const seed = 0; //min=0 max=500 step=1 Setting seed to 0 resets it to Date.now() so it becomes a dynamic seed
const gridSize = 10; //min=4 max=15 step=1
const nSeeds = .1; //min=0 max=.5 step=.01
const nHoles = .1; //min=0 max=.8 step=.01
const growCycles = .3; //min=.2 max=.5 step=.01
const minNodeRadius = .5; //min=.1 max=1 step=.05
const maxNodeRadius = 1; //min=.1 max=1 step=.05
const innerRingSize = .5;//min=0 max=1 step=.01
const outerRingSize = .5;//min=0 max=1 step=.01
//const bgColor = 0;//min=0 max=2 step=1 (None, Black, Grey)
const outerColor = 2;//min=0 max=2 step=1 (None, Black, Grey)
const tryInnerColor = 0;//min=0 max=2 step=1 (None, Black, Grey)
const tryCoreColor = 1;//min=0 max=2 step=1 (None, Black, Grey)
const penSize = .30; //noRandom min=.15 max=.5 step=.01

const bg = 0; //bgColor;
const outer = outerColor;//outerColor == bg? (outerColor+1)%3: outerColor;
const inner = tryInnerColor == outer? (tryInnerColor+1)%3: tryInnerColor;
const core = tryCoreColor == inner? (tryCoreColor+1)%3: tryCoreColor;

// You can find the Turtle API reference here: https://turtletoy.net/syntax
Canvas.setpenopacity(.8);

// Seedable random number generator by David Bau: http://davidbau.com/archives/2010/01/30/random_seeds_coded_hints_and_quintillions.html
!function(a,b,c,d,e,f,g,h,i){function j(a){var b,c=a.length,e=this,f=0,g=e.i=e.j=0,h=e.S=[];for(c||(a=[c++]);d>f;)h[f]=f++;for(f=0;d>f;f++)h[f]=h[g=s&g+a[f%c]+(b=h[f])],h[g]=b;(e.g=function(a){for(var b,c=0,f=e.i,g=e.j,h=e.S;a--;)b=h[f=s&f+1],c=c*d+h[s&(h[f]=h[g=s&g+b])+(h[g]=b)];return e.i=f,e.j=g,c})(d)}function k(a,b){var c,d=[],e=typeof a;if(b&&"object"==e)for(c in a)try{d.push(k(a[c],b-1))}catch(f){}return d.length?d:"string"==e?a:a+"\0"}function l(a,b){for(var c,d=a+"",e=0;e<d.length;)b[s&e]=s&(c^=19*b[s&e])+d.charCodeAt(e++);return n(b)}function m(c){try{return o?n(o.randomBytes(d)):(a.crypto.getRandomValues(c=new Uint8Array(d)),n(c))}catch(e){return[+new Date,a,(c=a.navigator)&&c.plugins,a.screen,n(b)]}}function n(a){return String.fromCharCode.apply(0,a)}var o,p=c.pow(d,e),q=c.pow(2,f),r=2*q,s=d-1,t=c["seed"+i]=function(a,f,g){var h=[];f=1==f?{entropy:!0}:f||{};var o=l(k(f.entropy?[a,n(b)]:null==a?m():a,3),h),s=new j(h);return l(n(s.S),b),(f.pass||g||function(a,b,d){return d?(c[i]=a,b):a})(function(){for(var a=s.g(e),b=p,c=0;q>a;)a=(a+c)*d,b*=d,c=s.g(1);for(;a>=r;)a/=2,b/=2,c>>>=1;return(a+c)/b},o,"global"in f?f.global:this==c)};if(l(c[i](),b),g&&g.exports){g.exports=t;try{o=require("crypto")}catch(u){}}else h&&h.amd&&h(function(){return t})}(this,[],Math,256,6,52,"object"==typeof module&&module,"function"==typeof define&&define,"random");
Math.seedrandom(''+(seed === 0? Date.now(): seed));
// Add a seed in seedrandom, then Math.random will use this seed

