GBDK 2020 Docs 4.4.0 API Documentation for GBDK 2020

Data Structures | Macros | Typedefs | Functions | Variables
gb.h File Reference
`#include <types.h>`
`#include <stdint.h>`
`#include <gbdk/version.h>`
`#include <gb/hardware.h>`

Go to the source code of this file.

## Data Structures
struct | joypads_t
struct | OAM_item_t

## Macros
#define | NINTENDO
#define | SYSTEM_60HZ 0x00
#define | SYSTEM_50HZ 0x01
#define | GAMEBOY
#define | J_UP 0x04U
#define | J_DOWN 0x08U
#define | J_LEFT 0x02U
#define | J_RIGHT 0x01U
#define | J_A 0x10U
#define | J_B 0x20U
#define | J_SELECT 0x40U
#define | J_START 0x80U
#define | M_DRAWING 0x01U
#define | M_TEXT_OUT 0x02U
#define | M_TEXT_INOUT 0x03U
#define | M_NO_SCROLL 0x04U
#define | M_NO_INTERP 0x08U
#define | S_BANK 0x08U
#define | S_PALETTE 0x10U
#define | S_FLIPX 0x20U
#define | S_FLIPY 0x40U
#define | S_PRIORITY 0x80U
#define | S_PAL(n) n
#define | EMPTY_IFLAG 0x00U
#define | VBL_IFLAG 0x01U
#define | LCD_IFLAG 0x02U
#define | TIM_IFLAG 0x04U
#define | SIO_IFLAG 0x08U
#define | JOY_IFLAG 0x10U
#define | DMG_BLACK 0x03
#define | DMG_DARK_GRAY 0x02
#define | DMG_LITE_GRAY 0x01
#define | DMG_WHITE 0x00
#define | DMG_PALETTE(C0, C1, C2, C3) ((uint8_t)((((C3) & 0x03) << 6) | (((C2) & 0x03) << 4) | (((C1) & 0x03) << 2) | ((C0) & 0x03)))
#define | SCREENWIDTH DEVICE_SCREEN_PX_WIDTH
#define | SCREENHEIGHT DEVICE_SCREEN_PX_HEIGHT
#define | MINWNDPOSX DEVICE_WINDOW_PX_OFFSET_X
#define | MINWNDPOSY DEVICE_WINDOW_PX_OFFSET_Y
#define | MAXWNDPOSX (DEVICE_WINDOW_PX_OFFSET_X + DEVICE_SCREEN_PX_WIDTH - 1)
#define | MAXWNDPOSY (DEVICE_WINDOW_PX_OFFSET_Y + DEVICE_SCREEN_PX_HEIGHT - 1)
#define | DMG_TYPE 0x01
#define | MGB_TYPE 0xFF
#define | CGB_TYPE 0x11
#define | GBA_NOT_DETECTED 0x00
#define | GBA_DETECTED 0x01
#define | DEVICE_SUPPORTS_COLOR (_cpu == CGB_TYPE)
#define | VBL_DONE _vbl_done
#define | IO_IDLE 0x00U
#define | IO_SENDING 0x01U
#define | IO_RECEIVING 0x02U
#define | IO_ERROR 0x04U
#define | CURRENT_BANK _current_bank
#define | BANK(VARNAME) ( (uint8_t) & __bank_ ## VARNAME )
#define | BANKREF(VARNAME)
#define | BANKREF_EXTERN(VARNAME) extern const void __bank_ ## VARNAME;
#define | SWITCH_ROM(b) (_current_bank = (b), rROMB0 = (b))
#define | SWITCH_RAM(b) (rRAMB = (b))
#define | ENABLE_RAM (rRAMG = 0x0A)
#define | DISABLE_RAM (rRAMG = 0x00)
#define | SWITCH_ROM_MEGADUCK(b) SWITCH_ROM(b)
#define | SWITCH_ROM_MBC1(b) SWITCH_ROM(b)
#define | SWITCH_RAM_MBC1(b) SWITCH_RAM(b)
#define | ENABLE_RAM_MBC1 ENABLE_RAM
#define | DISABLE_RAM_MBC1 DISABLE_RAM
#define | SWITCH_16_8_MODE_MBC1 (*(volatile uint8_t *)0x6000 = 0x00)
#define | SWITCH_4_32_MODE_MBC1 (*(volatile uint8_t *)0x6000 = 0x01)
#define | SWITCH_ROM_MBC5(b) (_current_bank = (b), rROMB1 = 0, rROMB0 = (b))
#define | SWITCH_ROM_MBC5_8M(b) (rROMB1 = ((uint16_t)(b) >> 8), rROMB0 = (b))
#define | SWITCH_RAM_MBC5(b) SWITCH_RAM(b)
#define | ENABLE_RAM_MBC5 ENABLE_RAM
#define | DISABLE_RAM_MBC5 DISABLE_RAM
#define | DISPLAY_ON LCDC_REG|=LCDCF_ON
#define | DISPLAY_OFF display_off();
#define | HIDE_LEFT_COLUMN
#define | SHOW_LEFT_COLUMN
#define | SET_BORDER_COLOR(C)
#define | SHOW_BKG LCDC_REG|=LCDCF_BGON
#define | HIDE_BKG LCDC_REG&=~LCDCF_BGON
#define | SHOW_WIN LCDC_REG|=LCDCF_WINON
#define | HIDE_WIN LCDC_REG&=~LCDCF_WINON
#define | SHOW_SPRITES LCDC_REG|=LCDCF_OBJON
#define | HIDE_SPRITES LCDC_REG&=~LCDCF_OBJON
#define | SPRITES_8x16 LCDC_REG|=LCDCF_OBJ16
#define | SPRITES_8x8 LCDC_REG&=~LCDCF_OBJ16
#define | COMPAT_PALETTE(C0, C1, C2, C3) ((uint8_t)(((C3) << 6) | ((C2) << 4) | ((C1) << 2) | (C0)))
#define | set_bkg_2bpp_data set_bkg_data
#define | set_tile_map set_bkg_tiles
#define | set_tile_submap set_bkg_submap
#define | set_tile_xy set_bkg_tile_xy
#define | set_attribute_xy set_bkg_attribute_xy
#define | set_sprite_2bpp_data set_sprite_data
#define | DISABLE_OAM_DMA _shadow_OAM_base = 0
#define | DISABLE_VBL_TRANSFER DISABLE_OAM_DMA
#define | ENABLE_OAM_DMA _shadow_OAM_base = (uint8_t)((uint16_t)&shadow_OAM >> 8)
#define | ENABLE_VBL_TRANSFER ENABLE_OAM_DMA
#define | MAX_HARDWARE_SPRITES 40
#define | HARDWARE_SPRITE_CAN_FLIP_X 1
#define | HARDWARE_SPRITE_CAN_FLIP_Y 1
#define | fill_rect fill_bkg_rect

## Typedefs
typedef void(* | int_handler) (void) NONBANKED
typedef struct OAM_item_t | OAM_item_t

## Functions
void | remove_VBL (int_handler h)
void | remove_LCD (int_handler h)
void | remove_TIM (int_handler h)
void | remove_SIO (int_handler h)
void | remove_JOY (int_handler h)
void | add_VBL (int_handler h)
void | add_LCD (int_handler h)
void | add_TIM (int_handler h)
void | add_low_priority_TIM (int_handler h)
void | add_SIO (int_handler h)
void | add_JOY (int_handler h)
void | nowait_int_handler (void)
void | wait_int_handler (void)
uint8_t | cancel_pending_interrupts (void)
void | mode (uint8_t m)
uint8_t | get_mode (void) PRESERVES_REGS(b
uint8_t | get_system (void)
void | send_byte (void)
void | receive_byte (void)
void | delay (uint16_t d) PRESERVES_REGS(h
uint8_t | joypad (void) PRESERVES_REGS(b
uint8_t | waitpad (uint8_t mask) PRESERVES_REGS(b
void | waitpadup (void) PRESERVES_REGS(a
uint8_t | joypad_init (uint8_t npads, joypads_t *joypads) OLDCALL
void | joypad_ex (joypads_t *joypads) PRESERVES_REGS(b
void | enable_interrupts (void) PRESERVES_REGS(a
void | disable_interrupts (void) PRESERVES_REGS(a
void | set_interrupts (uint8_t flags) PRESERVES_REGS(b
void | reset (void)
void | vsync (void) PRESERVES_REGS(b
void | wait_vbl_done (void) PRESERVES_REGS(b
void | display_off (void) PRESERVES_REGS(b
void | refresh_OAM (void) PRESERVES_REGS(b
void | hiramcpy (uint8_t dst, const void *src, uint8_t n) OLDCALL PRESERVES_REGS(b
void | set_vram_byte (uint8_t *addr, uint8_t v) PRESERVES_REGS(b
uint8_t | get_vram_byte (uint8_t *addr) PRESERVES_REGS(b
uint8_t * | get_bkg_xy_addr (uint8_t x, uint8_t y) OLDCALL PRESERVES_REGS(b
void | set_2bpp_palette (uint16_t palette)
void | set_1bpp_colors_ex (uint8_t fgcolor, uint8_t bgcolor, uint8_t mode) OLDCALL
void | set_1bpp_colors (uint8_t fgcolor, uint8_t bgcolor)
void | set_bkg_data (uint8_t first_tile, uint8_t nb_tiles, const uint8_t *data) OLDCALL PRESERVES_REGS(b
void | set_bkg_1bpp_data (uint8_t first_tile, uint8_t nb_tiles, const uint8_t *data) OLDCALL PRESERVES_REGS(b
void | get_bkg_data (uint8_t first_tile, uint8_t nb_tiles, uint8_t *data) OLDCALL PRESERVES_REGS(b
void | set_bkg_tiles (uint8_t x, uint8_t y, uint8_t w, uint8_t h, const uint8_t *tiles) OLDCALL PRESERVES_REGS(b
void | set_bkg_based_tiles (uint8_t x, uint8_t y, uint8_t w, uint8_t h, const uint8_t *tiles, uint8_t base_tile)
void | set_bkg_attributes (uint8_t x, uint8_t y, uint8_t w, uint8_t h, const uint8_t *tiles)
void | set_bkg_submap (uint8_t x, uint8_t y, uint8_t w, uint8_t h, const uint8_t *map, uint8_t map_w) OLDCALL
void | set_bkg_based_submap (uint8_t x, uint8_t y, uint8_t w, uint8_t h, const uint8_t *map, uint8_t map_w, uint8_t base_tile)
void | set_bkg_submap_attributes (uint8_t x, uint8_t y, uint8_t w, uint8_t h, const uint8_t *map, uint8_t map_w)
void | get_bkg_tiles (uint8_t x, uint8_t y, uint8_t w, uint8_t h, uint8_t *tiles) OLDCALL PRESERVES_REGS(b
uint8_t * | set_bkg_tile_xy (uint8_t x, uint8_t y, uint8_t t)
uint8_t * | set_bkg_attribute_xy (uint8_t x, uint8_t y, uint8_t a)
uint8_t | get_bkg_tile_xy (uint8_t x, uint8_t y) OLDCALL PRESERVES_REGS(b
void | move_bkg (uint8_t x, uint8_t y)
void | scroll_bkg (int8_t x, int8_t y)
uint8_t * | get_win_xy_addr (uint8_t x, uint8_t y) OLDCALL PRESERVES_REGS(b
void | set_win_data (uint8_t first_tile, uint8_t nb_tiles, const uint8_t *data) OLDCALL PRESERVES_REGS(b
void | set_win_1bpp_data (uint8_t first_tile, uint8_t nb_tiles, const uint8_t *data) OLDCALL PRESERVES_REGS(b
void | get_win_data (uint8_t first_tile, uint8_t nb_tiles, uint8_t *data) OLDCALL PRESERVES_REGS(b
void | set_win_tiles (uint8_t x, uint8_t y, uint8_t w, uint8_t h, const uint8_t *tiles) OLDCALL PRESERVES_REGS(b
void | set_win_based_tiles (uint8_t x, uint8_t y, uint8_t w, uint8_t h, const uint8_t *tiles, uint8_t base_tile)
void | set_win_submap (uint8_t x, uint8_t y, uint8_t w, uint8_t h, const uint8_t *map, uint8_t map_w) OLDCALL
void | set_win_based_submap (uint8_t x, uint8_t y, uint8_t w, uint8_t h, const uint8_t *map, uint8_t map_w, uint8_t base_tile)
void | get_win_tiles (uint8_t x, uint8_t y, uint8_t w, uint8_t h, uint8_t *tiles) OLDCALL PRESERVES_REGS(b
uint8_t * | set_win_tile_xy (uint8_t x, uint8_t y, uint8_t t)
uint8_t | get_win_tile_xy (uint8_t x, uint8_t y) OLDCALL PRESERVES_REGS(b
void | move_win (uint8_t x, uint8_t y)
void | scroll_win (int8_t x, int8_t y)
void | set_sprite_data (uint8_t first_tile, uint8_t nb_tiles, const uint8_t *data) OLDCALL PRESERVES_REGS(b
void | set_sprite_1bpp_data (uint8_t first_tile, uint8_t nb_tiles, const uint8_t *data) OLDCALL PRESERVES_REGS(b
void | get_sprite_data (uint8_t first_tile, uint8_t nb_tiles, uint8_t *data) OLDCALL PRESERVES_REGS(b
void | SET_SHADOW_OAM_ADDRESS (void *address)
void | set_sprite_tile (uint8_t nb, uint8_t tile)
uint8_t | get_sprite_tile (uint8_t nb)
void | set_sprite_prop (uint8_t nb, uint8_t prop)
uint8_t | get_sprite_prop (uint8_t nb)
void | move_sprite (uint8_t nb, uint8_t x, uint8_t y)
void | scroll_sprite (uint8_t nb, int8_t x, int8_t y)
void | hide_sprite (uint8_t nb)
void | set_data (uint8_t *vram_addr, const uint8_t *data, uint16_t len)
void | get_data (uint8_t *data, uint8_t *vram_addr, uint16_t len)
void | vmemcpy (uint8_t *dest, uint8_t *sour, uint16_t len)
void | set_tiles (uint8_t x, uint8_t y, uint8_t w, uint8_t h, uint8_t *vram_addr, const uint8_t *tiles) OLDCALL
void | set_tile_data (uint8_t first_tile, uint8_t nb_tiles, const uint8_t *data, uint8_t base) OLDCALL PRESERVES_REGS(b
void | get_tiles (uint8_t x, uint8_t y, uint8_t w, uint8_t h, uint8_t *vram_addr, uint8_t *tiles) OLDCALL
void | set_native_tile_data (uint16_t first_tile, uint8_t nb_tiles, const uint8_t *data)
void | set_bkg_native_data (uint8_t first_tile, uint8_t nb_tiles, const uint8_t *data)
void | set_sprite_native_data (uint8_t first_tile, uint8_t nb_tiles, const uint8_t *data)
void | init_win (uint8_t c) OLDCALL PRESERVES_REGS(b
void | init_bkg (uint8_t c) OLDCALL PRESERVES_REGS(b
void | vmemset (void *s, uint8_t c, size_t n) OLDCALL PRESERVES_REGS(b
void | fill_bkg_rect (uint8_t x, uint8_t y, uint8_t w, uint8_t h, uint8_t tile) OLDCALL PRESERVES_REGS(b
void | fill_win_rect (uint8_t x, uint8_t y, uint8_t w, uint8_t h, uint8_t tile) OLDCALL PRESERVES_REGS(b

