From 1b172e02cde4bca53c0afd3bfc367f81b6b1a90b Mon Sep 17 00:00:00 2001
From: Demonstrandum <samuel@knutsen.co>
Date: Mon, 24 Jul 2023 09:43:17 +0200
Subject: [PATCH] Avoid redefining global properties.

---
 lib/BasicCanvas.js | 233 ++++++++++++++++++++++++---------------------
 1 file changed, 123 insertions(+), 110 deletions(-)

diff --git a/lib/BasicCanvas.js b/lib/BasicCanvas.js
index d5be8c8..fdc7658 100755
--- a/lib/BasicCanvas.js
+++ b/lib/BasicCanvas.js
@@ -19,11 +19,18 @@ if (in_node) {
   }
 }
 
+let already_patched = (typeof window !== 'undefined'
+    && typeof window._basiccanvas_imported !== 'undefined')
+    || Object.prototype.hasOwnProperty('clone');
+
 // Basic semi-related tools.
 export const clone = obj => Object.assign(Object.create(Object.getPrototypeOf(obj)), obj);
-Object.prototype.clone = function () {
-  return clone(this);
-};
+
+if (!already_patched) {
+  Object.prototype.clone = function () {
+    return clone(this);
+  };
+}
 
 export const type = element => (
   ({}).toString.call(element).match(/\s([a-zA-Z]+)/)[1].toLowerCase()
@@ -60,120 +67,126 @@ export const style = string => {
 export const css = (s, ...exps) => style(plain(s, ...exps));
 
 // Patching and Monkey Patching prototypes.
-Math.TAU = 2 * Math.PI;
-Math.HALF_PI = Math.PI * 0.5;
-Math.triangle = t => Math.abs(((t - 1) % 4) - 2) - 1;
+if (!already_patched) {
+  Math.TAU = 2 * Math.PI;
+  Math.HALF_PI = Math.PI * 0.5;
+  Math.triangle = t => Math.abs(((t - 1) % 4) - 2) - 1;
 
-Number.prototype.roundTo = function (dp) {
-  return parseFloat((this).toFixed(dp));
-};
-Number.prototype.times = function (fn) {
-  for (let i = 1; i <= this.valueOf(); ++i)
-    fn(i);
-};
+  Number.prototype.roundTo = function (dp) {
+    return parseFloat((this).toFixed(dp));
+  };
+  Number.prototype.times = function (fn) {
+    for (let i = 1; i <= this.valueOf(); ++i)
+      fn(i);
+  };
 
