box2d-native-1 C++ methods with abstract class return type returns to JS object of abstract class

created swig typemap for b2Shape *, made corresponding changes in demo
made demo an independent package

Author: zuker

.travis.yml

@@ -3,7 +3,8 @@ env:
   - CXX=g++-4.9
 language: node_js
 node_js:
-  - "4.2.1"
+  - 4.2
+  - stable
 addons:
   apt:
     sources:

Box2D.i

@@ -9,6 +9,44 @@
 %rename(subtract) operator-=;
 %rename(multiply) operator*=;
 
+%typemap(out) b2Shape* {
+  swig_type_info *info = SWIGTYPE_p_b2CircleShape;
+  b2Shape *shape = 0;
+  shape = $1;
+  if (shape) {
+  	switch (shape->GetType())
+      {
+      	case b2Shape::e_circle:
+      		{
+      			info = SWIGTYPE_p_b2CircleShape;
+      		}
+      		break;
+
+      	case b2Shape::e_edge:
+      		{
+      			info = SWIGTYPE_p_b2EdgeShape;
+      		}
+      		break;
+
+      	case b2Shape::e_chain:
+      		{
+      			info = SWIGTYPE_p_b2ChainShape;
+      		}
+      		break;
+
+      	case b2Shape::e_polygon:
+      		{
+      			info = SWIGTYPE_p_b2PolygonShape;
+      		}
+      		break;
+
+        default:
+            break;
+			}
+  }
+  $result = SWIG_NewPointerObj(SWIG_as_voidptr($1), info, 0 |  0 );
+}
+
 %{
 #include "Box2D/Box2D.h"
 %}

