GBDK 2020 Docs  4.2.0
API Documentation for GBDK 2020
nes.h File Reference
#include <types.h>
#include <stdint.h>
#include <gbdk/version.h>
#include <nes/hardware.h>
#include <nes/rgb_to_nes_macro.h>

Go to the source code of this file.

Data Structures

struct  joypads_t
 
struct  OAM_item_t
 

Macros

#define NINTENDO_NES
 
#define RGB(r, g, b)   RGB_TO_NES(((r) | ((g) << 2) | ((b) << 4)))
 
#define RGB8(r, g, b)   RGB_TO_NES((((r) >> 6) | (((g) >> 6) << 2) | (((b) >> 6) << 4)))
 
#define RGBHTML(RGB24bit)   RGB_TO_NES((((RGB24bit) >> 22) | ((((RGB24bit) & 0xFFFF) >> 14) << 2) | ((((RGB24bit) & 0xFF) >> 6) << 4)))
 
#define RGB_RED   0x16
 
#define RGB_DARKRED   0x06
 
#define RGB_GREEN   0x2A
 
#define RGB_DARKGREEN   0x1A
 
#define RGB_BLUE   0x12
 
#define RGB_DARKBLUE   0x02
 
#define RGB_YELLOW   0x28
 
#define RGB_DARKYELLOW   0x18
 
#define RGB_CYAN   0x2C
 
#define RGB_AQUA   0x1C
 
#define RGB_PINK   0x24
 
#define RGB_PURPLE   0x14
 
#define RGB_BLACK   0x0F
 
#define RGB_DARKGRAY   0x00
 
#define RGB_LIGHTGRAY   0x10
 
#define RGB_WHITE   0x30
 
#define J_UP   0x10U
 
#define J_DOWN   0x20U
 
#define J_LEFT   0x40U
 
#define J_RIGHT   0x80U
 
#define J_A   0x01U
 
#define J_B   0x02U
 
#define J_SELECT   0x04U
 
#define J_START   0x08U
 
#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_PALETTE   0x10U
 
#define S_FLIPX   0x40U
 
#define S_FLIPY   0x80U
 
#define S_PRIORITY   0x20U
 
#define S_PAL(n)   n
 
#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 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_DUMMY(b)
 
#define SWITCH_ROM_UNROM(b)   _switch_prg0(b)
 
#define SWITCH_ROM   SWITCH_ROM_UNROM
 
#define SWITCH_RAM(b)   0
 
#define ENABLE_RAM
 
#define DISABLE_RAM
 
#define DISPLAY_ON    display_on();
 
#define DISPLAY_OFF    display_off();
 
#define HIDE_LEFT_COLUMN    shadow_PPUMASK &= ~(PPUMASK_SHOW_BG_LC | PPUMASK_SHOW_SPR_LC); \
 
#define SHOW_LEFT_COLUMN    shadow_PPUMASK |= (PPUMASK_SHOW_BG_LC | PPUMASK_SHOW_SPR_LC);
 
#define SHOW_BKG    shadow_PPUMASK |= PPUMASK_SHOW_BG;
 
#define HIDE_BKG    shadow_PPUMASK &= ~PPUMASK_SHOW_BG;
 
#define SHOW_SPRITES    shadow_PPUMASK |= PPUMASK_SHOW_SPR;
 
#define HIDE_SPRITES    shadow_PPUMASK &= ~PPUMASK_SHOW_SPR;
 
#define SPRITES_8x16    shadow_PPUCTRL |= PPUCTRL_SPR_8X16;
 
#define SPRITES_8x8    shadow_PPUCTRL &= ~PPUCTRL_SPR_8X16;
 
