

/* Shared render-funnel screen-X cull widening ([widescreen.cull] auto_screen_x):
 * the gcc emit, the sljit JIT, and the interpreter all route a flagged
 * `sltiu rt, sx, 0x140/0x141` through this one helper so every overlay execution
 * path widens identically. Returns the sltiu verdict (1 = keep). 0 at 4:3. */
int  psx_ws_cull_sltiu(uint32_t sx, uint32_t imm);
/* True if a run of instruction words carries the screen-extent reject signature
 * (a sltiu 0x140/0x141 AND a sltiu 0xE0/0xF1). Used by sljit/interp to gate the
 * widening to real render funnels. */
int  psx_ws_func_has_screen_cull(const uint32_t *words, int n);

/* Backdrop screen-X correction ([widescreen.backdrop] x_sites). The parallax
 * 2D backdrop layer computes screen-X without the GTE, so it misses the
 * widescreen squash; the recompiler emits this on each backdrop handler's
 * final screenX store to squash it around the screen centre (identity at 4:3).
 * Pulls far backdrop pieces in from past the 320px edge to cover the 16:9 FOV. */
int  psx_ws_backdrop_x(int x);

/* Backdrop PRELOAD ([widescreen.cull] auto_backdrop). psx_ws_backdrop_preload()
 * is nonzero only while native-wide widescreen is engaged (0 at 4:3 / boot /
 * FMV / full-2D), so the rewrite is byte-identical when off. psx_ws_backdrop_value()
 * is the one value substitution shared by the gcc emit, the sljit JIT, and the
 * interpreter for a detected window bound: it returns `orig` unless preload is
 * engaged, in which case it forces the bound to preload the WHOLE finite tile
 * row (START -> 0, END -> large sentinel pinned by the generator's high clamp to
 * extent-1). Every column is submitted, so the widened 16:9 viewport never gaps;
 * the generator's clamps + the byte-sized row extent keep it bounded. */
int      psx_ws_backdrop_preload(void);
uint32_t psx_ws_backdrop_value(uint32_t orig, int is_end, int window_cols);

/* auto_backdrop diagnostic ring (always-on). The interpreter records every
 * window rewrite (with the live extent / DL count / camera-X); `ws_backdrop_ring`
 * dumps it. psx_ws_backdrop_ring_json() formats the recent entries into `buf`
 * (returns bytes written, excluding the caller's JSON envelope). */
void psx_ws_backdrop_ring_note(uint32_t pc, int kind, int wcols, uint32_t orig,
                               uint32_t finalv, int extent, int camx, int count,
                               uint32_t base, uint32_t dl);
int  psx_ws_backdrop_ring_json(char *buf, int cap);

/* Live-tunable backdrop widen amount (ws_backdrop_margin command): <0 whole-row,
 * 0 off, >0 N-column widen. g_ws_bd_from_interp is the interp's one-shot
 * "I will record the rich entry myself" flag (see gpu.c / dirty_ram_interp.c). */
extern int g_ws_bd_margin;
extern int g_ws_bd_from_interp;

/* Native-wide: nonzero if the GP0 prim currently being drawn is sprite-tagged
 * (a character / Tomba / HUD element). The GL 2D-backdrop stretch uses this to
 * EXCLUDE foreground sprites (only the untagged 2D backdrop is stretched). */
int psx_ws_prim_is_tagged(void);

/* Flower-field backdrop data-structure address range + a predicate matching the
 * prim being drawn against it (gp0_cmd_source_addr ∈ [lo,hi]). The dirty-RAM
 * interp sets lo/hi when the backdrop generator runs; the GL stretch gate uses
 * psx_ws_prim_in_backdrop() to identify the flower-field tiles precisely. */
extern uint32_t g_ws_backdrop_lo, g_ws_backdrop_hi;
int psx_ws_prim_in_backdrop(void);

/* Backdrop store-site registry: the runtime registers the [widescreen.backdrop]
 * x_sites here (from game.toml) so the dirty-RAM interpreter applies the same
 * psx_ws_backdrop_x() squash at those `sh` PCs that the recompiler emits into
 * native cache DLLs — overlay code frequently runs interpreted, where the emit
 * can't reach. PCs are masked to the physical (KUSEG) range. */
void psx_ws_set_backdrop_sites(const uint32_t* pcs, int n);
int  psx_ws_is_backdrop_site(uint32_t pc);

/* Live widescreen state for diagnostics (TCP gpu_state). All pointers
 * optional. last_tag_frame/cur_frame let the caller see game_mode freshness. */
typedef struct {
    int      configured;        /* ws_xnum != ws_xden */
    int      active;            /* squash currently applied this frame */
    int      game_mode;         /* tagged char/billboard prim within 2 frames */
    int      present_native_43; /* frame presents pillarboxed 4:3 (FMV/full-2D) */
    int      x_margin;          /* psx_ws_x_margin() right now */
    int      xnum, xden;        /* squash factor */
    int      mode;              /* 0 = off, 1 = squash, 2 = native-wide */
    int      nw_extra;          /* native-wide frame growth (display px), 0 if off */
    uint64_t cur_frame;
    uint32_t last_tag_frame;    /* frame of newest tagged prim */
} GpuWsDebug;
void gpu_ws_get_debug(GpuWsDebug* out);

/* Diagnostic: force psx_ws_x_margin() to return v (>=0) regardless of state,
 * or -1 to restore the normal computed margin. For live cull-margin sweeps. */
void gpu_ws_set_margin_override(int v);

/* Always-on draw-census ring: every drawn primitive records frame / source
 * addr / camera / first-vertex screen pos, so object spawn/despawn and edge
 * culls are observable in data. Dump frames [f0,f1] to a CSV file. */
int      gpu_ws_census_dump(uint32_t f0, uint32_t f1, const char *path);
void     gpu_ws_census_set(int on);
uint64_t gpu_ws_census_seq(void);

#ifdef __cplusplus
}
#endif

#endif /* PSXRECOMP_GPU_H */