// LL 2021

const turtle = new Slowpoke();

const view = 0; // min=0 max=2 step=1 (Isometric,Perspective,Side)
const style = 2; // min=2 max=3 step=1 (Silhouette,Hatched)
const render = 1; // min=0 max=1 step=1 (Voxels,Marching cubes)
const density = 1; // min=0 max=3 step=1 (Low,Medium,High,Ultra (Ultra slow))
const mod = 9; // min=-32 max=32 step=1
const cutout = 0; // min=-1 max=100 step=1

const perspective = [3, 1.7, 3][view];
const camera_theta = [0.25, 0.2, 0][view];
const camera_phi = [0.25, 0.3, 0][view];
const camera_r = [22, 22, 15][view];
const look_at_z = [0, -7, 0][view];
const inside_lines = 0.2;

const seed = 0;            /// min=0 max=100 step=1

const detail_max_length = 100;

var silhouette = new Silhouette();

const noise = SimplexNoise(seed ? seed : Math.floor(Math.random() * 1000));

function walk(i, t) {
	if (i==0) {
		if (t == 0 || t == 1) initOnce();
		initFrame(t);
	}

	if (silhouette.faceCount() < 1) {
	    //console.log(`Slowpoke draw: ${slowpoke_draw} skip: ${slowpoke_skip}`)
		return false;
   	}
	
	silhouette.nextFace().draw();

	return true;
}

function initFrame(t) {
	const cameraOffset = [
		 camera_r * perspective ** 3 * Math.cos((camera_theta+t*2) * Math.PI) * Math.sin((camera_phi/2+0.5) * Math.PI),
		 camera_r * perspective ** 3 * Math.sin((camera_theta+t*2) * Math.PI) * Math.sin((camera_phi/2+0.5) * Math.PI),
		-camera_r * perspective ** 3 * Math.cos((camera_phi/2+0.5) * Math.PI)
		];
	const cameraLookAt = [0, 0, look_at_z];
	viewProjectionMatrix = setupCamera(add3(cameraOffset, cameraLookAt), cameraLookAt);

	polygons = new Polygons();
	
	silhouette.processFrameModels();
	silhouette.sortFaces();
}

function initOnce(t) {
	seed_t = (t < 1 && seed == 0) ? (Math.random() * 100 | 0) : seed;
	rng = undefined;

	initScene();

	silhouette.processOnceModels();

}

function initScene() {
	const count = [32,64,128,256][density];
	const mdl = makeVoxelCube(count);

	const matrix = new Matrix();
	matrix.scale(64 / count);
	mdl.transform(matrix);

