IwGameAds has been updated

IwGameAds the open source cross platform ad mediation system for Marmalade SDK users has been updated to use the very latest Marmalade SDK as well as additional features such as user agent detection for iOS and Android, which should improve ad delivery. It is now also available under the MIT license, To get the latest you should now download it from Github

IwGame Engine v0.29 Released – XOML is evolving

New here? What’s IwGame? IwGame is an open source free to use cross platform game engine for iPhone, iPad, Android, Bada, Playbook, Symbian, Windows Mobile, LG-TV, Windows and Mac, built on top of the Marmalade SDK. You can find out more and download the SDK from our IwGame Engine page.

The Universe conspired against me this week, first of all landing me with a nice flu, followed directly by some horrible sickness bug that featured projectile vomiting of the likes only seen in movies such as the Exorcist! Thankfully the Universe decided to give me a break this week so an IwGame Engine update got finished.

Most of the changes this week are XOML related as this is the general direction we want to take the game engine. A good mix of XOML mark-up and solid coding should make games and media apps very quick and easy to develop.

Oh and we got a new logo for the IwGame Engine woohoo! Feel free to use the logo in any of your IwGame powered products, or if you want to link to us.

Ok, onto the list of iwGame Engine changes for v0.29:

  • New style system added to XOML. Actors and scenes can now use a style to reduce repetition
  • Actors and scenes now handle events such as OnSuspend, OnTapped, OnBeginTouch etc.. When an event fires it executes a collection of actions
  • Actions added to XOML to allow definition of collections of actions that can be executed. Many default actions are suppported such as ChangeScene, KillScene, PlayTimeline, PlaySound etc.. Custom actions can also be added toextend the system
  • CIwGame now handles touch begin touch, end touch and tapped events
  • CIwGame now has new Postdraw() method for adding in custom post draw rendering
  • Actors can now be made tappable and now handle OnTapped(), OnBeginTouch() and OnEndTouchEvents()
  • Actors have new HitTest() method that can be used to check if a point is inside the actors visual
  • XOML now supports creation of cameras
  • XOML now supports creation of variables and update of variables using actions, supports string, bool, int, float, vec2, vec3 and vec4
  • XOML files can now load other XOML files with new LoadXOML tag as well as LoadXOML action
  • Scenes now support a type field
  • CIwGameBitmapSprite now supports image transforms (flips. mirrors etc) which can be also applied to actors visuals using FlipX and FlipY attributes
  • You now change the current time of a CIwGameAnimInstance and CIwGameAnimTimeline
  • Bug Fix – Actor visibile state now works properly
  • Bug Fix – CIwGameShape::setShape() now works
  • Bug Fix – Transform is now reset after CIwGameAdsView finishes rendering
  • Bug Fix – JPEG file detection fixed, was not detecting certain types of JPEG files
  • Bug Fix – CIwGameString::FindNext() crash fixed

Quite a few changes and bug fixes. Note that someo f the bug fixes directly affected IwGameAds so an update to that API will be released shortly.

Lets take a look at the changes in more detail.

XOML Variables

XOML got variables, but why? Well, there are a number of reasons:

  • We want to be able to define values that can be read by the main code
  • We want to change these values via actions
  • When we implement the UI system we are looking to add data binding capabilities that will rely on values

You can declare a variable in XOML like this:

    <Variable Name="PlayerName" Type="string" Value="Player One" />
    <Variable Name="PlayerScore" Type="int" Value="0" />
    <Variable Name="PlayColour" Type="vec4" Value="255, 128, 64, 8" />

You can later modify the value of that variable using a SetVar action, more on this later.

Each scene contains its own variables collection and the global resource system also contains a global variables collection.

