zzox / palette-shader

script to generate posterization shaders for use in HaxeFlixel/OpenFL

GPL Palette Posterization Shader Generator

Made for HaxeFlixel, which in turn uses OpenFL and OpenGL, and can be adapted for other engines that use OpenGL. This repo includes a generator script, a few palettes with their respective fragment shaders, and the example PaletteShader.hx file used in my game isle. The generated posterization shader "snaps" each pixel's color to the nearest color in an included palette. When applied to the main camera it ensures no colors besides the colors in the included palette are displayed.

Usage

1. Make sure node is installed.
2. Run with node gpl-parser.js [PALETTE_FILE_NAME] [OUTPUT_FILE_NAME] to generate a shader from a gpl palette.

NOTE: This script makes shaders specifically for HaxeFlixel. It obtains the current pixel color with vec4 color = flixel_texture2D(bitmap, openfl_TextureCoordv);; this line (and potentially others) may need to be changed to work with other engines.