	silhouette.addModel(mdl);
}

/////////////////////////////////////////////////////////////////////
// Prototype Silhouette utility code - Created by Lionel Lemarie 2021
// https://turtletoy.net/turtle/334500a2c5
function Silhouette(){const t=[],s=[];class e{constructor(){this.faces=[],this.edges=[],this.hide_overlap=!0}transform(t){this.faces.forEach(s=>{s.transform(t)})}processOnce(){this.updateEdgeList()}processFrame(){this.faces.forEach(t=>{t.projectAndAdd()}),this.findStaticOutlines(),this.findProjectedOutlines(),this.updateOutlineMasks()}updateOutlineMasks(){this.edges.forEach(t=>{t.faces.forEach(s=>{const e=s.points.length;if(e>1)for(var o=0;o<e;o++){const n=i(s.points[o]),h=i(s.points[(o+1)%e]);t.hash!=n+h&&t.hash!=h+n||(t.state?s.outline_mask|=1<<o:s.outline_mask&=~(1<<o))}})})}addFace(t){const s=new o(t);this.faces.push(s)}merge(t){t.faces.forEach(t=>{this.faces.push(t)})}subdivideDetail(t){for(var s=this.faces.length,e=!0;e;){const i=this.faces;this.faces=[],i.forEach(s=>{const e=s.getSubdivided(t);this.faces=[...this.faces,...e]}),e=this.faces.length!=s,s=this.faces.length}}subdivideCount(t){for(;t-- >0;){const t=this.faces;this.faces=[],t.forEach(t=>{const s=t.getSubdivided(0);this.faces=[...this.faces,...s]})}}updateEdgeList(){this.edges=[];const t={};this.faces.forEach(s=>{const e=s.points.length;if(e>1)for(var o=0;o<e;o++){const n=i(s.points[o]),h=i(s.points[(o+1)%e]);if(n+h in t){const e=t[n+h];this.addFaceToEdge(e,s)}else if(h+n in t){const e=t[h+n];this.addFaceToEdge(e,s)}else{const e=this.edges.length;t[n+h]=e,this.edges.push({faces:[s],hash:n+h,state:1})}}})}addFaceToEdge(t,s){var e=!0;this.edges[t].faces.forEach(t=>{t.matches(s)&&(e=!1,this.hide_overlap&&(t.overlap=!0),s.overlap=!0)}),e&&this.edges[t].faces.push(s)}findStaticOutlines(){this.edges.forEach(t=>{t.state=1;for(var s=0,e=t.faces.length;s<e&&t.state;s++){if(t.faces[s].overlap)continue;const o=t.faces[s].getStaticNormal();for(var i=s+1;i<e&&t.state;i++){if(t.faces[i].overlap)continue;const s=t.faces[i].getStaticNormal();len3(sub3(o,s))<2*inside_lines&&(t.state=0)}}})}findProjectedOutlines(){this.edges.forEach(t=>{var s=!1,e=!1;t.faces.forEach(t=>{if(!t.overlap){const i=t.getProjectedNormal(),o=.001;i[2]<o&&(e=!0),i[2]>=-o&&(s=!0)}}),s&&e&&(t.state=1)})}}function i(t){return`${Math.round(100*t[0])},${Math.round(100*t[1])},${Math.round(100*t[2])}`}class o{constructor(t){this.points=[...t],this.z=0,this.projected_points=[],this.outline_mask=-1,this.overlap=!1}draw(){if(!(this.projected_points.length<2||this.overlap)){var t=!0;if(this.projected_points.forEach(s=>t&=Math.min(Math.abs(s[0]),Math.abs(s[1]))<100),t)if(0==style)for(var s=0;s<this.projected_points.length;s++)this.outline_mask&1<<s&&(turtle.jump(this.projected_points[s]),turtle.goto(this.projected_points[(s+1)%this.projected_points.length]));else{const t=polygons.create();if(t.addPoints(...this.projected_points),1==style)t.addOutline();else if(style>1){for(s=0;s<this.projected_points.length;s++)this.outline_mask&1<<s&&t.addSegments(t.cp[s],t.cp[(s+1)%this.projected_points.length]);if(style>2){const s=.15,e=s+(.9-s)*this.getLight();t.addHatching(-Math.PI/4,e)}}polygons.draw(turtle,t,!0)}}}getStaticNormal(){return void 0===this.cached_static_normal&&(this.points.length<3?this.cached_static_normal=[0,1,0]:this.cached_static_normal=normalize3(cross3(sub3(this.points[1],this.points[0]),sub3(this.points[2],this.points[0])))),this.cached_static_normal}getProjectedNormal(){return this.projected_points.length<3?[0,1,0]:normalize3(cross3(sub3(this.projected_points[1],this.projected_points[0]),sub3(this.projected_points[2],this.projected_points[0])))}getLight(){return.5*this.getProjectedNormal()[0]+.5}transform(t){for(var s=0,e=this.points.length;s<e;s++)this.points[s]=t.transform(this.points[s])}projectAndAdd(){this.overlap||(this.projected_points=[],this.z=0,this.points.forEach(t=>{const s=project(t);void 0!==s&&(this.projected_points.push(s),this.z+=s[2])}),this.projected_points.length>0&&(this.z/=this.projected_points.length),silhouette.addFace(this))}getSubdivided(t){var s=-1;const e=this.points.length;for(var i=0;i<e;i++){const o=len3(sub3(this.points[(i+1)%e],this.points[i]));o>t&&(t=o,s=i)}if(s>=0){if(4==e){const t=[];return t.push(new o([this.points[0],this.points[1],this.points[2]])),t.push(new o([this.points[2],this.points[3],this.points[0]])),t}{const t=[],n=mulf(add3(this.points[(s+1)%e],this.points[s]),.5);for(i=0;i<e;i++)i!=s&&t.push(new o([this.points[i],this.points[(i+1)%e],n]));return t}}return[this]}matches(t){const s=t.points.length;if(s!=this.points.length)return!1;if(s<1)return!0;var e=void 0;{const n=i(this.points[0]);for(var o=0;o<s;o++){if(n==i(t.points[o])){e=o;break}}}if(void 0===e)return!1;for(o=1;o<s;o++){const h=(e-o+s)%s;if(i(this.points[o])!=i(t.points[h])){for(var n=1;n<s;n++){const o=(e+n)%s;if(i(this.points[n])!=i(t.points[o]))return!1}return!0}}return!0}}return{addModel:s=>{t.push(s)},newModel:()=>new e,processFrameModels:()=>{t.forEach(t=>{t.processFrame()})},processOnceModels:()=>{t.forEach(t=>{t.processOnce()})},modelCount:()=>t.length,sortFaces:()=>{s.sort(function(t,s){return t.z-s.z})},nextFace:()=>s.shift(),faceCount:()=>s.length,addFace:t=>{s.push(t)}}}
class Matrix{constructor(){this.identity()}identity(){return this.matrix=[1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1],this}translate(t,i,r){const a=new Matrix;return a.matrix[12]=t,a.matrix[13]=i,a.matrix[14]=r,this.multiply(a)}scale(t,i,r){void 0===i&&(i=t),void 0===r&&(r=i);const a=new Matrix;return a.matrix[0]*=t,a.matrix[5]*=i,a.matrix[10]*=r,this.multiply(a)}rotateX(t){const i=new Matrix;return i.matrix[5]=Math.cos(t),i.matrix[9]=Math.sin(t),i.matrix[6]=-Math.sin(t),i.matrix[10]=Math.cos(t),this.multiply(i)}rotateY(t){const i=new Matrix;return i.matrix[0]=Math.cos(t),i.matrix[8]=-Math.sin(t),i.matrix[2]=Math.sin(t),i.matrix[10]=Math.cos(t),this.multiply(i)}rotateZ(t){const i=new Matrix;return i.matrix[0]=Math.cos(t),i.matrix[1]=-Math.sin(t),i.matrix[4]=Math.sin(t),i.matrix[5]=Math.cos(t),this.multiply(i)}multiply(t){const i=[...this.matrix],r=[...t.matrix];this.matrix=[];for(let t=0;16>t;t+=4)for(let a=0;4>a;a++)this.matrix[t+a]=i[t+0]*r[0+a]+i[t+1]*r[4+a]+i[t+2]*r[8+a]+i[t+3]*r[12+a];return this}transform(t){const i=[...t];for(let r=0;r<3;r++)i[r]=this.matrix[r]*t[0]+this.matrix[r+4]*t[1]+this.matrix[r+8]*t[2]+this.matrix[r+12];return i}}

const cube_points = [];
for (var z=-1; z<=1; z+=2) { for (var y=-1; y<=1; y+=2) { for (var x=-1; x<=1; x+=2) { cube_points.push([x, y, z]); } } }
const cube_faces = [ [0, 1, 2, 3], [7, 3, 5, 1], [6, 2, 7, 3], [0, 4, 1, 5], [4, 0, 6, 2], [6, 7, 4, 5] ];