XOML Styles

XOML now supports the styling of actors and scenes using the new Style tag. XOML styles enable you to create a set of properties and values that are common across a range of objects then apply tat style the to them all. Hers a quick


<Style Name="BasicActorStyle">
    <Set Property="Size" Value="60, 60" />
    <Set Property="Angle" Value="0" />
    <Set Property="SrcRect" Value="0, 0, 36, 40" />
    <Set Property="Image" Value="Sprites" />
    <Set Property="Timeline" Value="Player1Intro1" />
    <Set Property="Shape" Value="PlayerShape" />
    <Set Property="Box2dMaterial" Value="BounceyBall" />
    <Set Property="CollisionFlags" Value="1, 1, 1" />

<TestActor Name=”Player2″ Style=”BasicActorStyle” Position=”0, -150″ />

The TestActor Player2 will be assigned all of the values in the properties defined in the style saving you a whole bunch of typing as well as making your mark-up much more readable and easier to maintain.

XOML Events And Actions

Actors and scenes now support various events that can fire off user defined actions. The following events are currently defined:


  • OnSuspend – Called when a scene is suspended
  • OnResume – Called when a scene is resumed


  • OnTapped – Called when the user taps an actor
  • OnBeginTouch – Called when the user begins to touch an actor
  • OnEndTouch – Called when the user stops touching an actor

More will be added as we think of them or when requested. You can also add your own custom events youself. Check out the CIwGameActor class for a reference on how to do this.

Events wouldn’t really be much use unless we could carry out some kind of action when the event occurred. Actions are defined in XOML using the Actions tag, heres an example:

<Scene Name="GameScene3" Style="GenericSceneStyle" OnSuspend="SuspendActions">
    <Actions Name="SuspendActions">
        <Action Method="SetTimeline" Param1="SceneTransition1" />
        <Action Method="PlaySound" Param1="explosion" />

You actually create a group of actions that are all executed when the action is called by an event.

The following actions are currently supported:

  • ChangeScene – Changes the currently focused scene to the specified scene
  • SuspendScene – Suspends the specified sceme
  • ResumeScene– Resumes the specified sceme
  • HideScene– Hides the specified sceme
  • ShowScene– Shows the specified sceme
  • ActivateScene – Activates the specified sceme
  • DeactivateScene – Deactivates the specified sceme
  • KillScene – Destroys and removes the specified sceme from the game, all contained resources amd actors will be also be destroyed
  • HideActor – Hides the specified actor
  • ShowActor – Shows the specified actor
  • ActivateActor – Activates the specified actor
  • DeactivateActor – Deactivates the specified actor
  • KillActor – Kills and removes the specified actor
  • PlayTimeline – Plays the specified timeline. If no timeline is supplied then the current actor / scenes timeline will be restarted (depends on where the action was defined)
  • StopTimeline – Stops the specified timeline. If no timeline is supplied then the current timeline will be stopped. (depends on where the action was defined)
  • SetTimeline – Changes to the specified timeline. If no timeline is supplied then the current timeline will changed and restarted. (depends on where the action was defined)
  • PlaySound – Starts playing a sound effect
  • PlayMusic – Starts the playing specified music file
  • StopMusic – Stops the music player playing
  • LoadXOML – Loads a XOML file into scene or globally. If a scene is provided then the XOML will be loaded into that scene
  • SetVar – Sets the value of a variable

Again, more will be added as we think of them or when requested. You can also add your own custom actions youself. Check out the CIwGameXomlAction_Actors class for a reference on how to do this.

Coupled together the events and actions system provide a very powerful way of creating fully interactive content without having to write a single line of code.

Loading Other XOML Files

It is now possible to load other XOML files from a XOML file using the new LoadXOML tag. Heres an example:

<LoadXOML File="Common.xml" />
<LoadXOML File="Sceme2.xml" />
<LoadXOML File="Scene3.xml" />

You can also (as shown in the actions section) load a XOML file from an action.

Using this system you can create fully interactive navigation based content. Think adventure games, books, magazines and informational apps etc..