## Variables
uint8_t | c
uint8_t | d
uint8_t | e
uint8_t | h
uint8_t | l
uint8_t | _cpu
uint8_t | _is_GBA
volatile uint16_t | sys_time
__REG | _vbl_done
volatile uint8_t | _io_status
volatile uint8_t | _io_in
volatile uint8_t | _io_out
__REG | _current_bank
void | b
uint16_t | _current_1bpp_colors
uint8_t | _map_tile_offset
uint8_t | _submap_tile_offset
volatile struct OAM_item_t | shadow_OAM []
__REG | _shadow_OAM_base

## Detailed Description

Gameboy specific functions.

## Macro Definition Documentation

## ◆ NINTENDO

#define NINTENDO

## ◆ SYSTEM_60HZ

#define SYSTEM_60HZ 0x00

## ◆ SYSTEM_50HZ

#define SYSTEM_50HZ 0x01

## ◆ GAMEBOY

#define GAMEBOY

## ◆ J_UP

#define J_UP 0x04U

Joypad bits. A logical OR of these is used in the wait_pad and joypad functions. For example, to see if the B button is pressed try

uint8_t keys; keys = joypad(); if (keys & J_B) { ... }

See also
  joypad

## ◆ J_DOWN

#define J_DOWN 0x08U

## ◆ J_LEFT

#define J_LEFT 0x02U

## ◆ J_RIGHT

#define J_RIGHT 0x01U

## ◆ J_A

#define J_A 0x10U

## ◆ J_B

#define J_B 0x20U

## ◆ J_SELECT

#define J_SELECT 0x40U

## ◆ J_START

#define J_START 0x80U

## ◆ M_DRAWING

#define M_DRAWING 0x01U

Screen modes. Normally used by internal functions only.

See also
  mode()

## ◆ M_TEXT_OUT

#define M_TEXT_OUT 0x02U

## ◆ M_TEXT_INOUT

#define M_TEXT_INOUT 0x03U

## ◆ M_NO_SCROLL

#define M_NO_SCROLL 0x04U

Set this in addition to the others to disable scrolling

If scrolling is disabled, the cursor returns to (0,0)

See also
  mode()

## ◆ M_NO_INTERP

#define M_NO_INTERP 0x08U

Set this to disable interpretation

See also
  mode()

## ◆ S_BANK

#define S_BANK 0x08U

If this bit set clear, the tile from the second VRAM bank is used

See also
  set_sprite_prop()

## ◆ S_PALETTE

#define S_PALETTE 0x10U

If this is set, sprite colours come from OBJ1PAL. Else they come from OBJ0PAL

See also
  set_sprite_prop().

## ◆ S_FLIPX

#define S_FLIPX 0x20U

If set the sprite will be flipped horizontally.

See also
  set_sprite_prop()

## ◆ S_FLIPY

#define S_FLIPY 0x40U

If set the sprite will be flipped vertically.

See also
  set_sprite_prop()

## ◆ S_PRIORITY

#define S_PRIORITY 0x80U

If this bit is clear, then the sprite will be displayed on top of the background and window.

See also
  set_sprite_prop()

## ◆ S_PAL

#define S_PAL | ( |  | n | ) | n

Defines how palette number is encoded in OAM. Required for the png2asset tool's metasprite output.

## ◆ EMPTY_IFLAG

#define EMPTY_IFLAG 0x00U

Disable calling of interrupt service routines

## ◆ VBL_IFLAG

#define VBL_IFLAG 0x01U

VBlank Interrupt occurs at the start of the vertical blank.

During this period the video ram may be freely accessed.

See also
  set_interrupts(),
  add_VBL

## ◆ LCD_IFLAG

#define LCD_IFLAG 0x02U

LCD Interrupt when triggered by the STAT register.

See also
  set_interrupts(),
  add_LCD

## ◆ TIM_IFLAG

#define TIM_IFLAG 0x04U

Timer Interrupt when the timer TIMA_REG overflows.

See also
  set_interrupts(),
  add_TIM

## ◆ SIO_IFLAG

#define SIO_IFLAG 0x08U

Serial Link Interrupt occurs when the serial transfer has completed.

See also
  set_interrupts(),
  add_SIO

## ◆ JOY_IFLAG

#define JOY_IFLAG 0x10U

Joypad Interrupt occurs on a transition of the keypad.

See also
  set_interrupts(),
  add_JOY

## ◆ DMG_BLACK

#define DMG_BLACK 0x03

## ◆ DMG_DARK_GRAY

#define DMG_DARK_GRAY 0x02

## ◆ DMG_LITE_GRAY

#define DMG_LITE_GRAY 0x01

## ◆ DMG_WHITE

#define DMG_WHITE 0x00

## ◆ DMG_PALETTE

#define DMG_PALETTE | ( |  | C0,
|  |  | C1,
|  |  | C2,
|  |  | C3
| ) |  | ((uint8_t)((((C3) & 0x03) << 6) | (((C2) & 0x03) << 4) | (((C1) & 0x03) << 2) | ((C0) & 0x03)))

Macro to create a DMG palette from 4 colors

Parameters

  C0 | Color for Index 0
  C1 | Color for Index 1
  C2 | Color for Index 2
  C3 | Color for Index 3

The resulting format is four greyscale colors packed into a single unsigned byte.

Example:

BGP_REG = DMG_PALETTE(DMG_BLACK, DMG_DARK_GRAY, DMG_LITE_GRAY, DMG_WHITE);
BGP_REG
__REG BGP_REG
Definition: hardware.h:315
DMG_WHITE
#define DMG_WHITE
Definition: gb.h:139
DMG_DARK_GRAY
#define DMG_DARK_GRAY
Definition: gb.h:137
DMG_LITE_GRAY
#define DMG_LITE_GRAY
Definition: gb.h:138
DMG_PALETTE
#define DMG_PALETTE(C0, C1, C2, C3)
Definition: gb.h:159
DMG_BLACK
#define DMG_BLACK
Definition: gb.h:136

See also
  OBP0_REG, OBP1_REG, BGP_REG
  DMG_BLACK, DMG_DARK_GRAY, DMG_LITE_GRAY, DMG_WHITE

## ◆ SCREENWIDTH

#define SCREENWIDTH DEVICE_SCREEN_PX_WIDTH

Width of the visible screen in pixels.

## ◆ SCREENHEIGHT

#define SCREENHEIGHT DEVICE_SCREEN_PX_HEIGHT

Height of the visible screen in pixels.

## ◆ MINWNDPOSX

#define MINWNDPOSX DEVICE_WINDOW_PX_OFFSET_X

The Minimum X position of the Window Layer (Left edge of screen)

See also
  move_win()

## ◆ MINWNDPOSY

#define MINWNDPOSY DEVICE_WINDOW_PX_OFFSET_Y

The Minimum Y position of the Window Layer (Top edge of screen)

See also
  move_win()

## ◆ MAXWNDPOSX

#define MAXWNDPOSX (DEVICE_WINDOW_PX_OFFSET_X + DEVICE_SCREEN_PX_WIDTH - 1)

The Maximum X position of the Window Layer (Right edge of screen)

See also
  move_win()

## ◆ MAXWNDPOSY

#define MAXWNDPOSY (DEVICE_WINDOW_PX_OFFSET_Y + DEVICE_SCREEN_PX_HEIGHT - 1)

The Maximum Y position of the Window Layer (Bottom edge of screen)

See also
  move_win()

## ◆ DMG_TYPE

#define DMG_TYPE 0x01

Hardware Model: Original GB or Super GB.

See also
  _cpu

## ◆ MGB_TYPE

#define MGB_TYPE 0xFF

Hardware Model: Pocket GB or Super GB 2.

See also
  _cpu

## ◆ CGB_TYPE

#define CGB_TYPE 0x11

Hardware Model: Color GB.

See also
  _cpu

## ◆ GBA_NOT_DETECTED

#define GBA_NOT_DETECTED 0x00

Hardware Model: DMG, CGB or MGB.

See also
  _cpu, _is_GBA

## ◆ GBA_DETECTED

#define GBA_DETECTED 0x01

Hardware Model: GBA.

See also
  _cpu, _is_GBA

## ◆ DEVICE_SUPPORTS_COLOR

#define DEVICE_SUPPORTS_COLOR (_cpu == CGB_TYPE)

Macro returns TRUE if device supports color

## ◆ VBL_DONE

#define VBL_DONE _vbl_done

## ◆ IO_IDLE

#define IO_IDLE 0x00U

Serial Link IO is completed

## ◆ IO_SENDING

#define IO_SENDING 0x01U

Serial Link Sending data

## ◆ IO_RECEIVING

#define IO_RECEIVING 0x02U

Serial Link Receiving data

## ◆ IO_ERROR

#define IO_ERROR 0x04U

Serial Link Error

## ◆ CURRENT_BANK

#define CURRENT_BANK _current_bank

## ◆ BANK

#define BANK | ( |  | VARNAME | ) | ( (uint8_t) & __bank_ ## VARNAME )

Obtains the bank number of VARNAME

Parameters

  VARNAME | Name of the variable which has a __bank_VARNAME companion symbol which is adjusted by bankpack

Use this to obtain the bank number from a bank reference created with BANKREF().

