const Show = 0; //min=0 max=2 step=1 (Main, Gradient, Tile showcase)
const Gen0 = 0; //min=0 max=1 step=1 (White-black, Black-white)
const MainInitialSize = 20; //min=5 max=100 step=5
const MainSplitProb = .60; //min=0 max=1 step=.05
const MainMaxGens = 3; //min=1 max=10 step=1
const MainBorderSize = 10; //min=0 max=30 step=1
const MainBorderColor = 0; //min=0 max=2 step=1 (Transparent, Black, White)
const GradGenRepeat = 3; //min=1 max=5 step=1
const GradStartSize = 140; //min=50 max=400 step=10
const GradGenerations = 7; //min=1 max=20 step=1

// You can find the Turtle API reference here: https://turtletoy.net/syntax
Canvas.setpenopacity(.7);

// Global code will be evaluated once.
const turtle = new Turtle();
const text = new Text();
const polygons = new Polygons();
turtle.radians();

let tileCollection = [];
let tile = null;

function generateTile(tileCollection, position, size, generation) {
    if(tileCollection[generation] === undefined) {
        tileCollection[generation] = [];
    }
    if(generation == MainMaxGens || Math.random() > Math.pow(MainSplitProb, 1 + generation)) {
        tileCollection[generation].push(new Tile(position, size, generation));
    } else {
        let positions = [[-size/4, -size/4], [size/4, -size/4], [-size/4, size/4], [size/4, size/4]];
        for(let i = 0; i < 4; i++) {
            generateTile(tileCollection, add(position, positions[i]), size / 2, generation + 1);
        }
    }
}

// The walk function will be called until it returns false.
function walk(i) {
    switch(Show) {
        case 0:
            let size = MainInitialSize;
            let generation = 0;
            
            if(i == 0) {
                let space = 200 - (MainBorderSize * 2);
                
                let columns = Math.ceil(space /size);
                columns += columns%2==0?1:0;
                let minX = (space - (size * columns)) / 2;

                for(let y = minX - (space / 2); y < (space / 2); y+=size) {
                    for(let x = minX - (space / 2); x < (space / 2); x+=size) {
                        generateTile(tileCollection, [x + (size / 2), y + (size / 2)], size / Math.pow(2, generation), generation)
                    }
                }
                
                if(MainBorderColor > 0) {
                    let p = polygons.create();
                    p.addPoints(
                        [-100 - (size * 2), -100 - (size * 2)],
                        [100 + (size * 2), -100 - (size * 2)],
                        [100 + (size * 2), 100 + (size * 2)],
                        [100 - MainBorderSize, 100 + (size * 2)],
                        [100 - MainBorderSize, -100 + MainBorderSize],
                        [-100 + MainBorderSize, -100 + MainBorderSize],
                        [-100 + MainBorderSize, 100 + (size * 2)],
                        [-100 - (size * 2), 100 + (size * 2)]
                    );
                    if(MainBorderColor == 1) { p.addHatching(0, .15); }
                    polygons.draw(turtle,p);
    
                    p = polygons.create();
                    p.addPoints(
                        [-100 - (size * 2), 100 - MainBorderSize],
                        [100 + (size * 2), 100 - MainBorderSize],
                        [100 + (size * 2), 100 + (size * 2)],
                        [-100 - (size * 2), 100 + (size * 2)]
                    );
                    if(MainBorderColor == 1) { p.addHatching(0, .15); }
                    polygons.draw(turtle,p);
                }
                
                return true;
            }

            for(let j = tileCollection.length - 1; j >= 0; j--) {
                if(tileCollection[j].length == 0) {
                    tileCollection.pop();
                    continue;
                }
                
                tile = tileCollection[j].pop();
                tile.render(turtle, (Math.random() * 15) | 0);
                
                return true;//tileCollection.length > 1;
            }
            return false;
        case 1:
            let cols = GradGenerations;
            let startSize = GradStartSize;
            let generationRepetition = GradGenRepeat;
            
            if(i < cols * generationRepetition) {
                let sizes = [];
                let generations = [];
                for(let i = 0; i < cols; i++) {
                    for(let j = 0; j < generationRepetition; j++) {
                        generations.push(i);
                        sizes.push(startSize  / Math.pow(2, i));
                    }
                }
                cols *= generationRepetition;
    
                let size = sizes[i];
                
                let baseX = i>0?sizes.slice(0, i).reduce((p,c)=>p+c, 0): 0;
                let startX = sizes.reduce((p,c)=>p+c);
                
                for(let y = -100; y < 100; y+=size) {
                    tileCollection.push(new Tile([100 - startX + baseX + (size / 2), y + (size / 2)], size, generations[i]));
                }
                
