path: root/src/main.c

/*
   Copyright (c) 2021 Bad Diode

   Permission to use, copy, modify, and distribute this software for any
   purpose with or without fee is hereby granted, provided that the above
   copyright notice and this permission notice appear in all copies.

   THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   WITH REGARD TO THIS SOFTWARE.
*/

#include <string.h>
#include <time.h>

#include "common.h"
#include "filesystem.c"

#include "uxn.h"
#include "ppu.c"
#include "apu.c"
#include "file.c"
#include "text.h"

#include "rom.c"

//
// Config parameters.
//

#if !defined(TEXT_MODE) || TEXT_MODE == 0
#define TEXT_LAYER FG_BACK
#else
#define TEXT_LAYER BG_BACK
#endif

#ifndef CONTROL_METHODS
#define CONTROL_METHODS CONTROL_CONTROLLER,CONTROL_MOUSE,CONTROL_KEYBOARD
#endif

#define PROF_ENABLE 0
#ifndef PROF_ENABLE
#define PROF_ENABLE 0
#endif

#if PROF_ENABLE > 0 && PROF_ENABLE < 3

#ifndef PROF_N_FRAMES
#define PROF_N_FRAMES 15
#endif

// Profile method 1: Average per N frames.
#if PROF_ENABLE == 1
#define TEXT_ENABLE 1
#define PROF(F,VAR) \
    do { \
        u32 __tmp_prof = profile_measure();\
        (F);\
        (VAR) += profile_measure() - __tmp_prof;\
    } while (0)

// Profile method 2: Maximum in N frames.
#elif PROF_ENABLE == 2
#define TEXT_ENABLE 1
#define PROF(F,VAR) \
    do { \
        u32 __tmp_prof = profile_measure();\
        (F);\
        (VAR) = MAX(profile_measure() - __tmp_prof, (VAR));\
    } while (0)
#endif

#ifndef PROF_SHOW_X
#define PROF_SHOW_X 0
#endif
#ifndef PROF_SHOW_Y
#define PROF_SHOW_Y 0
#endif

#define PROF_SHOW() \
    do { \
        txt_position((PROF_SHOW_X), (PROF_SHOW_Y));\
        txt_printf("INPUT  %.8lu\n", avg_input_cycles);\
        txt_printf("EVAL   %.8lu\n", avg_eval_cycles);\
        txt_printf("VIDEO\n");\
        txt_printf(">PIX   %.8lu\n", avg_ppu_pixel_cycles);\
        txt_printf(">FILL  %.8lu\n", avg_ppu_fill_cycles);\
        txt_printf(">1BPP  %.8lu\n", avg_ppu_icn_cycles);\
        txt_printf(">2BPP  %.8lu\n", avg_ppu_chr_cycles);\
        txt_printf(">FLIP  %.8lu\n", avg_flip_cycles);\
        txt_printf("AUDIO  %.8lu\n", avg_mix_cycles);\
        txt_printf("TOTAL  %.8lu\n", avg_frame_cycles);\
        u32 frame_time =\
            FP_DIV(\
                FP_NUM(avg_frame_cycles + 1, 2),\
                FP_NUM(2809, 2),\
                2) * 166;\
        u32 fps =\
            FP_DIV(\
                FP_NUM(280896 * 60, 2),\
                FP_NUM(avg_frame_cycles + 1, 2),\
                2);\
        txt_printf("TIME   %.8lu\n", frame_time >> 2);\
        txt_printf("FPS    %.8lu\n", (fps >> 2) + 1);\
        screen_fill(BG_BACK, 0, 0, 8 * 16, 8 * 12, 2);\
    } while (0)

static u32 prof_frame_counter = 0;

static u32 frame_cycles = 0;
static u32 ppu_pixel_cycles = 0;
static u32 ppu_fill_cycles = 0;
static u32 ppu_chr_cycles = 0;
static u32 ppu_icn_cycles = 0;
static u32 flip_cycles = 0;
static u32 eval_cycles = 0;
static u32 input_cycles = 0;
static u32 mix_cycles = 0;

static u32 avg_ppu_pixel_cycles = 0;
static u32 avg_ppu_fill_cycles = 0;
static u32 avg_ppu_chr_cycles = 0;
static u32 avg_ppu_icn_cycles = 0;
static u32 avg_flip_cycles = 0;
static u32 avg_eval_cycles = 0;
static u32 avg_input_cycles = 0;
static u32 avg_mix_cycles = 0;
static u32 avg_frame_cycles = 0;

