1. How to Create Your First
Windows 8 Metro-style Game
Chas. Boyd
Principal Program Manager
Microsoft Corporation

2. How to Create Your First Windows 8 Metro-style Game
Windows 8 metro-style apps are a huge new opportunity for all developers. Learn about the core components of the Windows8 platform specifically provided for metro-style games and how you can assemble them into your ideal game experience. Learn the latest tips and best practices for game graphics, input & animation, sound effects, and asset loading.

3. Three Presentations Today
Step by Step through Game Development
How to set up the game
How to code it <- You are here
How to optimize it

4. Agenda Quick summary of the platform
Step through the process of development
from a programmer’s perspective:
App Initialization
Opening a Window
Rendering Graphics
Loading and Saving
Adding Input Controls
Adding Sound Effects
Adding an Art Pipeline
This talk’s sample code is in C++

5. Platform Overview

6. Windows Kernel Services
Metro style apps
Desktop apps C
C++
Win32 C# VB
.NET SL
HTML
JavaScript
Internet Explorer
View C
C++ DX
XAML C# VB
JavaScript
HTML / CSS
Model Controller
Communication
& Data
Devices & Printing
WinRT APIs
Graphics & Media
System Services
Application Model
Kernel
Windows Kernel Services

7. Windows 8 Game Platform Technologies
Your Killer Game
Graphics
Movies & Cut Scenes
Game Input
Audio
Local Services
Connected Services
Tools
Direct3D
DirectX Video
Pointer
Point
WASAPI
PLM
Windows Live
Visual Studio
Direct2D
Media Foundation
Sensor API
XAudio2
AppData
Windows Store
Asset Viewers
HTML
XInput
Contracts
Xbox LIVE
Asset Processors
XAML

8. Windows Runtime All WinRT APIs are native
WinRT APIs feel natural in C++, C#/VB, and JavaScript
Reuse of portable C++ code just works
WinRT APIs provide rich access to devices, OS, and services
HTML5/CSS/JavaScript and XAML are great for Metro style apps
Providing a rich set of controls
Native DirectX is great for Metro style apps

9. Visual Studio Updated C++ language support
File->New Project templates for native DirectX C++ apps
DirectX HLSL shader compilation and syntax highlighting
Packaging compiled HLSL shaders into the .appx package
Support for other asset types in MSBuild and previewer
Visualization, processing and packaging of Textures, meshes, shaders, and audio
Debugging DirectX API calls

10. C++/Cx Win32 WRL WinRT CoCreateInstance ComPtr<IObject>
Foo^ foo = ref new Foo()
QueryInterface
foo.As(&bar)
N/A
AddRef / Release
std::vector
Platform::Array<>^

11. Chapter 1/6
App Initialization

12. App Model – Activation ref class MyApp : public IFrameworkView {
   
    MyApp();
    // IFrameworkView Methods
    virtual void Initialize(CoreApplicationView^ applicationView);
    virtual void SetWindow(CoreWindow^ window);
    virtual void Load(String^ entryPoint);
    virtual void Run();
    virtual void Uninitialize();

13. Activation – Run void MyApp::Run() {
auto dispatcher = CoreWindow::GetForCurrentThread()->Dispatcher;
while (!m_windowClosed)
dispatcher->ProcessEvents(CoreProcessEventsOption::ProcessAllIfPresent);
m_renderer->Update();
m_renderer->Render();
m_renderer->Present(); }

14. App Activation Timeline
Splash Screen
Loading Screen
Menu Screen
Gameplay
OS Loads your App
App Loads Loading Screen
App is running
Load()
Run()