function makeBox(w, h, d) {
	const model = silhouette.newModel();

	cube_faces.forEach(f => {
		const quad = [ [...cube_points[f[0]]], [...cube_points[f[1]]], [...cube_points[f[3]]], [...cube_points[f[2]]] ];
		quad.forEach(point => { point[0] *= w/2; point[1] *= h/2; point[2] *= d/2; });
		model.addFace(quad);
	});
	
	return model;
}

function makeVoxelCube(count) {
	const model = silhouette.newModel();
	for (var z=0; z<count; z++) {
		for (var y=0; y<count; y++) {
			for (var x=0; x<count; x++) {
        		const cx = (x - count / 2);
        		const cy = (y - count / 2);
        		const cz = (z - count / 2);
        		if (render) {
        			const polys = getTrianglesF(alienArt, x, y, z, count);
        			polys.forEach(poly => {
        			    model.addFace(poly.map(point => 
        			        [point[0]/2 + cx, point[1]/2 + cy, point[2]/2 + cz]
        			    ));
        			});
           		} else {
        			if (alienArt(x, y, z, count)) {
        				const mdl = makeBox(1, 1, 1);
        				mdl.transform(new Matrix().translate(cx, cy, cz));
        				model.merge(mdl);
        			}
        		}
			}
		}
	}
	return model;
}

function alienArt(x, y, z, count) {
	const co = (100-cutout) / 100 * count;
	const th = 1;
	if (x<0 || y< 0 || z < 0 || x >= count || y >= count || z >= count) return false;
	if (mod > 1) if ((x^y^z) % mod == 0) return false;
	if (mod < -1) if (((x*-mod)^(y*-mod)^(z*-mod)) % -mod == 0) return false;
	if (cutout >= 0) {
		if (x >= co && y >= co && z >= co) return false;
		if (x < count-th && y < count-th && z < count-th)
			if (x >= th && y >= th && z >= th)
				if (!(x>co-th) || !(y>co-th) || !(z>co-th))
    			    return false;
	} else {
	    const len = len3(sub3([x, y, z], [count/2, count/2, count/2]));
	    if (len > count * 0.5) return false;
	    if (len < count * 0.4) return false;
	}
	return true;
}