README.md

@@ -18,7 +18,7 @@ npm install node-gyp -g
 npm install box2d-native
 ```
 
-**IMPORTANT:** Installation tested only in Ubuntu 15.04 with Node.js v4.2.1.
+**IMPORTANT:** Installation tested only on Linux with Node.js >= 4.2.1.
 
 ## Usage
 
@@ -35,8 +35,12 @@ Original "namespaced" Box2D classes (`b2Vec2`, `b2World`...) are also exposed.
 
 ## Demo
 
+**IMPORTANT:** Runs only with Node.js v4.2.1
+
 ```
-npm run demo
+cd demo
+npm install
+npm start
 ```
 
 

demo/demo.js

@@ -1,5 +1,5 @@
 'use strict';
-let Box2D = require('../');
+let Box2D = require('box2d-native');
 let World = Box2D.World;
 let Vec2 = Box2D.Vec2;
 let b2Vec2 = Box2D.b2Vec2;
@@ -9,10 +9,7 @@ let b2Mul = Box2D.b2Mul;
 let b2Assert = Box2D.b2Assert;
 let b2_maxPolygonVertices = Box2D.b2_maxPolygonVertices;
 let b2Color = Box2D.b2Color;
-let _clientDebugDraw;
 let world = new World(new Vec2(0, -9.8));
-let _ = require('../node_modules/lodash');
-let util = require('util');
 let step;
 
 var bd_ground = new Box2D.b2BodyDef();
@@ -32,42 +29,31 @@ let fixture = ground.CreateFixture(shape, 0.0);
 let circleFixture = circle.CreateFixture(circleShape, 0.0);
 circleFixture.SetRestitution(0.5);
 
-fixture._shape = shape;
-circleFixture._shape = circleShape;
-
-ground._fixtures = [fixture];
-circle._fixtures = [circleFixture];
-
-world._bodies = [ground, circle];
 function DrawShape(fixture, xf, color, g_debugDraw) {
-
+  let shape = fixture.GetShape();
   switch (fixture.GetType())
   {
     case b2Shape.e_circle:
     {
-      let circle = fixture._shape;
-
-      let center = b2Mul(xf, circle.m_p);
-      let radius = circle.m_radius;
+      let center = b2Mul(xf, shape.m_p);
+      let radius = shape.m_radius;
       let axis = b2Mul(xf.q, new b2Vec2(1.0, 0.0));
         g_debugDraw.DrawSolidCircle(center, radius, axis, color);
     }
       break;
 
     case b2Shape.e_edge:
     {
-      let edge = fixture._shape;
-      let v1 = b2Mul(xf, edge.m_vertex1);
-      let v2 = b2Mul(xf, edge.m_vertex2);
+      let v1 = b2Mul(xf, shape.m_vertex1);
+      let v2 = b2Mul(xf, shape.m_vertex2);
         g_debugDraw.DrawSegment(v1, v2, color);
     }
       break;
 
     case b2Shape.e_chain:
     {
-      let chain = fixture.GetShape();
-      let count = chain.m_count;
-      const vertices = chain.m_vertices;
+      let count = shape.m_count;
+      const vertices = shape.m_vertices;
 
       let v1 = b2Mul(xf, vertices[0]);
       for (let i = 1; i < count; ++i)
@@ -82,14 +68,13 @@ function DrawShape(fixture, xf, color, g_debugDraw) {
 
     case b2Shape.e_polygon:
     {
-      let poly = fixture.GetShape();
-      let vertexCount = poly.m_count;
+      let vertexCount = shape.m_count;
       b2Assert(vertexCount <= b2_maxPolygonVertices);
       let vertices = new Array(b2_maxPolygonVertices);
 
       for (let i = 0; i < vertexCount; ++i)
       {
-        vertices[i] = b2Mul(xf, poly.m_vertices[i]);
+        vertices[i] = b2Mul(xf, shape.m_vertices[i]);
       }
 
         g_debugDraw.DrawSolidPolygon(vertices, vertexCount, color);
@@ -109,9 +94,9 @@ world.DrawDebugData = function () {
   let flags = this._debugDraw.GetFlags();
 
   if (flags & Box2D.b2Draw.e_shapeBit) {
-    for (let b, j = 0; b = this._bodies[j]; j++) {
+    for (let b = this.GetBodyList(); b; b = b.GetNext()) {
       let xf = b.GetTransform();
-      for (let i = 0, f; f = b._fixtures[i]; i++) {
+      for (let f = b.GetFixtureList(); f; f = f.GetNext()) {
         if (b.IsActive() == false)
         {
           DrawShape(f, xf, b2Color(0.5, 0.5, 0.3), this._debugDraw);

demo/package.json

@@ -1,4 +1,14 @@
 {
   "name": "box2d-native-demo",
-  "main": "index.js"
-}
+  "main": "index.js",
+  "engines": {
+    "node": "4.2.1"
+  },
+  "dependencies": {
+    "box2d-native": "file:..",
+    "electron-prebuilt": "^0.34.2"
+  },
+  "scripts": {
+    "start": "node node_modules/.bin/electron ."
+  }
+}

package.json

@@ -37,8 +37,7 @@
     "preinstall": "npm run clean && npm run get && npm run untar && npm run patch && npm run make && npm run wrap",
     "install": "node-gyp configure && node-gyp build",
     "postinstall": "npm run clean && node node_modules/.bin/babel Box2D.es6 --out-file Box2D.js --source-maps --whitelist strict,es6.modules,es6.parameters,es6.spread,es6.destructuring",
-    "test": "node node_modules/.bin/mocha -r tests/bootstrap.js tests/**/*.spec.js",
-    "demo": "node node_modules/.bin/electron demo/"
+    "test": "node node_modules/.bin/mocha -r tests/bootstrap.js tests/**/*.spec.js"
   },
   "contributors": [
     "Leonid Kuzmin <[email protected]> (https://github.com/zuker)"
@@ -50,7 +49,6 @@
     "lodash": "^3.10.1"
   },
   "devDependencies": {
-    "electron-prebuilt": "^0.34.2",
     "mocha": "^2.3.3",
     "should": "^7.1.1"
   }