See also
  BANKREF_EXTERN(), BANKREF()

## ◆ BANKREF

#define BANKREF | ( |  | VARNAME | ) |

Value:
void __func_ ## VARNAME(void) __banked __naked { \
__asm \
.local b___func_ ## VARNAME \
___bank_ ## VARNAME = b___func_ ## VARNAME \
.globl ___bank_ ## VARNAME \
__endasm; \
}

Creates a reference for retrieving the bank number of a variable or function

Parameters

  VARNAME | Variable name to use, which may be an existing identifier

See also
  BANK() for obtaining the bank number of the included data.

More than one `BANKREF()` may be created per file, but each call should always use a unique VARNAME.

Use BANKREF_EXTERN() within another source file to make the variable and it's data accesible there.

## ◆ BANKREF_EXTERN

#define BANKREF_EXTERN | ( |  | VARNAME | ) | extern const void __bank_ ## VARNAME;

Creates extern references for accessing a BANKREF() generated variable.

Parameters

  VARNAME | Name of the variable used with BANKREF()

This makes a BANKREF() reference in another source file accessible in the current file for use with BANK().

See also
  BANKREF(), BANK()

## ◆ SWITCH_ROM

#define SWITCH_ROM | ( |  | b | ) | (_current_bank = (b), rROMB0 = (b))

Makes default platform MBC switch the active ROM bank

Parameters

  b | ROM bank to switch to (max 255)

- When used with MBC1 the max bank is Bank 31 (512K).
- When used with MBC5 the max bank is Bank 255 (4MB).
- To use the full 8MB size of MBC5 see SWITCH_ROM_MBC5_8M().

- For MBC1 some banks in it's range are unavailable (typically 0x20, 0x40, 0x60).

Note
  Using SWITCH_ROM_MBC5_8M() should not be mixed with using SWITCH_ROM_MBC5() and SWITCH_ROM().

See also
  SWITCH_ROM_MBC1, SWITCH_ROM_MBC5, SWITCH_ROM_MEGADUCK

## ◆ SWITCH_RAM

#define SWITCH_RAM | ( |  | b | ) | (rRAMB = (b))

Switches SRAM bank on MBC1 and other compatible MBCs

Parameters

  b | SRAM bank to switch to

Before switching SRAM banks enable it using ENABLE_RAM

See also
  SWITCH_RAM_MBC1, SWITCH_RAM_MBC5

## ◆ ENABLE_RAM

#define ENABLE_RAM (rRAMG = 0x0A)

Enables SRAM on MBC1 and other compatible MBCs

## ◆ DISABLE_RAM

#define DISABLE_RAM (rRAMG = 0x00)

Disables SRAM on MBC1 and other compatible MBCs

## ◆ SWITCH_ROM_MEGADUCK

#define SWITCH_ROM_MEGADUCK | ( |  | b | ) | SWITCH_ROM(b)

Makes MEGADUCK MBC switch the active ROM bank

Parameters

  b | ROM bank to switch to (max `3` for 64K, or `7` for 128K)

## ◆ SWITCH_ROM_MBC1

#define SWITCH_ROM_MBC1 | ( |  | b | ) | SWITCH_ROM(b)

Makes MBC1 and other compatible MBCs switch the active ROM bank

Parameters

  b | ROM bank to switch to

For MBC1 some banks in it's range are unavailable (typically 0x20, 0x40, 0x60).

See pandocs for more details https://gbdev.io/pandocs/MBC1

## ◆ SWITCH_RAM_MBC1

#define SWITCH_RAM_MBC1 | ( |  | b | ) | SWITCH_RAM(b)

Switches SRAM bank on MBC1 and other compatible MBCs

Parameters

  b | SRAM bank to switch to

Before switching SRAM banks enable it using ENABLE_RAM

See also
  SWITCH_RAM, SWITCH_RAM_MBC5

## ◆ ENABLE_RAM_MBC1

#define ENABLE_RAM_MBC1 ENABLE_RAM

Enables SRAM on MBC1

## ◆ DISABLE_RAM_MBC1

#define DISABLE_RAM_MBC1 DISABLE_RAM

Disables SRAM on MBC1

## ◆ SWITCH_16_8_MODE_MBC1

#define SWITCH_16_8_MODE_MBC1 (*(volatile uint8_t *)0x6000 = 0x00)

## ◆ SWITCH_4_32_MODE_MBC1

#define SWITCH_4_32_MODE_MBC1 (*(volatile uint8_t *)0x6000 = 0x01)

## ◆ SWITCH_ROM_MBC5

#define SWITCH_ROM_MBC5 | ( |  | b | ) | (_current_bank = (b), rROMB1 = 0, rROMB0 = (b))

Makes MBC5 switch to the active ROM bank

Parameters

  b | ROM bank to switch to (max 255)

Supports up to ROM bank 255 (4 MB).

SWITCH_ROM_MBC5_8M may be used if the full 8MB size is needed.

Note
  Using SWITCH_ROM_MBC5_8M() should not be mixed with using SWITCH_ROM_MBC5() and SWITCH_ROM().

Note the order used here. Writing the other way around on a MBC1 always selects bank 1

## ◆ SWITCH_ROM_MBC5_8M

#define SWITCH_ROM_MBC5_8M | ( |  | b | ) | (rROMB1 = ((uint16_t)(b) >> 8), rROMB0 = (b))

Makes MBC5 to switch the active ROM bank using the full 8MB size.

See also
  CURRENT_BANK

Parameters

  b | ROM bank to switch to

This is an alternate to SWITCH_ROM_MBC5 which is limited to 4MB.

Note:

- Banked SDCC calls are not supported if you use this macro.
- The active bank number is not tracked by CURRENT_BANK if you use this macro.
- Using SWITCH_ROM_MBC5_8M() should not be mixed with using SWITCH_ROM_MBC5() and SWITCH_ROM().

Note the order used here. Writing the other way around on a MBC1 always selects bank 1

## ◆ SWITCH_RAM_MBC5

#define SWITCH_RAM_MBC5 | ( |  | b | ) | SWITCH_RAM(b)

Switches SRAM bank on MBC5

Parameters

  b | SRAM bank to switch to

Before switching SRAM banks enable it using ENABLE_RAM

## ◆ ENABLE_RAM_MBC5

#define ENABLE_RAM_MBC5 ENABLE_RAM

Enables SRAM on MBC5

## ◆ DISABLE_RAM_MBC5

#define DISABLE_RAM_MBC5 DISABLE_RAM

Disables SRAM on MBC5

## ◆ DISPLAY_ON

#define DISPLAY_ON LCDC_REG|=LCDCF_ON

Turns the display back on.

See also
  display_off, DISPLAY_OFF

## ◆ DISPLAY_OFF

#define DISPLAY_OFF display_off();

Turns the display off

Waits until the VBL before turning the display off.

See also
  display_off, DISPLAY_ON

## ◆ HIDE_LEFT_COLUMN

#define HIDE_LEFT_COLUMN

Does nothing for GB

## ◆ SHOW_LEFT_COLUMN

#define SHOW_LEFT_COLUMN

Does nothing for GB

## ◆ SET_BORDER_COLOR

#define SET_BORDER_COLOR | ( |  | C | ) |

Does nothing for GB

## ◆ SHOW_BKG

#define SHOW_BKG LCDC_REG|=LCDCF_BGON

Turns on the background layer. Sets bit 0 of the LCDC register to 1.

Doesn't work in CGB mode - the bit is reused to control sprite priority over background and window layers instead.

- If 1 (SHOW_BKG), everything works as usual.
- If 0 (HIDE_BKG), all sprites are always drawn over background and window, ignoring any other priority settings.

## ◆ HIDE_BKG

#define HIDE_BKG LCDC_REG&=~LCDCF_BGON

Turns off the background layer. Sets bit 0 of the LCDC register to 0.

Doesn't work in CGB mode - the bit is reused to control sprite priority over background and window layers instead.

- If 1 (SHOW_BKG), everything works as usual.
- If 0 (HIDE_BKG), all sprites are always drawn over background and window, ignoring any other priority settings.

## ◆ SHOW_WIN

#define SHOW_WIN LCDC_REG|=LCDCF_WINON

Turns on the Window layer Sets bit 5 of the LCDC register to 1.

This only controls Window visibility. If either the Background layer (which the window is part of) or the Display are not turned then the Window contents will not be visible. Those can be turned on using SHOW_BKG and DISPLAY_ON.

## ◆ HIDE_WIN

#define HIDE_WIN LCDC_REG&=~LCDCF_WINON

Turns off the window layer. Clears bit 5 of the LCDC register to 0.

## ◆ SHOW_SPRITES

#define SHOW_SPRITES LCDC_REG|=LCDCF_OBJON

Turns on the sprites layer. Sets bit 1 of the LCDC register to 1.

## ◆ HIDE_SPRITES

#define HIDE_SPRITES LCDC_REG&=~LCDCF_OBJON

Turns off the sprites layer. Clears bit 1 of the LCDC register to 0.

See also
  hide_sprite, hide_sprites_range

## ◆ SPRITES_8x16

#define SPRITES_8x16 LCDC_REG|=LCDCF_OBJ16

Sets sprite size to 8x16 pixels, two tiles one above the other. Sets bit 2 of the LCDC register to 1.

## ◆ SPRITES_8x8

#define SPRITES_8x8 LCDC_REG&=~LCDCF_OBJ16

Sets sprite size to 8x8 pixels, one tile. Clears bit 2 of the LCDC register to 0.

## ◆ COMPAT_PALETTE

#define COMPAT_PALETTE | ( |  | C0,
|  |  | C1,
|  |  | C2,
|  |  | C3
| ) |  | ((uint8_t)(((C3) << 6) | ((C2) << 4) | ((C1) << 2) | (C0)))

## ◆ set_bkg_2bpp_data

#define set_bkg_2bpp_data set_bkg_data

## ◆ set_tile_map

#define set_tile_map set_bkg_tiles

## ◆ set_tile_submap

#define set_tile_submap set_bkg_submap

## ◆ set_tile_xy

#define set_tile_xy set_bkg_tile_xy

## ◆ set_attribute_xy

#define set_attribute_xy set_bkg_attribute_xy

## ◆ set_sprite_2bpp_data

#define set_sprite_2bpp_data set_sprite_data

## ◆ DISABLE_OAM_DMA

#define DISABLE_OAM_DMA _shadow_OAM_base = 0

## ◆ DISABLE_VBL_TRANSFER

#define DISABLE_VBL_TRANSFER DISABLE_OAM_DMA

Disable OAM DMA copy each VBlank

## ◆ ENABLE_OAM_DMA

#define ENABLE_OAM_DMA _shadow_OAM_base = (uint8_t)((uint16_t)&shadow_OAM >> 8)

## ◆ ENABLE_VBL_TRANSFER

#define ENABLE_VBL_TRANSFER ENABLE_OAM_DMA

Enable OAM DMA copy each VBlank and set it to transfer default shadow_OAM array

## ◆ MAX_HARDWARE_SPRITES

#define MAX_HARDWARE_SPRITES 40

Amount of hardware sprites in OAM

## ◆ HARDWARE_SPRITE_CAN_FLIP_X

#define HARDWARE_SPRITE_CAN_FLIP_X 1

True if sprite hardware can flip sprites by X (horizontally)

## ◆ HARDWARE_SPRITE_CAN_FLIP_Y

#define HARDWARE_SPRITE_CAN_FLIP_Y 1

True if sprite hardware can flip sprites by Y (vertically)

## ◆ fill_rect

#define fill_rect fill_bkg_rect

## Typedef Documentation

## ◆ int_handler

typedef void(* int_handler) (void) NONBANKED

Interrupt handlers

## ◆ OAM_item_t

typedef struct OAM_item_t OAM_item_t

Sprite Attributes structure

Parameters

  x | X Coordinate of the sprite on screen
  y | Y Coordinate of the sprite on screen
  tile | Sprite tile number (see set_sprite_tile)
  prop | OAM Property Flags (see set_sprite_prop)

## Function Documentation

## ◆ remove_VBL()

void remove_VBL | ( | int_handler | h | ) |

The remove functions will remove any interrupt handler.

A handler of NULL will cause bad things to happen if the given interrupt is enabled.

Removes the VBL interrupt handler.

See also
  add_VBL()

Removes the VBL interrupt handler.

See also
  add_VBL()

## ◆ remove_LCD()

void remove_LCD | ( | int_handler | h | ) |

Removes the LCD interrupt handler.

See also
  add_LCD(), remove_VBL()

## ◆ remove_TIM()

void remove_TIM | ( | int_handler | h | ) |

Removes the TIM interrupt handler.

