makechr

makechr is a tool for generating NES graphics. Its primary operation is to take pixel art images and split it into components: chr, nametable, palette, attributes, and spritelist.

The goals of makechr are to be portable (written in python), fast (can process a busy image with 256 tiles and 4 full palettes in <300ms), powerful, easy to understand, and usable in command-line based builds. A GUI is available as well, though it is missing a few features.

Windows GUI builds are available in releases.

Input images should be 256px wide and 240px high, representing a full nametable, and must follow NES attribute and palette restrictions. Smaller images will have padded nametables, while images with greater width will result in up to 2 nametables, assuming horizontal arrangement.

An RGB palette is hard-coded in rgb.py, other palettes are not yet supported.

Example usage (command-line)

makechr image.png

This will output four files: chr.dat, nametable.dat, palette.dat, attribute.dat.

Dependencies

Pillow
protobuf
wxpython (GUI only)
watchdog (GUI only)

Command-line options

Run makechr -h to get details on command-line options.

--version        See the current version number.

-o [output]      Output filename. Use /dev/null to output nothing.

-c [rom]         Create an NES rom file that just displays the image.

-e [error_file]  Output errors to an image file.

-p [palette]     Palette to use for the input image.

-b [background_color] | [mask=fill]
                 Background color spec for the palette.

-s               Sprite mode.

-l               Lock tiles.

--lock-sprite-flips
                 Lock vertical and horizontal flip flags for sprites.

-t [strategy]    Strategy for traversing tiles when making output.

-r [chr_order]   Order that the CHR data appears in memory.

-z               Whether to show statistics at the end of processing.

--allow-overflow [components]
                 Components that allow overflow.

--makepal        Generate a palette binary file from an image.

-m [mem_file]    A ppu memory dump, representing the state of ppu ram.

--palette-view      [image]  Output a view of the palette.

--colorization-view [image]  Output a view showing the palettes per block.

--reuse-view        [image]  Output a view showing tile reuse.

--nametable-view    [image]  Output a view showing the nametable.

--chr-view          [image]  Output a view showing the entire page of chr.

--grid-view         [image]  Output the image file with grid.

--free-zone-view    [image]  Output a view showing free traversal zones.

Palette literal syntax

palette  = "P/" + (option + "/"){1-4}
option   = hexcolor + ("-" hexcolor){1-3}
hexcolor = [0-9a-f]{2}

Example:

P/0f-10-01-02/0f-10-30/

This is a palette using 2 options. It has the background color $0f (black). The first option has 4 colors, the second option has only 3 colors.