island-ctory/src/game.h

#ifndef IS_GAME_H_
#define IS_GAME_H_

#define _VRAM 0x8000
#define _VRAM8000 _VRAM
#define _VRAM8800 (_VRAM + 0x800)
#define _VRAM9000 (_VRAM + 0x1000)
#define _SCRN0 0x9800
#define _SCRN1 0x9c00

#define SCRN_X 160
#define SCRN_Y 144
#define SCRN_X_B 20
#define SCRN_Y_B 18

#define SCRN_VX 256
#define SCRN_VY 256
#define SCRN_VX_B 32
#define SCRN_VY_B 32

#define SCREEN_HEIGHT_TILES 18
#define SCREEN_WIDTH_TILES 20

#define ALLOC_SIZE_FONT 39
#define ALLOC_SIZE_PLAYER 52
#define ALLOC_SIZE_BACKGROUND 32
#define ALLOC_SIZE_ITEMS 20
#define ALLOC_SIZE_MONSTERS 108

#define TILE_INDEX_FONT 0
#define TILE_INDEX_PLAYER ALLOC_SIZE_FONT
#define TILE_INDEX_BACKGROUND (ALLOC_SIZE_FONT + ALLOC_SIZE_PLAYER)
#define TILE_INDEX_ITEMS \
    (ALLOC_SIZE_FONT + ALLOC_SIZE_PLAYER + ALLOC_SIZE_BACKGROUND)
#define TILE_INDEX_MONSTERS                                        \
    (ALLOC_SIZE_FONT + ALLOC_SIZE_PLAYER + ALLOC_SIZE_BACKGROUND + \
     ALLOC_SIZE_ITEMS)

#define TILE_SIZE 16  //!< Size of 1 tile in bytes
#define VRAM_TILE_PTR(idx) \
    ((void*)(_VRAM +       \
             (idx)*TILE_SIZE))  //!< Compute VRAM pointer for tile section

typedef enum {
    GAME_STATE_TITLE,
    GAME_STATE_LEVEL,
    GAME_STATE_MENU,
} game_state_t;

extern game_state_t game_state;

/**
 * @brief Render the title screen.
 */
void title(void);

/**
 * @brief Render the current game level.
 */
void level(void);

/**
 * @brief Enable interrupts.
 */
void interrupts_enable(void) __preserves_regs(a, b, c, d, e, h, l);

/**
 * @brief Disable interrupts.
 */
void interrupts_disable(void) __preserves_regs(a, b, c, d, e, h, l);

#endif