-Array.prototype.each = Array.prototype.forEach;
-Array.prototype.select = Array.prototype.filter;
-Array.prototype.reject = function (lambda, array) {
-  return this.filter((e) => !lambda(e), array)
-};
-Array.prototype.mag = function () {
-  return Math.sqrt(this.reduce((i, j) => i + j ** 2, 0));
-};
-Array.prototype.normalize = function () {
-  if (this.every(e => e === 0)) {
-    return this;
-  }
-  return this.map(e => e / this.mag());
-};
-Array.prototype.rotate = function (theta, origin=[0,0]) {
-  return [  // Only 2D
-    origin[0] + (this[0] - origin[0]) * Math.cos(theta) - (this[1] - origin[1]) * Math.sin(theta),
-    origin[1] + (this[0] - origin[0]) * Math.sin(theta) + (this[1] - origin[1]) * Math.cos(theta)
-  ];
-};
-Object.defineProperty(Array.prototype, 'x', {
-  get: function x() {
-    return this[0];
-  },
-  set: function x(new_x) {
-    return this[0] = new_x;
-  }
-});
-Object.defineProperty(Array.prototype, 'y', {
-  get: function y() {
-    return this[1];
-  },
-  set: function y(new_y) {
-    return this[1] = new_y;
-  }
-});
-Object.defineProperty(Array.prototype, 'z', {
-  get: function y() {
-    return this[2];
-  },
-  set: function z(new_z) {
-    return this[2] = new_z;
-  }
-});
-Object.defineProperty(Array.prototype, 'first', {
-  get: function first() {
-    return this[0];
-  },
-  set: function first(other) {
-    return this[0] = other;
-  }
-});
-Object.defineProperty(Array.prototype, 'last', {
-  get: function last() {
-    return this[this.length - 1];
-  },
-  set: function last(other) {
-    return this[this.length - 1] = other;
-  }
-});
-Object.defineProperty(Array.prototype, 'tail', {
-  get: function tail() {
-    return this.slice(1);
-  }
-});
-Object.defineProperty(Array.prototype, 'point', {
-  get: function point() {
-    return Point(this[0], this[1]);
-  }
-});
-Array.prototype.head = Array.prototype.first;
-
-String.prototype.replaceAll = function (search, replacement) {
-  return this.replace(new RegExp(search, 'g'), replacement);
-};
+  Array.prototype.each = Array.prototype.forEach;
+  Array.prototype.select = Array.prototype.filter;
+  Array.prototype.reject = function (lambda, array) {
+    return this.filter((e) => !lambda(e), array)
+  };
+  Array.prototype.mag = function () {
+    return Math.sqrt(this.reduce((i, j) => i + j ** 2, 0));
+  };
+  Array.prototype.normalize = function () {
+    if (this.every(e => e === 0)) {
+      return this;
+    }
+    return this.map(e => e / this.mag());
+  };
+  Array.prototype.rotate = function (theta, origin=[0,0]) {
+    return [  // Only 2D
+      origin[0] + (this[0] - origin[0]) * Math.cos(theta) - (this[1] - origin[1]) * Math.sin(theta),
+      origin[1] + (this[0] - origin[0]) * Math.sin(theta) + (this[1] - origin[1]) * Math.cos(theta)
+    ];
+  };
+  Object.defineProperty(Array.prototype, 'x', {
+    get: function x() {
+      return this[0];
+    },
+    set: function x(new_x) {
+      return this[0] = new_x;
+    }
+  });
+  Object.defineProperty(Array.prototype, 'y', {
+    get: function y() {
+      return this[1];
+    },
+    set: function y(new_y) {
+      return this[1] = new_y;
+    }
+  });
+  Object.defineProperty(Array.prototype, 'z', {
+    get: function y() {
+      return this[2];
+    },
+    set: function z(new_z) {
+      return this[2] = new_z;
+    }
+  });
+  Object.defineProperty(Array.prototype, 'first', {
+    get: function first() {
+      return this[0];
+    },
+    set: function first(other) {
+      return this[0] = other;
+    }
+  });
+  Object.defineProperty(Array.prototype, 'last', {
+    get: function last() {
+      return this[this.length - 1];
+    },
+    set: function last(other) {
+      return this[this.length - 1] = other;
+    }
+  });
+  Object.defineProperty(Array.prototype, 'tail', {
+    get: function tail() {
+      return this.slice(1);
+    }
+  });
+  Object.defineProperty(Array.prototype, 'point', {
+    get: function point() {
+      return Point(this[0], this[1]);
+    }
+  });
+  Array.prototype.head = Array.prototype.first;
 
-HTMLElement.prototype.html = function (s, ...exps) {
-  const contain = document.createElement('del');
-  contain.style.textDecoration = 'none';
-  contain.innerHTML = String.raw(s, ...exps);
-  this.appendChild(contain);
-};
+  String.prototype.replaceAll = function (search, replacement) {
+    return this.replace(new RegExp(search, 'g'), replacement);
+  };
+
+  HTMLElement.prototype.html = function (s, ...exps) {
+    const contain = document.createElement('del');
+    contain.style.textDecoration = 'none';
+    contain.innerHTML = String.raw(s, ...exps);
+    this.appendChild(contain);
+  };
 
-HTMLElement.prototype.css = function (properties) {
-  for (const property in properties) {
-    if (Object.prototype.hasOwnProperty.call(properties, property)) {
-      this.style[property] = properties[property];
+  HTMLElement.prototype.css = function (properties) {
+    for (const property in properties) {
+      if (Object.prototype.hasOwnProperty.call(properties, property)) {
+        this.style[property] = properties[property];
+      }
     }
-  }
-};
+  };
 
-Object.prototype.omap = function (lambda) {
-  return Object.assign({},
-    ...Object.keys(this).map(k =>
-      ({[k]: lambda(this[k])})));
-};
+  Object.prototype.omap = function (lambda) {
+    return Object.assign({},
+      ...Object.keys(this).map(k =>
+        ({[k]: lambda(this[k])})));
+  };
 
-Object.defineProperty(HTMLElement.prototype, 'elem', {
-  get: function elem() {
-    return this;
-  },
-});
+  Object.defineProperty(HTMLElement.prototype, 'elem', {
+    get: function elem() {
+      return this;
+    },
+  });
+}
+
+if (typeof window !== 'undefined') {
+  window._basiccanvas_imported = true;
+}
 
 // More interaction-specific tools
 export const click = (handler, canvas = null) => {