// Global code will be evaluated once.
init();
const turtle = new Turtle();
const polygons = new Polygons();
const grid = new SquareGrid(gridSize, 0);

const circlePath = (r, rot = 0, samples = null) => Array.from({length: samples === null? Math.max(10, r * 2 * Math.PI | 0): samples}).map((e, i, a, f = i * 2 * Math.PI / a.length + rot) => [r * Math.cos(f), r * Math.sin(f)]);

//SETUP SIZE CONSTRAINTS
    const mn = Math.min(maxNodeRadius, minNodeRadius);
    const mx = Math.max(maxNodeRadius, minNodeRadius);
    const minNr = mn * grid.cellSize / 2;
    const maxNr = Math.max(minNr, mx * grid.cellSize / 2);
    
    const maxOuterConncetionWidth = ((minNr**2) / 2)**.5;
    const bothRingWidths = maxOuterConncetionWidth;
    const rMod = [bothRingWidths];
    if(innerRingSize == 0) {
        rMod.push(bothRingWidths);
    } else if(outerRingSize == 0) {
        rMod.push(0);
    } else {
        const innerRingRatio = (1-innerRingSize) / ((1-innerRingSize) + (1-outerRingSize));
        rMod.push(bothRingWidths * innerRingRatio);
    }
    rMod.push(0);

const connectionOutlineVectors = [[],
    [[[0, - (rMod[0] - rMod[1])/2], [grid.cellSize / 2, 0]], [[0,   (rMod[0] - rMod[1])/2], [grid.cellSize / 2, 0]]],
    [[[0, - (rMod[0] - rMod[1])/2 - (rMod[1] - rMod[2])], [grid.cellSize / 2, 0]], [[0,   (rMod[0] - rMod[1])/2 + (rMod[1] - rMod[2])], [grid.cellSize / 2, 0]]],
];

const connectors = [
    [0   , [ 1,  0]],
    [ .25, [ 0,  1]],
    [ .5 , [-1,  0]],
    [ .75, [ 0, -1]]
];

populateCells(grid.cells, nSeeds * gridSize**2 | 0, nHoles * gridSize**2 | 0, growCycles * gridSize**2 | 0, connectors.map(e => [...e[1]]));

const backgroundHatching = bg == 0? null: [(center) => [1, penSize * bg]];
const outerHatching = outer == 0? null: [(center) => [1, penSize * outer]];
const innerHatching = inner == 0? null: [(center) => [1, penSize * inner]];
//const kernelHatching = [(center) => [new SpiralHatching(3 + Math.random() * 3 | 0, center, 1.1, 1, (.15/ penSize) * (Math.random() < .5? -2: 2))]];
const kernelHatching = core == 0? null: [(center) => [1, penSize * core]];

const iterator = grid.iterator();
// The walk function will be called until it returns false.
function walk(i) {
    const iteration = iterator.next();
    const cell = iteration.value;

    if(cell.value === false) {
        if(iteration.done) { drawBackground(polygons, turtle); }
        return !iteration.done;
    }
    
    for(let q = 0; q < 3; q++) {
        const cp = circlePath(cell.value - rMod[q]);
        
        const connections = [];
        let cpOutline = [];
        if(q > 0) {
            const tmpBreaks = [];
            for(let j = 0; j < connectors.length; j++) {
                const test = V.add(cell.colrow, connectors[j][1]);
                if(grid.isValid(...test)) {
                    if(grid.getCell(...test).value !== false) {
                        const rot = V.rot2d(-connectors[j][0] * 2 * Math.PI);
                        const straightLines = connectionOutlineVectors[q].map(ray => ray.map(v => V.trans(rot, v)));

                        tmpBreaks.push(Intersection.tour(cp, ...straightLines[0])[0]);
                        tmpBreaks.push(Intersection.tour(cp, ...straightLines[1])[0]);
                        