#if PROF_ENABLE == 1
#define FRAME_START()\
    do { \
        if (prof_frame_counter == PROF_N_FRAMES) {\
            avg_ppu_pixel_cycles = ppu_pixel_cycles / prof_frame_counter;\
            avg_ppu_fill_cycles  = ppu_fill_cycles / prof_frame_counter;\
            avg_ppu_chr_cycles   = ppu_chr_cycles / prof_frame_counter;\
            avg_ppu_icn_cycles   = ppu_icn_cycles / prof_frame_counter;\
            avg_flip_cycles      = flip_cycles / prof_frame_counter;\
            avg_eval_cycles      = eval_cycles / prof_frame_counter;\
            avg_input_cycles     = input_cycles / prof_frame_counter;\
            avg_mix_cycles       = mix_cycles / prof_frame_counter;\
            avg_frame_cycles     = frame_cycles / prof_frame_counter;\
            prof_frame_counter   = 0;\
            frame_cycles         = 0;\
            ppu_pixel_cycles     = 0;\
            ppu_fill_cycles      = 0;\
            ppu_chr_cycles       = 0;\
            ppu_icn_cycles       = 0;\
            flip_cycles          = 0;\
            eval_cycles          = 0;\
            input_cycles         = 0;\
            mix_cycles           = 0;\
        }\
        profile_start();\
    } while (0)
#elif PROF_ENABLE == 2
#define FRAME_START()\
    do { \
        if (prof_frame_counter == PROF_N_FRAMES) {\
            avg_ppu_pixel_cycles = ppu_pixel_cycles;\
            avg_ppu_fill_cycles  = ppu_fill_cycles;\
            avg_ppu_chr_cycles   = ppu_chr_cycles;\
            avg_ppu_icn_cycles   = ppu_icn_cycles;\
            avg_flip_cycles      = flip_cycles;\
            avg_eval_cycles      = eval_cycles;\
            avg_input_cycles     = input_cycles;\
            avg_mix_cycles       = mix_cycles;\
            avg_frame_cycles     = frame_cycles / prof_frame_counter;\
            prof_frame_counter   = 0;\
            frame_cycles         = 0;\
            ppu_pixel_cycles     = 0;\
            ppu_fill_cycles      = 0;\
            ppu_chr_cycles       = 0;\
            ppu_icn_cycles       = 0;\
            flip_cycles          = 0;\
            eval_cycles          = 0;\
            input_cycles         = 0;\
            mix_cycles           = 0;\
        }\
        profile_start();\
    } while (0)
#endif

#define FRAME_END() \
    do { \
        prof_frame_counter++;\
        frame_cycles += profile_stop();\
    } while (0)

#else

// No profiling.
#define PROF(F,VAR) (F)
#define PROF_SHOW()
#define FRAME_START()
#define FRAME_END()
#endif

static time_t seconds = 0;

typedef enum {
    CONTROL_CONTROLLER,
    CONTROL_MOUSE,
    CONTROL_KEYBOARD,
} ControlMethod;

const ControlMethod ctrl_methods[] = {
    CONTROL_METHODS
};
static ControlMethod ctrl_idx = 0;

#define MOUSE_DELTA 1
typedef struct Mouse {
    int x;
    int y;
} Mouse;

EWRAM_BSS
u8 uxn_ram[0x10300];

// static Uxn u;

static Mouse mouse = {SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2};