See also
  add_TIM(), remove_VBL()

## ◆ remove_SIO()

void remove_SIO | ( | int_handler | h | ) |

Removes the Serial Link / SIO interrupt handler.

See also
  add_SIO(),
  remove_VBL()

The default SIO ISR gets installed automatically if any of the standard SIO calls are used (send_byte(), receive_byte()).

Once installed the default SIO ISR cannot be removed. Only secondary chained SIO ISRs (added with add_SIO()) can be removed.

## ◆ remove_JOY()

void remove_JOY | ( | int_handler | h | ) |

Removes the JOY interrupt handler.

See also
  add_JOY(), remove_VBL()

## ◆ add_VBL()

void add_VBL | ( | int_handler | h | ) |

Adds a Vertical Blanking interrupt handler.

Parameters

  h | The handler to be called whenever a V-blank interrupt occurs.

Up to 4 handlers may be added, with the last added being called last.

Do not use the function definition attributes CRITICAL and INTERRUPT when declaring ISR functions added via add_VBL() (or LCD, etc). Those attributes are only required when constructing a bare jump from the interrupt vector itself (such as with ISR_VECTOR()).

ISR handlers added using add_VBL()/etc are instead called via the GBDK ISR dispatcher which makes the extra function attributes unecessary.

Note
  The default GBDK VBL is installed automatically.

See also
  ISR_VECTOR()

Adds a V-blank interrupt handler.

## ◆ add_LCD()

void add_LCD | ( | int_handler | h | ) |

Adds a LCD interrupt handler.

Called when the LCD interrupt occurs.

Up to 3 handlers may be added, with the last added being called last.

There are various sources controlled by the STAT_REG register ($FF41) which can trigger this interrupt. Common examples include triggering on specific scanlines using LY_REG == LYC_REG. Another is applying graphics effects on a per-scanline basis such as modifying the X and Y scroll registers (SCX_REG / SCY_REG registers).

Note
  LYC may not trigger with scanline 0 in the same way as other scanlines due to particular behavior with scanlines 153 and 0. Instead, using an add_VBL() interrupt handler for start of frame behavior may be more suitable.

Do not use the function definition attributes CRITICAL and INTERRUPT when declaring ISR functions added via add_VBL() (or LCD, etc). Those attributes are only required when constructing a bare jump from the interrupt vector itself (such as with ISR_VECTOR()).

ISR handlers added using add_VBL/LCD/etc are instead called via the GBDK ISR dispatcher which makes the extra function attributes unecessary.

If this ISR is to be called once per each scanline then make sure that the time it takes to execute is less than the duration of a scanline.

See also
  add_VBL, nowait_int_handler, ISR_VECTOR()

Adds a LCD interrupt handler.

## ◆ add_TIM()

void add_TIM | ( | int_handler | h | ) |

Adds a timer interrupt handler.

Can not be used together with add_low_priority_TIM

This interrupt occurs when the TIMA_REG register ($FF05) changes from $FF to $00.

Up to 4 handlers may be added, with the last added being called last.

Note
  For NES make sure to wrap TIM interrupt handlers with a nooverlay pragma. For more details see docs_nes_tim_overlay

See also
  add_VBL
  set_interrupts() with TIM_IFLAG, ISR_VECTOR()

## ◆ add_low_priority_TIM()

void add_low_priority_TIM | ( | int_handler | h | ) |

Adds a timer interrupt handler, that could be interrupted by the other interrupts, as well as itself, if it runs too slow.

Can not be used together with add_TIM

This interrupt occurs when the TIMA_REG register ($FF05) changes from $FF to $00.

Up to 4 handlers may be added, with the last added being called last.

See also
  add_VBL
  set_interrupts() with TIM_IFLAG, ISR_VECTOR()

## ◆ add_SIO()

void add_SIO | ( | int_handler | h | ) |

Adds a Serial Link transmit complete interrupt handler.

This interrupt occurs when a serial transfer has completed on the game link port.

Up to 4 handlers may be added, with the last added being called last.

The default SIO ISR gets installed automatically if any of the standard SIO calls are used (send_byte(), receive_byte()).

See also
  send_byte, receive_byte(), add_VBL()
  set_interrupts() with SIO_IFLAG

## ◆ add_JOY()

void add_JOY | ( | int_handler | h | ) |

Adds a joypad button change interrupt handler.

This interrupt occurs on a transition of any of the keypad input lines from high to low, if the relevant P1_REG bits 4 or 5 are set.

For details about configuring flags or reading the data see: https://gbdev.io/pandocs/Interrupt_Sources.html#int-60&ndash;joypad-interrupt https://gbdev.io/pandocs/Joypad_Input.html#ff00&ndash;p1joyp-joypad

Due to the fact that keypad "bounce" is virtually always present, software should expect this interrupt to occur one or more times for every button press and one or more times for every button release.

Up to 4 handlers may be added, with the last added being called last.

An example use of this is allowing the user to trigger an exit from the lower-power STOP cpu state.

See also
  joypad(), add_VBL(), IEF_HILO, P1F_5, P1F_4, P1F_3, P1F_2, P1F_1, P1F_0, P1F_GET_DPAD, P1F_GET_BTN, P1F_GET_NONE

## ◆ nowait_int_handler()

void nowait_int_handler | ( | void |  | ) |

Interrupt handler chain terminator that does not wait for .STAT

You must add this handler last in every interrupt handler chain if you want to change the default interrupt handler behaviour that waits for LCD controller mode to become 1 or 0 before return from the interrupt.

Example:

CRITICAL {
add_SIO(nowait_int_handler); // Disable wait on VRAM state before returning from SIO interrupt
}
CRITICAL
#define CRITICAL
Definition: types.h:46
nowait_int_handler
void nowait_int_handler(void)
add_SIO
void add_SIO(int_handler h)

See also
  wait_int_handler()

## ◆ wait_int_handler()

void wait_int_handler | ( | void |  | ) |

Default Interrupt handler chain terminator that waits for

See also
  STAT_REG and only returns at the BEGINNING of either Mode 0 or Mode 1.

Used by default at the end of interrupt chains to help prevent graphical glitches. The glitches are caused when an ISR interrupts a graphics operation in one mode but returns in a different mode for which that graphics operation is not allowed.

See also
  nowait_int_handler()

## ◆ cancel_pending_interrupts()

uint8_t cancel_pending_interrupts | ( | void |  | ) |
| inline

Cancel pending interrupts

## ◆ mode()

void mode | ( | uint8_t | m | ) |

Set the current screen mode - one of M_* modes

Normally used by internal functions only.

See also
  M_DRAWING, M_TEXT_OUT, M_TEXT_INOUT, M_NO_SCROLL, M_NO_INTERP

## ◆ get_mode()

uint8_t get_mode | ( | void |  | ) |

Returns the current mode

See also
  M_DRAWING, M_TEXT_OUT, M_TEXT_INOUT, M_NO_SCROLL, M_NO_INTERP

## ◆ get_system()

uint8_t get_system | ( | void |  | ) |
| inline

Returns the system gbdk is running on.

See also
  SYSTEM_50HZ, SYSTEM_60HZ, SYSTEM_BITS_DENDY, SYSTEM_BITS_NTSC, SYSTEM_BITS_PAL, SYSTEM_NTSC SYSTEM_PAL

## ◆ send_byte()

void send_byte | ( | void |  | ) |

Serial Link: Send the byte in _io_out out through the serial port

Make sure to enable interrupts for the Serial Link before trying to transfer data.

See also
  add_SIO(), remove_SIO()
  set_interrupts() with SIO_IFLAG

## ◆ receive_byte()

void receive_byte | ( | void |  | ) |

Serial Link: Receive a byte from the serial port into _io_in

Make sure to enable interrupts for the Serial Link before trying to transfer data.

See also
  add_SIO(), remove_SIO()
  set_interrupts() with SIO_IFLAG

## ◆ delay()

void delay | ( | uint16_t | d | ) |

Delays the given number of milliseconds. Uses no timers or interrupts, and can be called with interrupts disabled

## ◆ joypad()

uint8_t joypad | ( | void |  | ) |

Reads and returns the current state of the joypad. Follows Nintendo's guidelines for reading the pad. Return value is an OR of J_*

When testing for multiple different buttons, it's best to read the joypad state once into a variable and then test using that variable.

See also
  J_START, J_SELECT, J_A, J_B, J_UP, J_DOWN, J_LEFT, J_RIGHT

## ◆ waitpad()

uint8_t waitpad | ( | uint8_t | mask | ) |

Waits until at least one of the buttons given in mask are pressed.

Parameters

  mask | Bitmask indicating which buttons to wait for

Normally only used for checking one key, but it will support many, even J_LEFT at the same time as J_RIGHT. :)

Note
  Checks in a loop that doesn't HALT at all, so the CPU will be maxed out until this call returns.

See also
  joypad
  J_START, J_SELECT, J_A, J_B, J_UP, J_DOWN, J_LEFT, J_RIGHT

## ◆ waitpadup()

void waitpadup | ( | void |  | ) |

Waits for the directional pad and all buttons to be released.

Note
  Checks in a loop that doesn't HALT at all, so the CPU will be maxed out until this call returns.

## ◆ joypad_init()

uint8_t joypad_init | ( | uint8_t | npads,
|  | joypads_t * | joypads
| ) |  |

Initializes joypads_t structure for polling multiple joypads (for the GB and ones connected via SGB)

Parameters

  npads | number of joypads requested (1, 2 or 4)
  joypads | pointer to joypads_t structure to be initialized

Only required for joypad_ex, not required for calls to regular joypad()

Returns
  number of joypads avaliable

See also
  joypad_ex(), joypads_t

## ◆ joypad_ex()

void joypad_ex | ( | joypads_t * | joypads | ) |

Polls all avaliable joypads (for the GB and ones connected via SGB)

Parameters

  joypads | pointer to joypads_t structure to be filled with joypad statuses, must be previously initialized with joypad_init()

See also
  joypad_init(), joypads_t

## ◆ enable_interrupts()

void enable_interrupts | ( | void |  | ) |
| inline

Enables unmasked interrupts

Note
  Use CRITICAL {...} instead for creating a block of of code which should execute with interrupts temporarily turned off.

See also
  disable_interrupts, set_interrupts, CRITICAL

## ◆ disable_interrupts()

void disable_interrupts | ( | void |  | ) |
| inline

Disables interrupts

Note
  Use CRITICAL {...} instead for creating a block of of code which should execute with interrupts temporarily turned off.

This function may be called as many times as you like; however the first call to enable_interrupts will re-enable them.

See also
  enable_interrupts, set_interrupts, CRITICAL

## ◆ set_interrupts()

void set_interrupts | ( | uint8_t | flags | ) |

Clears any pending interrupts and sets the interrupt mask register IO to flags.

Parameters

  flags | A logical OR of *_IFLAGS

Note
  This disables and then re-enables interrupts so it must be used outside of a critical section.

See also
  enable_interrupts(), disable_interrupts()
  VBL_IFLAG, LCD_IFLAG, TIM_IFLAG, SIO_IFLAG, JOY_IFLAG

## ◆ reset()

void reset | ( | void |  | ) |
| inline

Performs a soft reset.

For the Game Boy and related it does this by jumping to address 0x0150 which is in crt0.s (the c-runtime that executes before main() is called).

This performs various startup steps such as resetting the stack, clearing WRAM and OAM, resetting initialized variables and some display registers (scroll, window, LCDC), etc.

This is not the same a hard power reset.

## ◆ vsync()

void vsync | ( | void |  | ) |

HALTs the CPU and waits for the vertical blank interrupt and then returns when all registered VBL ISRs have completed.

This is often used in main loops to idle the CPU at low power until it's time to start the next frame. It's also useful for syncing animation with the screen re-draw.

Warning: If the VBL interrupt is disabled, this function will never return. If the screen is off this function returns immediately.

## ◆ wait_vbl_done()

void wait_vbl_done | ( | void |  | ) |

Obsolete. This function has been replaced by vsync(), which has identical behavior.

## ◆ display_off()

void display_off | ( | void |  | ) |

Turns the display off.

Waits until the VBL before turning the display off.

See also
  DISPLAY_ON

## ◆ refresh_OAM()

void refresh_OAM | ( | void |  | ) |

Copies data from shadow OAM to OAM

## ◆ hiramcpy()

void hiramcpy | ( | uint8_t | dst,
|  | const void * | src,
|  | uint8_t | n
| ) |  |

Copies data from somewhere in the lower address space to part of hi-ram.