#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   64
 
#define HARDWARE_SPRITE_CAN_FLIP_X   1
 
#define HARDWARE_SPRITE_CAN_FLIP_Y   1
 
#define fill_rect   fill_bkg_rect
 

Typedefs

typedef uint8_t palette_color_t
 
typedef void(* int_handler) (void) NONBANKED
 
typedef struct OAM_item_t OAM_item_t
 

Functions

void set_bkg_palette (uint8_t first_palette, uint8_t nb_palettes, const palette_color_t *rgb_data) OLDCALL
 
void set_sprite_palette (uint8_t first_palette, uint8_t nb_palettes, const palette_color_t *rgb_data) OLDCALL
 
void set_bkg_palette_entry (uint8_t palette, uint8_t entry, palette_color_t rgb_data) OLDCALL
 
void set_sprite_palette_entry (uint8_t palette, uint8_t entry, palette_color_t rgb_data) OLDCALL
 
void remove_VBL (int_handler h)
 
void remove_LCD (int_handler h)
 
void add_VBL (int_handler h)
 
void add_LCD (int_handler h)
 
void mode (uint8_t m) OLDCALL
 
uint8_t get_mode (void) OLDCALL
 
void delay (uint16_t d) OLDCALL
 
uint8_t joypad (void) OLDCALL
 
uint8_t waitpad (uint8_t mask) OLDCALL
 
void waitpadup (void)
 
uint8_t joypad_init (uint8_t npads, joypads_t *joypads) OLDCALL
 
void joypad_ex (joypads_t *joypads) OLDCALL
 
void enable_interrupts (void)
 
void disable_interrupts (void)
 
void vsync (void)
 
void wait_vbl_done (void)
 
void display_on (void)
 
void display_off (void)
 
void refresh_OAM (void)
 
void set_vram_byte (uint8_t *addr, uint8_t v) OLDCALL
 
uint8_tget_bkg_xy_addr (uint8_t x, uint8_t y) OLDCALL
 
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
 
void set_bkg_1bpp_data (uint8_t first_tile, uint8_t nb_tiles, const uint8_t *data) OLDCALL
 
void set_bkg_tiles (uint8_t x, uint8_t y, uint8_t w, uint8_t h, const uint8_t *tiles) OLDCALL
 
void set_bkg_attributes_nes16x16 (uint8_t x, uint8_t y, uint8_t w, uint8_t h, const uint8_t *attributes) OLDCALL
 
void set_bkg_attributes (uint8_t x, uint8_t y, uint8_t w, uint8_t h, const uint8_t *attributes)
 
void set_bkg_submap_attributes_nes16x16 (uint8_t x, uint8_t y, uint8_t w, uint8_t h, const uint8_t *map, uint8_t map_w) OLDCALL
 
void set_bkg_submap_attributes (uint8_t x, uint8_t y, uint8_t w, uint8_t h, const uint8_t *attributes, uint8_t map_w)
 
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_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 get_bkg_tiles (uint8_t x, uint8_t y, uint8_t w, uint8_t h, uint8_t *tiles) OLDCALL
 
uint8_tset_bkg_tile_xy (uint8_t x, uint8_t y, uint8_t t) OLDCALL
 
void set_bkg_attribute_xy_nes16x16 (uint8_t x, uint8_t y, uint8_t a)
 
void 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
 
void move_bkg (uint8_t x, uint8_t y)
 
void scroll_bkg (int8_t x, int8_t y)
 
void set_sprite_data (uint8_t first_tile, uint8_t nb_tiles, const uint8_t *data) OLDCALL
 
void set_sprite_1bpp_data (uint8_t first_tile, uint8_t nb_tiles, const uint8_t *data) OLDCALL
 
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) OLDCALL
 
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 (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 set_native_tile_data (uint16_t first_tile, uint8_t nb_tiles, const uint8_t *data)
 
void init_bkg (uint8_t c) OLDCALL
 
void vmemset (void *s, uint8_t c, size_t n) OLDCALL
 
void fill_bkg_rect (uint8_t x, uint8_t y, uint8_t w, uint8_t h, uint8_t tile) OLDCALL
 
void flush_shadow_attributes (void) OLDCALL
 
uint8_t _switch_prg0 (uint8_t bank) OLDCALL
 

Variables

volatile uint16_t sys_time
 
volatile uint8_t _current_bank
 
uint16_t _current_1bpp_colors
 
uint8_t _map_tile_offset
 
uint8_t _submap_tile_offset
 
volatile struct OAM_item_t shadow_OAM []
 
uint8_t _shadow_OAM_base
 

Detailed Description

NES specific functions.

