Module gba::palram

Module that allows interacting with palette memory, (PALRAM).

The PALRAM contains 256 Color values for Background use, and 256 Color values for Object use.

Each block of PALRAM can be viewed as "8 bits per pixel" (8bpp), where there's a single palette of 256 entries. It can also be viewed as "4 bits per pixel" (4bpp), where there's 16 "palbank" entries that each have 16 slots. Both interpretations are correct, simultaneously. If you're a real palette wizard you can carefully arrange for some things to use 4bpp mode while other things use 8bpp mode and have it all look good.

Transparency

In 8bpp mode the 0th palette index is "transparent" when used in an image (giving you 255 usable slots). In 4bpp mode the 0th palbank index of each palbank is considered a transparency pixel (giving you 15 usable slots per palbank).

Clear Color

The 0th palette index of the background palette holds the color that the display will show if no background or object draws over top of a given pixel during rendering.

Constants

PALRAM_BG	The PALRAM for background colors, 256 slot view.
PALRAM_OBJ	The PALRAM for object colors, 256 slot view.

Functions

index_palram_bg_4bpp	Obtains the address of the specified 4bpp background palbank and palslot.
index_palram_bg_8bpp	Obtains the address of the specified 8bpp background palette slot.
index_palram_obj_4bpp	Obtains the address of the specified 4bpp object palbank and palslot.
index_palram_obj_8bpp	Obtains the address of the specified 8bpp object palette slot.