// Copyright (c) 2023 Lachlan McDonald
// This work is licensed under the MIT License (MIT)
// https://github.com/lachlanmcdonald/magicavoxel-shaders
//
// This script utilises or modifies code from other projects or publications.
// Please see the attributions below for more information:
//
// 1. Copyright (c) 2020 ValgoBoi <https://github.com/ValgoBoi/clover-noise>
//    MIT License (MIT)
//    https://github.com/ValgoBoi/clover-noise/blob/master/LICENSE
//
// xs brush/weave [Mode] [Size] [Line Color] [Line Width] [Seed]
//
// xs_begin
// author : '@lmcdx.bsky.social'
// arg : { name = 'Mode'  var = 'm_mode'  range = '0 2'  value = '0'  step = '1'  precision = '0' }
// arg : { name = 'Size'  var = 'm_size'  range = '1 256'  value = '4'  step = '1'  precision = '0' }
// arg : { name = 'Line Color'  var = 'm_line_color'  range = '0 255'  value = '10'  step = '1'  precision = '0' }
// arg : { name = 'Line Width'  var = 'm_line_width'  range = '0 256'  value = '1'  step = '1'  precision = '0' }
// arg : { name = 'Seed'  var = 'global_seed'  range = '1 100'  value = '1'  step = '1'  precision = '0' }
// xs_end

int mode = int(m_mode);
float size = m_size;
float line_color = m_line_color;
float line_width = m_line_width;

float hash(vec2 p, float seed) {
	p += seed + global_seed;
	return fract(1e4 * sin(17.0 * p.x + p.y * 0.1) * (0.1 + abs(sin(p.y * 13.0 + p.x))));
}

float hash(vec2 co) {
	return hash(co, 0.0);
}

float pal(float p) {
	float f = floor(mix(0.0, float(i_num_color_sels), p));
	return color_sel(f);
}

float map(vec3 v) {
	float j = size + line_width;

	if (mod(v.x, j) > size) {
		return line_color;
	} else if (mod(v.y, j) > size) {
		return line_color;
	} else {
		float row = floor(v.y / j);
		float col = floor(v.x / j);
		float d = hash(vec2(row, col));
		vec2 k = v.xy - (vec2(col, row) * j);

		float color;
		float inner;
		vec2 xy;

		if (mod(row + col, 2.0) == 0.0) {
			inner = floor(k.x / (size / 2.0));
			xy = vec2(inner, d);
		} else {
			inner = floor(k.y / (size / 2.0));
			xy = vec2(d, inner);
		}

		if (mode == 0) {
			color = hash(xy);
		} else if (mode == 1) {
			float d = row + col + inner;
			color = (mod(d, float(i_num_color_sels)) / float(i_num_color_sels));
		} else if (mode == 2) {
			color = mod(inner, 2.0);
		}

		return pal(color);
	}
}