Macro Definition Documentation

◆ NINTENDO_NES

#define NINTENDO_NES

◆ RGB

#define RGB (   r,
  g,
  b 
)    RGB_TO_NES(((r) | ((g) << 2) | ((b) << 4)))

◆ RGB8

#define RGB8 (   r,
  g,
  b 
)    RGB_TO_NES((((r) >> 6) | (((g) >> 6) << 2) | (((b) >> 6) << 4)))

◆ RGBHTML

#define RGBHTML (   RGB24bit)    RGB_TO_NES((((RGB24bit) >> 22) | ((((RGB24bit) & 0xFFFF) >> 14) << 2) | ((((RGB24bit) & 0xFF) >> 6) << 4)))

◆ RGB_RED

#define RGB_RED   0x16

Common colors based on the EGA default palette.

Manually entered from https://www.nesdev.org/wiki/PPU_palettes#RGBI

◆ RGB_DARKRED

#define RGB_DARKRED   0x06

◆ RGB_GREEN

#define RGB_GREEN   0x2A

◆ RGB_DARKGREEN

#define RGB_DARKGREEN   0x1A

◆ RGB_BLUE

#define RGB_BLUE   0x12

◆ RGB_DARKBLUE

#define RGB_DARKBLUE   0x02

◆ RGB_YELLOW

#define RGB_YELLOW   0x28

◆ RGB_DARKYELLOW

#define RGB_DARKYELLOW   0x18

◆ RGB_CYAN

#define RGB_CYAN   0x2C

◆ RGB_AQUA

#define RGB_AQUA   0x1C

◆ RGB_PINK

#define RGB_PINK   0x24

◆ RGB_PURPLE

#define RGB_PURPLE   0x14

◆ RGB_BLACK

#define RGB_BLACK   0x0F

◆ RGB_DARKGRAY

#define RGB_DARKGRAY   0x00

◆ RGB_LIGHTGRAY

#define RGB_LIGHTGRAY   0x10

◆ RGB_WHITE

#define RGB_WHITE   0x30

◆ J_UP

#define J_UP   0x10U

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   0x20U

◆ J_LEFT

#define J_LEFT   0x40U

◆ J_RIGHT

#define J_RIGHT   0x80U

◆ J_A

#define J_A   0x01U

◆ J_B

#define J_B   0x02U

◆ J_SELECT

#define J_SELECT   0x04U

◆ J_START

#define J_START   0x08U

◆ 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_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   0x40U

If set the sprite will be flipped horizontally.

See also
set_sprite_prop()

◆ S_FLIPY

#define S_FLIPY   0x80U

If set the sprite will be flipped vertically.

See also
set_sprite_prop()

◆ S_PRIORITY

#define S_PRIORITY   0x20U

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.

◆ 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
C0Color for Index 0
C1Color for Index 1
C2Color for Index 2
C3Color for Index 3

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

Example:

#define DMG_WHITE
Definition: gb.h:131
#define DMG_DARK_GRAY
Definition: gb.h:129
#define DMG_LITE_GRAY
Definition: gb.h:130
#define DMG_PALETTE(C0, C1, C2, C3)
Definition: gb.h:151
#define DMG_BLACK
Definition: gb.h:128
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.

◆ CURRENT_BANK

#define CURRENT_BANK   _current_bank

◆ BANK

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

Obtains the bank number of VARNAME

Parameters
VARNAMEName 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
VARNAMEVariable 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
VARNAMEName 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_DUMMY

#define SWITCH_ROM_DUMMY (   b)

Dummy macro for no-bank-switching WIP prototype

Parameters
bROM bank to switch to

◆ SWITCH_ROM_UNROM

#define SWITCH_ROM_UNROM (   b)    _switch_prg0(b)

Macro for simple UNROM-like switching (write bank# to single 8-bit register)

Parameters
bROM bank to switch to

◆ SWITCH_ROM

#define SWITCH_ROM   SWITCH_ROM_UNROM

Makes default mapper switch the active ROM bank

Parameters
bROM bank to switch to (max 255)
See also
SWITCH_ROM_UNROM

◆ SWITCH_RAM

#define SWITCH_RAM (   b)    0

No-op at the moment. Placeholder for future mappers / test compatibility.

Parameters
bSRAM bank to switch to

◆ ENABLE_RAM

#define ENABLE_RAM

No-op at the moment. Placeholder for future mappers / test compatibility.

◆ DISABLE_RAM

#define DISABLE_RAM

No-op at the moment. Placeholder for future mappers / test compatibility.

