morisono · October 21, 2025 07:19 · Sep 17, 2015 · Jul 6, 2015 · Jul 6, 2015 · Jul 3, 2015
diff --git a/Readme.md b/Readme.md
@@ -1,4 +1,10 @@
 Make a circle circle pack to fill any arbitrary shape (loaded from an SVG file) inspired by http://mathematica.stackexchange.com/questions/40334/generating-visually-pleasing-circle-packs
 
 Live example:
-http://bl.ocks.org/gouldingken/8d0b7a05b0b0156da3b8
+http://bl.ocks.org/gouldingken/8d0b7a05b0b0156da3b8
+
+Gist:
+https://gist.github.com/gouldingken/8d0b7a05b0b0156da3b8
+
+The same approach using squares instead of circles:
+http://bl.ocks.org/gouldingken/25df41d631a3557d80b7
diff --git a/Readme.md b/Readme.md
@@ -0,0 +1,4 @@
+Make a circle circle pack to fill any arbitrary shape (loaded from an SVG file) inspired by http://mathematica.stackexchange.com/questions/40334/generating-visually-pleasing-circle-packs
+
+Live example:
+http://bl.ocks.org/gouldingken/8d0b7a05b0b0156da3b8
diff --git a/circlePackShape.js b/circlePackShape.js
@@ -104,7 +104,7 @@ $(document).ready(function () {
     var $canvas = $('<canvas>').attr(_canvasProps).appendTo('body');
     var $canvas2 = $('<canvas>').attr(_canvasProps).appendTo('body');
     var ctx = $canvas[0].getContext('2d');
-    _drawSvg(ctx, 'data/note.svg', function() {
+    _drawSvg(ctx, 'note.svg', function() {
         var imgData = ctx.getImageData(0, 0, _canvasProps.width, _canvasProps.height);
         _placeCircles(imgData);
         _drawCircles($canvas2[0].getContext('2d'));

diff --git a/index.html b/index.html
@@ -4,9 +4,8 @@
     <meta charset="UTF-8">
     <title>Shape Circles</title>
     <script src="https://code.jquery.com/jquery-2.1.3.min.js"></script>
-    <link rel="stylesheet" href="styles/main.css"/>
 </head>
 <body>
-<script src="js/main.js"></script>
+<script src="circlePackShape.js"></script>
 </body>
 </html>
diff --git a/index.html b/index.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html>
+<head lang="en">
+    <meta charset="UTF-8">
+    <title>Shape Circles</title>
+    <script src="https://code.jquery.com/jquery-2.1.3.min.js"></script>
+    <link rel="stylesheet" href="styles/main.css"/>
+</head>
+<body>
+<script src="js/main.js"></script>
+</body>
+</html>
diff --git a/note.svg b/note.svg
diff --git a/main.js → circlePackShape.js b/main.js → circlePackShape.js
diff --git a/main.js b/main.js
@@ -0,0 +1,113 @@
+var _canvasProps = {width: 300, height: 300};
+var _options = {spacing: 1, numCircles: 1000, minSize: 1, maxSize: 10, higherAccuracy: false};
+var _placedCirclesArr = [];
+
+var _isFilled = function (imgData, imageWidth, x, y) {
+    x = Math.round(x);
+    y = Math.round(y);
+    var a = imgData.data[((imageWidth * y) + x) * 4 + 3];
+    return a > 0;
+};
+
+var _isCircleInside = function (imgData, imageWidth, x, y, r) {
+    //if (!_isFilled(imgData, imageWidth, x, y)) return false;
+    //--use 4 points around circle as good enough approximation
+    if (!_isFilled(imgData, imageWidth, x, y - r)) return false;
+    if (!_isFilled(imgData, imageWidth, x, y + r)) return false;
+    if (!_isFilled(imgData, imageWidth, x + r, y)) return false;
+    if (!_isFilled(imgData, imageWidth, x - r, y)) return false;
+    if (_options.higherAccuracy) {
+        //--use another 4 points between the others as better approximation
+        var o = Math.cos(Math.PI / 4);
+        if (!_isFilled(imgData, imageWidth, x + o, y + o)) return false;
+        if (!_isFilled(imgData, imageWidth, x - o, y + o)) return false;
+        if (!_isFilled(imgData, imageWidth, x - o, y - o)) return false;
+        if (!_isFilled(imgData, imageWidth, x + o, y - o)) return false;
+    }
+    return true;
+};
+
+var _touchesPlacedCircle = function (x, y, r) {
+    return _placedCirclesArr.some(function (circle) {
+        return _dist(x, y, circle.x, circle.y) < circle.size + r + _options.spacing;//return true immediately if any match
+    });
+};
+
+var _dist = function (x1, y1, x2, y2) {
+    var a = x1 - x2;
+    var b = y1 - y2;
+    return Math.sqrt(a * a + b * b);
+};
+
+var _placeCircles = function (imgData) {
+    var i = _circles.length;
+    _placedCirclesArr = [];
+    while (i > 0) {
+        i--;
+        var circle = _circles[i];
+        var safety = 1000;
+        while (!circle.x && safety-- > 0) {
+            var x = Math.random() * _canvasProps.width;
+            var y = Math.random() * _canvasProps.height;
+            if (_isCircleInside(imgData, _canvasProps.width, x, y, circle.size)) {
+                if (!_touchesPlacedCircle(x, y, circle.size)) {
+                    circle.x = x;
+                    circle.y = y;
+                    _placedCirclesArr.push(circle);
+                }
+            }
+        }
+    }
+};
+
+var _makeCircles = function () {
+    var circles = [];
+    for (var i = 0; i < _options.numCircles; i++) {
+        var circle = {
+            color: _colors[Math.round(Math.random() * _colors.length)],
+            size: _options.minSize + Math.random() * Math.random() * (_options.maxSize - _options.minSize) //do random twice to prefer more smaller ones
+        };
+        circles.push(circle);
+    }
+    circles.sort(function (a, b) {
+        return a.size - b.size;
+    });
+    return circles;
+};
+
+var _drawCircles = function (ctx) {
+    ctx.save();
+    $.each(_circles, function (i, circle) {
+        ctx.fillStyle = circle.color;
+        ctx.beginPath();
+        ctx.arc(circle.x, circle.y, circle.size, 0, 2 * Math.PI);
+        ctx.closePath();
+        ctx.fill()
+    });
+
+    ctx.restore();
+};
+
+var _drawSvg = function (ctx, path, callback) {
+    var img = new Image(ctx);
+    img.onload = function () {
+        ctx.drawImage(img, 0, 0);
+        callback();
+    };
+    img.src = path;
+};
+
+var _colors = ['#993300', '#a5c916', '#00AA66', '#FF9900'];
+var _circles = _makeCircles();
+
+$(document).ready(function () {
+    var $canvas = $('<canvas>').attr(_canvasProps).appendTo('body');
+    var $canvas2 = $('<canvas>').attr(_canvasProps).appendTo('body');
+    var ctx = $canvas[0].getContext('2d');
+    _drawSvg(ctx, 'data/note.svg', function() {
+        var imgData = ctx.getImageData(0, 0, _canvasProps.width, _canvasProps.height);
+        _placeCircles(imgData);
+        _drawCircles($canvas2[0].getContext('2d'));
+    });
+
+});