2. Real life
Johan Lindfors

4. windows phone for games
• impressive performance
• sensors and touch
• potentially xbox-live
• ads and trials

5. kinectimals

6. harvest

7. implode

8. doodle fit

9. ilomilo

10. other favorites

11. xna in 1 minute
• a comprehensive framework for games
• integrated management of content
• games with 2d and ”sprites”
• games with 3d and ”meshes”
• shared features for pc, wp, xbox

12. initialize update render

13. managing content
• content pipeline
• import common files
• leverage compile time
• optimized binary format
• extensible

14. first some 2d
• x and y (and z)
• spriteBatch
• sprites/sprite sheets
• blending

15. and then some 3d
• x, y and z
• camera is described with matrices
• view
• projection
• world matrix transforms objects relatively
• movement (translation)
• rotation
• size (scale)

16. demo

17. effects - shaders
• configurable
• basic
• skinned
• environmentMap
• dualTexture
• alphaTest

18. demo

19. ”hardware scaler”
• 800x480 = 384 000 pixels
• 600x360 = 216 000 pixels (56%)
• 400x240 = 96 000 pixels (25%)
graphics.PreferredBackBufferHeight = 800;
graphics.PreferredBackBufferWidth = 480;

20. performance tips
• manage the stack and heap
• reference types live on the _______!
• value types live on the _______!
• pass large structures by reference
Matrix a, b, c;
c = Matrix.Multiply(a, b); // copies 192 bytes!
Matrix.Multiply(ref a, ref b, out c);
• don’t foreach or linq (know code cost)

21. performance tips
• gc is ”simpler” than on pc
• allocate objects early, reuse
• GC.Collect() can be your friend!
• after load, while paused
• cpu or gpu based?
• you can go up to 60 fps (60 hz)

22. demo

23. sound and music
• soundEffect
• load as content
• wp handles 64 simultaneously
• possible to change
• pitch
• volume
• 3d location

24. orientation
graphics.SupportedOrientations =
DisplayOrientation.Portrait |
DisplayOrientation.LandscapeLeft |
DisplayOrientation.LandscapeRight;
• default is ”LandscapeLeft”

25. orientation
Window.OrientationChanged += (s, e) =>
{
switch (Window.CurrentOrientation)
{
case DisplayOrientation.Portrait:
graphics.PreferredBackBufferHeight = 800;
graphics.PreferredBackBufferWidth = 480;
break;
default:
graphics.PreferredBackBufferHeight = 480;
graphics.PreferredBackBufferWidth = 800;
break;
}
graphics.ApplyChanges();
};

26. accelerometer
using Microsoft.Devices.Sensors;
• measures acceleration in X, Y and Z
• values returned between -1 and +1
• event based
• read values in event, store for usage

27. start accelerometer
Accelerometer accel;
private void startAccelerometer() {
accel = new Accelerometer();
accel.ReadingChanged += new
EventHandler
<AccelerometerReadingEventArgs>
(accel_ReadingChanged);
accel.Start();
}

28. read the accelerometer
Vector3 accelReading;
void accel_ReadingChanged(object sender,
AccelerometerReadingEventArgs e)
{
lock (this)
{
accelReading.X = (float)e.X;
accelReading.Y = (float)e.Y;
accelReading.Z = (float)e.Z;
}
}

29. touch
• windows phone handles 4 touch points
• all points have unique id
• pressed | moved | released
TouchCollection touches;
protected override void Update(GameTime gt)
{
touches = TouchPanel.GetState();
...
}

30. gestures
• wp can also handle gestures
• tap | drag | hold | flick | pinch ...
TouchPanel.EnabledGestures =
GestureType.Flick;
while (TouchPanel.IsGestureAvailable) {
GestureSample g = TouchPanel.ReadGesture();
if (g.GestureType == GestureType.Flick)
{ ... }
}

31. network
• http, rest, xml, sockets...
void wc_OpenReadCompleted(object sender,
OpenReadCompletedEventArgs e) {
if (e.Error == null)
{
mapImage = Texture2D.FromStream(
graphics.GraphicsDevice,
e.Result);
}
}

32. xbox live
• avatars and “trials” available for all
• developers with agreements
• profile
• invites
• achievements
• leaderboard
• gamerServices
• contact: wpgames@microsoft.com

33. trial mode
#if DEBUG
Guide.SimulateTrialMode = true;
#endif
bool isTrial = Guide.IsTrialMode;
...
Guide.ShowMarketplace(PlayerIndex.One);
• call to IsTrialMode takes 60 ms, cache!
• be creative in feature set
• trial or free light?

34. ads
• instead of user paying for app
• not for swedish apps yet*
using Microsoft.Advertising.Mobile.Xna;
...
AdManager adManager;
Ad bannerAd;
*not from Microsoft that is, there are options

35. marketplace
• local structure
• test kit in VS2010
• updates
• auto-publish

36. protect yourself
• ready for obfuscation?
public void d(bp.b A_0)
{
this.l = A_0;
this.i = new List<string>();
this.i.Add(am.a().e("SK_NO"));
this.i.Add(am.a().e("SK_YES"));
this.g = bo.a;
SignedInGamer.SignedIn += new
EventHandler<SignedInEventArgs>(this.d);
}

38. news in mango
• silverlight + xna
• fast application switching
• profiling
• combined api for movement

39. demo

40. tripeaks solitaire
• fabrication games
• true 3D
• all code in objective-c

41. -(BOOL) animate
{
if([self animation] == nil)
{
[self draw];
return NO;
}
else
{
BOOL animationDone = [[self animation] animate];
[self draw];
if (animationDone)
{
x += [[self animation] currentX];
y += [[self animation] currentY];
z += [[self animation] currentZ];
rotation += [[self animation] currentRotation];
[animations removeObjectAtIndex:0];
}
return animationDone;
}
}

42. public bool Animate()
{
if (this.Animation == null)
{
this.Draw();
return false;
}
else
{
bool animationDone = this.Animation.Animate();
this.Draw();
if (animationDone)
{
x += this.Animation.CurrentX;
y += this.Animation.CurrentY;
z += this.Animation.CurrentZ;
rotation += this.Animation.CurrentRotation;
animations.RemoveAt(0);
}
return animationDone;
}
}

43. public bool Animate(GraphicsDevice graphics, BasicEffect effect)
{
if (this.Animation == null)
{
this.Draw(graphics, effect);
return false;
}
else
{
bool animationDone = this.Animation.Animate();
this.Draw(graphics, effect);
if (animationDone)
{
x += this.Animation.CurrentX;
y += this.Animation.CurrentY;
z += this.Animation.CurrentZ;
rotation += this.Animation.CurrentRotation;
animations.RemoveAt(0);
}
return animationDone;
}
}

44. demo

45. future of xna?
• silverlight 5.0
• subset of XNA
• focused on business apps
• windows 8
• leverages directx 11
• likely to attract commercial studios

46. johan.lindfors@coderox.se

47. resources
• create.msdn.com
• jodegreef.wordpress.com - angry pigs
• www.xnaresources.com
• http://msdn.microsoft.com/en-
us/library/bb417503(XNAGameStudio.41).aspx
• programmeramera.se
• www.coderox.se