Scene Cameras

Cameras can now be defined in XOML and attached to scenes. You can also switch a scenes camera using the animation system.

Image Transforms for Sprites and Actors

Sprites and actors can now use an image transform allowing you to flip the source image used to render the object. The ne FlipX and FlipY attributes are now available in XOML.

Well thats it for this update. IwGame now has some very cool features that should hopefully make game / app development much easier and quicker for everyone.

We are going to assess the possibility of wrapping up Marmalades cool UI system with XOML very soon, will keep you all posted on how that goes. I am also looking at producing a new article on in-app purchasing with the Marmalade SDK, which will form the basis of in-app purchasing for the IwGame engine.

Marmalade SDK Tutorial – Quick and easy audio and music using s3eAudio and IwSound

This tutorial is part of the Marmalade SDK tutorials collection. To see the tutorials index click here

Today we are going to cover playing sound and music the very quick and very easy way using the Marmalade SDK. As usual if you just want the associated article source code then you can Download it from here. If you want the details on sound and audio with Marmalade then please read on.

I like to separate audio playback into two distinct categories, which are music and sound (or sound effects). The Marmalade SDK has two systems for playing audio:

  • S3E Audio – The S3E audio system uses the devices built-in codec’s to play back compressed audio files such as MP3. QCP and AAC (good for playing background music)
  • S3E Sound – The S3E sound system uses software mixing to play multiple uncompressed sounds simultaneously (good for playing back sound effects, such as button clicks or in-game sound effects)

Now a little more detail

S3E Audio

S3E audio uses the devices built in audio codec’s to play back compressed audio files such as MP3. QCP and AAC, although you do need to query the system to find out if the audio format is supported using
s3eBool s3eAudioIsCodecSupported ( s3eAudioCodec codec )

Valid codecs include:

  • S3E_AUDIO_CODEC_MP3 – MP3 files.
  • S3E_AUDIO_CODEC_AAC – Raw AAC files.
  • S3E_AUDIO_CODEC_AACPLUS – AAC plus files.
  • S3E_AUDIO_CODEC_QCP – QCP files.
  • S3E_AUDIO_CODEC_PCM – PCM files.
  • S3E_AUDIO_CODEC_SPF – SPF files.
  • S3E_AUDIO_CODEC_AMR – AMR files.
  • S3E_AUDIO_CODEC_MP4 – MP4 or M4A files with AAC audio.

This s3e audio system can play back audio from either a file or a memory buffer. Note when you play back a file you cannot play a file that is within a compressed derbh file as the device does not know about Marmalades derbh format. If you are using auto derbh to auto compress all of your data on deployment then you should include the audio file as an asset in your MKB’s asset section and not inside a resource group.

Here is a summary of a number of important s3e audio functions:

  • s3eBool s3eAudioIsPlaying ()
  • s3eResult s3eAudioPause ()
  • s3eResult s3eAudioPlay (const char *filename, uint32 repeatCount)
  • s3eResult s3eAudioPlayFromBuffer (void *buffer, uint32 bufferLen, uint32 repeatCount)
  • s3eResult s3eAudioResume ()

Its pretty obvious what these functions are doing so I wont go into any details other than to mention that passing a value of 0 to repeatCount causes the music to repeat playback forever.

S3E Sound

I’m not actually going to cover S3E in much depth as I did promise quick and easy sound, instead I will use the example sound engine that ships with Marmalade (located in $MARMALADE_ROOT/examples/SoundEngine). SoundEngine sits on top of S3E Sound, so if you want to see the internals of the code it’s right there for you to study. If you want to implement your very own audio engine then I suggest you start by checking out Marmalade’s s3e sound docs here

Marmalade’s Sound Engine (IwSound)

Marmalade’s IwSound example sound engine lets you easily organise sounds into resource groups and then playback and control these sound effects very easily in-game. Even though IwSound is an example sound engine it is very capable and covers much of which most developers need. In my opinion it should be included as a standard Marmalade SDK module.