                return i < cols;
            }
            
            tile = tileCollection.pop();
            tile.render(turtle, (Math.random() * 15) | 0);
            
            return tileCollection.length > 1;
        case 2:
            const cy = ((i+1) / 4) | 0;
            const cx = (i+1) % 4;
            
            if(i < 15) {
                let t = new Tile([-75 + (cx * 50), -75 + (cy * 50)], 25, Gen0);
                t.render(turtle, i);
            } else {
                const p = polygons.create();
                p.addPoints([-60, -100], [100, -100], [100, 100], [-100, 100], [-100, -57], [-75, -53], [-55, -75]);
                p.addHatching(Math.PI/4, 1);
                polygons.draw(turtle,p);
                
                turtle.jump(-93, -91);
                text.print(turtle, 'Carlson\'s\nWinged\nTruchet\nTiles', .2);
            }
            
            return i < 15;
    }
    
    return false;
}

const rts = (p, a) => [
    Math.cos(a * (Math.PI / 2)) * p[0] + Math.sin(a * (Math.PI / 2)) * p[1],
    Math.cos(a * (Math.PI / 2)) * p[1] - Math.sin(a * (Math.PI / 2)) * p[0]
];
// vec2 helper functions
const add = (a, b) => [a[0]+b[0], a[1]+b[1]];
const sub = (a, b) => [a[0]-b[0], a[1]-b[1]];
const scl = (a, b) => [a[0]*b, a[1]*b];

class Tile {
    constructor(position, size, generation = 0) {
        this.position = position;
        this.size = size;
        this.generation = generation;
    }
    raster(turtle) {
        turtle.jump(sub(this.position, [this.size/2, this.size/2]));
        for(let i = 0; i < 4; i++) {
            turtle.forward(this.size);
            turtle.right(Math.PI / 2);
        }
    }
    render(turtle, type) {
        //base 4 circles
        for(let i = 0; i < 4; i++) {
            let p = polygons.create();
            this.addCirclePoints(p, [-.5, 0], 1/6, 0, Math.PI * 2, i);
            if(this.generation % 2 == 0) {
                p.addHatching(0, .15);
            }
            polygons.draw(turtle, p);
        }
        
        let p = null;
        switch(type) {
            case 0:
            case 1:
                for(let i = 0; i < 2; i++) {
                    p = polygons.create();
                    this.addCirclePoints(p, [.5, -.5], 2/3, Math.PI, Math.PI / 2, i * 2 + type);
                    this.addCirclePoints(p, [.5, -.5], 1/3, Math.PI / 2, Math.PI, i * 2 + type);
                    if(this.generation % 2 == 0) {
                        p.addHatching(0, .15);
                    }
                    polygons.draw(turtle, p);
                }
                break;
            case 2:
            case 3:
                p = polygons.create();
                p.addPoints(
                    add(scl(rts([-.5, -1/6], type - 2), this.size), this.position),
                    add(scl(rts([.5, -1/6], type - 2), this.size), this.position),
                    add(scl(rts([.5, 1/6], type - 2), this.size), this.position),
                    add(scl(rts([-.5, 1/6], type - 2), this.size), this.position)
                );
                if(this.generation % 2 == 0) {
                    p.addHatching(0, .15);
                }
                polygons.draw(turtle, p);
                break;
            case 4:
                break;
            case 5:
                p = polygons.create();
                
                this.addCirclePoints(p, [-.5, -.5], 1/3, Math.PI / 2, 0);
                this.addCirclePoints(p, [.5, -.5], 1/3, Math.PI, Math.PI / 2);
                this.addCirclePoints(p, [.5, .5], 1/3, -Math.PI / 2, -Math.PI);
                this.addCirclePoints(p, [-.5, .5], 1/3, 0, -Math.PI /2);
                
                if(this.generation % 2 == 0) {
                    p.addHatching(0, .15);
                }
        
                polygons.draw(turtle, p);
                break;
            case 6:
                for(let i = 0; i < 2; i++) {
                    p = polygons.create();
                    p.addPoints(
                        add(scl(rts([-.5, -1/6], type - 6 + i), this.size), this.position),
                        add(scl(rts([.5, -1/6], type - 6 + i), this.size), this.position),
                        add(scl(rts([.5, 1/6], type - 6 + i), this.size), this.position),
                        add(scl(rts([-.5, 1/6], type - 6 + i), this.size), this.position)
                    );
                    if(this.generation % 2 == 0) {
                        p.addHatching(0, .15);
                    }
                    polygons.draw(turtle, p);
                }
                break;
            case 7:
            case 8:
            case 9:
            case 10:
                p = polygons.create();
                this.addCirclePoints(p, [.5, -.5], 2/3, Math.PI, Math.PI / 2, type - 7);
                this.addCirclePoints(p, [.5, -.5], 1/3, Math.PI / 2, Math.PI, type - 7);
                if(this.generation % 2 == 0) {
                    p.addHatching(0, .15);
                }
                polygons.draw(turtle, p);
                break;
            case 11:
            case 12:
            case 13:
            case 14:
                p = polygons.create();
                
