#ifndef PSX_GPU_GL_RENDERER_H
#define PSX_GPU_GL_RENDERER_H

/* GL backend context + present entry points, called from main.cpp's window
 * setup and present path when [video] renderer = "opengl".  The backend's
 * rasterization vtable is obtained separately via gl_backend_get()
 * (gpu_render.h).  SDL_Window is forward-declared (SDL typedefs it from this
 * same struct tag) so this header needs no SDL include. */

#include <stdint.h>

struct SDL_Window;

#ifdef __cplusplus
extern "C" {
#endif

/* Create the GL context on a window made with SDL_WINDOW_OPENGL.
 * Returns 1 on success, 0 to fall back to the SDL_Renderer present path. */
int  gl_renderer_init_context(struct SDL_Window *win);

/* Present an ARGB8888 image (BGRA byte order) as a letterboxed quad + swap.
 * Used for 24-bit (FMV) frames and the PSX_GL_FORCE_CPU_PRESENT diagnostic.
 * force_4_3 = pillarbox at native 4:3 even on a wide display aspect (FMVs
 * are authored 4:3 and get no GTE squash to compensate the stretch). */
void gl_renderer_present(const uint32_t *pixels, int src_w, int src_h, int linear,
                         int force_4_3);

/* Clear to black + swap (display-disabled frame). */
void gl_renderer_present_blank(void);

/* Sync the authoritative FBO down to CPU VRAM if the GPU side is ahead (else
 * a no-op). The 24-bit (FMV) present path, screenshots, and the debug server
 * call this before reading CPU VRAM. */
void gl_renderer_sync_cpu(void);

/* THE present path for 15-bit frames: blit the display region straight from
 * the authoritative VRAM FBO into a letterboxed rect (no readback).
 * Deterministic — used for every 15-bit frame. linear = filter on scale.
 * force_4_3 pins to native 4:3 (15-bit MDEC FMV frames on a wide aspect). */
void gl_renderer_present_vram(int disp_x, int disp_y, int w, int h, int linear,
                              int force_4_3);

/* Display aspect for the present letterbox (default 4:3). A wide aspect
 * stretches the 4:3 frame; pair with gte_set_display_aspect (cpu_state.h)
 * for the widescreen field-of-view hack. */
void gl_renderer_set_display_aspect(int num, int den);

void gl_renderer_shutdown(void);

/* Diagnostics (debug server): read GPU-side VRAM without touching the CPU
 * array; report coherency flags + dirty rects. fbo_peek returns 0 when the
 * GL pipeline is inactive. */
int  gl_renderer_fbo_peek(int x, int y, int w, int h, uint16_t *out);
void gl_renderer_diag(int *gpu_dirty, int pending[5], int pack[5]);

/* Always-on coherency event ring (debug server "gl_coh_ring"): every upload
 * flush, fill, copy, draw bbox, pack, full readback, present, and probe
 * perturbation, with rect + frame. An op that flushes internally records its
 * own event AFTER the FLUSH it caused (the event after a FLUSH = trigger). */
enum {
    GL_COH_FLUSH    = 1,   /* CPU->FBO upload flush (pending box)     */
    GL_COH_FILL     = 2,   /* GP0(02) fill rect                       */
    GL_COH_COPY_SRC = 3,   /* GP0(80) copy, source rect               */
    GL_COH_COPY     = 4,   /* GP0(80) copy, dest rect                 */
    GL_COH_DRAW     = 5,   /* drawn prim bbox (clipped to draw area)  */
    GL_COH_PACK     = 6,   /* hr FBO -> raw mirror pack (dirty box)   */
    GL_COH_ENSURE   = 7,   /* full FBO -> CPU VRAM readback           */
    GL_COH_PRESENT  = 8,   /* 15-bit present blit (display rect)      */
    GL_COH_UPLOAD   = 9,   /* bulk CPU->VRAM transfer_in dest rect    */
    GL_COH_PEEK     = 10,  /* gl_fbo_peek probe (perturbs: flushes)   */
    GL_COH_DIFF     = 11,  /* gl_vram_diff probe (perturbs: flushes)  */
};

typedef struct {
    uint32_t frame;
    uint8_t  kind;
    int16_t  x0, y0, x1, y1;   /* native VRAM coords, inclusive */
} GlCohEvent;

uint64_t gl_renderer_coh_total(void);
/* Fetch event by absolute sequence number; 0 if evicted or out of range. */
int gl_renderer_coh_get(uint64_t seq, GlCohEvent *out);

#ifdef __cplusplus
}
#endif

#endif /* PSX_GPU_GL_RENDERER_H */