Parameters

  dst | Offset in high ram (0xFF00 and above) to copy to.
  src | Area to copy from
  n | Number of bytes to copy.

## ◆ set_vram_byte()

void set_vram_byte | ( | uint8_t * | addr,
|  | uint8_t | v
| ) |  |

Set byte in vram at given memory location

Parameters

  addr | address to write to
  v | value

## ◆ get_vram_byte()

uint8_t get_vram_byte | ( | uint8_t * | addr | ) |

Get byte from vram at given memory location

Parameters

  addr | address to read from

Returns
  read value

Note
  In general avoid reading from VRAM since that memory is not accessible at all times. It is also not supported by GBDK on the NES platform. See coding guidelines for more details.

## ◆ get_bkg_xy_addr()

uint8_t* get_bkg_xy_addr | ( | uint8_t | x,
|  | uint8_t | y
| ) |  |

Get address of X,Y tile of background map

## ◆ set_2bpp_palette()

void set_2bpp_palette | ( | uint16_t | palette | ) |
| inline

Sets palette for 2bpp color translation for GG/SMS, does nothing on GB

## ◆ set_1bpp_colors_ex()

void set_1bpp_colors_ex | ( | uint8_t | fgcolor,
|  | uint8_t | bgcolor,
|  | uint8_t | mode
| ) |  |

Sets the Foreground and Background colors used by the set_*_1bpp_*() functions

Parameters

  fgcolor | Foreground color
  bgcolor | Background color
  mode | Draw Mode

See set_1bpp_colors for details.

## ◆ set_1bpp_colors()

void set_1bpp_colors | ( | uint8_t | fgcolor,
|  | uint8_t | bgcolor
| ) |  |
| inline

Sets the Foreground and Background colors used by the set_*_1bpp_*() functions

Parameters

  fgcolor | Foreground color to use
  bgcolor | Background color to use

The default colors are:

- Foreground: DMG_BLACK
- Background: DMG_WHITE

Example:

// Use DMG_BLACK as the Foreground color and DMG_LITE_GRAY
// as the Background color when loading 1bpp tile data.
set_1bpp_colors(DMG_BLACK, DMG_LITE_GRAY);
set_1bpp_colors
void set_1bpp_colors(uint8_t fgcolor, uint8_t bgcolor)
Definition: gb.h:1038

See also
  DMG_BLACK, DMG_DARK_GRAY, DMG_LITE_GRAY, DMG_WHITE
  set_bkg_1bpp_data, set_win_1bpp_data, set_sprite_1bpp_data

## ◆ set_bkg_data()

void set_bkg_data | ( | uint8_t | first_tile,
|  | uint8_t | nb_tiles,
|  | const uint8_t * | data
| ) |  |

Sets VRAM Tile Pattern data for the Background / Window

Parameters

  first_tile | Index of the first tile to write
  nb_tiles | Number of tiles to write
  data | Pointer to (2 bpp) source tile data

Writes nb_tiles tiles to VRAM starting at first_tile, tile data is sourced from data. Each Tile is 16 bytes in size (8x8 pixels, 2 bits-per-pixel).

Note
  Sprite Tiles 128-255 share the same memory region as Background Tiles 128-255.

GBC only: VBK_REG determines which bank of tile patterns are written to.

- VBK_REG = VBK_BANK_0 indicates the first bank
- VBK_REG = VBK_BANK_1 indicates the second

See also
  set_win_data, set_tile_data

## ◆ set_bkg_1bpp_data()

void set_bkg_1bpp_data | ( | uint8_t | first_tile,
|  | uint8_t | nb_tiles,
|  | const uint8_t * | data
| ) |  |

Sets VRAM Tile Pattern data for the Background / Window using 1bpp source data

Parameters

  first_tile | Index of the first Tile to write
  nb_tiles | Number of Tiles to write
  data | Pointer to (1bpp) source Tile Pattern data

Similar to set_bkg_data, except source data is 1 bit-per-pixel which gets expanded into 2 bits-per-pixel.

For a given bit that represent a pixel:

- 0 will be expanded into the Background color
- 1 will be expanded into the Foreground color

See set_1bpp_colors for details about setting the Foreground and Background colors.

See also
  SHOW_BKG, HIDE_BKG, set_bkg_tiles
  set_win_1bpp_data, set_sprite_1bpp_data

## ◆ get_bkg_data()

void get_bkg_data | ( | uint8_t | first_tile,
|  | uint8_t | nb_tiles,
|  | uint8_t * | data
| ) |  |

Copies from Background / Window VRAM Tile Pattern data into a buffer

Parameters

  first_tile | Index of the first Tile to read from
  nb_tiles | Number of Tiles to read
  data | Pointer to destination buffer for Tile Pattern data

Note
  In general avoid reading from VRAM since that memory is not accessible at all times. It is also not supported by GBDK on the NES platform. See coding guidelines for more details.

Copies nb_tiles tiles from VRAM starting at first_tile, Tile data is copied into data.

Each Tile is 16 bytes, so the buffer pointed to by data should be at least nb_tiles x 16 bytes in size.

See also
  get_win_data, get_data

## ◆ set_bkg_tiles()

void set_bkg_tiles | ( | uint8_t | x,
|  | uint8_t | y,
|  | uint8_t | w,
|  | uint8_t | h,
|  | const uint8_t * | tiles
| ) |  |

Sets a rectangular region of Background Tile Map.

Parameters

  x | X Start position in Background Map tile coordinates. Range 0 - 31
  y | Y Start position in Background Map tile coordinates. Range 0 - 31
  w | Width of area to set in tiles. Range 1 - 32
  h | Height of area to set in tiles. Range 1 - 32
  tiles | Pointer to source tile map data

Entries are copied from map at tiles to the Background Tile Map starting at x, y writing across for w tiles and down for h tiles.

Use set_bkg_submap() instead when:

- Source map is wider than 32 tiles.
- Writing a width that does not match the source map width and more than one row high at a time.

One byte per source tile map entry.

Writes that exceed coordinate 31 on the x or y axis will wrap around to the Left and Top edges.

Note
  Patterns 128-255 overlap with patterns 128-255 of the sprite Tile Pattern table.

GBC only: VBK_REG determines whether Tile Numbers or Tile Attributes get set.

- VBK_REG = VBK_TILES Tile Numbers are written
- VBK_REG = VBK_ATTRIBUTES Tile Attributes are written

GBC Tile Attributes are defined as:

- Bit 7 - Priority flag. When this is set, it puts the tile above the sprites with colour 0 being transparent.
  0: Below sprites
  1: Above sprites
  Note: SHOW_BKG needs to be set for these priorities to take place.
- Bit 6 - Vertical flip. Dictates which way up the tile is drawn vertically.
  0: Normal
  1: Flipped Vertically
- Bit 5 - Horizontal flip. Dictates which way up the tile is drawn horizontally.
  0: Normal
  1: Flipped Horizontally
- Bit 4 - Not used
- Bit 3 - Character Bank specification. Dictates from which bank of Background Tile Patterns the tile is taken.
  0: Bank 0
  1: Bank 1
- Bit 2 - See bit 0.
- Bit 1 - See bit 0.
- Bit 0 - Bits 0-2 indicate which of the 7 BKG colour palettes the tile is assigned.

See also
  SHOW_BKG
  set_bkg_data, set_bkg_submap, set_win_tiles, set_tiles

## ◆ set_bkg_based_tiles()

void set_bkg_based_tiles | ( | uint8_t | x,
|  | uint8_t | y,
|  | uint8_t | w,
|  | uint8_t | h,
|  | const uint8_t * | tiles,
|  | uint8_t | base_tile
| ) |  |
| inline

Sets a rectangular region of Background Tile Map. The offset value in base_tile is added to the tile ID for each map entry.

Parameters

  x | X Start position in Background Map tile coordinates. Range 0 - 31
  y | Y Start position in Background Map tile coordinates. Range 0 - 31
  w | Width of area to set in tiles. Range 1 - 32
  h | Height of area to set in tiles. Range 1 - 32
  tiles | Pointer to source tile map data
  base_tile | Offset each tile ID entry of the source map by this value. Range 1 - 255

This is identical to set_bkg_tiles() except that it adds the base_tile parameter for when a tile map's tiles don't start at index zero. (For example, the tiles used by the map range from 100 -> 120 in VRAM instead of 0 -> 20).

See also
  set_bkg_tiles for more details

## ◆ set_bkg_attributes()

void set_bkg_attributes | ( | uint8_t | x,
|  | uint8_t | y,
|  | uint8_t | w,
|  | uint8_t | h,
|  | const uint8_t * | tiles
| ) |  |
| inline

Sets a rectangular region of Background Tile Map Attributes.

Parameters

  x | X Start position in Background Map tile coordinates. Range 0 - 31
  y | Y Start position in Background Map tile coordinates. Range 0 - 31
  w | Width of area to set in tiles. Range 1 - 32
  h | Height of area to set in tiles. Range 1 - 32
  tiles | Pointer to source tile map attribute data

Entries are copied from map at tiles to the Background Tile Map starting at x, y writing across for w tiles and down for h tiles.

Use set_bkg_submap_attributes() instead when:

- Source map is wider than 32 tiles.
- Writing a width that does not match the source map width and more than one row high at a time.

One byte per source tile map entry.

Writes that exceed coordinate 31 on the x or y axis will wrap around to the Left and Top edges.

GBC Tile Attributes are defined as:

- Bit 7 - Priority flag. When this is set, it puts the tile above the sprites with colour 0 being transparent.
  0: Below sprites
  1: Above sprites
  Note: SHOW_BKG needs to be set for these priorities to take place.
- Bit 6 - Vertical flip. Dictates which way up the tile is drawn vertically.
  0: Normal
  1: Flipped Vertically
- Bit 5 - Horizontal flip. Dictates which way up the tile is drawn horizontally.
  0: Normal
  1: Flipped Horizontally
- Bit 4 - Not used
- Bit 3 - Character Bank specification. Dictates from which bank of Background Tile Patterns the tile is taken.
  0: Bank 0
  1: Bank 1
- Bit 2 - See bit 0.
- Bit 1 - See bit 0.
- Bit 0 - Bits 0-2 indicate which of the 7 BKG colour palettes the tile is assigned.

See also
  SHOW_BKG
  set_bkg_data, set_bkg_submap_attributes, set_win_tiles, set_tiles

Note
  On the Game Boy this is only usable in Game Boy Color mode

## ◆ set_bkg_submap()

void set_bkg_submap | ( | uint8_t | x,
|  | uint8_t | y,
|  | uint8_t | w,
|  | uint8_t | h,
|  | const uint8_t * | map,
|  | uint8_t | map_w
| ) |  |
| inline

Sets a rectangular area of the Background Tile Map using a sub-region from a source tile map. Useful for scrolling implementations of maps larger than 32 x 32 tiles.

Parameters

  x | X Start position in both the Source Tile Map and hardware Background Map tile coordinates. Range 0 - 255
  y | Y Start position in both the Source Tile Map and hardware Background Map tile coordinates. Range 0 - 255
  w | Width of area to set in tiles. Range 1 - 255
  h | Height of area to set in tiles. Range 1 - 255
  map | Pointer to source tile map data
  map_w | Width of source tile map in tiles. Range 1 - 255

Entries are copied from map to the Background Tile Map starting at x, y writing across for w tiles and down for h tiles, using map_w as the rowstride for the source tile map.

The x and y parameters are in Source Tile Map tile coordinates. The location tiles will be written to on the hardware Background Map is derived from those, but only uses the lower 5 bits of each axis, for range of 0-31 (they are bit-masked: `x & 0x1F` and `y & 0x1F`). As a result the two coordinate systems are aligned together.

In order to transfer tile map data in a way where the coordinate systems are not aligned, an offset from the Source Tile Map pointer can be passed in: `(map_ptr + x + (y * map_width))`.

For example, if you want the tile id at `1,2` from the source map to show up at `0,0` on the hardware Background Map (instead of at `1,2`) then modify the pointer address that is passed in: `map_ptr + 1 + (2 * map_width)`

Use this instead of set_bkg_tiles when the source map is wider than 32 tiles or when writing a width that does not match the source map width.

One byte per source tile map entry.

Writes that exceed coordinate 31 on the x or y axis will wrap around to the Left and Top edges.

See set_bkg_tiles for setting CGB attribute maps with VBK_REG.

