island-ctory/src/title.c

#include <string.h>

#include "game.h"
#include "sdk/assets.h"
#include "sdk/hardware.h"
#include "sdk/joypad.h"
#include "sdk/oam.h"
#include "sdk/video.h"

ASSET(bg_tiles, "bg/title.2bpp");
ASSET(bg_map, "bg/title.map");

void title(void) {
    // NOTE: Replace with lcdc_off() if necessary
    rLCDC &= ~LCDC_ON;

    // Copy title screen to VRAM
    memcpy((uint8_t *)_VRAM, &bg_tiles[0], bg_tiles_end - bg_tiles);

    uint8_t *vram_ptr = (uint8_t *)_SCRN0;
    const uint8_t *map_ptr = &bg_map[0];

    for (uint8_t y = 0; y < SCRN_Y_B; ++y) {
        memcpy(vram_ptr, map_ptr, SCRN_X_B);
        vram_ptr += SCRN_VX_B;
        map_ptr += SCRN_X_B;
    }

    rLCDC |= LCDC_ON;
    while (1) {
        joypad_update();
        if (joypad_state & PAD_START) {
            game_state = GAME_STATE_LEVEL;
            break;
        }

        // Wait for VBLANK. Clear IF since global interrupts are disabled.
        HALT();
        rIF = 0;
    }
}