Simple Sprite -- Your First OAM Sprite

Screenshot

What This Example Shows

How to display a single 32x32 pixel sprite on screen using the SNES Object Attribute Memory (OAM). This is the simplest possible sprite program – no animation, no input, just one sprite at the center of the screen.

Prerequisites

Read text/print_string first – it covers consoleInit(), VRAM, and the PPU basics.

Controls

No interactive controls. A static sprite is displayed at the center of the screen.

Build & Run

cd $OPENSNES_HOME
make -C examples/sprites/simple_sprite

Then open simple_sprite.sfc in your emulator (Mesen2 recommended).

How It Works

1. Load sprite graphics into VRAM

dmaCopyVram(sprite32, 0x2100, sprite32_end - sprite32);

Sprite tiles go to a different VRAM region than background tiles. Here we load them at word address $2100. The SNES has a shared 64 KB VRAM – backgrounds and sprites coexist by using non-overlapping address ranges.

2. Load the sprite palette

dmaCopyCGram(palsprite32, 128, 32);

CGRAM (Color Generator RAM) holds 256 entries. The first 128 are for backgrounds, the last 128 are for sprites. Offset 128 = first sprite palette (palette 0 in sprite terms). Each palette is 16 colors (32 bytes in 15-bit SNES format).

3. Configure OBJ size

oamInit(OBJ_SIZE8_L32, 1);

The SNES supports two sprite sizes simultaneously: "small" and "large". Here we use 8x8 small / 32x32 large. The second parameter (1) sets the name base – the VRAM region where sprite tiles start ($2000 in word addressing).

4. Place the sprite

oamSet(0, 112, 96, 0x0010, 0, 3, 0);
oamSetSize(0, OBJ_LARGE);

oamSet() configures OAM entry 0:

• Position: (112, 96) – roughly centered on the 256x224 screen
• Tile number: 0x0010 – calculated as (0x2100 - 0x2000) / 16
• Palette: 0 (first sprite palette)
• Priority: 3 (in front of all backgrounds)

oamSetSize() selects the "large" size (32x32) for this sprite. Visibility is controlled by Y position; oamSet placed it on-screen.

5. Enable display

setMode(BG_MODE1, 0);
setMainScreen(LAYER_OBJ);
setScreenOn();

Mode 1 is used but we only enable sprites (LAYER_OBJ) on the main screen – no backgrounds needed for this demo.

SNES Concepts

OAM (Object Attribute Memory)

The SNES has 128 sprite entries in OAM, each with:

• X/Y position (9-bit X, 8-bit Y)
• Tile number (9 bits – selects which VRAM tiles to display)
• Palette (3 bits – selects from 8 sprite palettes)
• Priority (2 bits – controls layering with backgrounds)
• Horizontal/vertical flip flags

Plus 32 bytes of "high table" storing the X position MSB and size-select bit for each sprite (2 bits per sprite, packed 4 per byte).

CGRAM Split

Colors 0-127 are for backgrounds, colors 128-255 are for sprites. Sprite palette 0 starts at CGRAM offset 128, palette 1 at 144, and so on. Each palette holds 16 colors (32 bytes).

Name Base

The VRAM word address where the PPU starts looking for sprite tiles. Set via oamInit() or register $2101 (OBJSEL). The tile number in each OAM entry is an offset from this base.

Project Structure

File	Purpose
main.c	Sprite loading, OAM setup, display configuration
data.asm	Sprite tile data and palette via .INCBIN
res/sprite32.png	Source 32x32 sprite image
Makefile	LIB_MODULES := console dma sprite

Going Further

• Move the sprite: Add padHeld() input reading and update the X/Y position in the main loop with oamSet().
• Change the palette: Write different colors to CGRAM offset 128 and see the sprite change appearance without reloading tiles.
• Explore related examples:
  • sprites/animated_sprite – Add movement and animation frames
  • sprites/dynamic_sprite – Stream sprite tiles to VRAM each frame