                        connections.push(straightLines);
                    }
                }
            }
            const breaks = tmpBreaks.filter(b => b !== undefined);
            
            if(breaks.length == 0) {
                cpOutline = [[...cp, cp[0]]];
            } else {
                for(let j = 1; j < breaks.length; j+=2) {
                    const outline = [breaks[j].position];

                    if(breaks[j].tourIndex != breaks[(j+1)%breaks.length].tourIndex) {
                        const startIndex = (breaks[j].tourIndex + 1) % cp.length;
                        const stopIndex = (breaks[(j+1)%breaks.length].tourIndex);
                        const max = stopIndex < startIndex? (cp.length - startIndex) + stopIndex: stopIndex - startIndex;
                        for(let k = 0; k <= max; k++) {
                            outline.push(cp[(startIndex + k)%cp.length]);
                        }
                    }
                    outline.push(breaks[(j+1)%breaks.length].position);
                    
                    cpOutline.push(outline);
                }
            }
        }
    
        const circleP = polygons.create();
        circleP.addPoints(...cp.map(pt => V.add(pt, cell.center)));
        if(q > 0) {
            cpOutline.forEach(path => path.map(pt => V.add(pt, cell.center)).forEach((e, i, a) => {
                if(i == a.length - 1) return;
                circleP.addSegments(e, a[(i+1)%a.length]);
            }));
            if(q == 1) {
                if(innerHatching != null) innerHatching.forEach(ch => circleP.addHatching(...ch(cell.center)));
            } else {
                if(outerHatching != null) outerHatching.forEach(ch => circleP.addHatching(...ch(cell.center)));
            }
        } else {
            if(kernelHatching != null) kernelHatching.forEach(ch => circleP.addHatching(...ch(cell.center)));
            circleP.addOutline();
        }
        polygons.draw(turtle, circleP);
        
        if(q > 0) {
            connections.forEach(connection => {
                const straightP = polygons.create();
                straightP.addPoints(
                   V.add(cell.center, connection[0][0]),
                   V.add(cell.center, V.add(connection[0][0], connection[0][1])),
                   V.add(cell.center, V.add(connection[1][0], connection[1][1])),
                   V.add(cell.center, connection[1][0])
                );
                connection.forEach(ray => {
                    straightP.addSegments(V.add(cell.center, ray[0]), V.add(cell.center, V.add(ray[0], ray[1])));
                });
                if(q == 1) {
                    if(innerHatching != null) innerHatching.forEach(ch => straightP.addHatching(...ch(cell.center)));
                } else {
                    if(outerHatching != null) outerHatching.forEach(ch => straightP.addHatching(...ch(cell.center)));
                }
                polygons.draw(turtle, straightP);
            });
        }
    }
    
    if(iteration.done) { drawBackground(polygons, turtle); }
    
    return !iteration.done;
}

function drawBackground(polygons, turtle) {
    if(backgroundHatching === null) return;
    const backgroundP = polygons.create();
    backgroundP.addPoints([-97.5, -97.5], [97.5, -97.5], [97.5, 97.5], [-97.5, 97.5]);
    backgroundHatching.forEach(bh => backgroundP.addHatching(...bh()));
    backgroundP.addOutline();
    polygons.draw(turtle, backgroundP);
}

function populateCells(cells, nSeeds, nHoles, growCycles, connectors) {
    const newNodeRadius = () => minNr + Math.random() * (maxNr-minNr);
    
    const cellCount = cells.length * cells[0].length;
    
    const seeds = [];
    //seeds
    while(cells.reduce((a, c) => a + c.reduce((a, c) => a + (c !== false? 1: 0), 0), 0) < Math.max(1, nSeeds)) {
        const c = [Math.random() * gridSize | 0, Math.random() * gridSize | 0];
        cells[c[0]][c[1]] = newNodeRadius();
        seeds.push(c);
    }
    
    const isOutOfBounds = (pt) => pt[0] < 0 || gridSize <= pt[0] || pt[1] < 0 || gridSize <= pt[1];
    //grow
    while(cells.reduce((a, c) => a + c.reduce((a, c) => a + (c !== false? 1: 0), 0), 0) < Math.min(cellCount, nSeeds + growCycles)) {
        const c = seeds.sort((a,b) => Math.random() * 2 - 1)[0];
        const neighbor = connectors.sort((a,b) => Math.random() * 2 - 1)[0];
        const target = V.add(c, neighbor);
        if(isOutOfBounds(target)) {
            continue;
        }
        if(cells[target[0]][target[1]] !== false) {
            continue;
        }
        
        cells[target[0]][target[1]] = newNodeRadius();
        seeds.push(target);
    }
    
    //holes
    for(let i = 0; i < nHoles; i++) {
        const c = [Math.random() * gridSize | 0, Math.random() * gridSize | 0];
        cells[c[0]][c[1]] = false;
    }
}