// http://paulbourke.net/geometry/polygonise/
const tri_table = [ [], [0, 8, 3], [0, 1, 9], [1, 8, 3, 9, 8, 1], [1, 2, 10], [0, 8, 3, 1, 2, 10], [9, 2, 10, 0, 2, 9], [2, 8, 3, 2, 10, 8, 10, 9, 8], [3, 11, 2], [0, 11, 2, 8, 11, 0], [1, 9, 0, 2, 3, 11], [1, 11, 2, 1, 9, 11, 9, 8, 11], [3, 10, 1, 11, 10, 3], [0, 10, 1, 0, 8, 10, 8, 11, 10], [3, 9, 0, 3, 11, 9, 11, 10, 9], [9, 8, 10, 10, 8, 11], [4, 7, 8], [4, 3, 0, 7, 3, 4], [0, 1, 9, 8, 4, 7], [4, 1, 9, 4, 7, 1, 7, 3, 1], [1, 2, 10, 8, 4, 7], [3, 4, 7, 3, 0, 4, 1, 2, 10], [9, 2, 10, 9, 0, 2, 8, 4, 7], [2, 10, 9, 2, 9, 7, 2, 7, 3, 7, 9, 4], [8, 4, 7, 3, 11, 2], [11, 4, 7, 11, 2, 4, 2, 0, 4], [9, 0, 1, 8, 4, 7, 2, 3, 11], [4, 7, 11, 9, 4, 11, 9, 11, 2, 9, 2, 1], [3, 10, 1, 3, 11, 10, 7, 8, 4], [1, 11, 10, 1, 4, 11, 1, 0, 4, 7, 11, 4], [4, 7, 8, 9, 0, 11, 9, 11, 10, 11, 0, 3], [4, 7, 11, 4, 11, 9, 9, 11, 10], [9, 5, 4], [9, 5, 4, 0, 8, 3], [0, 5, 4, 1, 5, 0], [8, 5, 4, 8, 3, 5, 3, 1, 5], [1, 2, 10, 9, 5, 4], [3, 0, 8, 1, 2, 10, 4, 9, 5], [5, 2, 10, 5, 4, 2, 4, 0, 2], [2, 10, 5, 3, 2, 5, 3, 5, 4, 3, 4, 8], [9, 5, 4, 2, 3, 11], [0, 11, 2, 0, 8, 11, 4, 9, 5], [0, 5, 4, 0, 1, 5, 2, 3, 11], [2, 1, 5, 2, 5, 8, 2, 8, 11, 4, 8, 5], [10, 3, 11, 10, 1, 3, 9, 5, 4], [4, 9, 5, 0, 8, 1, 8, 10, 1, 8, 11, 10], [5, 4, 0, 5, 0, 11, 5, 11, 10, 11, 0, 3], [5, 4, 8, 5, 8, 10, 10, 8, 11], [9, 7, 8, 5, 7, 9], [9, 3, 0, 9, 5, 3, 5, 7, 3], [0, 7, 8, 0, 1, 7, 1, 5, 7], [1, 5, 3, 3, 5, 7], [9, 7, 8, 9, 5, 7, 10, 1, 2], [10, 1, 2, 9, 5, 0, 5, 3, 0, 5, 7, 3], [8, 0, 2, 8, 2, 5, 8, 5, 7, 10, 5, 2], [2, 10, 5, 2, 5, 3, 3, 5, 7], [7, 9, 5, 7, 8, 9, 3, 11, 2], [9, 5, 7, 9, 7, 2, 9, 2, 0, 2, 7, 11], [2, 3, 11, 0, 1, 8, 1, 7, 8, 1, 5, 7], [11, 2, 1, 11, 1, 7, 7, 1, 5], [9, 5, 8, 8, 5, 7, 10, 1, 3, 10, 3, 11], [5, 7, 0, 5, 0, 9, 7, 11, 0, 1, 0, 10, 11, 10, 0], [11, 10, 0, 11, 0, 3, 10, 5, 0, 8, 0, 7, 5, 7, 0], [11, 10, 5, 7, 11, 5], [10, 6, 5], [0, 8, 3, 5, 10, 6], [9, 0, 1, 5, 10, 6], [1, 8, 3, 1, 9, 8, 5, 10, 6], [1, 6, 5, 2, 6, 1], [1, 6, 5, 1, 2, 6, 3, 0, 8], [9, 6, 5, 9, 0, 6, 0, 2, 6], [5, 9, 8, 5, 8, 2, 5, 2, 6, 3, 2, 8], [2, 3, 11, 10, 6, 5], [11, 0, 8, 11, 2, 0, 10, 6, 5], [0, 1, 9, 2, 3, 11, 5, 10, 6], [5, 10, 6, 1, 9, 2, 9, 11, 2, 9, 8, 11], [6, 3, 11, 6, 5, 3, 5, 1, 3], [0, 8, 11, 0, 11, 5, 0, 5, 1, 5, 11, 6], [3, 11, 6, 0, 3, 6, 0, 6, 5, 0, 5, 9], [6, 5, 9, 6, 9, 11, 11, 9, 8], [5, 10, 6, 4, 7, 8], [4, 3, 0, 4, 7, 3, 6, 5, 10], [1, 9, 0, 5, 10, 6, 8, 4, 7], [10, 6, 5, 1, 9, 7, 1, 7, 3, 7, 9, 4], [6, 1, 2, 6, 5, 1, 4, 7, 8], [1, 2, 5, 5, 2, 6, 3, 0, 4, 3, 4, 7], [8, 4, 7, 9, 0, 5, 0, 6, 5, 0, 2, 6], [7, 3, 9, 7, 9, 4, 3, 2, 9, 5, 9, 6, 2, 6, 9], [3, 11, 2, 7, 8, 4, 10, 6, 5], [5, 10, 6, 4, 7, 2, 4, 2, 0, 2, 7, 11], [0, 1, 9, 4, 7, 8, 2, 3, 11, 5, 10, 6], [9, 2, 1, 9, 11, 2, 9, 4, 11, 7, 11, 4, 5, 10, 6], [8, 4, 7, 3, 11, 5, 3, 5, 1, 5, 11, 6], [5, 1, 11, 5, 11, 6, 1, 0, 11, 7, 11, 4, 0, 4, 11], [0, 5, 9, 0, 6, 5, 0, 3, 6, 11, 6, 3, 8, 4, 7], [6, 5, 9, 6, 9, 11, 4, 7, 9, 7, 11, 9], [10, 4, 9, 6, 4, 10], [4, 10, 6, 4, 9, 10, 0, 8, 3], [10, 0, 1, 10, 6, 0, 6, 4, 0], [8, 3, 1, 8, 1, 6, 8, 6, 4, 6, 1, 10], [1, 4, 9, 1, 2, 4, 2, 6, 4], [3, 0, 8, 1, 2, 9, 2, 4, 9, 2, 6, 4], [0, 2, 4, 4, 2, 6], [8, 3, 2, 8, 2, 4, 4, 2, 6], [10, 4, 9, 10, 6, 4, 11, 2, 3], [0, 8, 2, 2, 8, 11, 4, 9, 10, 4, 10, 6], [3, 11, 2, 0, 1, 6, 0, 6, 4, 6, 1, 10], [6, 4, 1, 6, 1, 10, 4, 8, 1, 2, 1, 11, 8, 11, 1], [9, 6, 4, 9, 3, 6, 9, 1, 3, 11, 6, 3], [8, 11, 1, 8, 1, 0, 11, 6, 1, 9, 1, 4, 6, 4, 1], [3, 11, 6, 3, 6, 0, 0, 6, 4], [6, 4, 8, 11, 6, 8], [7, 10, 6, 7, 8, 10, 8, 9, 10], [0, 7, 3, 0, 10, 7, 0, 9, 10, 6, 7, 10], [10, 6, 7, 1, 10, 7, 1, 7, 8, 1, 8, 0], [10, 6, 7, 10, 7, 1, 1, 7, 3], [1, 2, 6, 1, 6, 8, 1, 8, 9, 8, 6, 7], [2, 6, 9, 2, 9, 1, 6, 7, 9, 0, 9, 3, 7, 3, 9], [7, 8, 0, 7, 0, 6, 6, 0, 2], [7, 3, 2, 6, 7, 2], [2, 3, 11, 10, 6, 8, 10, 8, 9, 8, 6, 7], [2, 0, 7, 2, 7, 11, 0, 9, 7, 6, 7, 10, 9, 10, 7], [1, 8, 0, 1, 7, 8, 1, 10, 7, 6, 7, 10, 2, 3, 11], [11, 2, 1, 11, 1, 7, 10, 6, 1, 6, 7, 1], [8, 9, 6, 8, 6, 7, 9, 1, 6, 11, 6, 3, 1, 3, 6], [0, 9, 1, 11, 6, 7], [7, 8, 0, 7, 0, 6, 3, 11, 0, 11, 6, 0], [7, 11, 6], [7, 6, 11], [3, 0, 8, 11, 7, 6], [0, 1, 9, 11, 7, 6], [8, 1, 9, 8, 3, 1, 11, 7, 6], [10, 1, 2, 6, 11, 7], [1, 2, 10, 3, 0, 8, 6, 11, 7], [2, 9, 0, 2, 10, 9, 6, 11, 7], [6, 11, 7, 2, 10, 3, 10, 8, 3, 10, 9, 8], [7, 2, 