Basic mechanical unit tests for the separating axis algorithm.

Makefile

@@ -2,6 +2,7 @@
 
 HAML=/usr/bin/haml
 COFFEE = coffee
+TSC=tsc
 LESSCSS=lessc
 SED=sed
 COMPILER=uglifyjs 
@@ -11,14 +12,20 @@ INCLUDES= js/jquery-1.6.2.min.js js/underscore.js js/backbone.js js/jquery-ui-1.
 all: index.html style.css js/magnets.js js/sat.js js/wordlist.js
 
 js/magnets.js: src/magnets.coffee
-	$(COFFEE) --compile --lint  --output js/ $<
+	$(COFFEE) --compile --output js/ $<
 
 js/wordlist.js: src/wordlist.coffee
-	$(COFFEE) --compile --lint --bare --output js/ $<
+	$(COFFEE) --compile --no-header --bare --output js/ $<
 	$(SED) -i -e '$$ s/;$$//' $@
 
-js/sat.js: src/sat.coffee
-	$(COFFEE) --compile --lint  --output js/ $<
+js/sat.js: src/sat.ts
+	$(TSC) $< --outDir js/ --module "commonjs"
+
+js/test_sat.js: src/test_sat.ts
+	$(TSC) $< --outDir js/ --module "commonjs"
+
+test: js/test_sat.js js/sat.js
+	node_modules/nodeunit/bin/nodeunit js/test_sat.js
 
 style.css: src/style.less
 	$(LESSCSS) $< $@

src/sat.ts

@@ -0,0 +1,135 @@
+/**
+ Copyright (c) 2012, 2016 Elf M. Sternberg
+
+ Much of the code here I would never have understood if it hadn't been
+ for the patient work of Caleb Helbling (http://www.propulsionjs.com/),
+ as well as the Wikipedia pages for the Separating Axis Theorem.  It
+ took me a week to wrap my head around these ideas.
+ 
+ Permission is hereby granted, free of charge, to any person obtaining a copy
+ of this software and associated documentation files (the "Software"), to deal
+ in the Software without restriction, including without limitation the rights
+ to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ copies of the Software, and to permit persons to whom the Software is
+ furnished to do so, subject to the following conditions:
+  
+ The above copyright notice and this permission notice shall be included in
+ all copies or substantial portions of the Software.
+  
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ THE SOFTWARE.
+*/
+
+
+class Vector {
+    x: number;
+    y; number;
+
+    constructor(x: number, y: number) {
+        this.x = x;
+        this.y = y;
+    }
+
+    add(v2: Vector) {
+        return new Vector(this.x + v2.x, this.y + v2.y);
+    }
+
+    scalar(s: number) {
+        return new Vector(this.x * s, this.y * s);
+    }
+
+    magnitude2 () {
+        return this.x * this.x + this.y * this.y;
+    }
+
+    magnitude() { 
+        return Math.sqrt(this.magnitude2()); 
+    }
+
+    normalize() {
+        const mag = this.magnitude();
+        return new Vector(this.x / mag, this.y / mag);
+    }
+
+    leftNormal() {
+        return new Vector(this.y * -1, this.x)
+    }
+}
+
+var range = (function() {
+    var memos = {}
+    var range = (length) => {
+        if (memos[length]) {
+            return memos[length];
+        }
+        return memos[length] = Array.apply(null, {length: length}).map(Number.call, Number);
+    }
+    return range;
+})();
+
+var colliding = (shape1, shape2) => {
+    var genAxes = (shape) => {
+        if (shape.length < 3) {
+            throw "Cannot handle non-polygons";
+        }
+        
+        var axis = (pi) => {
+            const p1 = shape[pi];
+            const p2 = shape[pi == (shape.length - 1) ? 0 : pi + 1];
+            return (new Vector(p1.x - p2.x, p1.y - p2.y)).normalize();
+        }
+        
+        return range(shape.length).map(axis);
+    }
+
+    var genProjection = (shape, axis) => {
+        var min = axis.dot(shape[0]);
+        var max = min;
+        for (let i of range(shape.length()).shift()) {
+            var p = axis.dot(shape[i])
+            if (p < min) { min = p; }
+            if (p > max) { max = p; }
+        }
+        return {min: min, max: max}
+    }
+
+    var axes1 = genAxes(shape1);
+    var axes2 = genAxes(shape2);
+    var axes = axes1.concat(axes);
+    for (let axis of axes) {
+        var proj1 = genProjection(shape1, axis);
+        var proj2 = genProjection(shape2, axis);
+        if (! ((proj1.min >= proj2.min && proj1.min <= proj2.max) ||
+               (proj1.max >= proj2.min && proj1.max <= proj2.max) ||
+               (proj2.min >= proj1.min && proj2.min <= proj1.max) ||
+               (proj2.max >= proj1.min && proj2.max <= proj1.max)))
+            return false;
+    }
+    return true;
+}
+
+module.exports = {
+    Vector: Vector,
+    colliding: colliding
+}            
+
+        
+    
+
+        
+        
+
+            
+            
+        
+
+
+
+    
+
+        

src/test_sat.ts

@@ -0,0 +1,40 @@
+var testCase = require('nodeunit').testCase;
+var Vector = require('./sat').Vector;
+
+module.exports = testCase({
+    "TestAddition": (test) => {
+        var m = (new Vector(1, 1)).add(new Vector(-1, -1));
+        test.ok(m.x == 0 && m.y == 0);
+        var n = (new Vector(1, 1)).add(new Vector(1, 1));
+        test.ok(n.x == 2 && n.y == 2);
+        test.done();
+    },
+
+    "TestScalar": (test) => {
+        var m = (new Vector(2, 2)).scalar(2);
+        test.ok(m.x == 4 && m.y == 4);
+        test.done();
+    },
+
+    "TestMag2": (test) => {
+        var m = (new Vector(2, 2)).magnitude2();
+        test.ok(m == 8);
+        test.done();
+    },
+
+    "TestMag": (test) => {
+        var m = (new Vector(2, 2)).magnitude();
+        test.ok(m == Math.sqrt(8));
+        test.done();
+    },
+
+    "TestNormalize": (test) => {
+        var m = (new Vector(5, 0)).normalize();
+        test.ok(m.x == 1 && m.y == 0);
+        m = (new Vector(0, 5)).normalize();
+        test.ok(m.x == 0 && m.y == 1);
+        m = (new Vector(4, 3)).normalize().magnitude2();
+        test.ok(m == 1);
+        test.done();
+    }
+});

tsconfig.json

@@ -0,0 +1,14 @@
+{
+    "compilerOptions": {
+        // types option has been previously configured
+         "types": [
+            // add node as an option
+            "node"
+         ],
+         // typeroots option has been previously configured
+         "typeroots": [
+            // add path to @types
+            "../node_modules/@types"
+         ]
+    }
+}