////////////////////////////////////////////////////////////////
// Square Grid utility code - Created by Jurgen Westerhof 2024
// Modified: https://turtletoy.net/turtle/6c24a2a461
////////////////////////////////////////////////////////////////
function SquareGrid(grid, padding=2, margin = 5, populateFn = (column, row) => false, canvasSize = 200) {
    class SquareGrid {
        //cells[column][row] is a 2d array holding the values of the grid
        constructor(grid, padding = 2, margin = 5, populateFn = (column, row) => false, canvasSize = 200) {this.gridSize = grid;this.padding = padding;this.margin = margin;this.cells = Array.from({length: this.gridSize}).map((e, column) => Array.from({length: this.gridSize}).map((e, row) => populateFn(column, row)));this.canvasSize = canvasSize;this.resetCellSize();}
        resetCellSize() { this.cellSize = ((this.canvasSize - this.margin - this.margin - ((this.gridSize - 1) * this.padding)) / this.gridSize);}
        getColumnRow(i) { return [i % this.gridSize, i / this.gridSize | 0]; }
        getCellCenter(col, row) { return [col, row].map(v => this.margin - 100 + (v * this.padding) + ((v + .5) * this.cellSize)); }
        getCell(col, row) { return { center: this.getCellCenter(col, row), colrow: [col, row], iteration: col + row * this.gridSize, size: this.cellSize, value: this.cells[col][row] }}
        get length() { return this.gridSize**2; }
        *iterator() { let ptr = 0; while(ptr < this.length - 1) { yield this.getCell(...this.getColumnRow(ptr++)); } return this.getCell(...this.getColumnRow(ptr++)); }
        getValue(col, row) { return this.cells[col][row]; }
        setValue(col, row, value) { this.cells[col][row] = value; }
        isValid(col, row) { return 0 <= col && col < this.gridSize && 0 <= row && row < this.gridSize; }
    }
    return new SquareGrid(grid, padding, margin, populateFn, canvasSize);
}

function init() {
    ///////////////////////////////////////////////////////
    // Vector functions - Created by Jurgen Westerhof 2024
    // https://turtletoy.net/turtle/d068ad6040
    ///////////////////////////////////////////////////////
    class Vector {
        static add  (a,b) { return a.map((v,i)=>v+b[i]); }
        static sub  (a,b) { return a.map((v,i)=>v-b[i]); }
        static mul  (a,b) { return a.map((v,i)=>v*b[i]); }
        static div  (a,b) { return a.map((v,i)=>v/b[i]); }
        static scale(a,s) { return a.map(v=>v*s); }
    
        static det(m)                { return m.length == 1? m[0][0]: m.length == 2 ? m[0][0]*m[1][1]-m[0][1]*m[1][0]: m[0].reduce((r,e,i) => r+(-1)**(i+2)*e*this.det(m.slice(1).map(c => c.filter((_,j) => i != j))),0); }
        static angle(a)              { return Math.PI - Math.atan2(a[1], -a[0]); } //compatible with turtletoy heading
        static rot2d(angle)          { return [[Math.cos(angle), -Math.sin(angle)], [Math.sin(angle), Math.cos(angle)]]; }
        static rot3d(yaw,pitch,roll) { return [[Math.cos(yaw)*Math.cos(pitch), Math.cos(yaw)*Math.sin(pitch)*Math.sin(roll)-Math.sin(yaw)*Math.cos(roll), Math.cos(yaw)*Math.sin(pitch)*Math.cos(roll)+Math.sin(yaw)*Math.sin(roll)],[Math.sin(yaw)*Math.cos(pitch), Math.sin(yaw)*Math.sin(pitch)*Math.sin(roll)+Math.cos(yaw)*Math.cos(roll), Math.sin(yaw)*Math.sin(pitch)*Math.cos(roll)-Math.cos(yaw)*Math.sin(roll)],[-Math.sin(pitch), Math.cos(pitch)*Math.sin(roll), Math.cos(pitch)*Math.cos(roll)]]; }
        static trans(matrix,a)       { return a.map((v,i) => a.reduce((acc, cur, ci) => acc + cur * matrix[ci][i], 0)); }
        //Mirror vector a in a ray through [0,0] with direction mirror
        static mirror2d(a,mirror)    { return [Math.atan2(...mirror)].map(angle => this.trans(this.rot2d(angle), this.mul([-1,1], this.trans(this.rot2d(-angle), a)))).pop(); }