◆ DISPLAY_ON

#define DISPLAY_ON    display_on();

Turns the display back on.

See also
display_off, DISPLAY_OFF

◆ DISPLAY_OFF

#define DISPLAY_OFF    display_off();

Turns the display off immediately.

See also
display_off, DISPLAY_ON

◆ HIDE_LEFT_COLUMN

#define HIDE_LEFT_COLUMN    shadow_PPUMASK &= ~(PPUMASK_SHOW_BG_LC | PPUMASK_SHOW_SPR_LC); \

Blanks leftmost column, so it is not garbaged when you use horizontal scroll

See also
SHOW_LEFT_COLUMN

◆ SHOW_LEFT_COLUMN

#define SHOW_LEFT_COLUMN    shadow_PPUMASK |= (PPUMASK_SHOW_BG_LC | PPUMASK_SHOW_SPR_LC);

Shows leftmost column

See also
HIDE_LEFT_COLUMN

◆ SHOW_BKG

#define SHOW_BKG    shadow_PPUMASK |= PPUMASK_SHOW_BG;

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

◆ HIDE_BKG

#define HIDE_BKG    shadow_PPUMASK &= ~PPUMASK_SHOW_BG;

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

◆ SHOW_SPRITES

#define SHOW_SPRITES    shadow_PPUMASK |= PPUMASK_SHOW_SPR;

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

◆ HIDE_SPRITES

#define HIDE_SPRITES    shadow_PPUMASK &= ~PPUMASK_SHOW_SPR;

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

◆ SPRITES_8x16

#define SPRITES_8x16    shadow_PPUCTRL |= PPUCTRL_SPR_8X16;

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    shadow_PPUCTRL &= ~PPUCTRL_SPR_8X16;

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   64

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

◆ palette_color_t

◆ 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
xX Coordinate of the sprite on screen
yY Coordinate of the sprite on screen - 1
tileSprite tile number (see set_sprite_tile)
propOAM Property Flags (see set_sprite_prop)

Function Documentation

◆ set_bkg_palette()

void set_bkg_palette ( uint8_t  first_palette,
uint8_t  nb_palettes,
const palette_color_t rgb_data 
)

◆ set_sprite_palette()

void set_sprite_palette ( uint8_t  first_palette,
uint8_t  nb_palettes,
const palette_color_t rgb_data 
)

◆ set_bkg_palette_entry()

void set_bkg_palette_entry ( uint8_t  palette,
uint8_t  entry,
palette_color_t  rgb_data 
)

◆ set_sprite_palette_entry()

void set_sprite_palette_entry ( uint8_t  palette,
uint8_t  entry,
palette_color_t  rgb_data 
)

◆ 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()

◆ add_VBL()

void add_VBL ( int_handler  h)

Adds a Vertical Blanking interrupt handler.

Parameters
hThe handler to be called whenever a V-blank interrupt occurs.

Only a single handler is currently supported for NES.

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.
On the current NES implementation, this handler is actually faked, and called before vblank occurs, by vsync(). Writes to PPU registers should be done to the shadow_ versions, so they are updated by the default VBL handler only when vblank actually occurs.
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 scanline matches the _lcd_scanline variables.

Only a single handler is currently supported for NES.

The use-case is to indicate to the user when the video hardware is about to redraw a given LCD line. This can be useful for dynamically controlling the scrolling registers to perform special video effects.

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
On the current NES implementation, this handler is actually faked, and called by the default VBL handler after a manual delay loop. Only one such faked "interrupt" is possible per frame. This means the CPU cycles wasted in the delay loop increase with higher values of _lcd_scanline. In practice, it makes this functionality mostly suited for a top status bar.
See also
add_VBL, nowait_int_handler, ISR_VECTOR()

Adds a LCD interrupt handler.

◆ 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

◆ 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. 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

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

Reads and returns the current state of the joypad.

◆ waitpad()

uint8_t waitpad ( uint8_t  mask)

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

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

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

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

Parameters
maskBitmask 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

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

◆ waitpadup()

void waitpadup ( void  )

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

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.

