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Background

This sample's primary intent is to serve as a Getting Started sample for Cocos2d-HTML5 with BlackBerry 10. In this sample, a few key concepts have been implemented including: Cocos2d-HTML5 initialization, parsing TMX files, Box2DWeb implementation, Web Workers, and more. See the Key Features section for complete details.

If you have any feedback or find any issues, please feel free to report them in the Issues section, or contact me directly via Twitter: @WaterlooErik

Key Features

Cocos2d-HTML5 with BlackBerry 10

This sample provides a basic skeleton implementation of the following files:

  • config.xml: Defines the basic properties (name, content, etc.) for our BlackBerry 10 WebWorks/HTML5 application.
  • index.html: Our main content to load, initializes WebWorks and kicks off Cocos2d-HTML5.
  • main.js: Creates our Cocos2d-HTML5 application and preloads our resources.
  • SceneStart.js: Initiates our main Cocos2d-HTML5 Scene and Layer, and kicks off the physics Web Worker.

Because this is a sample intended for the BlackBerry platform, to run this application on a desktop browser you will need to either:

  • Modify index.html to explicitly call onwebworksready(); instead of adding the event listener; or
  • Leverage the Ripple Emulator in Chrome for the missing WebWorks functionality.

To successfully compile this application, there are two approaches. First, if you've cloned this repository from Github, you're already set as the BB10-WebWorks-Community-Samples/Boxquest/cocos folder should already be populated. You can also copy the cocos folder to the appropriate tutorials to allow them to run as well. This is possible since the Cocos2d-HTML5 framework is included as a submodule in Github and is the recommended approach.

Alternatively, you can download the Cocos2d-HTML5 framework from Github, however for best results please use this specific version: https://github.com/cocos2d/cocos2d-html5/tree/a02ffc496de71ec3c51a98ce4a71dffaab0a69e8

Once downloaded, the process would be the same; specifically to copy the Cocos2d-HTML5 framework into the cocos subfolders of the main project and tutorials. For reference, the file structure should be that cocos2d is a direct child of the cocos folder.

Virtual Controls (Freewill.js)

Freewill.js is a Joystick and Button framework intially developed for Cocos2d-HTML5. It was then generalized to be framework agnostic while developing PeaksAndValleys. There have been some slight modifications to meet the requirements for this sample, but ultimately Freewill.js can be leveraged in any HTML5 application requiring virtual controls. For a basic sample implementation, please see: https://github.com/oros/Freewill.js

The code is currently commented out, but if you would like to use the keyboard to control the hero, you can make the modifications in SceneStart.js to accept keyboard input instead of leveraging Freewill.js.

Box2DWeb Implementation

Note that Cocos2d-HTML5 inclusion of Box2D is actually disabled in index.html. This was done to preserve control over which version of Box2D is being used within this sample. Instead Box2DWeb version 2.1.a.3 was downloaded from the following URL and imported directly into Box2dWebWorker.js: http://box2dweb.googlecode.com/svn/trunk/

Web Workers

On the initial implementation of Box2dWeb, I experienced a lot of issues with objects falling through walls and missing collisions. I also noticed that when the implementation was tested outside of the Cocos2d-HTML5 framework, these issues did not occur. Initially, I had been performing the physics calculations within a scheduled update function in my primary Cocos2d-HTML5 Layer.

It seems that there may be some timing issues with Cocos2d-HTML's update and the requirements of Box2DWeb's update implementations. Upon moving all of Box2dWeb's initialization and processing into a separate Web Worker, all collision issues disappeared.

While this requires passing values between the main application thread and Web Worker to maintain object positions and orientations, the end result is a fully functioning implementation with the bonus of putting less strain on the main application thread where UI and rendering occur.

TMX Importing

TMX files can be created using Tiled and store tilemap information that can be loaded into a Cocos2d-HTML5 application. There were a few issues encountered however when loading a TMX file on the BlackBerry platform:

The TMX object (cc.TMXTiledMap) would not actually display the TMX image until a refresh was completed. This is an issue for a BlackBerry WebWorks application where you do not have any browser navigation at hand.

To counter the image display, instead of adding a cc.TMXTiledMap to the Layer, we actually add a cc.Sprite with a picture of the tilemap. Tiled permits you to export an image of the tilemap, so this part was relatively easy. We do still process the cc.TMXTiledMap object behind the scenes when creating our walls with Box2DWeb and placing various objects (spawns, coins, etc.) around the world.

The TMX extension on the filename was causing the Ripple Emulator to associate an improper MIME type and fail loading.

A TMX file is actually just an XML file with a custom name, so to counter the Ripple Emulator issue, I simply renamed the exported TMX file to XML, and loaded that into the Cocos2d-HTML5 application instead of the TMX version. The underlying files are exactly the same, it is simply the extension that changes.

Custom Level Creation with Tiled

As noted, Tiled was used to create the TMX file that contains the information about the world. Our application then processes that TMX file and generates the world at runtime. As such, it is possible to replace the existing TMX file with your own version. To get a better understanding of how this file was created, it would be simplest to view 0-0.tmx with Tiled.

Please note that 0-0.tmx relies on tiles.png in the images folder.

There are a few things to keep in mind regarding the TMX layers:

  • Layer0 is where you perform your drawing.
  • walls is an object layer. Each object you place will be converted into a static (fixed) body by Box2DWeb.
  • coins represents objects that will be collectible and are denoted by the yellow blocks in the game.
  • portals represents the starting point and finish point for the level. The first portal placed will act as the spawn and the second portal will act as the finish. The finish portal only becomes visible once all coins are collected.

Map Panning (TODO)

Currently the application expects a 1280x768 pixel world as no re-sizing is performed on any of the objects. The goal is to allow for much larger worlds and have the camera pan to follow the hero as the hero moves around the world.

Level Completion (TODO)

Currently nothing happens when you make it to the finish portal.

Advanced Physics (TODO)

No friction on ice, decreased gravity in water, lava collision detection, etc.

Tested With

  • BlackBerry 10 WebWorks SDK 1.0.4.5
  • BlackBerry Dev Alpha B, 10.0.9.1675

Known Issues

Currently performance is suffering a little when packaged as a WebWorks application vs. running in the browser. Investigating.

Thank You!

Immense thanks to the following people. They might not know how much they helped me, but I appreciate it none the less.