3, 6, 2, 7], [7, 0, 8, 7, 6, 0, 6, 2, 0], [2, 7, 6, 2, 3, 7, 0, 1, 9], [1, 6, 2, 1, 8, 6, 1, 9, 8, 8, 7, 6], [10, 7, 6, 10, 1, 7, 1, 3, 7], [10, 7, 6, 1, 7, 10, 1, 8, 7, 1, 0, 8], [0, 3, 7, 0, 7, 10, 0, 10, 9, 6, 10, 7], [7, 6, 10, 7, 10, 8, 8, 10, 9], [6, 8, 4, 11, 8, 6], [3, 6, 11, 3, 0, 6, 0, 4, 6], [8, 6, 11, 8, 4, 6, 9, 0, 1], [9, 4, 6, 9, 6, 3, 9, 3, 1, 11, 3, 6], [6, 8, 4, 6, 11, 8, 2, 10, 1], [1, 2, 10, 3, 0, 11, 0, 6, 11, 0, 4, 6], [4, 11, 8, 4, 6, 11, 0, 2, 9, 2, 10, 9], [10, 9, 3, 10, 3, 2, 9, 4, 3, 11, 3, 6, 4, 6, 3], [8, 2, 3, 8, 4, 2, 4, 6, 2], [0, 4, 2, 4, 6, 2], [1, 9, 0, 2, 3, 4, 2, 4, 6, 4, 3, 8], [1, 9, 4, 1, 4, 2, 2, 4, 6], [8, 1, 3, 8, 6, 1, 8, 4, 6, 6, 10, 1], [10, 1, 0, 10, 0, 6, 6, 0, 4], [4, 6, 3, 4, 3, 8, 6, 10, 3, 0, 3, 9, 10, 9, 3], [10, 9, 4, 6, 10, 4], [4, 9, 5, 7, 6, 11], [0, 8, 3, 4, 9, 5, 11, 7, 6], [5, 0, 1, 5, 4, 0, 7, 6, 11], [11, 7, 6, 8, 3, 4, 3, 5, 4, 3, 1, 5], [9, 5, 4, 10, 1, 2, 7, 6, 11], [6, 11, 7, 1, 2, 10, 0, 8, 3, 4, 9, 5], [7, 6, 11, 5, 4, 10, 4, 2, 10, 4, 0, 2], [3, 4, 8, 3, 5, 4, 3, 2, 5, 10, 5, 2, 11, 7, 6], [7, 2, 3, 7, 6, 2, 5, 4, 9], [9, 5, 4, 0, 8, 6, 0, 6, 2, 6, 8, 7], [3, 6, 2, 3, 7, 6, 1, 5, 0, 5, 4, 0], [6, 2, 8, 6, 8, 7, 2, 1, 8, 4, 8, 5, 1, 5, 8], [9, 5, 4, 10, 1, 6, 1, 7, 6, 1, 3, 7], [1, 6, 10, 1, 7, 6, 1, 0, 7, 8, 7, 0, 9, 5, 4], [4, 0, 10, 4, 10, 5, 0, 3, 10, 6, 10, 7, 3, 7, 10], [7, 6, 10, 7, 10, 8, 5, 4, 10, 4, 8, 10], [6, 9, 5, 6, 11, 9, 11, 8, 9], [3, 6, 11, 0, 6, 3, 0, 5, 6, 0, 9, 5], [0, 11, 8, 0, 5, 11, 0, 1, 5, 5, 6, 11], [6, 11, 3, 6, 3, 5, 5, 3, 1], [1, 2, 10, 9, 5, 11, 9, 11, 8, 11, 5, 6], [0, 11, 3, 0, 6, 11, 0, 9, 6, 5, 6, 9, 1, 2, 10], [11, 8, 5, 11, 5, 6, 8, 0, 5, 10, 5, 2, 0, 2, 5], [6, 11, 3, 6, 3, 5, 2, 10, 3, 10, 5, 3], [5, 8, 9, 5, 2, 8, 5, 6, 2, 3, 8, 2], [9, 5, 6, 9, 6, 0, 0, 6, 2], [1, 5, 8, 1, 8, 0, 5, 6, 8, 3, 8, 2, 6, 2, 8], [1, 5, 6, 2, 1, 6], [1, 3, 6, 1, 6, 10, 3, 8, 6, 5, 6, 9, 8, 9, 6], [10, 1, 0, 10, 0, 6, 9, 5, 0, 5, 6, 0], [0, 3, 8, 5, 6, 10], [10, 5, 6], [11, 5, 10, 7, 5, 11], [11, 5, 10, 11, 7, 5, 8, 3, 0], [5, 11, 7, 5, 10, 11, 1, 9, 0], [10, 7, 5, 10, 11, 7, 9, 8, 1, 8, 3, 1], [11, 1, 2, 11, 7, 1, 7, 5, 1], [0, 8, 3, 1, 2, 7, 1, 7, 5, 7, 2, 11], [9, 7, 5, 9, 2, 7, 9, 0, 2, 2, 11, 7], [7, 5, 2, 7, 2, 11, 5, 9, 2, 3, 2, 8, 9, 8, 2], [2, 5, 10, 2, 3, 5, 3, 7, 5], [8, 2, 0, 8, 5, 2, 8, 7, 5, 10, 2, 5], [9, 0, 1, 5, 10, 3, 5, 3, 7, 3, 10, 2], [9, 8, 2, 9, 2, 1, 8, 7, 2, 10, 2, 5, 7, 5, 2], [1, 3, 5, 3, 7, 5], [0, 8, 7, 0, 7, 1, 1, 7, 5], [9, 0, 3, 9, 3, 5, 5, 3, 7], [9, 8, 7, 5, 9, 7], [5, 8, 4, 5, 10, 8, 10, 11, 8], [5, 0, 4, 5, 11, 0, 5, 10, 11, 11, 3, 0], [0, 1, 9, 8, 4, 10, 8, 10, 11, 10, 4, 5], [10, 11, 4, 10, 4, 5, 11, 3, 4, 9, 4, 1, 3, 1, 4], [2, 5, 1, 2, 8, 5, 2, 11, 8, 4, 5, 8], [0, 4, 11, 0, 11, 3, 4, 5, 11, 2, 11, 1, 5, 1, 11], [0, 2, 5, 0, 5, 9, 2, 11, 5, 4, 5, 8, 11, 8, 5], [9, 4, 5, 2, 11, 3], [2, 5, 10, 3, 5, 2, 3, 4, 5, 3, 8, 4], [5, 10, 2, 5, 2, 4, 4, 2, 0], [3, 10, 2, 3, 5, 10, 3, 8, 5, 4, 5, 8, 0, 1, 9], [5, 10, 2, 5, 2, 4, 1, 9, 2, 9, 4, 2], [8, 4, 5, 8, 5, 3, 3, 5, 1], [0, 4, 5, 1, 0, 5], [8, 4, 5, 8, 5, 3, 9, 0, 5, 0, 3, 5], [9, 4, 5], [4, 11, 7, 4, 9, 11, 9, 10, 11], [0, 8, 3, 4, 9, 7, 9, 11, 7, 9, 10, 11], [1, 10, 11, 1, 11, 4, 1, 4, 0, 7, 4, 11], [3, 1, 4, 3, 4, 8, 1, 10, 4, 7, 4, 11, 10, 11, 4], [4, 11, 7, 9, 11, 4, 9, 2, 11, 9, 1, 2], [9, 7, 4, 9, 11, 7, 9, 1, 11, 2, 11, 1, 0, 8, 3], [11, 7, 4, 11, 4, 2, 2, 4, 0], [11, 7, 4, 11, 4, 2, 8, 3, 4, 3, 2, 4], [2, 9, 10, 2, 7, 9, 2, 3, 7, 7, 4, 9], [9, 10, 7, 9, 7, 4, 10, 2, 7, 8, 7, 0, 2, 0, 7], [3, 7, 10, 3, 10, 2, 7, 4, 10, 1, 10, 0, 4, 0, 10], [1, 10, 2, 8, 7, 4], [4, 9, 1, 4, 1, 7, 7, 1, 3], [4, 9, 1, 4, 1, 7, 0, 8, 1, 8, 7, 1], [4, 0, 3, 7, 4, 3], [4, 8, 7], [9, 10, 8, 10, 11, 8], [3, 0, 9, 3, 9, 11, 11, 9, 10], [0, 1, 10, 0, 10, 8, 8, 10, 11], [3, 1, 10, 11, 3, 10], [1, 2, 11, 1, 11, 9, 9, 11, 8], [3, 0, 9, 3, 9, 11, 1, 2, 9, 2, 11, 9], [0, 2, 11, 8, 0, 11], [3, 2, 11], [2, 3, 8, 2, 8, 10, 10, 8, 9], [9, 10, 2, 0, 9, 2], [2, 3, 8, 2, 8, 10, 0, 1, 8, 1, 10, 8], [1, 10, 2], [1, 3, 8, 9, 1, 8], [0, 9, 1], [0, 3, 8], [] ];
const edges = [ [0, 1], [1, 2], [2, 3], [3, 0], [4, 5], [5, 6], [6, 7], [7, 4], [4, 0], [5, 1], [6, 2], [7, 3] ];
const v_xyz = [ [-1, -1, -1], [1, -1, -1], [1, -1, 1], [-1, -1, 1], [-1, 1, -1], [1, 1, -1], [1, 1, 1], [-1, 1, 1] ];

