With Observable SlowPoke
Based on line art by Regolo Bizzi - behance.net/regolo
Log in to post a comment.
// Forked from "Amsterdam" by reinder // https://turtletoy.net/turtle/d30c1379c9 // Amsterdam. Created by Reinder Nijhoff 2021 - @reindernijhoff // // https://turtletoy.net/turtle/d30c1379c9# const gridSize = 25; //min=1 max=50 step=1 const projectionMargin = 0; //min=0 max=10 step=.1 const segmentCapture = .08; // min=.01 max=1 step=.01 const captureWidth = 200; //min=10 max=200 step=1 // You can find the Turtle API reference here: https://turtletoy.net/syntax const GRID = { TOP: 1, RIGHT: 2, BOTTOM: 4, LEFT: 8 }; // Global code will be evaluated once. turtlelib_init(); const turtle = new ObservableSlowPoke(); const sls = FlyEyeFactory( turtle, gridSize,// gridSize, [projectionMargin-100, projectionMargin-100], //gridTopLeft, [100-projectionMargin, 100-projectionMargin], //gridBottomRight, projectionMargin, //gridMargin, [-captureWidth/2, -captureWidth/2], //sampleTopLeft, [captureWidth/2, captureWidth/2], //sampleBottomRight, segmentCapture//sampleTileSizeFraction ); const shape = 1; // min=0, max=2, step=1 (Hexagon, Square, Triangle) const recursion = 5; // min=1, max=10, step=1 const rotMode = 0; // min=0, max=4, step=1 (Mode 1, Mode 2, Mode 3, Mode 4, Mode 5) const rotDist = 2; // min=1, max=5, step=0.01 const rotFalloff = .85; // min=0.5, max=1, step=0.01 Canvas.setpenopacity(rotMode === 4?.5: 1); function* drawPolygons() { const ts = Math.sin(Math.PI * 2 / 3); const tss = 4/3; // too much magic code here const def = shape == 0 ? { rotations: 6, step: [.5, 0], polygons: [[[0,-4/3*ts],[-1, 2/3*ts],[1, 2/3*ts]],[[0,2/3*ts],[1,-4/3*ts],[-1,-4/3*ts]]] } : shape == 1 ? { rotations: 4, step: [1, 0], polygons: [[[-1,-1], [1,-1], [1,1], [-1,1]]] } : { rotations: 4, step: [1, 0], polygons: [[[-2,1],[2,1],[0,-1]], [[-2,-1],[0,1],[2,-1]]] }; for (let r = 0; r<recursion; r++) { const s = Math.pow(0.5, r) * 50; // size of base shape for recursion level const n = 1 + 4 * (Math.pow(2, r)-1); // number of shapes const min_dist = rotDist * Math.pow(rotFalloff, r); // start position of first shape of this recursion level const start = shape == 0 ? sub(scale([-.5,ts], 100 - 2 * s), [0,-2/3*ts*s]) : shape == 1 ? scale([-1,1], 100 - 1.5 * s) : sub(scale([-1,1], 100 - 2 * s), [0,-.5*s]); let f = rotMode ? 1 : r % 2 == 0 ? 1 : -1; for (let j=0; j<def.rotations; j++) { if (rotMode >= 2) { f = rotMode == 2 ? 1 : -1; } const mat = rot(j * Math.PI * 2 / def.rotations); // draw all shapes for recursion level and rotate for (let i=0; i<n; i++) { const polygon = def.polygons[i % def.polygons.length]; const center = add(start, scale(def.step, i*s)); drawPoly(polygon.map(c => trans(mat, add(center, scale(c, .5 * s)))), min_dist, f = -f); rotMode === 4 && drawPoly(polygon.map(c => trans(mat, add(center, scale(c, .5 * s)))), min_dist, f = -f); yield true; } } } } const iterator = drawPolygons(); function walk(i) { return !iterator.next().done; } function drawPoly(p, min_distance, rot) { for(let r=0;r<100;r++) { // draw polygon turtle.jump(p[p.length-1]); p.forEach(c => turtle.goto(c)); // rotate polygon const c = p; p = []; for (let i=0; i<c.length; i++) { const c0 = c[i]; const c1 = c[(i+rot+c.length) % c.length]; const d = dist(c0, c1); if (d <= min_distance) return; p[i] = lerp(c0, c1, min_distance / d); } } } // // 2D Vector math // function rot(a) { return [Math.cos(a), -Math.sin(a), Math.sin(a), Math.cos(a)]; } function trans(m, a) { return [m[0]*a[0]+m[2]*a[1], m[1]*a[0]+m[3]*a[1]]; } function scale(a,b) { return [a[0]*b,a[1]*b]; } function add(a,b) { return [a[0]+b[0],a[1]+b[1]]; } function sub(a,b) { return [a[0]-b[0],a[1]-b[1]]; } function dist(a,b) { return Math.hypot(...sub(a,b)); } function lerp(a,b,t) { return [a[0]*(1-t)+b[0]*t,a[1]*(1-t)+b[1]*t]; } //////////////////////////////////////////////////////////////// // Slowpoke utility code. Created by Reinder Nijhoff 2019 // https://turtletoy.net/turtle/cfe9091ad8 //////////////////////////////////////////////////////////////// function ObservableSlowPoke(x, y) { const linesDrawn = {}; class Slowpoke extends ObservableTurtle { 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(8)+'_'+p[0].toFixed(8)+o[1].toFixed(8)+'_'+p[1].toFixed(8); const h2 = p[0].toFixed(8)+'_'+o[0].toFixed(8)+p[1].toFixed(8)+'_'+o[1].toFixed(8); if (linesDrawn[h1] || linesDrawn[h2]) { super.up(); super.goto(p); super.down(); return; } linesDrawn[h1] = linesDrawn[h2] = true; } super.goto(p); } } return new Slowpoke(x,y); } function FlyEyeFactory(turtle, gridSize, gridTopLeft, gridBottomRight, gridMargin, sampleTopLeft, sampleBottomRight, sampleTileSizeFraction) { const sampleWidth = sampleBottomRight[0] - sampleTopLeft[0]; const sampleHeight = sampleBottomRight[1] - sampleTopLeft[1]; const tileWidth = sampleWidth * sampleTileSizeFraction; const tileHeight = sampleHeight * sampleTileSizeFraction; const sampleCenterTopLeft = V.add(sampleTopLeft, [tileWidth/2, tileHeight/2]); const columnIncrement = gridSize == 1? 0: (sampleWidth - tileWidth) / (gridSize - 1); const rowIncrement = gridSize == 1? 0: (sampleHeight - tileHeight) / (gridSize - 1); const gridWidth = gridBottomRight[0] - gridTopLeft[0]; const gridHeight = gridBottomRight[1] - gridTopLeft[1]; const gridTileWidth = (gridWidth - gridMargin * Math.max(1, gridSize - 1)) / gridSize; const gridTileHeight = (gridHeight - gridMargin * Math.max(1, gridSize - 1)) / gridSize; const flyEyeSegments = []; for(let c = 0; c < gridSize; c++) { for(let r = 0; r < gridSize; r++) { flyEyeSegments.push( new SquareLens( turtle, [ V.add(sampleTopLeft, [columnIncrement * c, rowIncrement * r]), V.add( V.add(sampleTopLeft, [columnIncrement * c, rowIncrement * r]), [tileWidth, tileHeight] ) ], [ V.add(gridTopLeft, [c * (gridTileWidth + gridMargin), r * (gridTileHeight + gridMargin)]), V.add( V.add(gridTopLeft, [c * (gridTileWidth + gridMargin), r * (gridTileHeight + gridMargin)]), [gridTileWidth, gridTileHeight] ) ], (c == 0? GRID.LEFT: 0) | (r == 0? GRID.TOP: 0) | (c == gridSize - 1? GRID.RIGHT: 0) | (r == gridSize - 1? GRID.BOTTOM: 0) ) ); } } return flyEyeSegments; } function ObservableTurtle(x, y) { class ObservableTurtle extends Turtle { constructor(x, y) { super(x, y); this.observers = []; } goto(x, y) { const isDown = this.isdown(); const from = this.pos(); this.up(); super.goto(x, y); if(isDown) { this.notifyObservers(from, this.pos()); this.down(); } } registerObserver(o) { return this.observers.push(o) - 1; } notifyObservers(...data) { this.observers.forEach(o => o.update(...data)) } } return new ObservableTurtle(x, y); } function SquareLens(turtleToObserve, lookAt, projectTo, edge = 0, projector = null) { class SquareLens { constructor(turtleToObserve, lookAt, projectTo, bottomOrRight, projector) { this.turtleToObserve = turtleToObserve; this.turtleToObserve.registerObserver(this); this.edge = edge; this.projector = projector == null? new Turtle(): projector; this.lookAt = lookAt; this.projectTo = projectTo; this.midLookAt = V.add(this.lookAt[0], V.scale(V.sub(...this.lookAt.map(l => l).reverse()), .5)); this.midProjectTo = V.add(this.projectTo[0], V.scale(V.sub(...this.projectTo.map(l => l).reverse()), .5)); this.lookAtBox = [[0, 0], [1, 0], [1, 1], [0, 1]].map(e => e.map((w, i) => this.lookAt[e[i]][i])); this.lookAtBoxEdges = this.lookAtBox.map((e, i, a) => [e, V.sub(a[(i+1)%a.length], e)]); this.ratios = lookAt[0].map((e, i, a) => (projectTo[1][i] - projectTo[0][i])/(lookAt[1][i] - lookAt[0][i])); } update(...data) { let from = data[0]; let to = data[1]; const intersections = this.lookAtBoxEdges.map(edge => Intersection.info(...edge, data[0], V.sub(to, from))).filter(int => int !== false && (0 <= int[1] && int[1] < 1 && 0 <= int[2] && int[2] <= 1)); const insiders = data.map(pt => Intersection.inside(this.lookAtBox, pt)); const collinear = (() => { //check if segment from-to overlaps with border (collinear) if(from[0] == to[0]) { //vertical line //make the line go bottom let fromY = Math.min(from[1], to[1]); let toY = Math.max(from[1], to[1]); if(fromY < this.lookAt[0][1] && toY < this.lookAt[0][1] || fromY > this.lookAt[1][1] && toY > this.lookAt[1][1]) { return false; } if(from[0] != this.lookAt[0][0] && from[0] != this.lookAt[1][0]) { return false; } if(from[0] == this.lookAt[1][0] &&//right lookat (this.edge & GRID.RIGHT) == 0) { //if it's not the right lens return false; //skip collinear } if(fromY <= this.lookAt[0][1]) { from = [from[0], this.lookAt[0][1]]; } if(lookAt[1][1] <= toY) { to = [from[0], this.lookAt[1][1]]; } return true; } else if (from[1] == to[1]) { //horizontal line //make the line go right let fromX = Math.min(from[0], to[0]); let toX = Math.max(from[0], to[0]); if(fromX < this.lookAt[0][0] && toX < this.lookAt[0][0] || fromX > this.lookAt[1][0] && toX > this.lookAt[1][0]) { return false; } if(from[1] != this.lookAt[0][1] && from[1] != this.lookAt[1][1]) { return false; } if(from[1] == this.lookAt[1][1] &&//bottom lookat (this.edge & GRID.BOTTOM) == 0) { //if it's not the bottom lens return false; //skip collinear } if(fromX <= this.lookAt[0][0]) { from = [this.lookAt[0][0], from[1]]; } if(lookAt[1][0] <= toX) { to = [this.lookAt[1][0], from[1]]; } return true; } return false; })(); if(!collinear && !insiders.every(i => i)) { //if not both inside if(intersections.length == 0) { //and not intersections return; //bail } intersections.sort((a, b) => a[2] < b[2]? -1: 1); if(insiders.every(i => !i)) { //both outside from = intersections[0][0]; to = intersections[intersections.length - 1][0]; } else { //one inside if(insiders[0]) { to = intersections[intersections.length - 1][0]; } else { from = intersections[0][0]; } } } this.projector.jump(V.add(V.mul(V.sub(from, this.midLookAt), this.ratios), this.midProjectTo)); this.projector.goto(V.add(V.mul(V.sub(to, this.midLookAt), this.ratios), this.midProjectTo)); } } return