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

Parameters
npadsnumber of joypads requested (1, 2 or 4)
joypadspointer 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

See also
joypad_init(), joypads_t

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

Parameters
joypadspointer to joypads_t structure to be filled with joypad statuses, must be previously initialized with joypad_init()
See also
joypad_init(), joypads_t

Polls all avaliable joypads

Parameters
joypadspointer 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

◆ vsync()

void vsync ( void  )

Waits for the vertical blank interrupt.

This is often used in main loops to idle the CPU 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.

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.

HALTs the CPU and waits for the vertical blank interrupt.

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_on()

void display_on ( void  )

Turns the display on.

See also
DISPLAY_ON

◆ display_off()

void display_off ( void  )
inline

Turns the display off.

Waits until the VBL interrupt before turning the display off.

See also
DISPLAY_ON

Turns the display off.

See also
DISPLAY_ON

◆ refresh_OAM()

void refresh_OAM ( void  )

Copies data from shadow OAM to OAM

◆ set_vram_byte()

void set_vram_byte ( uint8_t addr,
uint8_t  v 
)

Set byte in vram at given memory location

Parameters
addraddress to write to
vvalue

◆ 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 
)

◆ set_1bpp_colors()

void set_1bpp_colors ( uint8_t  fgcolor,
uint8_t  bgcolor 
)
inline

◆ 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

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.

See also
set_tile_data

Sets VRAM Tile Pattern data for the Background / Window

Parameters
first_tileIndex of the first tile to write
nb_tilesNumber of tiles to write
dataPointer 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.

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 using 1bpp source 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 color 0
  • 1 will be expanded into color 1, 2 or 3 depending on color argument
See also
SHOW_BKG, HIDE_BKG, set_bkg_tiles

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

Parameters
first_tileIndex of the first Tile to write
nb_tilesNumber of Tiles to write
dataPointer 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

◆ 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.

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.

See also
SHOW_BKG
set_bkg_data, set_bkg_submap, set_win_tiles, set_tiles

Sets a rectangular region of Background Tile Map.

Parameters
xX Start position in Background Map tile coordinates. Range 0 - 31
yY Start position in Background Map tile coordinates. Range 0 - 31
wWidth of area to set in tiles. Range 1 - 32
hHeight of area to set in tiles. Range 1 - 32
tilesPointer 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.

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_attributes_nes16x16()

void set_bkg_attributes_nes16x16 ( uint8_t  x,
uint8_t  y,
uint8_t  w,
uint8_t  h,
const uint8_t attributes 
)

Sets a rectangular region of Background Tile Map Attributes.

Parameters
xX Start position in Background Map tile coordinates. Range 0 - 15
yY Start position in Background Map tile coordinates. Range 0 - 14
wWidth of area to set in tiles. Range 1 - 16
hHeight of area to set in tiles. Range 1 - 15
attributesPointer 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.

NES 16x16 Tile Attributes are tightly packed into 4 attributes per byte, with each 16x16 area of a 32x32 pixel block using the bits as follows: D1-D0: Top-left 16x16 pixels D3-D2: Top-right 16x16 pixels D5-D4: Bottom-left 16x16 pixels D7-D6: Bottom-right 16x16 pixels

https://www.nesdev.org/wiki/PPU_attribute_tables

See also
SHOW_BKG
set_bkg_data, set_bkg_submap_attributes, set_win_tiles, set_tiles

◆ set_bkg_attributes()

void set_bkg_attributes ( uint8_t  x,
uint8_t  y,
uint8_t  w,
uint8_t  h,
const uint8_t attributes 
)
inline

Sets a rectangular region of Background Tile Map Attributes.

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 attribute entry.

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

Please note that this is just a wrapper function for set_bkg_attributes_nes16x16() and divides the coordinates and dimensions by 2 to achieve this. It is intended to make code more portable by using the same coordinate system that systems with the much more common 8x8 attribute resolution would use.

See also
SHOW_BKG
set_bkg_data, set_bkg_submap_attributes, set_win_tiles, set_tiles

◆ set_bkg_submap_attributes_nes16x16()

void set_bkg_submap_attributes_nes16x16 ( uint8_t  x,
uint8_t  y,
uint8_t  w,
uint8_t  h,
const uint8_t map,
uint8_t  map_w 
)

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 30 tiles / 16x15 attributes.