function getTriangles(voxel_grid, grid_size, x, y, z, cxyz, r) {
	var cube_index = 0;
	for (var i=0; i<8; i++) {
		const dx = v_xyz[i][0] * .5 + .5, dy = v_xyz[i][1] * .5 + .5, dz = v_xyz[i][2] * .5 + .5;
		const idx = (x+dx) + (y+dy) * grid_size + (z+dz) * grid_size * grid_size;
		if (idx in voxel_grid && voxel_grid[idx] == 1) {
			cube_index |= 1 << i;
		}
	}
	const polys = [];
	var points = [];
	tri_table[cube_index].forEach( (t, i) => {
		const p0 = add3(mulf(v_xyz[edges[t][0]], r), cxyz);
		const p1 = add3(mulf(v_xyz[edges[t][1]], r), cxyz);
		const point = add3(p0, mulf(sub3(p1, p0), .5));
		points.push(point);
		if (((i+1)%3) == 0) {
			polys.push(points);
			points = [];
		}
	});
	return polys;
}

function getTrianglesF(func, x, y, z, count) {
	var cube_index = 0;
	for (var i=0; i<8; i++) {
		const dx = v_xyz[i][0] * .5 + .5, dy = v_xyz[i][1] * .5 + .5, dz = v_xyz[i][2] * .5 + .5;
		if (func(x+dx, y+dy, z+dz, count)) {
			cube_index |= 1 << i;
		}
	}
	const polys = [];
	var points = [];
	tri_table[cube_index].forEach( (t, i) => {
		const p0 = v_xyz[edges[t][0]];
		const p1 = v_xyz[edges[t][1]];
		const point = add3(p0, mulf(sub3(p1, p0), .5));
		points.push(point);
		if (((i+1)%3) == 0) {
			polys.push(points);
			points = [];
		}
	});
	return polys;
}

function project(op) {
	const p = transform4([op[0], op[2], op[1], 1], viewProjectionMatrix);
	const s = 5 * perspective **3;
	if (p[2] < 0) return undefined;
	return [ p[0]/p[3]*s, -p[1]/p[3]*s, p[2] ];
}