15. Handling Window Events
Chapter 2/6
Handling Window Events

16. ViewStates Widescreen (1366 x 768+) Portrait Snap view (required)
Minimum (1024 x 768)
Portrait
Snap view (required)

17. ViewStates void MyApp::SetWindow(CoreWindow^ window) {
    window->SizeChanged +=
     ref new TypedEventHandler<CoreWindow^, WindowSizeChangedEventArgs^>(
this, &MyApp::OnWindowSizeChanged);
    ApplicationView::GetForCurrentView()->ViewStateChanged +=
     ref new TypedEventHandler
<ApplicationView^, ApplicationViewStateChangedEventArgs^>(
this, &MyApp::OnViewStateChanged); }

18. Resize Handler void DirectXApp::OnWindowSizeChanged(
_In_ CoreWindow^ sender,
_In_ WindowSizeChangedEventArgs^ args ) {
if (m_window->Bounds.Width != m_windowBounds.Width ||
m_window->Bounds.Height != m_windowBounds.Height)
m_d2dContext->SetTarget(nullptr);
m_d2dTargetBitmap = nullptr;
m_renderTargetView = nullptr;
m_depthStencilView = nullptr;
CreateWindowSizeDependentResources(); }

19. Window Activation – Focus Changed
void MyApp::OnWindowActivationChanged(
CoreWindow^ sender,
WindowActivatedEventArgs^ args) {
auto state = args->WindowActivationState;
if(state == CoreWindowActivationState::Deactivated)
OutputDebugString("Focus Lost");
if(state == CoreWindowActivationState::CodeActivated ||
state == CoreWindowActivationState::PointerActivated)
OutputDebugString("Focus Regained"); }

20. Rotation Preferences {
DisplayOrientations::None; // Enable rotation by OS/Accelerometer
DisplayOrientations::Landscape; // Lock rotation by OS/Accelerometer
DisplayOrientations::LandscapeFlipped; // and enable this orientation
DisplayOrientations::Portrait;
DisplayOrientations::PortraitFlipped; }
using namespace Windows::Graphics::Display;
DisplayProperties::AutoRotationPreferences = DisplayOrientations::Landscape
| DisplayOrientations::LandscapeFlipped;

21. Chapter 3/6
Rendering Graphics

22. 3D Graphics via Direct3D 11
3D Graphics uses the same API as on Desktop/Classic
WinRT API set includes only the latest DirectX 11 syntax
DirectX 11 API supports multiple hardware generations
via FeatureLevels: Feature_Level_9, Feature_Level_10, Feature_Level_11
Direct3D 11 updated for Windows 8

23. Creating a swap chain
Windows::UI::Core::CoreWindow^ coreWindow; // app’s core window Microsoft::WRL::ComPtr<ID3D11Device1> d3dDevice; // renderer Microsoft::WRL::ComPtr<IDXGISwapChain1> dxgiSwapChain; // front/back buffers of RT // Obtain the final swap chain for this window from the DXGI factory. dxgiFactory->CreateSwapChainForImmersiveWindow( d3dDevice.Get(), // the Direct3D device that will render to it DX::GetIUnknown(coreWindow), // IUnknown interface on our core window &swapChainDesc, // double or triple buffered, stereo, etc. nullptr, // allow on all displays &dxgiSwapChain // the resulting swap chain object );

24. void myApp::Render() {
m_d3dContext->OMSetRenderTargets( // rebind every frame! 1,
m_renderTargetView.GetAddressOf(),
m_depthStencilView.Get() );
if (!m_loadingComplete) // only draw the cube once it's loaded
return; // (this is async)
m_d3dContext->IASetVertexBuffers(
0, 1,
m_vertexBuffer.GetAddressOf(),
&stride,
&offset );
m_d3dContext->IASetIndexBuffer(
m_indexBuffer.Get(),
DXGI_FORMAT_R16_UINT, 0 );

25. m_d3dContext->IASetPrimitiveTopology(D3D11_PRIMITIVE_TOPOLOGY_TRIANGLELIST);
m_d3dContext->IASetInputLayout(m_inputLayout.Get());
m_d3dContext->VSSetConstantBuffers(
0, 1,
m_constantBuffer.GetAddressOf() );
m_d3dContext->VSSetShader( m_vertexShader.Get(),
nullptr, 0 );
m_d3dContext->PSSetShader( m_pixelShader.Get(),
m_d3dContext->DrawIndexed( m_indexCount, 0, 0 ); }