Before we begin looking at the code we will take a quick look at some of the important classes that make up IwSound.

  • CIwSoundData – This class represents the actual data of your sounds (you do not need to deal with this class directly)
  • CIwSoundSpec – This class describes a sound, think of it as a sound material that specifies details about your sound data and how you want it played. You create instances of sounds from their sound specs.
  • CIwSoundInst – This class represents a playing instance of a sound spec, a new CIwSoundInst is returned each time you play a sound from a sound spec (internally these are pooled to reduce memory fragmentation). Its worth noting here that you can only play a finite number of sound effects simultaneously.
  • CIwSoundManager – The sound manager, used to update the sound engine and gives access to such things as master volume, pan and pitch etc.. The sound manager also uses the following app.icf setting to allow you to set the maximum number of simultaneous sound effects that can be played:


Ok, now we have a basic understanding of the classes we are going to use, lets take a look at how to play something.

// Get a pointer to the sound group CIwResGroup* sound_group = IwGetResManager()->GetCurrentGroup(); // Get the sound spec for our silly_sound sound effect CIwSoundSpec* SoundSpec = (CIwSoundSpec*)sound_group->GetResNamed("silly_sound", IW_SOUND_RESTYPE_SPEC); // Play the sound effect CIwSoundInst* SoundInstance = SoundSpec->Play();

And that’s all you need to load and play sounds from a group

If you would like to change attributes of the played back sound effect, such as its volume, frequency etc.. then you can call the following functions on the sound instance:

  • void SetVol(iwsfixed vol);
  • void SetPan(iwsfixed pan);
  • void SetPitch(iwsfixed pitch);
  • void Stop();
  • void Pause();
  • void Resume();

Note the vol, pan and pitch are fixed point parameters (IW_GEOM_ONE representing the value of 1.0f)

Also note that you should never delete sound instances as they are managed by the IwSoundManager. Sound specs are managed by the resource system so do not delete those either.

Lastly, the IwSound engine manager Update method needs to be called every frame:


Creating and organising sound effects with IwSound

Ok, we have looked at the basics of playing sound using IwSound, now we will look at how to organise our sounds into groups to allow the resource manager to manage them for us. If you do not know what the resource manager is then take a look at one of my previous blogs on the subject here

Firstly we need to add the WAV files that represent our individual sound files to the group like this:

// Sound sample WAV files "./silly_sound.wav" "./explosion.wav"

Next we create a CIwSoundSpec for each sound effect that we want to play:

// Create sound specs (can be thought of as sound materials) CIwSoundSpec { name "explosion" # The name we want to use to refer to this sound effect in our code data "explosion" # The wav file name (without .wav) vol 0.7 # Default volume to be played at loop false # Do we want this sound effect to play forever? } CIwSoundSpec { name "silly_sound" # The name we want to use to refer to this sound effect in our code data "silly_sound" # The wav file name (without .wav) vol 0.7 # Default volume to be played at loop false # Do we want this sound effect to play forever? }

Finally, we create a sound group to contain all of our sound specs:

// Create a sound group to contain all of our sound specs CIwSoundGroup { name "sound_effects" # Name of our sound group addSpec "silly_sound" # Add the silly_sound sound spec to our sound group addSpec "explosion" # Add the explosion sound spec to our sound group }

To save you hours of pulling your hair out and trying out different WAV formats, it’s worth noting that IwSound supports mono PCM (8 and 16 bit) and mono ADPCM (IMA but not Microsoft’s) WAV formats.

And finally finally, you need to add this code somewhere at the start of your main() function so that the resource manager can convert your WAV files into a usable format when you run the resource build mode (Win32 debug build will build resources used by the resource manager)

#ifdef IW_BUILD_RESOURCES IwGetResManager()->AddHandler(new CIwResHandlerWAV); #endif

This line basically adds a WAV resource handler to the resource management system so that when it loads your .WAV files during resource build mode it knows how to convert them.

