Godot Palette Swap

Replaces a Sprite color with another one using a mask.

If an inconsistency appears between Intel/Amd/Nvidia GPU, Feel free to fix and commit it, but take this as a warning for production use.

Requirements

Godot >= 3.x

Installation

Copy the palette_swap_material.tres from

.\godot_pallete_swap\resources

and use it as a material in your sprites.

Usage

First you need to create a pow 2 palette texture. The shader read only the first row of the palette.

Pow 2 means, the palette width should be 2 ^ x, example values: 1, 2, 4, 8, 16, 32, 64, 128...

Example:

Megaman has 3 colors:

but 3 isn't pow two so the palette width should be expanded to the next compatible value which is 4 and filled with anything.

Then you need to create a mask to use that palette, where each palette index is a red value in the mask, and a 255 color means ignore that pixel. This image should be imported in godot Lossless, unfiltered with mipmaps off

The formula for mask colors in rgb 255 values: (palette_pixel_index / palette_size) * 255, rounded up to the nearest value

For example the megaman palette, has 4 colors:

Where the first color is the outline, with index 0, using the formula:

(0 / 4) * 255 = 0

The second one is 64:

(1 / 4) * 255 = 63,75 ~ 64

The third one is 128:

(2 / 4) * 255 = 127,5 ~ 128

and fill the rest of the mask with white (255)

This is the result:

All this explanation could be summarized in this image:

License

MIT License

Author: Hearto Lazor