// 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/tiles_uneven [Mode] [Min] [Max] [Line Color] [Line Width] [Noise] [Seed]
//
// xs_begin
// author : '@lmcdx.bsky.social'
// arg : { name = 'Mode'  var = 'm_mode'  range = '0 5'  value = '0'  step = '1'  precision = '0' }
// arg : { name = 'Min'  var = 'm_min'  range = '1 256'  value = '4'  step = '1'  precision = '0' }
// arg : { name = 'Max'  var = 'm_max'  range = '1 256'  value = '8'  step = '1'  precision = '0' }
// arg : { name = 'Line Color'  var = 'm_line_color'  range = '0 255'  value = '16'  step = '1'  precision = '0' }
// arg : { name = 'Line Width'  var = 'm_line_width'  range = '0 256'  value = '1'  step = '1'  precision = '0' }
// arg : { name = 'Noise'  var = 'm_noise'  range = '0 100'  value = '0'  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 thickness = m_line_width;
float size_min = min(m_min, m_max) + thickness;
float size_max = max(m_min, m_max) + thickness;
float line_color = m_line_color;
float noise = m_noise / 100.0;

struct Series {
	float index;
	float size;
	float local;
};

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);
}

Series findSeries(int limit, vec2 seed_multiplier) {
	float cell_index = 0.0;
	float cell_size = 0.0;
	int last_index = 0;

	for (int i = 0; i <= limit;) {
		vec2 seed = vec2(float(i) * size_max) * seed_multiplier;

		last_index = i;
		cell_index += 1.0;
		cell_size = floor(mix(size_min, size_max + 1.0, hash(seed)));
		i += int(cell_size);
	}

	float local_pos = (cell_index == 0.0) ? float(limit) : float(limit - last_index);
	Series j = Series(cell_index, cell_size, local_pos);
	return j;
}

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

float noisePal(float p, vec3 v) {
	if (noise > 0.0) {
		float d = hash(v.xy, global_seed * 2.0);
		return d <= noise ? pal(d) : pal(p);
	} else {
		return pal(p);
	}
}

float map(vec3 v) {
	Series x = findSeries(int(v.x), vec2(64.0,  0.0));

	float offset = ceil(mix(size_min, size_max, hash(vec2(x.index, 0.0))));
	float k = mod(x.index, 2.0) == 0.0 ? v.y : v.y + offset;
	Series y = findSeries(int(k), vec2( 0.0, 64.0));

	vec2 index = vec2(x.index, y.index);
	vec2 local = vec2(x.local, y.local);
	vec2 size = vec2(x.size, y.size);

	if (all(lessThan(local.xy, size.xy - vec2(thickness)))) {
		if (mode == 0) {
			float f = hash(index.xy);
			return noisePal(f, v);
		} else if (mode == 1) {
			float f = smoothstep(size_min * size_min,
								 size_max * size_max,
								 size.x * size.y);
			return noisePal(f, v);
		} else if (mode == 2) {
			float f = mod(index.x, float(i_num_color_sels)) / float(i_num_color_sels);
			return noisePal(f, v);
		} else if (mode == 3) {
			float f = mod(index.y, float(i_num_color_sels)) / float(i_num_color_sels);
			return noisePal(f, v);
		} else if (mode == 4) {
			float f = hash(index.xy);
			return f > 0.5 ? noisePal(0.0, v) : noisePal(1.0, v);
		} else if (mode == 5) {
			return mod(index.y, 2.0) == 0.0 ? noisePal(0.0, v) : noisePal(1.0, v);
		}
	} else {
		return line_color;
	}
}