                this.addCirclePoints(p, [-.5, -.5], 1/3, Math.PI / 2, 0, type - 11);
                this.addCirclePoints(p, [.5, -.5], 1/3, Math.PI, Math.PI / 2, type - 11);
                p.addPoints(
                    add(scl(rts([.5, 1/6], type - 11), this.size), this.position),
                    add(scl(rts([-.5, 1/6], type - 11), this.size), this.position)
                );

                if(this.generation % 2 == 0) {
                    p.addHatching(0, .15);
                }
        
                polygons.draw(turtle, p);
                break;
            default:
                break;
        }

        //base tile
        p = polygons.create();
        
        this.addCirclePoints(p, [-.5, -.5], 1/3, Math.PI / 2, Math.PI * 2);
        this.addCirclePoints(p, [.5, -.5], 1/3, -Math.PI, Math.PI / 2);
        this.addCirclePoints(p, [.5, .5], 1/3, -Math.PI / 2, Math.PI);
        this.addCirclePoints(p, [-.5, .5], 1/3, Math.PI*2, Math.PI /-2);
        
        if(this.generation % 2 == 1) {
            p.addHatching(0, .15);
        }

        polygons.draw(turtle, p);

        return;
    }
    addCirclePoints(p, c, r, s, e, rotation = 0) {
        const f = 40;
        for (let i=0; i<=f; i++) {
            p.addPoints(add(scl(rts(add(c, [Math.cos(s+(e-s)*i/f)*r, Math.sin(s+(e-s)*i/f)*r]), rotation), this.size), this.position));
        }
        return p;
    }
}