See also
  SHOW_BKG
  set_bkg_data, set_bkg_tiles, set_win_submap, set_tiles

## ◆ set_bkg_based_submap()

void set_bkg_based_submap | ( | uint8_t | x,
|  | uint8_t | y,
|  | uint8_t | w,
|  | uint8_t | h,
|  | const uint8_t * | map,
|  | uint8_t | map_w,
|  | uint8_t | base_tile
| ) |  |
| inline

Sets a rectangular area of the Background Tile Map using a sub-region from a source tile map. The offset value in base_tile is added to the tile ID for each map entry.

Parameters

  x | X Start position in both the Source Tile Map and hardware Background Map tile coordinates. Range 0 - 255
  y | Y Start position in both the Source Tile Map and hardware Background Map tile coordinates. Range 0 - 255
  w | Width of area to set in tiles. Range 1 - 255
  h | Height of area to set in tiles. Range 1 - 255
  map | Pointer to source tile map data
  map_w | Width of source tile map in tiles. Range 1 - 255
  base_tile | Offset each tile ID entry of the source map by this value. Range 1 - 255

This is identical to set_bkg_submap() except that it adds the base_tile parameter for when a tile map's tiles don't start at index zero. (For example, the tiles used by the map range from 100 -> 120 in VRAM instead of 0 -> 20).

See also
  set_bkg_submap for more details

## ◆ set_bkg_submap_attributes()

void set_bkg_submap_attributes | ( | uint8_t | x,
|  | uint8_t | y,
|  | uint8_t | w,
|  | uint8_t | h,
|  | const uint8_t * | map,
|  | uint8_t | map_w
| ) |  |
| inline

Sets a rectangular area of the Background Tile Map Attributes using a sub-region from a source tile attribute map. Useful for scrolling implementations of maps larger than 32 x 32 tiles.

Parameters

  x | X Start position in both the Source Tile Map and hardware Background Map tile coordinates. Range 0 - 255
  y | Y Start position in both the Source Tile Map and hardware Background Map tile coordinates. Range 0 - 255
  w | Width of area to set in tiles. Range 1 - 255
  h | Height of area to set in tiles. Range 1 - 255
  map | Pointer to source tile map attribute data
  map_w | Width of source tile map in tiles. Range 1 - 255

Entries are copied from map to the Background Tile Map starting at x, y writing across for w tiles and down for h tiles, using map_w as the rowstride for the source tile map.

The x and y parameters are in Source Tile Map tile coordinates. The location tiles will be written to on the hardware Background Map is derived from those, but only uses the lower 5 bits of each axis, for range of 0-31 (they are bit-masked: `x & 0x1F` and `y & 0x1F`). As a result the two coordinate systems are aligned together.

In order to transfer tile map data in a way where the coordinate systems are not aligned, an offset from the Source Tile Map pointer can be passed in: `(map_ptr + x + (y * map_width))`.

For example, if you want the tile id at `1,2` from the source map to show up at `0,0` on the hardware Background Map (instead of at `1,2`) then modify the pointer address that is passed in: `map_ptr + 1 + (2 * map_width)`

Use this instead of set_bkg_tiles when the source map is wider than 32 tiles or when writing a width that does not match the source map width.

One byte per source tile map entry.

Writes that exceed coordinate 31 on the x or y axis will wrap around to the Left and Top edges.

See set_bkg_tiles for setting CGB attribute maps with VBK_REG.

See also
  SHOW_BKG
  set_bkg_data, set_bkg_attributes, set_win_submap, set_tiles

Note
  On the Game Boy this is only usable in Game Boy Color mode

## ◆ get_bkg_tiles()

void get_bkg_tiles | ( | uint8_t | x,
|  | uint8_t | y,
|  | uint8_t | w,
|  | uint8_t | h,
|  | uint8_t * | tiles
| ) |  |

Copies a rectangular region of Background Tile Map entries into a buffer.

Parameters

  x | X Start position in Background Map tile coordinates. Range 0 - 31
  y | Y Start position in Background Map tile coordinates. Range 0 - 31
  w | Width of area to copy in tiles. Range 0 - 31
  h | Height of area to copy in tiles. Range 0 - 31
  tiles | Pointer to destination buffer for Tile Map data

Note
  In general avoid reading from VRAM since that memory is not accessible at all times. It is also not supported by GBDK on the NES platform. See coding guidelines for more details.

Entries are copied into tiles from the Background Tile Map starting at x, y reading across for w tiles and down for h tiles.

One byte per tile.

The buffer pointed to by tiles should be at least x x y bytes in size.

See also
  get_win_tiles, get_bkg_tile_xy, get_tiles, get_vram_byte

## ◆ set_bkg_tile_xy()

uint8_t* set_bkg_tile_xy | ( | uint8_t | x,
|  | uint8_t | y,
|  | uint8_t | t
| ) |  |

Set single tile t on background layer at x,y

Parameters

  x | X-coordinate
  y | Y-coordinate
  t | tile index

Returns
  returns the address of tile, so you may use faster set_vram_byte() later

## ◆ set_bkg_attribute_xy()

uint8_t* set_bkg_attribute_xy | ( | uint8_t | x,
|  | uint8_t | y,
|  | uint8_t | a
| ) |  |
| inline

Set single attribute data a on background layer at x,y

Parameters

  x | X-coordinate
  y | Y-coordinate
  a | tile attributes

Returns
  returns the address of tile attribute, so you may use faster set_vram_byte() later

Note
  On the Game Boy this is only usable in Game Boy Color mode

## ◆ get_bkg_tile_xy()

uint8_t get_bkg_tile_xy | ( | uint8_t | x,
|  | uint8_t | y
| ) |  |

Get single tile t on background layer at x,y

Parameters

  x | X-coordinate
  y | Y-coordinate

Returns
  returns tile index

Note
  In general avoid reading from VRAM since that memory is not accessible at all times. It is also not supported by GBDK on the NES platform. See coding guidelines for more details.

## ◆ move_bkg()

void move_bkg | ( | uint8_t | x,
|  | uint8_t | y
| ) |  |
| inline

Moves the Background Layer to the position specified in x and y in pixels.

Parameters

  x | X axis screen coordinate for Left edge of the Background
  y | Y axis screen coordinate for Top edge of the Background

0,0 is the top left corner of the GB screen. The Background Layer wraps around the screen, so when part of it goes off the screen it appears on the opposite side (factoring in the larger size of the Background Layer versus the screen size).

The background layer is always under the Window Layer.

See also
  SHOW_BKG, HIDE_BKG

## ◆ scroll_bkg()

void scroll_bkg | ( | int8_t | x,
|  | int8_t | y
| ) |  |
| inline

Moves the Background relative to it's current position.

Parameters

  x | Number of pixels to move the Background on the X axis Range: -128 - 127
  y | Number of pixels to move the Background on the Y axis Range: -128 - 127

See also
  move_bkg

## ◆ get_win_xy_addr()

uint8_t* get_win_xy_addr | ( | uint8_t | x,
|  | uint8_t | y
| ) |  |

Get address of X,Y tile of window map

## ◆ set_win_data()

void set_win_data | ( | uint8_t | first_tile,
|  | uint8_t | nb_tiles,
|  | const uint8_t * | data
| ) |  |

Sets VRAM Tile Pattern data for the Window / Background

Parameters

  first_tile | Index of the first tile to write
  nb_tiles | Number of tiles to write
  data | Pointer to (2 bpp) source Tile Pattern data.

This is the same as set_bkg_data, since the Window Layer and Background Layer share the same Tile pattern data.

See also
  set_bkg_data
  set_win_tiles, set_bkg_data, set_data
  SHOW_WIN, HIDE_WIN

## ◆ set_win_1bpp_data()

void set_win_1bpp_data | ( | uint8_t | first_tile,
|  | uint8_t | nb_tiles,
|  | const uint8_t * | data
| ) |  |

Sets VRAM Tile Pattern data for the Window / Background using 1bpp source data

Parameters

  first_tile | Index of the first tile to write
  nb_tiles | Number of tiles to write
  data | Pointer to (1bpp) source Tile Pattern data

This is the same as set_bkg_1bpp_data, since the Window Layer and Background Layer share the same Tile pattern data.

For a given bit that represent a pixel:

- 0 will be expanded into the Background color
- 1 will be expanded into the Foreground color

See set_1bpp_colors for details about setting the Foreground and Background colors.

See also
  set_bkg_data, set_win_data, set_1bpp_colors
  set_bkg_1bpp_data, set_sprite_1bpp_data

## ◆ get_win_data()

void get_win_data | ( | uint8_t | first_tile,
|  | uint8_t | nb_tiles,
|  | uint8_t * | data
| ) |  |

Copies from Window / Background VRAM Tile Pattern data into a buffer

Parameters

  first_tile | Index of the first Tile to read from
  nb_tiles | Number of Tiles to read
  data | Pointer to destination buffer for Tile Pattern Data

Note
  In general avoid reading from VRAM since that memory is not accessible at all times. It is also not supported by GBDK on the NES platform. See coding guidelines for more details.

This is the same as get_bkg_data, since the Window Layer and Background Layer share the same Tile pattern data.

See also
  get_bkg_data, get_data

## ◆ set_win_tiles()

void set_win_tiles | ( | uint8_t | x,
|  | uint8_t | y,
|  | uint8_t | w,
|  | uint8_t | h,
|  | const uint8_t * | tiles
| ) |  |

Sets a rectangular region of the Window Tile Map.

Parameters

  x | X Start position in Window Map tile coordinates. Range 0 - 31
  y | Y Start position in Window Map tile coordinates. Range 0 - 31
  w | Width of area to set in tiles. Range 1 - 32
  h | Height of area to set in tiles. Range 1 - 32
  tiles | Pointer to source tile map data

Entries are copied from map at tiles to the Window Tile Map starting at x, y writing across for w tiles and down for h tiles.

Use set_win_submap() instead when:

- Source map is wider than 32 tiles.
- Writing a width that does not match the source map width and more than one row high at a time.

One byte per source tile map entry.

Writes that exceed coordinate 31 on the x or y axis will wrap around to the Left and Top edges.

Note
  Patterns 128-255 overlap with patterns 128-255 of the sprite Tile Pattern table.

GBC only: VBK_REG determines whether Tile Numbers or Tile Attributes get set.

- VBK_REG = VBK_TILES Tile Numbers are written
- VBK_REG = VBK_ATTRIBUTES Tile Attributes are written

For more details about GBC Tile Attributes see set_bkg_tiles.

See also
  SHOW_WIN, HIDE_WIN, set_win_submap, set_bkg_tiles, set_bkg_data, set_tiles

## ◆ set_win_based_tiles()

void set_win_based_tiles | ( | uint8_t | x,
|  | uint8_t | y,
|  | uint8_t | w,
|  | uint8_t | h,
|  | const uint8_t * | tiles,
|  | uint8_t | base_tile
| ) |  |
| inline

Sets a rectangular region of the Window Tile Map. The offset value in base_tile is added to the tile ID for each map entry.

Parameters

  x | X Start position in Window Map tile coordinates. Range 0 - 31
  y | Y Start position in Window Map tile coordinates. Range 0 - 31
  w | Width of area to set in tiles. Range 1 - 32
  h | Height of area to set in tiles. Range 1 - 32
  tiles | Pointer to source tile map data
  base_tile | Offset each tile ID entry of the source map by this value. Range 1 - 255

This is identical to set_win_tiles() except that it adds the base_tile parameter for when a tile map's tiles don't start at index zero. (For example, the tiles used by the map range from 100 -> 120 in VRAM instead of 0 -> 20).

See also
  set_win_tiles for more details

## ◆ set_win_submap()

void set_win_submap | ( | uint8_t | x,
|  | uint8_t | y,
|  | uint8_t | w,
|  | uint8_t | h,
|  | const uint8_t * | map,
|  | uint8_t | map_w
| ) |  |
| inline

Sets a rectangular area of the Window Tile Map using a sub-region from a source tile map.

Parameters

  x | X Start position in both the Source Tile Map and hardware Window Map tile coordinates. Range 0 - 255
  y | Y Start position in both the Source Tile Map and hardware Window Map tile coordinates. Range 0 - 255
  w | Width of area to set in tiles. Range 1 - 255
  h | Height of area to set in tiles. Range 1 - 255
  map | Pointer to source tile map data
  map_w | Width of source tile map in tiles. Range 1 - 255

Entries are copied from map to the Window Tile Map starting at x, y writing across for w tiles and down for h tiles, using map_w as the rowstride for the source tile map.