// int
// uxn_halt(Uxn *u, u8 instr, u8 err, u16 addr) {
//     (void)u;
//     txt_printf("HALTED\n");
//     txt_printf("I: %lu\n", instr);
//     txt_printf("E: %lu\n", err);
//     txt_printf("A: %lu\n", addr);
//     while (true);
// }

IWRAM_CODE
u8
screen_dei(u8 *d, u8 port) {
    // switch(port) {
    //     case 0x2: return (SCREEN_WIDTH >> 8);
    //     case 0x3: return (SCREEN_WIDTH);
    //     case 0x4: return (SCREEN_HEIGHT >> 8);
    //     case 0x5: return (SCREEN_HEIGHT);
    //     default: return d[port];
    // }
}

IWRAM_CODE
void
screen_deo(u8 *ram, u8 *d, u8 port) {
    // switch(port) {
    //     case 0xe: {
    //         u8 ctrl = d[0xe];
    //         u8 color = ctrl & 0x3;
    //         u16 x0 = PEEK2(d + 0x8);
    //         u16 y0 = PEEK2(d + 0xa);
    //         u8 *layer = (ctrl & 0x40) ? FG_BACK : BG_BACK;
    //         if(ctrl & 0x80) {
    //             u16 x1 = SCREEN_WIDTH - 1;
    //             u16 y1 = SCREEN_HEIGHT - 1;
    //             if(ctrl & 0x10) x1 = x0, x0 = 0;
    //             if(ctrl & 0x20) y1 = y0, y0 = 0;
    //             PROF(screen_fill(layer, x0, y0, x1, y1, color), ppu_fill_cycles);
    //         } else {
    //             PROF(ppu_pixel(layer, x0, y0, color), ppu_pixel_cycles);
    //             if(d[0x6] & 0x1) POKE2(d + 0x8, x0 + 1); /* auto x+1 */
    //             if(d[0x6] & 0x2) POKE2(d + 0xa, y0 + 1); /* auto y+1 */
    //         }
    //         break;
    //     }
    //     case 0xf: {
    //         u16 x, y, dx, dy, addr;
    //         u8 n, twobpp = !!(d[0xf] & 0x80);
    //         x    = PEEK2(d + 0x8);
    //         y    = PEEK2(d + 0xa);
    //         addr = PEEK2(d + 0xc);
    //         n = d[0x6] >> 4;
    //         dx = (d[0x6] & 0x01) << 3;
    //         dy = (d[0x6] & 0x02) << 2;
    //         if(addr > 0x10000 - ((n + 1) << (3 + twobpp))) {
    //             return;
    //         }
    //         u8 *layer = (d[0xf] & 0x40) ? FG_BACK : BG_BACK;
    //         u8 color = d[0xf] & 0xf;
    //         u8 flipx = d[0xf] & 0x10;
    //         u8 flipy = d[0xf] & 0x20;
    //         for(size_t i = 0; i <= n; i++) {
    //             u8 *sprite = &ram[addr];
    //             if (twobpp) {
    //                 PROF(ppu_2bpp(layer,
    //                             x + dy * i,
    //                             y + dx * i,
    //                             sprite,
    //                             color,
    //                             flipx, flipy), ppu_chr_cycles);
    //             } else {
    //                 PROF(ppu_1bpp(layer,
    //                             x + dy * i,
    //                             y + dx * i,
    //                             sprite,
    //                             color,
    //                             flipx, flipy), ppu_icn_cycles);
    //             }
    //             addr += (d[0x6] & 0x04) << (1 + twobpp);
    //         }
    //         POKE2(d + 0xc, addr);   /* auto addr+length */
    //         POKE2(d + 0x8, x + dx); /* auto x+8 */
    //         POKE2(d + 0xa, y + dy); /* auto y+8 */
    //         break;
    //     }
    // }
}

