Cross-platform command line tool to convert an indexed-color bitmap (.bmp) into CHR data for use in developing Nintendo Entertainment System (NES) ROMs.
Bitmaps should use indexed color mode, be 128px wide, height should be a multiple of 8px.
Pixel values are assigned by palette_index % 4, so multiple 4-color palettes can be used in the same bitmap if you so desire, and it will all get "flattened" to 2bpp pixel data.
The palettes themselves are not imported, so it's up to you to use colors that resemble in-game colors.
On the command line:
bmp2chr mybitmap.bmp
Just run cargo build to compile or download binaries from releases.