////////////////////////////////////////////////////////////////
// Polygon Clipping utility code - Created by Reinder Nijhoff 2019
// (Polygon binning by Lionel Lemarie 2021)
// https://turtletoy.net/turtle/a5befa1f8d
////////////////////////////////////////////////////////////////
function Polygons(){const t=[],s=25,e=Array.from({length:s**2},t=>[]),n=class{constructor(){this.cp=[],this.dp=[],this.aabb=[]}addPoints(...t){let s=1e5,e=-1e5,n=1e5,h=-1e5;(this.cp=[...this.cp,...t]).forEach(t=>{s=Math.min(s,t[0]),e=Math.max(e,t[0]),n=Math.min(n,t[1]),h=Math.max(h,t[1])}),this.aabb=[s,n,e,h]}addSegments(...t){t.forEach(t=>this.dp.push(t))}addOutline(){for(let t=0,s=this.cp.length;t<s;t++)this.dp.push(this.cp[t],this.cp[(t+1)%s])}draw(t){for(let s=0,e=this.dp.length;s<e;s+=2)t.jump(this.dp[s]),t.goto(this.dp[s+1])}addHatching(t,s){const e=new n;e.cp.push([-1e5,-1e5],[1e5,-1e5],[1e5,1e5],[-1e5,1e5]);const h=Math.sin(t)*s,o=Math.cos(t)*s,a=200*Math.sin(t),i=200*Math.cos(t);for(let t=.5;t<150/s;t++)e.dp.push([h*t+i,o*t-a],[h*t-i,o*t+a]),e.dp.push([-h*t+i,-o*t-a],[-h*t-i,-o*t+a]);e.boolean(this,!1),this.dp=[...this.dp,...e.dp]}inside(t){let s=0;for(let e=0,n=this.cp.length;e<n;e++)this.segment_intersect(t,[.1,-1e3],this.cp[e],this.cp[(e+1)%n])&&s++;return 1&s}boolean(t,s=!0){const e=[];for(let n=0,h=this.dp.length;n<h;n+=2){const h=this.dp[n],o=this.dp[n+1],a=[];for(let s=0,e=t.cp.length;s<e;s++){const n=this.segment_intersect(h,o,t.cp[s],t.cp[(s+1)%e]);!1!==n&&a.push(n)}if(0===a.length)s===!t.inside(h)&&e.push(h,o);else{a.push(h,o);const n=o[0]-h[0],i=o[1]-h[1];a.sort((t,s)=>(t[0]-h[0])*n+(t[1]-h[1])*i-(s[0]-h[0])*n-(s[1]-h[1])*i);for(let n=0;n<a.length-1;n++)(a[n][0]-a[n+1][0])**2+(a[n][1]-a[n+1][1])**2>=.001&&s===!t.inside([(a[n][0]+a[n+1][0])/2,(a[n][1]+a[n+1][1])/2])&&e.push(a[n],a[n+1])}}return(this.dp=e).length>0}segment_intersect(t,s,e,n){const h=(n[1]-e[1])*(s[0]-t[0])-(n[0]-e[0])*(s[1]-t[1]);if(0===h)return!1;const o=((n[0]-e[0])*(t[1]-e[1])-(n[1]-e[1])*(t[0]-e[0]))/h,a=((s[0]-t[0])*(t[1]-e[1])-(s[1]-t[1])*(t[0]-e[0]))/h;return o>=0&&o<=1&&a>=0&&a<=1&&[t[0]+o*(s[0]-t[0]),t[1]+o*(s[1]-t[1])]}};return{list:()=>t,create:()=>new n,draw:(n,h,o=!0)=>{reducedPolygonList=function(n){const h={},o=200/s;for(var a=0;a<s;a++){const c=a*o-100,r=[0,c,200,c+o];if(!(n[3]<r[1]||n[1]>r[3]))for(var i=0;i<s;i++){const c=i*o-100;r[0]=c,r[2]=c+o,n[0]>r[2]||n[2]<r[0]||e[i+a*s].forEach(s=>{const e=t[s];n[3]<e.aabb[1]||n[1]>e.aabb[3]||n[0]>e.aabb[2]||n[2]<e.aabb[0]||(h[s]=1)})}}return Array.from(Object.keys(h),s=>t[s])}(h.aabb);for(let t=0;t<reducedPolygonList.length&&h.boolean(reducedPolygonList[t]);t++);h.draw(n),o&&function(n){t.push(n);const h=t.length-1,o=200/s;e.forEach((t,e)=>{const a=e%s*o-100,i=(e/s|0)*o-100,c=[a,i,a+o,i+o];c[3]<n.aabb[1]||c[1]>n.aabb[3]||c[0]>n.aabb[2]||c[2]<n.aabb[0]||t.push(h)})}(h)}}}