u8
audio_dei(int instance, u8 *d, u8 port) {
    // AudioChannel *c = &channels[instance];
    // switch(port) {
    //     // case 0x4: return apu_get_vu(instance);
    //     case 0x2: {
    //         POKE2(d + 0x2, c->pos);
    //         c->pos <<= 12; // fixed point.
    //         break;
    //     }
    // }
    return d[port];
}

void
audio_deo(int instance, u8 *d, u8 port, Uxn *u) {
    // AudioChannel *c = &channels[instance];
    // if (port == 0xf) {
    //     u16 length = 0;
    //     u16 adsr = 0;
    //     u16 addr = 0;
    //     u8 pitch = d[0xf] & 0x7f;
    //     adsr = PEEK2(d + 0x8);
    //     length = PEEK2(d + 0xa);
    //     addr = PEEK2(d + 0xc);
    //     u8 *data = &u->ram[addr];
    //     u32 vol = MAX(d[0xe] >> 4, d[0xe] & 0xf) * 4 / 3;
    //     bool loop = !(d[0xf] & 0x80);
    //     update_channel(c, data, length, pitch, adsr, vol, loop);
    // }
}

u8
datetime_dei(u8 *d, u8 port) {
    struct tm *t = gmtime(&seconds);
    switch(port) {
        case 0x0: return (t->tm_year + 1900) >> 8;
        case 0x1: return (t->tm_year + 1900);
        case 0x2: return t->tm_mon;
        case 0x3: return t->tm_mday;
        case 0x4: return t->tm_hour;
        case 0x5: return t->tm_min;
        case 0x6: return t->tm_sec;
        case 0x7: return t->tm_wday;
        case 0x8: return t->tm_yday >> 8;
        case 0x9: return t->tm_yday;
        case 0xa: return t->tm_isdst;
        default: return d[port];
    }
}

u8
file_dei(u8 id, u8 *d, u8 port) {
    // UxnFile *c = &uxn_file[id];
    // u16 res;
    // switch(port) {
    //     case 0xc:
    //     case 0xd: {
    //         res = file_read(c, &d[port], 1);
    //         POKE2(d + 0x2, res);
    //         break;
    //     }
    // }
    return d[port];
}

void
file_deo(u8 id, u8 *ram, u8 *d, u8 port) {
    // u16 a, b, res;
    // UxnFile *f = &uxn_file[id];
    // switch(port) {
    //     case 0x5: {
    //         a = PEEK2(d + 0x4);
    //         b = PEEK2(d + 0xa);
    //         if(b > 0x10000 - a) {
    //             b = 0x10000 - a;
    //         }
    //         res = file_stat(f, &ram[a], b);
    //         POKE2(d + 0x2, res);
    //     } break;
    //     case 0x6: {
    //         // TODO: no file deletion for now
    //         // res = file_delete();
    //         // POKE2(d + 0x2, res);
    //     } break;
    //     case 0x9: {
    //         a = PEEK2(d + 0x8);
    //         res = file_init(f, &ram[a]);
    //         POKE2(d + 0x2, res);
    //     } break;
    //     case 0xd: {
    //         a = PEEK2(d + 0xc);
    //         b = PEEK2(d + 0xa);
    //         if(b > 0x10000 - a) {
    //             b = 0x10000 - a;
    //         }
    //         res = file_read(f, &ram[a], b);
    //         POKE2(d + 0x2, res);
    //     } break;
    //     case 0xf: {
    //         a = PEEK2(d + 0xe);
    //         b = PEEK2(d + 0xa);
    //         if(b > 0x10000 - a) {
    //             b = 0x10000 - a;
    //         }
    //         res = file_write(f, &ram[a], b, d[0x7]);
    //         POKE2(d + 0x2, res);
    //     } break;
    // }
}

void
console_deo(u8 *d, u8 port) {
    // switch(port) {
    // case 0x8:
    //     txt_putc(d[port]);
    //     return;
    // case 0x9:
    //     txt_printf("ERROR: %c");
    //     txt_putc(d[port]);
    //     return;
    // }
}

