Pixelorama/src/Shaders/SetIndices.gdshader

shader_type canvas_item;
render_mode unshaded;

#include "res://src/Shaders/FindPaletteColorIndex.gdshaderinc"
uniform sampler2D rgb_texture : filter_nearest;
uniform sampler2D palette_texture : filter_nearest;


void fragment() {
	vec4 color = texture(rgb_texture, UV);
	if (color.a <= 0.0001) {
		COLOR.r = 0.0;
	}
	else {
		int color_index = find_index(color, textureSize(palette_texture, 0).x, palette_texture);
		COLOR.r = float(color_index + 1) / 255.0;
	}
}