Loading Sprite Graphics

We have allocated VRAM Bank F for holding our sprite graphics in a previous chapters. Bank F is 16KB big, so it can hold up to 512 16-color tiles.

We will load the 16x16 graphic into tiles 0->3.

First, make some definitions to where your going to load things. Also add a neat definition to translate tile numbers into VRAM addresses.

#define tiles_ball      0 // ball tiles (16x16 tile 0->3)

#define tile2objram(t) (SPRITE_GFX + (t) * 16)

Now DMA copy the tiles into VRAM (in your setupGraphics functions).

    dmaCopyHalfWords( 3, gfx_ballTiles, tile2objram(tiles_ball), gfx_ballTilesLen );

And the Palette...

We need to copy the palette to the sprite palette ram. The main engine's sprite palette is located at addresse 0x5000200->0x50003FF. The layout is the same as the BG one, with the first color of each 16 color palette transparent (and only color 0 is transparent in 256 color mode).

We will load our palette to the first 16-color sprite palette.

Add this definition to calculate an address in the sprite palette. SPRITE_PALETTE is the libnds definition for this region. Also add the palette index you will use.

#define pal2objram(p) (SPRITE_PALETTE + (p) * 16)
#define pal_ball      0 // ball palette (entry 0->15)

Now DMA copy the palette into the memory.

    dmaCopyHalfWords( 3, gfx_ballPal, pal2objram(pal_ball), gfx_ballPalLen );

We are now ready to start adding sprites to the display.... In the next chapter!