#define RAM_PAGES 0x10

static void
system_cmd(u8 *ram, u16 addr) {
    if(ram[addr] == 0x01) {
        // NOTE: Handle rom paging on a case by case basis if a rom has to be
        // split in multiple chunks. The GBA compiler doesn't like allocating
        // big arrays, but it's fine if we split it into chunks of 64KB, for
        // example.
        //
        // u16 i, length = PEEK2(ram + addr + 1);
        // u16 a_page = PEEK2(ram + addr + 1 + 2);
        // u16 a_addr = PEEK2(ram + addr + 1 + 4);
        // u16 b_addr = PEEK2(ram + addr + 1 + 8);
        // u8 *rom = uxn_rom;
        // for(i = 0; i < length; i++) {
        //     switch (a_page % RAM_PAGES) {
        //         case 0: { rom = uxn_rom;   } break;
        //         case 1: { rom = uxn_rom_2; } break;
        //         case 2: { rom = uxn_rom_3; } break;
        //         case 3: { rom = uxn_rom_4; } break;
        //         case 4: { rom = uxn_rom_5; } break;
        //         case 5: { rom = uxn_rom_6; } break;
        //         case 6: { rom = uxn_rom_7; } break;
        //     }
        //     ram[(u16)(b_addr + i)] = rom[(u16)(a_addr + i)];
        // }
    }
}

void
system_deo(Uxn *u, u8 *d, u8 port) {
    // switch(port) {
    //     case 0x3: {
    //         system_cmd(u->ram, PEEK2(d + 2));
    //     } break;
    // }
}

u8
uxn_dei(Uxn *u, u8 addr) {
    u8 p = addr & 0x0f, d = addr & 0xf0;
    switch(d) {
        case 0x20: return screen_dei(&u->dev[d], p);
        case 0x30: return audio_dei(0, &u->dev[d], p);
        case 0x40: return audio_dei(1, &u->dev[d], p);
        case 0x50: return audio_dei(2, &u->dev[d], p);
        case 0x60: return audio_dei(3, &u->dev[d], p);
        case 0xa0: return file_dei(0, &u->dev[d], p);
        case 0xb0: return file_dei(1, &u->dev[d], p);
        case 0xc0: return datetime_dei(&u->dev[d], p);
    }
    return u->dev[addr];
}

void
uxn_deo(Uxn *u, u8 addr) {
	u8 p = addr & 0x0f, d = addr & 0xf0;
	switch(d) {
        case 0x00:
            system_deo(u, &u->dev[d], p);
            if(p > 0x7 && p < 0xe) {
                putcolors(&u->dev[0x8]);
            }
            break;
        case 0x10: console_deo(&u->dev[d], p); break;
        case 0x20: screen_deo(u->ram, &u->dev[d], p); break;
        case 0x30: audio_deo(0, &u->dev[d], p, u); break;
        case 0x40: audio_deo(1, &u->dev[d], p, u); break;
        case 0x50: audio_deo(2, &u->dev[d], p, u); break;
        case 0x60: audio_deo(3, &u->dev[d], p, u); break;
        case 0xa0: file_deo(0, u->ram, &u->dev[d], p); break;
        case 0xb0: file_deo(1, u->ram, &u->dev[d], p); break;
	}
}

void
init_uxn() {
    // Initialize uxn.
    u32 fill = 0;
    dma_fill(uxn_ram, fill, 0x10300, 3);
    // uxn_boot(u, uxn_ram, uxn_dei, uxn_deo);