The x and y parameters are in Source Tile Map tile coordinates. The location tiles will be written to on the hardware Background Map is derived from those, but only uses the lower 5 bits of each axis, for range of 0-31 (they are bit-masked: `x & 0x1F` and `y & 0x1F`). As a result the two coordinate systems are aligned together.

In order to transfer tile map data in a way where the coordinate systems are not aligned, an offset from the Source Tile Map pointer can be passed in: `(map_ptr + x + (y * map_width))`.

For example, if you want the tile id at `1,2` from the source map to show up at `0,0` on the hardware Background Map (instead of at `1,2`) then modify the pointer address that is passed in: `map_ptr + 1 + (2 * map_width)`

Use this instead of set_win_tiles when the source map is wider than 32 tiles or when writing a width that does not match the source map width.

One byte per source tile map entry.

Writes that exceed coordinate 31 on the x or y axis will wrap around to the Left and Top edges.

GBC only: VBK_REG determines whether Tile Numbers or Tile Attributes get set.

- VBK_REG = VBK_TILES Tile Numbers are written
- VBK_REG = VBK_ATTRIBUTES Tile Attributes are written

See set_bkg_tiles for details about CGB attribute maps with VBK_REG.

See also
  SHOW_WIN, HIDE_WIN, set_win_tiles, set_bkg_submap, set_bkg_tiles, set_bkg_data, set_tiles

## ◆ set_win_based_submap()

void set_win_based_submap | ( | uint8_t | x,
|  | uint8_t | y,
|  | uint8_t | w,
|  | uint8_t | h,
|  | const uint8_t * | map,
|  | uint8_t | map_w,
|  | uint8_t | base_tile
| ) |  |
| inline

Sets a rectangular area of the Window Tile Map using a sub-region from a source tile map. The offset value in base_tile is added to the tile ID for each map entry.

Parameters

  x | X Start position in both the Source Tile Map and hardware Window Map tile coordinates. Range 0 - 255
  y | Y Start position in both the Source Tile Map and hardware Window Map tile coordinates. Range 0 - 255
  w | Width of area to set in tiles. Range 1 - 255
  h | Height of area to set in tiles. Range 1 - 255
  map | Pointer to source tile map data
  map_w | Width of source tile map in tiles. Range 1 - 255
  base_tile | Offset each tile ID entry of the source map by this value. Range 1 - 255

This is identical to set_win_submap() except that it adds the base_tile parameter for when a tile map's tiles don't start at index zero. (For example, the tiles used by the map range from 100 -> 120 in VRAM instead of 0 -> 20).

See also
  set_win_submap for more details

## ◆ get_win_tiles()

void get_win_tiles | ( | uint8_t | x,
|  | uint8_t | y,
|  | uint8_t | w,
|  | uint8_t | h,
|  | uint8_t * | tiles
| ) |  |

Copies a rectangular region of Window Tile Map entries into a buffer.

Parameters

  x | X Start position in Window Map tile coordinates. Range 0 - 31
  y | Y Start position in Window Map tile coordinates. Range 0 - 31
  w | Width of area to copy in tiles. Range 0 - 31
  h | Height of area to copy in tiles. Range 0 - 31
  tiles | Pointer to destination buffer for Tile Map data

Note
  In general avoid reading from VRAM since that memory is not accessible at all times. It is also not supported by GBDK on the NES platform. See coding guidelines for more details.

Entries are copied into tiles from the Window Tile Map starting at x, y reading across for w tiles and down for h tiles.

One byte per tile.

The buffer pointed to by tiles should be at least x x y bytes in size.

See also
  get_bkg_tiles, get_bkg_tile_xy, get_tiles, get_vram_byte

## ◆ set_win_tile_xy()

uint8_t* set_win_tile_xy | ( | uint8_t | x,
|  | uint8_t | y,
|  | uint8_t | t
| ) |  |

Set single tile t on window layer at x,y

Parameters

  x | X-coordinate
  y | Y-coordinate
  t | tile index

Returns
  returns the address of tile, so you may use faster set_vram_byte() later

## ◆ get_win_tile_xy()

uint8_t get_win_tile_xy | ( | uint8_t | x,
|  | uint8_t | y
| ) |  |

Get single tile t on window layer at x,y

Parameters

  x | X-coordinate
  y | Y-coordinate

Returns
  returns the tile index

Note
  In general avoid reading from VRAM since that memory is not accessible at all times. It is also not supported by GBDK on the NES platform. See coding guidelines for more details.

## ◆ move_win()

void move_win | ( | uint8_t | x,
|  | uint8_t | y
| ) |  |
| inline

Moves the Window to the x, y position on the screen.

Parameters

  x | X coordinate for Left edge of the Window (actual displayed location will be X - 7)
  y | Y coordinate for Top edge of the Window

7,0 is the top left corner of the screen in Window coordinates. The Window is locked to the bottom right corner.

The Window is always over the Background layer.

See also
  SHOW_WIN, HIDE_WIN

## ◆ scroll_win()

void scroll_win | ( | int8_t | x,
|  | int8_t | y
| ) |  |
| inline

Move the Window relative to its current position.

Parameters

  x | Number of pixels to move the window on the X axis Range: -128 - 127
  y | Number of pixels to move the window on the Y axis Range: -128 - 127

See also
  move_win

## ◆ set_sprite_data()

void set_sprite_data | ( | uint8_t | first_tile,
|  | uint8_t | nb_tiles,
|  | const uint8_t * | data
| ) |  |

Sets VRAM Tile Pattern data for Sprites

Parameters

  first_tile | Index of the first tile to write
  nb_tiles | Number of tiles to write
  data | Pointer to (2 bpp) source Tile Pattern data

Writes nb_tiles tiles to VRAM starting at first_tile, tile data is sourced from data. Each Tile is 16 bytes in size (8x8 pixels, 2 bits-per-pixel).

Note
  Sprite Tiles 128-255 share the same memory region as Background Tiles 128-255.

GBC only: VBK_REG determines which bank of tile patterns are written to.

- VBK_REG = VBK_BANK_0 indicates the first bank
- VBK_REG = VBK_BANK_1 indicates the second

## ◆ set_sprite_1bpp_data()

void set_sprite_1bpp_data | ( | uint8_t | first_tile,
|  | uint8_t | nb_tiles,
|  | const uint8_t * | data
| ) |  |

Sets VRAM Tile Pattern data for Sprites using 1bpp source data

Parameters

  first_tile | Index of the first tile to write
  nb_tiles | Number of tiles to write
  data | Pointer to (1bpp) source Tile Pattern data

Similar to set_sprite_data, except source data is 1 bit-per-pixel which gets expanded into 2 bits-per-pixel.

For a given bit that represent a pixel:

- 0 will be expanded into the Background color
- 1 will be expanded into the Foreground color

See set_1bpp_colors for details about setting the Foreground and Background colors.

See also
  SHOW_SPRITES, HIDE_SPRITES, set_sprite_tile
  set_bkg_1bpp_data, set_win_1bpp_data

## ◆ get_sprite_data()

void get_sprite_data | ( | uint8_t | first_tile,
|  | uint8_t | nb_tiles,
|  | uint8_t * | data
| ) |  |

Copies from Sprite VRAM Tile Pattern data into a buffer

Parameters

  first_tile | Index of the first tile to read from
  nb_tiles | Number of tiles to read
  data | Pointer to destination buffer for Tile Pattern data

Note
  In general avoid reading from VRAM since that memory is not accessible at all times. It is also not supported by GBDK on the NES platform. See coding guidelines for more details.

Copies nb_tiles tiles from VRAM starting at first_tile, tile data is copied into data.

Each Tile is 16 bytes, so the buffer pointed to by data should be at least nb_tiles x 16 bytes in size.

## ◆ SET_SHADOW_OAM_ADDRESS()

void SET_SHADOW_OAM_ADDRESS | ( | void * | address | ) |
| inline

Enable OAM DMA copy each VBlank and set it to transfer any 256-byte aligned array

## ◆ set_sprite_tile()

void set_sprite_tile | ( | uint8_t | nb,
|  | uint8_t | tile
| ) |  |
| inline

Sets sprite number nb__in the OAM to display tile number __tile.

Parameters

  nb | Sprite number, range 0 - 39
  tile | Selects a tile (0 - 255) from memory at 8000h - 8FFFh In CGB Mode this could be either in VRAM Bank 0 or 1, depending on Bit 3 of the OAM Attribute Flag (see set_sprite_prop)

In 8x16 mode:

- The sprite will also display the next tile (tile + 1) directly below (y + 8) the first tile.
- The lower bit of the tile number is ignored: the upper 8x8 tile is (tile & 0xFE), and the lower 8x8 tile is (tile | 0x01).
- See: SPRITES_8x16

## ◆ get_sprite_tile()

uint8_t get_sprite_tile | ( | uint8_t | nb | ) |
| inline

Returns the tile number of sprite number nb in the OAM.

Parameters

  nb | Sprite number, range 0 - 39

See also
  set_sprite_tile for more details

## ◆ set_sprite_prop()

void set_sprite_prop | ( | uint8_t | nb,
|  | uint8_t | prop
| ) |  |
| inline

Sets the OAM Property Flags of sprite number nb to those defined in prop.

Parameters

  nb | Sprite number, range 0 - 39
  prop | Property setting (see bitfield description)

The bits in prop represent:

- Bit 7 - Priority flag. When this is set the sprites appear behind the background and window layer.
  0: infront
  1: behind
- Bit 6 - Vertical flip. Dictates which way up the sprite is drawn vertically.
  0: normal
  1:upside down
- Bit 5 - Horizontal flip. Dictates which way up the sprite is drawn horizontally.
  0: normal
  1:back to front
- Bit 4 - DMG/Non-CGB Mode Only. Assigns either one of the two b/w palettes to the sprite.
  0: OBJ palette 0
  1: OBJ palette 1
- Bit 3 - GBC only. Dictates from which bank of Sprite Tile Patterns the tile is taken.
  0: Bank 0
  1: Bank 1
- Bit 2 - See bit 0.
- Bit 1 - See bit 0.
- Bit 0 - GBC only. Bits 0-2 indicate which of the 7 OBJ colour palettes the sprite is assigned.

It's recommended to use GBDK constants (eg: S_FLIPY) to configure sprite properties as these are crossplatform.

// Load palette data into the first palette
set_sprite_palette(4, 1, exampleSprite_palettes)
// Set the OAM value for the sprite
// These flags tell the sprite to flip both vertically and horizontally.
set_sprite_prop(0, S_FLIPY | S_FLIPX);
S_FLIPY
#define S_FLIPY
Definition: gb.h:96
set_sprite_prop
void set_sprite_prop(uint8_t nb, uint8_t prop)
Definition: gb.h:1945
S_FLIPX
#define S_FLIPX
Definition: gb.h:92
set_sprite_palette
#define set_sprite_palette(first_palette, nb_palettes, rgb_data)
Definition: msx.h:558

See also
  S_PALETTE, S_FLIPX, S_FLIPY, S_PRIORITY

## ◆ get_sprite_prop()

uint8_t get_sprite_prop | ( | uint8_t | nb | ) |
| inline

Returns the OAM Property Flags of sprite number nb.

Parameters

  nb | Sprite number, range 0 - 39

See also
  set_sprite_prop for property bitfield settings

## ◆ move_sprite()

void move_sprite | ( | uint8_t | nb,
|  | uint8_t | x,
|  | uint8_t | y
| ) |  |
| inline

Moves sprite number nb to the x, y position on the screen.

Parameters

  nb | Sprite number, range 0 - 39
  x | X Position. Specifies the sprites horizontal position on the screen (minus 8). An offscreen value (X=0 or X>=168) hides the sprite, but the sprite still affects the priority ordering - a better way to hide a sprite is to set its Y-coordinate offscreen.
  y | Y Position. Specifies the sprites vertical position on the screen (minus 16). An offscreen value (for example, Y=0 or Y>=160) hides the sprite.

Moving the sprite to 0,0 (or similar off-screen location) will hide it.

## ◆ scroll_sprite()

void scroll_sprite | ( | uint8_t | nb,
|  | int8_t | x,
|  | int8_t | y
| ) |  |
| inline

Moves sprite number nb relative to its current position.