        static approx(a,b,p) { return this.len(this.sub(a,b)) < (p === undefined? .001: p); }
        static norm  (a)     { return this.scale(a,1/this.len(a)); }
        static len   (a)     { return Math.hypot(...a); }
        static lenSq (a)     { return a.reduce((a,c)=>a+c**2,0); }
        static lerp  (a,b,t) { return a.map((v, i) => v*(1-t) + b[i]*t); }
        static dist  (a,b)   { return Math.hypot(...this.sub(a,b)); }
        
        static dot  (a,b)   { return a.reduce((a,c,i) => a+c*b[i], 0); }
        static cross(...ab) { return ab[0].map((e, i) => ab.map(v => v.filter((ee, ii) => ii != i))).map((m,i) => (i%2==0?-1:1)*this.det(m)); }
    }
    this.V = Vector;
    
    class Intersection2D {
        //a-start, a-direction, b-start, b-direction
        //returns false on no intersection or [[intersection:x,y], scalar a-direction, scalar b-direction
        static info(as, ad, bs, bd) {
            const d = V.sub(bs, as), det = -V.det([bd, ad]);
            if(det === 0) return false;
            const res = [V.det([d, bd]) / det, V.det([d, ad]) / det];
            return [V.add(as, V.scale(ad, res[0])), ...res];
        }
        static ray(a, b, c, d) {
            return this.info(a, b, c, d);
        }
        static segment(a,b,c,d, inclusiveStart = true, inclusiveEnd = true) {
            const i = this.info(a, V.sub(b, a), c, V.sub(d, c));
            return i === false? false: (
                (inclusiveStart? 0<=i[1] && 0<=i[2]: 0<i[1] && 0<i[2])
             && (inclusiveEnd?   i[1]<=1 && i[2]<=1: i[1]<1 && i[2]<1)
            )?i[0]:false;
        }
        static tour(tour, segmentStart, segmentDirection) {
            return tour.map((e, i, a) => [i, this.info(e, V.sub(a[(i+1)%a.length], e), segmentStart, segmentDirection)])
                .filter(e => e[1] !== false && 0 <= e[1][1] && e[1][1] <= 1)
                .filter(e => 0 <= e[1][2])// && e[1][2] <= 1)
                .map(e => ({
                    position: e[1][0],
                    tourIndex: e[0],
                    tourSegmentPortion: e[1][1],
                    segmentPortion: e[1][2],
                })
            );
        }
    }
    this.Intersection = Intersection2D;
}

////////////////////////////////////////////////////////////////
// Polygon Clipping utility code - Created by Reinder Nijhoff 2019
// (Polygon binning by Lionel Lemarie 2021) https://turtletoy.net/turtle/95f33bd383
// (Delegated Hatching by Jurgen Westerhof 2024) https://turtletoy.net/turtle/d068ad6040
// https://turtletoy.net/turtle/a5befa1f8d
//
// const polygons = new Polygons();
// const p = polygons.create();
// polygons.draw(turtle, p);
// polygons.list();
//
// p.addPoints(...[[x,y],]);
// p.addSegments(...[[x,y],]);
// p.addOutline();
// p.addHatching(angle, distance); OR p.addHatching(HatchObject); where HatchObject has a method 'hatch(PolygonClass, thisPolygonInstance)'
// p.inside([x,y]);
// p.boolean(polygon, diff = true);
// p.segment_intersect([x,y], [x,y], [x,y], [x,y]);
////////////////////////////////////////////////////////////////
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) {if(typeof t == 'object') return t.hatch(n, this);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)}}}