Parameters
xX Start position in both the Source Attribute Map and hardware Background Map attribute coordinates. Range 0 - 255
yY Start position in both the Source Attribute Map and hardware Background Map attribute coordinates. Range 0 - 255
wWidth of area to set in Attributes. Range 1 - 127
hHeight of area to set in Attributes. Range 1 - 127
mapPointer to source tile map data
map_wWidth of source tile map in tiles. Range 1 - 127

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

The x and y parameters are in Source Attribute Map Attribute 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 0-15 (they are bit-masked: x & 0xF and y & 0xF). 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 Attribute 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 attribute map entry.

Writes that exceed coordinate 15/14 on the x / 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_submap_attributes()

void set_bkg_submap_attributes ( uint8_t  x,
uint8_t  y,
uint8_t  w,
uint8_t  h,
const uint8_t attributes,
uint8_t  map_w 
)
inline

Sets a rectangular area of the Background Tile Map attributes using a sub-region from a source tile map. Useful for scrolling implementations of maps larger than 32 x 30 tiles.

Please note that this is just a wrapper function for set_bkg_submap_attributes_nes16x16() and divides the coordinates and dimensions by 2 to achieve this. It is intended to make code more portable by using the same coordinate system that systems with the much more common 8x8 attribute resolution would use.

See also
SHOW_BKG
set_bkg_data, set_bkg_tiles, set_win_submap, 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
xX Start position in Background Map tile coordinates. Range 0 - 31
yY Start position in Background Map tile coordinates. Range 0 - 31
wWidth of area to set in tiles. Range 1 - 32
hHeight of area to set in tiles. Range 1 - 32
tilesPointer to source tile map data
base_tileOffset 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_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.

@ param x X Start position in Background Map tile coordinates. Range 0 - 31 @ param y Y Start position in Background Map tile coordinates. Range 0 - 31 @ param w Width of area to set in tiles. Range 1 - 255 @ param h Height of area to set in tiles. Range 1 - 255 @ param map Pointer to source tile map data @ param 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.

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

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
xX Start position in both the Source Tile Map and hardware Background Map tile coordinates. Range 0 - 255
yY Start position in both the Source Tile Map and hardware Background Map tile coordinates. Range 0 - 255
wWidth of area to set in tiles. Range 1 - 255
hHeight of area to set in tiles. Range 1 - 255
mapPointer to source tile map data
map_wWidth 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
xX Start position in Background Map tile coordinates. Range 0 - 31
yY Start position in Background Map tile coordinates. Range 0 - 31
wWidth of area to set in tiles. Range 1 - 255
hHeight of area to set in tiles. Range 1 - 255
mapPointer to source tile map data
map_wWidth of source tile map in tiles. Range 1 - 255
base_tileOffset 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

◆ 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.

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_bkg_tile_xy, get_tiles

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

Parameters
xX Start position in Background Map tile coordinates. Range 0 - 31
yY Start position in Background Map tile coordinates. Range 0 - 31
wWidth of area to copy in tiles. Range 0 - 31
hHeight of area to copy in tiles. Range 0 - 31
tilesPointer 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
xX-coordinate
yY-coordinate
ttile index
Returns
returns the address of tile, so you may use faster set_vram_byte() later

◆ set_bkg_attribute_xy_nes16x16()

void set_bkg_attribute_xy_nes16x16 ( uint8_t  x,
uint8_t  y,
uint8_t  a 
)

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

Parameters
xX-coordinate
yY-coordinate
atile attributes

◆ set_bkg_attribute_xy()

void 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

Please note that this is just a wrapper function for set_bkg_submap_attributes_nes16x16() and divides the coordinates and dimensions by 2 to achieve this. It is intended to make code more portable by using the same coordinate system that systems with the much more common 8x8 attribute resolution would use.

Parameters
xX-coordinate
yY-coordinate
atile attributes

◆ 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
xX-coordinate
yY-coordinate
Returns
returns tile index

Get single tile t on background layer at x,y

Parameters
xX-coordinate
yY-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
xX axis screen coordinate for Left edge of the Background
yY 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
xNumber of pixels to move the Background on the X axis
Range: -128 - 127
yNumber of pixels to move the Background on the Y axis
Range: -128 - 127
See also
move_bkg

◆ 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

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=0 indicates the first bank
  • VBK_REG=1 indicates the second

Sets VRAM Tile Pattern data for Sprites

Parameters
first_tileIndex of the first tile to write
nb_tilesNumber of tiles to write
dataPointer 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.