////////////////////////////////////////////////////////////////
// Simplex Noise utility code. Created by Reinder Nijhoff 2020
// https://turtletoy.net/turtle/6e4e06d42e
// Based on: http://webstaff.itn.liu.se/~stegu/simplexnoise/simplexnoise.pdf
////////////////////////////////////////////////////////////////
function SimplexNoise(t=1){const r=[[1,1,0],[-1,1,0],[1,-1,0],[-1,-1,0],[1,0,1],[-1,0,1],[1,0,-1],[-1,0,-1],[0,1,1],[0,-1,1],[0,1,-1],[0,-1,-1]],o=new Uint8Array(512),a=(Math.sqrt(3)-1)/2,n=(3-Math.sqrt(3))/6,s=(t,r)=>t[0]*r[0]+t[1]*r[1],h=(t,r)=>[t[0]-r[0],t[1]-r[1]];return new class{constructor(t=1){for(let t=0;t<512;t++)o[t]=255&t;for(let r=0;r<255;r++){const a=(t=this.hash(r+t))%(256-r)+r,n=o[r];o[r+256]=o[r]=o[a],o[a+256]=o[a]=n}}noise2D(t){const e=s(t,[a,a]),c=[Math.floor(t[0]+e),Math.floor(t[1]+e)],l=255&c[0],M=255&c[1],i=s(c,[n,n]),f=h(t,h(c,[i,i])),u=f[0]>f[1]?[1,0]:[0,1],m=h(h(f,u),[-n,-n]),x=h(f,[1-2*n,1-2*n]);let q=Math.max(0,.5-s(f,f))**4*s(r[o[l+o[M]]%12],f);return q+=Math.max(0,.5-s(m,m))**4*s(r[o[l+u[0]+o[M+u[1]]]%12],m),70*(q+=Math.max(0,.5-s(x,x))**4*s(r[o[l+1+o[M+1]]%12],x))}hash(t){const r=1103515245*((t=1103515245*(t>>1^t))^t>>3);return r^r>>16}}(t)}

// Random with seed
var rng;
function random() { if (rng === undefined) rng = new RNG(seed_t); return rng.nextFloat(); }
function RNG(t){return new class{constructor(t){this.m=2147483648,this.a=1103515245,this.c=12345,this.state=t||Math.floor(Math.random()*(this.m-1))}nextFloat(){return this.state=(this.a*this.state+this.c)%this.m,this.state/(this.m-1)}}(t)}

////////////////////////////////////////////////////////////////
// Projection from reinder's https://turtletoy.net/turtle/b3acf08303
let viewProjectionMatrix;
function setupCamera(t,e){const m=lookAt4m(t,e,[0,0,1]),n=perspective4m(.25,1);return multiply4m(n,m)}
function lookAt4m(o,n,r){const s=new Float32Array(16);n=normalize3(sub3(o,n)),r=normalize3(cross3(r,n));const t=normalize3(cross3(n,r));return s[0]=r[0],s[1]=t[0],s[2]=n[0],s[3]=0,s[4]=r[1],s[5]=t[1],s[6]=n[1],s[7]=0,s[8]=r[2],s[9]=t[2],s[10]=n[2],s[11]=0,s[12]=-(r[0]*o[0]+r[1]*o[1]+r[2]*o[2]),s[13]=-(t[0]*o[0]+t[1]*o[1]+t[2]*o[2]),s[14]=-(n[0]*o[0]+n[1]*o[1]+n[2]*o[2]),s[15]=1,s}
function perspective4m(t,n){const e=new Float32Array(16).fill(0,0);return e[5]=1/Math.tan(t/2),e[0]=e[5]/n,e[10]=e[11]=-1,e}
function multiply4m(t,r){const l=new Float32Array(16);for(let n=0;16>n;n+=4)for(let o=0;4>o;o++)l[n+o]=r[n+0]*t[0+o]+r[n+1]*t[4+o]+r[n+2]*t[8+o]+r[n+3]*t[12+o];return l}
function transform4(r,n){const t=new Float32Array(4);for(let o=0;4>o;o++)t[o]=n[o]*r[0]+n[o+4]*r[1]+n[o+8]*r[2]+n[o+12];return t}

function normalize3(a) { const len = len3(a); return scale3(a,len3<0.0001?1:1/len); }
function scale3(a,b) { return [a[0]*b,a[1]*b,a[2]*b]; }
function len3(a) { return Math.sqrt(dot3(a,a)); }
function add3(a,b) { return [a[0]+b[0],a[1]+b[1],a[2]+b[2]]; }
function sub3(a,b) { return [a[0]-b[0],a[1]-b[1],a[2]-b[2]]; }
function dot3(a,b) { return a[0]*b[0]+a[1]*b[1]+a[2]*b[2]; }
function cross3(a,b) { return [a[1]*b[2]-a[2]*b[1],a[2]*b[0]-a[0]*b[2],a[0]*b[1]-a[1]*b[0]]; }
function mulf(v, f) { return [v[0]*f,v[1]*f,v[2]*f]; }

////////////////////////////////////////////////////////////////
// Slowpoke utility code. Created by Reinder Nijhoff 2019
// https://turtletoy.net/turtle/cfe9091ad8
////////////////////////////////////////////////////////////////

var slowpoke_draw = 0, slowpoke_skip = 0;

function Slowpoke(x, y) {
    const linesDrawn = {};
    class Slowpoke extends Turtle {
        goto(x, y) {
            const p = Array.isArray(x) ? [...x] : [x, y];
            if (this.isdown()) {
                const o = [this.x(), this.y()];
                const h1 = o[0].toFixed(2)+'_'+p[0].toFixed(2)+o[1].toFixed(2)+'_'+p[1].toFixed(2);
                const h2 = p[0].toFixed(2)+'_'+o[0].toFixed(2)+p[1].toFixed(2)+'_'+o[1].toFixed(2);
                if (linesDrawn[h1] || linesDrawn[h2]) {
                    super.up();
                    super.goto(p);
                    super.down();
                    slowpoke_skip++;
                    return;
                }
                slowpoke_draw++;
                linesDrawn[h1] = linesDrawn[h2] = true;
            } 
            super.goto(p);
        }
    }
    return new Slowpoke(x,y);
}