    // Copy rom to VM.
    u8 uxn_rom[32] = {
        // Hello world (h)
        // 0x80, 0x68, 0x80, 0x18, 0x17,
        //
        // ADD test
        // 0x80, 0x04, 0x80, 0x03, 0x80, 0x02, 0x80, 0x01, 0x18, 0x18
        // SUB test
        // 0x80, 0x04, 0x80, 0x03, 0x80, 0x02, 0x80, 0x01, 0x19, 0x19, 0x19
        // LIT2 04 03 LIT2 02 01 ADD ADD ADD BRK
        // 0xa0, 0x04, 0x03,
        // 0xa0, 0x04, 0x03, 0xa0, 0x02, 0x01,
        // 0xa0, 0x04, 0x03, 0xa0, 0x02, 0x01, 0x18, 0x18, 0x00
        // #0004 #0008 ADD
        // 0xa0, 0x00, 0x04, 0xa0, 0x00, 0x08, 0x18,
        // #0004 #0008 ADD2
        0x80, 0xFF, 0xff,
        0xa0, 0x00, 0x08, 0xa0, 0x00, 0x04, 0x38,
        // 0xa0, 0x00, 0x08, 0xa0, 0x00, 0x03, 0x39,
        // 0xa0, 0x00, 0x01, 0x38,
        //
        // 0x80, 0xFF, 0xff,
        // 0xa0, 0xba, 0xdd,
        // 0xa0, 0x10, 0xde,
        // 0xa0, 0xfe, 0xed,
        // 0xa0, 0xde, 0xaf,
        // 0xa0, 0xba, 0xdd,
        // 0xa0, 0x10, 0xde,
        // 0xa0, 0xfe, 0xed,
        // 0xa0, 0xde, 0xaf,
        //
        // #0008 #0003 SUB2
        // 0xa0, 0x00, 0x08, 0xa0, 0x00, 0x03,
    };
    memcpy(uxn_ram + PAGE_PROGRAM, uxn_rom, sizeof(uxn_rom));
}

IWRAM_CODE
void
handle_input(Uxn *u) {
    // poll_keys();
    // if (key_tap(KEY_SELECT)) {
    //     // Reset control variables on method switch.
    //     switch (ctrl_methods[ctrl_idx]) {
    //         case CONTROL_CONTROLLER: {
    //             u8 *d = &u->dev[0x80];
    //             d[2] = 0;
    //             uxn_eval(u, PEEK2(d));
    //             d[3] = 0;
    //         } break;
    //         case CONTROL_MOUSE: {
    //             u8 *d = &u->dev[0x90];
    //             d[6] = 0;
    //             d[7] = 0;
    //             POKE2(d + 0x2, -10);
    //             POKE2(d + 0x4, -10);
    //             uxn_eval(u, PEEK2(d));
    //         } break;
    //         case CONTROL_KEYBOARD: {
    //             toggle_keyboard();
    //         } break;
    //     }

    //     // Update ctrl_idx.
    //     ctrl_idx = (ctrl_idx + 1 > (int)LEN(ctrl_methods) - 1) ? 0 : ctrl_idx + 1;

    //     // Initialize controller variables here.
    //     if (ctrl_methods[ctrl_idx] == CONTROL_KEYBOARD) {
    //         toggle_keyboard();
    //     }
    // }

    // if (ctrl_methods[ctrl_idx] == CONTROL_CONTROLLER) {
    //     u8 *d = &u->dev[0x80];
    //     // TODO: We don't need ifs if we use KEY_INPUTS directly and maybe just
    //     // swap some things if needed.
    //     u8 *flag = &d[2];
    //     if (key_tap(KEY_A)) {
    //         *flag |= 0x01;
    //     } else {
    //         *flag &= ~0x01;
    //     }
    //     if (key_tap(KEY_B)) {
    //         *flag |= 0x02;
    //     } else {
    //         *flag &= ~0x02;
    //     }
    //     if (key_tap(KEY_L)) {
    //         *flag |= 0x04;
    //     } else {
    //         *flag &= ~0x04;
    //     }
    //     if (key_tap(KEY_R)) {
    //         *flag |= 0x08;
    //     } else {
    //         *flag &= ~0x08;
    //     }
    //     if (key_tap(KEY_UP)) {
    //         *flag |= 0x10;
    //     } else {
    //         *flag &= ~0x10;
    //     }
    //     if (key_tap(KEY_DOWN)) {
    //         *flag |= 0x20;
    //     } else {
    //         *flag &= ~0x20;
    //     }
    //     if (key_tap(KEY_LEFT)) {
    //         *flag |= 0x40;
    //     } else {
    //         *flag &= ~0x40;
    //     }
    //     if (key_tap(KEY_RIGHT)) {
    //         *flag |= 0x80;
    //     } else {
    //         *flag &= ~0x80;
    //     }