◆ 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

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 color 0
  • 1 will be expanded into color 3
See also
SHOW_SPRITES, HIDE_SPRITES, set_sprite_tile

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

Parameters
first_tileIndex of the first tile to write
nb_tilesNumber of tiles to write
dataPointer 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

◆ 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
nbSprite number, range 0 - 63
tileSelects a tile (0 - 255) from PPU memory at 0000h - 0FFFh / 1000h - 1FFFh

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
nbSprite number, range 0 - 63
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
nbSprite number, range 0 - 39
propProperty 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.

◆ get_sprite_prop()

uint8_t get_sprite_prop ( uint8_t  nb)
inline

Returns the OAM Property Flags of sprite number nb.

Parameters
nbSprite 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
nbSprite number, range 0 - 63
xX Position. Specifies the sprites horizontal position on the screen (minus 8).
yY Position. Specifies the sprites vertical position on the screen (minus 16).
An offscreen value (Y>=240) 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
nbSprite number, range 0 - 63
xNumber of pixels to move the sprite on the X axis
Range: -128 - 127
yNumber 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 Y position 240.

Parameters
nbSprite number, range 0 - 63

◆ 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.

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

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

◆ 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.

Parameters
xX Start position in Map tile coordinates. Range 0 - 31
yY Start position in Map tile coordinates. Range 0 - 31
wWidth of area to set in tiles. Range 1 - 32
hHeight of area to set in tiles. Range 1 - 32
vram_addrPointer to destination VRAM Address
tilesPointer 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 32x30 Tile Maps in VRAM at addresses 2000h-23FFh and 2400h-27FFh.

See also
set_bkg_tiles

◆ set_tile_data()

void set_tile_data ( uint16_t  first_tile,
uint8_t  nb_tiles,
const uint8_t data 
)
inline

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

See also
set_bkg_data, set_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 in the native format

Parameters
first_tileIndex of the first tile to write
nb_tilesNumber of tiles to write
dataPointer to source tile data

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

See also
set_tile_data

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

Parameters
first_tileIndex of the first tile to write
nb_tilesNumber of tiles to write
dataPointer 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.

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_tileIndex of the first tile to write
nb_tilesNumber of tiles to write
dataPointer to source tile data

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

Sets VRAM Tile Pattern data for Sprites in the native format

Parameters
first_tileIndex of the first tile to write
nb_tilesNumber of tiles to write
dataPointer 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.

◆ 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_tileIndex of the first tile to write (0 - 511)
nb_tilesNumber of tiles to write
dataPointer 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:

  • NES: loads 2bpp tiles data

◆ init_bkg()

void init_bkg ( uint8_t  c)

Initializes the entire Background Tile Map with Tile Number c

Parameters
cTile number to fill with

Note: This function avoids writes during modes 2 & 3

Initializes the entire Background Tile Map with Tile Number c

Parameters
cTile 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
sStart address in VRAM
cTile number to fill with
nSize of memory region (in bytes) to fill

Note: This function avoids writes during modes 2 & 3

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

Parameters
sStart address in VRAM
cTile number to fill with
nSize 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
xX Start position in Background Map tile coordinates. Range 0 - 31
yY Start position in Background Map tile coordinates. Range 0 - 31
wWidth of area to set in tiles. Range 0 - 31
hHeight of area to set in tiles. Range 0 - 31
tileFill value

◆ flush_shadow_attributes()

void flush_shadow_attributes ( void  )

"Flushes" the updates to the shadow attributes so they are written to the transfer buffer, and then written to PPU memory on next vblank.

This function must be called to see visible changes to attributes on the NES target. But it will automatically be called by vsync(), so the use-cases for calling it manually are rare in practice.

◆ _switch_prg0()

uint8_t _switch_prg0 ( uint8_t  bank)

Variable Documentation

◆ 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)

◆ _current_bank

volatile uint8_t _current_bank
extern

Tracks current active ROM bank

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()

◆ _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

uint8_t _shadow_OAM_base
extern

MSB of shadow_OAM address is used by OAM DMA copying routine