////////////////////////////////////////////////////////////////
// Text utility code. Created by Reinder Nijhoff 2019
// https://turtletoy.net/turtle/1713ddbe99
// Jurgen 2021: Fixed Text.print() to restore turtle._fullCircle
//.             if was in e.g. degrees mode (or any other)
////////////////////////////////////////////////////////////////
function Text() {class Text {print (t, str, scale = 1, italic = 0, kerning = 1) {let fc = t._fullCircle;t.radians();let pos = [t.x(), t.y()], h = t.h(), o = pos;str.split('').map(c => {const i = c.charCodeAt(0) - 32;if (i < 0 ) {pos = o = this.rotAdd([0, 48*scale], o, h);} else if (i > 96 ) {pos = this.rotAdd([16*scale, 0], o, h);} else {const d = dat[i], lt = d[0]*scale, rt = d[1]*scale, paths = d[2];paths.map( p => {t.up();p.map( s=> {t.goto(this.rotAdd([(s[0]-s[1]*italic)*scale - lt, s[1]*scale], pos, h));t.down();});});pos = this.rotAdd([(rt - lt)*kerning, 0], pos, h);}});t._fullCircle = fc;}rotAdd (a, b, h) {return [Math.cos(h)*a[0] - Math.sin(h)*a[1] + b[0], Math.cos(h)*a[1] + Math.sin(h)*a[0] + b[1]];}}const dat = ('br>eoj^jl<jqirjskrjq>brf^fe<n^ne>`ukZdz<qZjz<dgrg<cmqm>`thZhw<lZlw<qao_l^h^e_caccdeefggmiojpkqmqporlshsercp>^vs^as<f^h`hbgdeeceacaab_d^f^h_k`n`q_s^<olmmlolqnspsrrspsnqlol>]wtgtfsereqfphnmlpjrhsdsbraq`o`makbjifjekckaj_h^f_eaecffhimporqssstrtq>eoj`i_j^k_kajcid>cqnZl\\j_hcghglhqjulxnz>cqfZh\\j_lcmhmllqjuhxfz>brjdjp<egom<ogem>]wjajs<ajsj>fnkojpiojnkokqis>]wajsj>fnjniojpkojn>_usZaz>`ti^f_dbcgcjdofrisksnrpoqjqgpbn_k^i^>`tfbhak^ks>`tdcdbe`f_h^l^n_o`pbpdofmicsqs>`te^p^jfmfogphqkqmppnrkshserdqco>`tm^clrl<m^ms>`to^e^dgefhekenfphqkqmppnrkshserdqco>`tpao_l^j^g_ebdgdlepgrjsksnrppqmqlpingkfjfggeidl>`tq^gs<c^q^>`th^e_dadceegfkgnhpjqlqopqorlshserdqcocldjfhigmfoepcpao_l^h^>`tpeohmjjkikfjdhcecddaf_i^j^m_oapepjoomrjshserdp>fnjgihjikhjg<jniojpkojn>fnjgihjikhjg<kojpiojnkokqis>^vrabjrs>]wagsg<amsm>^vbarjbs>asdcdbe`f_h^l^n_o`pbpdofngjijl<jqirjskrjq>]xofndlcicgdfeehekfmhnknmmnk<icgefhfkgmhn<ocnknmpnrntluiugtdsbq`o_l^i^f_d`bbad`g`jambodqfrislsorqqrp<pcokompn>asj^bs<j^rs<elol>_tc^cs<c^l^o_p`qbqdpfoglh<chlhoipjqlqopqorlscs>`urcqao_m^i^g_eadccfckdnepgrismsorqprn>_tc^cs<c^j^m_oapcqfqkpnopmrjscs>`sd^ds<d^q^<dhlh<dsqs>`rd^ds<d^q^<dhlh>`urcqao_m^i^g_eadccfckdnepgrismsorqprnrk<mkrk>_uc^cs<q^qs<chqh>fnj^js>brn^nnmqlrjshsfreqdndl>_tc^cs<q^cl<hgqs>`qd^ds<dsps>^vb^bs<b^js<r^js<r^rs>_uc^cs<c^qs<q^qs>_uh^f_daccbfbkcndpfrhslsnrppqnrkrfqcpan_l^h^>_tc^cs<c^l^o_p`qbqepgohlici>_uh^f_daccbfbkcndpfrhslsnrppqnrkrfqcpan_l^h^<koqu>_tc^cs<c^l^o_p`qbqdpfoglhch<jhqs>`tqao_l^h^e_caccdeefggmiojpkqmqporlshsercp>brj^js<c^q^>_uc^cmdpfrisksnrppqmq^>asb^js<r^js>^v`^es<j^es<j^os<t^os>`tc^qs<q^cs>asb^jhjs<r^jh>`tq^cs<c^q^<csqs>cqgZgz<hZhz<gZnZ<gznz>cqc^qv>cqlZlz<mZmz<fZmZ<fzmz>brj\\bj<j\\rj>asazsz>fnkcieigjhkgjfig>atpeps<phnfleiegfehdkdmepgrislsnrpp>`sd^ds<dhffhekemfohpkpmopmrkshsfrdp>asphnfleiegfehdkdmepgrislsnrpp>atp^ps<phnfleiegfehdkdmepgrislsnrpp>asdkpkpiognfleiegfehdkdmepgrislsnrpp>eqo^m^k_jbjs<gene>atpepuoxnylzizgy<phnfleiegfehdkdmepgrislsnrpp>ate^es<eihfjemeofpips>fni^j_k^j]i^<jejs>eoj^k_l^k]j^<kekvjyhzfz>are^es<oeeo<ikps>fnj^js>[y_e_s<_ibfdegeifjijs<jimfoeretfuius>ateees<eihfjemeofpips>atiegfehdkdmepgrislsnrppqmqkphnfleie>`sdedz<dhffhekemfohpkpmopmrkshsfrdp>atpepz<phnfleiegfehdkdmepgrislsnrpp>cpgegs<gkhhjfleoe>bsphofleieffehfjhkmlompopporlsisfrep>eqj^jokrmsos<gene>ateeeofrhsksmrpo<peps>brdejs<pejs>_ubefs<jefs<jens<rens>bseeps<pees>brdejs<pejshwfydzcz>bspees<eepe<esps>cqlZj[i\\h^h`ibjckekgii<j[i]i_jakbldlfkhgjkllnlpkrjsiuiwjy<ikkmkojqirhthvixjylz>fnjZjz>cqhZj[k\\l^l`kbjcieigki<j[k]k_jaibhdhfihmjilhnhpirjskukwjy<kkimiojqkrltlvkxjyhz>^vamakbhdgfghhlknlplrksi<akbidhfhhillnmpmrlsisg>brb^bscsc^d^dsese^f^fsgsg^h^hsisi^j^jsksk^l^lsmsm^n^nsoso^p^psqsq^r^rs').split('>').map(r=> { return [r.charCodeAt(0)-106,r.charCodeAt(1)-106, r.substr(2).split('<').map(a => {const ret = []; for (let i=0; i<a.length; i+=2) {ret.push(a.substr(i, 2).split('').map(b => b.charCodeAt(0)-106));} return ret; })]; });return new Text();}

////////////////////////////////////////////////////////////////
// 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)}}}