Parameters

  nb | Sprite number, range 0 - 39
  x | Number of pixels to move the sprite on the X axis Range: -128 - 127
  y | Number of pixels to move the sprite on the Y axis Range: -128 - 127

See also
  move_sprite for more details about the X and Y position

## ◆ hide_sprite()

void hide_sprite | ( | uint8_t | nb | ) |
| inline

Hides sprite number nb by moving it to zero position by Y.

Parameters

  nb | Sprite number, range 0 - 39

See also
  hide_sprites_range, HIDE_SPRITES

## ◆ set_data()

void set_data | ( | uint8_t * | vram_addr,
|  | const uint8_t * | data,
|  | uint16_t | len
| ) |  |

Copies arbitrary data to an address in VRAM without taking into account the state of LCDC bits 3 or 4.

Parameters

  vram_addr | Pointer to destination VRAM Address
  data | Pointer to source buffer
  len | Number of bytes to copy

Copies len bytes from a buffer at data to VRAM starting at vram_addr.

GBC only: VBK_REG determines which bank of tile patterns are written to.

- VBK_REG = VBK_BANK_0 indicates the first bank
- VBK_REG = VBK_BANK_1 indicates the second

See also
  set_bkg_data, set_win_data, set_bkg_tiles, set_win_tiles, set_tile_data, set_tiles

## ◆ get_data()

void get_data | ( | uint8_t * | data,
|  | uint8_t * | vram_addr,
|  | uint16_t | len
| ) |  |

Copies arbitrary data from an address in VRAM into a buffer without taking into account the state of LCDC bits 3 or 4.

Parameters

  vram_addr | Pointer to source VRAM Address
  data | Pointer to destination buffer
  len | Number of bytes to copy

Note
  In general avoid reading from VRAM since that memory is not accessible at all times. It is also not supported by GBDK on the NES platform. See coding guidelines for more details.

Copies len bytes from VRAM starting at vram_addr into a buffer at data.

GBC only: VBK_REG determines which bank of tile patterns are written to.

- VBK_REG = VBK_BANK_0 indicates the first bank
- VBK_REG = VBK_BANK_1 indicates the second

See also
  get_bkg_data, get_win_data, get_bkg_tiles, get_win_tiles, get_tiles

## ◆ vmemcpy()

void vmemcpy | ( | uint8_t * | dest,
|  | uint8_t * | sour,
|  | uint16_t | len
| ) |  |

Copies arbitrary data from an address in VRAM into a buffer

Parameters

  dest | Pointer to destination buffer (may be in VRAM)
  sour | Pointer to source buffer (may be in VRAM)
  len | Number of bytes to copy

Copies len bytes from or to VRAM starting at sour into a buffer or to VRAM at dest.

GBC only: VBK_REG determines which bank of tile patterns are written to.

- VBK_REG = VBK_BANK_0 indicates the first bank
- VBK_REG = VBK_BANK_1 indicates the second

## ◆ set_tiles()

void set_tiles | ( | uint8_t | x,
|  | uint8_t | y,
|  | uint8_t | w,
|  | uint8_t | h,
|  | uint8_t * | vram_addr,
|  | const uint8_t * | tiles
| ) |  |

Sets a rectangular region of Tile Map entries at a given VRAM Address without taking into account the state of LCDC bit 3.

Parameters

  x | X Start position in Map tile coordinates. Range 0 - 31
  y | Y Start position in Map tile coordinates. Range 0 - 31
  w | Width of area to set in tiles. Range 1 - 32
  h | Height of area to set in tiles. Range 1 - 32
  vram_addr | Pointer to destination VRAM Address
  tiles | Pointer to source Tile Map data

Entries are copied from tiles to Tile Map at address vram_addr starting at x, y writing across for w tiles and down for h tiles.

One byte per source tile map entry.

There are two 32x32 Tile Maps in VRAM at addresses 9800h-9BFFh and 9C00h-9FFFh.

GBC only: VBK_REG determines whether Tile Numbers or Tile Attributes get set.

- VBK_REG = VBK_TILES Tile Numbers are written
- VBK_REG = VBK_ATTRIBUTES Tile Attributes are written

See also
  set_bkg_tiles, set_win_tiles

## ◆ set_tile_data()

void set_tile_data | ( | uint8_t | first_tile,
|  | uint8_t | nb_tiles,
|  | const uint8_t * | data,
|  | uint8_t | base
| ) |  |

Sets VRAM Tile Pattern data starting from given base address without taking into account the state of LCDC bit 4.

Parameters

  first_tile | Index of the first tile to write
  nb_tiles | Number of tiles to write
  data | Pointer to (2 bpp) source Tile Pattern data.
  base | MSB of the destination address in VRAM (usually 0x80 or 0x90 which gives 0x8000 or 0x9000)

See also
  set_bkg_data, set_win_data, set_data

## ◆ get_tiles()

void get_tiles | ( | uint8_t | x,
|  | uint8_t | y,
|  | uint8_t | w,
|  | uint8_t | h,
|  | uint8_t * | vram_addr,
|  | uint8_t * | tiles
| ) |  |

Copies a rectangular region of Tile Map entries from a given VRAM Address into a buffer without taking into account the state of LCDC bit 3.

Parameters

  x | X Start position in Background Map tile coordinates. Range 0 - 31
  y | Y Start position in Background Map tile coordinates. Range 0 - 31
  w | Width of area to copy in tiles. Range 0 - 31
  h | Height of area to copy in tiles. Range 0 - 31
  vram_addr | Pointer to source VRAM Address
  tiles | Pointer to destination buffer for Tile Map data

Note
  In general avoid reading from VRAM since that memory is not accessible at all times. It is also not supported by GBDK on the NES platform. See coding guidelines for more details.

Entries are copied into tiles from the Background Tile Map starting at x, y reading across for w tiles and down for h tiles.

One byte per tile.

There are two 32x32 Tile Maps in VRAM at addresses 9800h - 9BFFh and 9C00h - 9FFFh.

The buffer pointed to by tiles should be at least x x y bytes in size.

See also
  get_bkg_tiles, get_win_tiles

## ◆ set_native_tile_data()

void set_native_tile_data | ( | uint16_t | first_tile,
|  | uint8_t | nb_tiles,
|  | const uint8_t * | data
| ) |  |
| inline

Sets VRAM Tile Pattern data in the native format

Parameters

  first_tile | Index of the first tile to write (0 - 511)
  nb_tiles | Number of tiles to write
  data | Pointer to source Tile Pattern data.

When `first_tile` is larger than 256 on the GB/AP, it will write to sprite data instead of background data.

The bit depth of the source Tile Pattern data depends on which console is being used:

- Game Boy/Analogue Pocket: loads 2bpp tiles data
- SMS/GG: loads 4bpp tile data

## ◆ set_bkg_native_data()

void set_bkg_native_data | ( | uint8_t | first_tile,
|  | uint8_t | nb_tiles,
|  | const uint8_t * | data
| ) |  |
| inline

Sets VRAM Tile Pattern data for the Background / Window in the native format

Parameters

  first_tile | Index of the first tile to write
  nb_tiles | Number of tiles to write
  data | Pointer to source tile data

Writes nb_tiles tiles to VRAM starting at first_tile, tile data is sourced from data.

GBC only: VBK_REG determines which bank of tile patterns are written to.

- VBK_REG = VBK_BANK_0 indicates the first bank
- VBK_REG = VBK_BANK_1 indicates the second

See also
  set_win_data, set_tile_data

## ◆ set_sprite_native_data()

void set_sprite_native_data | ( | uint8_t | first_tile,
|  | uint8_t | nb_tiles,
|  | const uint8_t * | data
| ) |  |
| inline

Sets VRAM Tile Pattern data for Sprites in the native format

Parameters

  first_tile | Index of the first tile to write
  nb_tiles | Number of tiles to write
  data | Pointer to source tile data

Writes nb_tiles tiles to VRAM starting at first_tile, tile data is sourced from data.

GBC only: VBK_REG determines which bank of tile patterns are written to.

- VBK_REG = VBK_BANK_0 indicates the first bank
- VBK_REG = VBK_BANK_1 indicates the second

## ◆ init_win()

void init_win | ( | uint8_t | c | ) |

Initializes the entire Window Tile Map with Tile Number c

Parameters

  c | Tile number to fill with

Note
  This function avoids writes during modes 2 & 3

## ◆ init_bkg()

void init_bkg | ( | uint8_t | c | ) |

Initializes the entire Background Tile Map with Tile Number c

Parameters

  c | Tile number to fill with

Note
  This function avoids writes during modes 2 & 3

## ◆ vmemset()

void vmemset | ( | void * | s,
|  | uint8_t | c,
|  | size_t | n
| ) |  |

Fills the VRAM memory region s of size n with Tile Number c

Parameters

  s | Start address in VRAM
  c | Tile number to fill with
  n | Size of memory region (in bytes) to fill

Note
  This function avoids writes during modes 2 & 3

## ◆ fill_bkg_rect()

void fill_bkg_rect | ( | uint8_t | x,
|  | uint8_t | y,
|  | uint8_t | w,
|  | uint8_t | h,
|  | uint8_t | tile
| ) |  |

Fills a rectangular region of Tile Map entries for the Background layer with tile.

Parameters

  x | X Start position in Background Map tile coordinates. Range 0 - 31
  y | Y Start position in Background Map tile coordinates. Range 0 - 31
  w | Width of area to set in tiles. Range 0 - 31
  h | Height of area to set in tiles. Range 0 - 31
  tile | Fill value

## ◆ fill_win_rect()

void fill_win_rect | ( | uint8_t | x,
|  | uint8_t | y,
|  | uint8_t | w,
|  | uint8_t | h,
|  | uint8_t | tile
| ) |  |

Fills a rectangular region of Tile Map entries for the Window layer with tile.

Parameters

  x | X Start position in Window Map tile coordinates. Range 0 - 31
  y | Y Start position in Window Map tile coordinates. Range 0 - 31
  w | Width of area to set in tiles. Range 0 - 31
  h | Height of area to set in tiles. Range 0 - 31
  tile | Fill value

## Variable Documentation

## ◆ c

void c

## ◆ d

void d

## ◆ e

void e

## ◆ h

void h

## ◆ l

void l

Initial value:
{
__asm__("ei")

## ◆ _cpu

uint8_t _cpu
| extern

GB CPU type

See also
  DMG_TYPE, MGB_TYPE, CGB_TYPE, cpu_fast(), cpu_slow(), _is_GBA

## ◆ _is_GBA

uint8_t _is_GBA
| extern

GBA detection

See also
  GBA_DETECTED, GBA_NOT_DETECTED, _cpu

## ◆ sys_time

volatile uint16_t sys_time
| extern

Global Time Counter in VBL periods (60Hz)

Increments once per Frame

Will wrap around every ~18 minutes (unsigned 16 bits = 65535 / 60 / 60 = 18.2)

## ◆ _vbl_done

__REG _vbl_done

Flag indicating the VBlank ISR has run

Flag gets cleared at the start of vsync() / wait_vbl_done() and set in the default VBlank ISR handler.

## ◆ _io_status

volatile uint8_t _io_status
| extern

Serial Link: Current IO Status. An OR of IO_*

## ◆ _io_in

volatile uint8_t _io_in
| extern

Serial Link: Byte just read after calling receive_byte()

## ◆ _io_out

volatile uint8_t _io_out
| extern

Serial Link: Write byte to send here before calling send_byte()

## ◆ _current_bank

__REG _current_bank

Tracks current active ROM bank

In most cases the CURRENT_BANK macro for this variable is recommended for use instead of the variable itself.

The active bank number is not tracked by _current_bank when SWITCH_ROM_MBC5_8M is used.

This variable is updated automatically when you call SWITCH_ROM_MBC1 or SWITCH_ROM_MBC5, SWITCH_ROM(), or call a BANKED function.

See also
  SWITCH_ROM_MBC1(), SWITCH_ROM_MBC5(), SWITCH_ROM()

## ◆ b

void b

## ◆ _current_1bpp_colors

uint16_t _current_1bpp_colors
| extern

## ◆ _map_tile_offset

uint8_t _map_tile_offset
| extern

## ◆ _submap_tile_offset

uint8_t _submap_tile_offset
| extern

## ◆ shadow_OAM

volatile struct OAM_item_t shadow_OAM[]
| extern

Shadow OAM array in WRAM, that is DMA-transferred into the real OAM each VBlank

## ◆ _shadow_OAM_base

__REG _shadow_OAM_base

MSB of shadow_OAM address is used by OAM DMA copying routine