What’s changed in our example code

We are basing our new Audio example project on the previous Resources example code. Firstly we will deal with what’s changed in our project MKB file, then we will deal with changes to Main.cpp source code and Level1.group resource group file.

If you view the Audio.mkb project file you will notice that we have added a module_path to the options section of our MKB:

options { module_path="$MARMALADE_ROOT/examples" }

This tells Marmalade where to look for modules. In our case we are directing Marmalade to look in the examples folder within the SDK as this is where the IwSound engine is located

Next we have added the SoundEngine module to our sub projects section to enable us to use the IwSound code:

subprojects { iw2d iwresmanager SoundEngine }

And lastly we add our music.mp3 test music file to the assets section of our MKB to make it available when deploying to devices:

assets { (data) music.mp3 (data-ram/data-gles1, data) Level1.group.bin }

Now lets turn to Main.cpp to see what has changed. Firstly we included the header file for IwSound:

#include "IwSound.h"

Then we initialise the IwSound module using:

// Init IwSound IwSoundInit();

We also added some code to ensure that our WAV resources get built during a resource build Win32 debug build run:

#ifdef IW_BUILD_RESOURCES // Tell resource system how to convert WAV files IwGetResManager()->AddHandler(new CIwResHandlerWAV); #endif

In addition, we added code to play our test music.mp3 file (Remember, s3e Audio uses the devices audio player so we firstly have to check that the device supports the MP3 codec):

// Play some MP3 music using s3e Audio (if the codec is supported) if (s3eAudioIsCodecSupported(S3E_AUDIO_CODEC_MP3)) s3eAudioPlay("music.mp3", 1);

Next we tell IwSound to update every frame by placing a call to IwGetSoundManager in our main loop:

// Update Iw Sound Manager IwGetSoundManager()->Update();

This ensures that the sound system and sound instances etc.. get updated regularly. Note that if you find that you play a few sound effects and then no more will play then you have missed out this line!

And now the juicy bit, here we find our explosion sound effect within the Level1 group and play it:

if (!PrevTouched) { CIwSoundSpec* SoundSpec = (CIwSoundSpec*)Level1Group->GetResNamed("explosion", IW_SOUND_RESTYPE_SPEC); CIwSoundInst* SoundInstance = SoundSpec->Play(); }

And finally before we exit the demo we shut down IwSound using:

// Shutdown IwSound IwSoundTerminate();

Ok, so now we’ve been through the changes to Main.cpp lets take a look at the changes to our resource group file Level1.group.

The first thing you will notice is that it contains a lot more stuff, that is mainly down to the fact that we need to define CIwSoundSpec for our sound effect as well as a CIwSoundGroup to include our sound specs in.

You will notice that the first addition is our sound effect wav file:

// Sound sample WAV files "./explosion.wav"

Next we create a sound spec (material) for our sound effect so that it can be played in-game:

// Create sound specs (can be thought of as sound materials) CIwSoundSpec { name "explosion" # The name we want to use to refer to this sound effect in our code data "explosion" # The WAv file name (without .wav) vol 0.7 # Default volume to be played at loop false # Do we want this sound effect to play forever? }

Lastly, we create a group to contain our sound spec:

// Create a sound group to contain all of our sound specs CIwSoundGroup { name "sound_effects" # Name of our sound group maxPolyphony 8 # Maximum sounds that can be played simultaneously killOldest false # Tell system not to stop the oldest sound effects from playing if we run out of channels addSpec "explosion" # Add the explosion sound spec to our sound group }

Ok. that’s it from me for now on audio, hopefully you find enough info in this article and source to be able to add sound and music to your games and apps. You can download the associated Audio project source code from here

I will update this blog article in the near future to act as a full reference for IwSound

Happy coding and don’t play with a grenade that has no pin!