26. Chapter 4/7
Loading and Saving

27. Process Lifetime Management
Suspend/Resume
App gets 5 seconds to work after suspend message
Apps are not notified before they are terminated
Running
App
suspending
Suspended
App
Terminated
App
User Launches App
Low Memory
resuming
Apps are notified when they have been resumed

28. Concurrency Tasks using namespace Concurrency; float f = 1.0f;
thread
float f = 1.0f;
task<int>([=]() {
return foo(f);
}).then([](int x)
bar(x);
}).then(baz);
// task defined with capturing lambda
// continuation lambda argument is return value of previous
// continuation using existing function baz()

29. State Persistence – Saving
void MyApp::OnSuspending(Object^ sender, SuspendingEventArgs^ args) {
    SuspendingDeferral^ deferral = args->SuspendingOperation->GetDeferral();
    task<void>([=]()
    {
        auto localState = ApplicationData::Current->LocalSettings->Values;
        auto roamingState = ApplicationData::Current->RoamingSettings->Values;
        localState->Insert(
"GameTime", PropertyValue::CreateSingle(m_gameTime));
        roamingState->Insert(
"MaxLevel", PropertyValue::CreateUInt32(m_maxLevelUnlocked));
    }).then([=]()
        deferral->Complete();
    }); }

30. State Persistence – Loading
void MyApp::Load(String^ entryPoint) {
    LoadMyGameStateAsync().then([=]()
    {
        auto localState = ApplicationData::Current->LocalSettings->Values;
        auto roamingState = ApplicationData::Current->RoamingSettings->Values;
        m_gameTime = safe_cast<IPropertyValue^>
(localState->Lookup("GameTime"))->GetSingle();
        m_maxLevelUnlocked = safe_cast<IPropertyValue^>
(roamingState->Lookup("MaxLevel"))->GetUInt32();
    }).then([=]()
        m_loadingComplete = true;
    }); }

31. File Input / Output task<byte*> LoadSkyAsync() {
auto folder = Package::Current->InstalledLocation;
return task<StorageFile^>(
folder->GetFileAsync("sky.dds")).then([](StorageFile^ file){
return FileIO::ReadBufferAsync(file);
}).then([](IBuffer^ buffer){
auto fileData = ref new Array<byte>(buffer->Length);
DataReader::FromBuffer(buffer)->ReadBytes(fileData);
return fileData->Data;
}); }
...
LoadSkyAsync().then([=](byte* skyTextureData)
CreateTexture(skyTextureData);
m_loadingComplete = true;

32. Chapter 5/7
Adding Input

33. Mouse and Touch Input
win->PointerPressed += ref new TypedEventHandler<CoreWindow^,PointerEventArgs^>
(this, &LonLatController::OnPointerPressed);
void LonLatController::OnPointerPressed(
_In_ CoreWindow^ sender,
_In_ PointerEventArgs^ args ) {
float2 position = float2( // position of contact
args->CurrentPoint->Position.X,
args->CurrentPoint->Position.Y );
m_lonLatLastPoint = position; // save for use in controller
m_lonLatPointerID = args->CurrentPoint->PointerId; }

34. Polling for Keyboard Input
// Arrow keys or WASD example
auto upKeyState = window->GetKeyAsyncState(VirtualKey::Up);
auto wKeyState = window->GetAsyncKeyState(VirtualKey::W);
if (upKeyState & CoreVirtualKeyStates::Down ||
wKeyState & CoreVirtualKeyStates::Down) {
m_playerPosition.y += 1.0f; }

35. Sensor fusion inputs and outputs
3D Accelerometer
Pass-Through
Accelerometer
3D Gyro
Gyro
3D Magnetometer
Sensor Fusion
Compass
Inclinometer
Device Orientation