    //     if (key_prev != key_curr) {
    //         uxn_eval(u, PEEK2(d));
    //     }
    //     d[3] = 0;
    // } else if (ctrl_methods[ctrl_idx] == CONTROL_MOUSE) {
    //     u8 *d = &u->dev[0x90];
    //     // Detect "mouse key press".
    //     u8 flag = d[6];
    //     bool event = false;
    //     if (key_tap(KEY_B)) {
    //         event = true;
    //         flag |= 0x01;
    //     } else if (key_released(KEY_B)) {
    //         event = true;
    //         flag &= ~0x01;
    //     }
    //     if (key_tap(KEY_A)) {
    //         event = true;
    //         flag |= 0x10;
    //     } else if (key_released(KEY_A)) {
    //         event = true;
    //         flag &= ~0x10;
    //     }

    //     // Handle chording.
    //     d[6] = flag;
    //     if(flag == 0x10 && (d[6] & 0x01)) {
    //         d[7] = 0x01;
    //     }
    //     if(flag == 0x01 && (d[6] & 0x10)) {
    //         d[7] = 0x10;
    //     }

    //     // Detect mouse movement.
    //     if (key_pressed(KEY_UP)) {
    //         event = true;
    //         mouse.y = CLAMP(mouse.y - MOUSE_DELTA, 0, SCREEN_HEIGHT - 8);
    //     } else if (key_pressed(KEY_DOWN)) {
    //         event = true;
    //         mouse.y = CLAMP(mouse.y + MOUSE_DELTA, 0, SCREEN_HEIGHT - 8);
    //     }
    //     if (key_pressed(KEY_LEFT)) {
    //         event = true;
    //         mouse.x = CLAMP(mouse.x - MOUSE_DELTA, 0, SCREEN_WIDTH - 8);
    //     } else if (key_pressed(KEY_RIGHT)) {
    //         event = true;
    //         mouse.x = CLAMP(mouse.x + MOUSE_DELTA, 0, SCREEN_WIDTH - 8);
    //     }

    //     // Eval mouse.
    //     POKE2(d + 0x2, mouse.x);
    //     POKE2(d + 0x4, mouse.y);
    //     if (event) {
    //         uxn_eval(u, PEEK2(d));
    //     }
    // } else if (ctrl_methods[ctrl_idx] == CONTROL_KEYBOARD) {
    //     u8 *d = &u->dev[0x80];
    //     if (key_tap(KEY_LEFT)) {
    //         update_cursor(cursor_position - 1);
    //     } else if (key_tap(KEY_RIGHT)) {
    //         update_cursor(cursor_position + 1);
    //     }
    //     if (key_tap(KEY_UP) && cursor_position >= KEYBOARD_ROW_SIZE) {
    //         update_cursor(cursor_position - KEYBOARD_ROW_SIZE);
    //     } else if (key_tap(KEY_DOWN)
    //             && cursor_position < LEN(keyboard) - KEYBOARD_ROW_SIZE) {
    //         update_cursor(cursor_position + KEYBOARD_ROW_SIZE);
    //     }
    //     if (key_tap(KEY_B)) {
    //         u8 symbol = keyboard[cursor_position].symbol;
    //         switch (symbol) {
    //             case 0x7f: {
    //                 // Backspace.
    //                 d[3] = 0x08;
    //             } break;
    //             case 0x14: {
    //                 // New line.
    //                 d[3] = 0x0d;
    //             } break;
    //             case 0x18: {
    //                 // Arrow up.
    //                 d[2] = 0x10;
    //             } break;
    //             case 0x19: {
    //                 // Arrow down.
    //                 d[2] = 0x20;
    //             } break;
    //             case 0x1b: {
    //                 // Arrow left.
    //                 d[2] = 0x40;
    //             } break;
    //             case 0x1a: {
    //                 // Arrow right.
    //                 d[2] = 0x80;
    //             } break;
    //             default: {
    //                 d[3] = symbol;
    //             } break;
    //         }
    //         uxn_eval(u, PEEK2(d));
    //         d[3] = 0;
    //     }
    // }
}