new SquareLens(turtleToObserve, lookAt, projectTo, edge, projector); } // Below is automatically maintained by Turtlelib 1.0 // Changes below this comment might interfere with its correct functioning. function turtlelib_init() { turtlelib_ns_c6665b0e9b_Jurgen_Vector_Math(); turtlelib_ns_c5f8fa95ed_Jurgen_Intersection(); } // Turtlelib Jurgen Vector Math v 4 - start - {"id":"c6665b0e9b","package":"Jurgen","name":"Vector Math","version":"4"} function turtlelib_ns_c6665b0e9b_Jurgen_Vector_Math() { ///////////////////////////////////////////////////////// // Vector functions - Created by Jurgen Westerhof 2024 // ///////////////////////////////////////////////////////// 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 equals(a,b) { return !a.some((e, i) => e != b[i]); } 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)); } static clamp(a,min,max) { return a.map((e,i) => Math.min(Math.max(e, min[i]), max[i])) }; static rotateClamp(a,min,max) { return a.map((e,i) => {const d = max[i]-min[i];if(d == 0) return min[i];while(e < min[i]) { e+=d; }while(e > max[i]) { e-=d; }return e;}); } } this.V = Vector; } // Turtlelib Jurgen Vector Math v 4 - end // Turtlelib Jurgen Intersection v 4 - start - {"id":"c5f8fa95ed","package":"Jurgen","name":"Intersection","version":"4"} function turtlelib_ns_c5f8fa95ed_Jurgen_Intersection() { /////////////////////////////////////////////////////////////// // Intersection functions - Created by Jurgen Westerhof 2024 // /////////////////////////////////////////////////////////////// class Intersection { //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]).map(e => ({position: e[1][0],tourIndex: e[0],tourSegmentPortion: e[1][1],segmentPortion: e[1][2],}));} static inside(tour, pt) { return tour.map((e,i,a) => this.segment(e, a[(i+1)%a.length], pt, [Number.MAX_SAFE_INTEGER, 0], true, false)).filter(e => e !== false).length % 2 == 1; } static circles(centerA, radiusA, centerB, radiusB) {const result = {intersect_count: 0,intersect_occurs: true,one_is_in_other: false,are_equal: false,point_1: [null, null],point_2: [null, null],};const dx = centerB[0] - centerA[0];const dy = centerB[1] - centerA[1];const dist = Math.hypot(dy, dx);if (dist > radiusA + radiusB) {result.intersect_occurs = false;}if (dist < Math.abs(radiusA - radiusB) && !N.approx(dist, Math.abs(radiusA - radiusB))) {result.intersect_occurs = false;result.one_is_in_other = true;}if (V.approx(centerA, centerB) && radiusA === radiusB) {result.are_equal = true;}if (result.intersect_occurs) {const centroid = (radiusA**2 - radiusB**2 + dist * dist) / (2.0 * dist);const x2 = centerA[0] + (dx * centroid) / dist;const y2 = centerA[1] + (dy * centroid) / dist;const prec = 10000;const h = (Math.round(radiusA**2 * prec)/prec - Math.round(centroid**2 * prec)/prec)**.5;const rx = -dy * (h / dist);const ry = dx * (h / dist);result.point_1 = [x2 + rx, y2 + ry];result.point_2 = [x2 - rx, y2 - ry];if (result.are_equal) {result.intersect_count = Infinity;} else if (V.equals(result.point_1, result.point_2)) {result.intersect_count = 1;} else {result.intersect_count = 2;}}return result;} } this.Intersection = Intersection; } // Turtlelib Jurgen Intersection v 4 - end