36. Reading orientation sensor data
using Windows::Devices::Sensors;
// Get current reading from sensor
OrientationSensorReading^ orientationReading = m_orientationsensor->GetCurrentReading();
SensorQuaternion^ quat = orientationReading->Quaternion;
// Transform quaternion from device orientation space to world space
// Orientation space is Z-up, right-handed coordinate system
// World space is Y-up, left-handed coordinate system
XMVECTOR orientationQuat = XMVectorSet(-quat->X, quat->Z, quat->Y, -quat->W);
// Create a rotation matrix from the quaternion
// This matrix can be used to rotate an object inside the scene to match
// the rotation of the device
XMMATRIX rotXMMatrix = XMMatrixRotationQuaternion(orientationQuat);

37. Game Controller Input
Windows 8 supports Xbox360 -compatible controllers
Check out new ControllerSketch sample
Demonstrates game controller usage from JavaScript app

38. Game Controller Button Input
if ( m_xinputState.Gamepad.wButtons & XINPUT_GAMEPAD_A ) {
m_aButtonWasPressed = true; }
else if ( m_aButtonWasPressed )
m_aButtonWasPressed = false; // Trigger once, only on button release
TriggerSoundEffect();

39. Game Controller D-pad Input
SHORT thumbLeftX = inputState.Gamepad.sThumbLX;
if (abs(thumbLeftX) < XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE)
thumbLeftX = 0;
SHORT thumbLeftY = inputState.Gamepad.sThumbLY;
if (abs(thumbLeftY) < XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE)
thumbLeftY = 0;
combinedTiltX += (float)thumbLeftX / f;
combinedTiltY += (float)thumbLeftY / f;

40. Chapter 6/7
Adding Sound Effects

41. Sound Effects
// Create the XAudio2 engine and mastering voice on the default audio device
XAudio2Create(&m_audioEngine);
m_audioEngine->CreateMasteringVoice(&m_masteringVoice); // Load all audio data for the sound effect into a single in-memory buffer
MediaLoader soundFile(ref new Platform::String(SOUND_FILE)); m_soundEffectBuffer = soundFile.ReadAll(); // Create a single source voice for a sound effect
m_audioEngine->CreateSourceVoice(&m_sourceVoice, &(soundFile.GetOutputWaveFormatEx()));
// Trigger sound effect: queue in-memory buffer for playback and start the voice XAUDIO2_BUFFER buf = {0}; buf.AudioBytes = m_soundEffectBuffer.size(); buf.pAudioData = &m_soundEffectBuffer[0]; buf.Flags = XAUDIO2_END_OF_STREAM; m_sourceVoice->SubmitSourceBuffer(&buf); m_sourceVoice->Start();

42. Creating an Asset Pipeline
Chapter 7/7
Creating an Asset Pipeline

43. Package Author-time Asset Build Step Packager Run-time Asset
shader.hlsl
fxc
shader.cso
Package
texture.bmp
dxtex
texture.dds
myApp
.appx
mesh.obj
obj2vbo
mesh.vbo
music.wav
myTool
music.wma

44. Package Bindable Run-time Loader Component API object Asset Installer
App
Bindable
API object
Run-time
Asset
Loader Component
Installer
shader.cso
D3D
Shader
Package
texture.dds
myApp
.appx
Texture Loader
Texture
mesh.vbo
Mesh
Loader
VertexBuffer
music.wma
myTool
Stream

45. Pro Dev Hints Find commands in the IDE via the search textport
Set up a multi-monitor dev PC with a touch monitor as the primary
To work with the samples, set a breakpoint inside the DX::ThrowIfFailed() macro in DirectSample.h line 18

46. Time to Act
Biggest opportunity. Ever. Windows 8 Consumer Preview is now available. Check out the store. Go build great games.

47. Q & A

48. 4/20/ :57 AM
© 2012 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.
© 2010 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.