#define STACK_SIZE 16
u8 stack[STACK_SIZE] = {0};
extern void uxn_eval_asm(u16 pc);

// TODO: This should be on the IWRAM for maximum speed, as these are operations
// we will use very often.
extern u8 wst[256];
extern u8 rst[256];
extern u8 io_ports[256];
extern uintptr_t wst_ptr;
extern uintptr_t rst_ptr;

int
main(void) {
    // Adjust system wait times.
    SYSTEM_WAIT = SYSTEM_WAIT_CARTRIDGE;

    // Initialize filesystem.
    fs_init();

    // Register interrupts.
    irq_init();
    irs_set(IRQ_VBLANK, sound_vsync);

    // Initialize PPU.
    video_init();

    // Initialize text engine.
// #ifdef TEXT_ENABLE
    txt_init(1, TEXT_LAYER);
    txt_position(0,0);
// #endif

    // Initialize UXN.
    init_uxn();

    // Enable sound.
    init_sound();

    // Main loop.
    // uxn_eval(&u, PAGE_PROGRAM);
    u8 frame_counter = 0;
    // NOTE: A VBLANK is 83776 cycles, anything other than that will make it so
    // we fail to render at 60FPS.

    // TODO: Initialize memory.
    // Initialize stack.
    for (size_t i = 0; i < 256; i++) {
        wst[i] = 0;
        rst[i] = 0;
        io_ports[i] = 0;
    }

    txt_printf("ROM\n\n");
    for (size_t i = 0; i < 32; i++) {
        if (i % 8 == 0) {
            txt_printf("\n");
        }
        txt_printf("%02x ", uxn_ram[i + PAGE_PROGRAM]);
    }
    txt_printf("\n\n");

    uxn_eval_asm(PAGE_PROGRAM);
    txt_printf("STACK\n");
    txt_printf("PTR: %d\n", wst_ptr - (uintptr_t)wst);
    for (size_t i = 0; i < STACK_SIZE; i++) {
        if (i % 8 == 0) {
            txt_printf("\n");
        }
        txt_printf("%02x ", wst[i]);
    }

    uintptr_t stack_base = wst;
    uintptr_t stack_size = wst_ptr - stack_base;
    while(true) {
        txt_position(0,0);
        // bios_vblank_wait();
        // FRAME_START();
        // // PROF(handle_input(&u), input_cycles);
        // // PROF(uxn_eval(&u, PEEK2(&u.dev[0x20])), eval_cycles);
        // // PROF(sound_mix(), mix_cycles);
        // // // TODO: allow configuration to do VSYNC at 15 or 30 fps to avoid too
        // // // much memory copying on demanding uxn roms.
        // // PROF_SHOW();
        // // PROF(flipbuf(), flip_cycles);
        // // frame_counter++;
        // // if (frame_counter == 60) {
        // //     seconds++;
        // //     frame_counter = 0;
        // // }
        // FRAME_END();
        bios_vblank_wait();
        FRAME_START();
        flipbuf();
        // screen_fill(0);
        // txt_printf("WST: 0x%08x\n", wst);
        // txt_printf("PTR: 0x%08x\n", wst_ptr);
        FRAME_END();
        PROF_SHOW();
        // txt_render();
        // txt_clear();
    }

    return 0;
}