锐普第一动画宣传片《一滴墨水》与版1

1、Building a High Performance 3D Games for Windows PhoneAdam SchaefferMicrosoft CorporationSESSION CODE: WPH308锐普PPT论坛chinakui首发Consistent sets of hardware capabilities defined by MicrosoftWindows Phone 7 HardwareResolutionTouch InputCPU / GPURAMHardware keyboard is optional锐普PPT论坛chinakui首发：锐普PPT论坛ch

2、inakui首发：The Evolution Of ProgrammingLow level controlStraight to the metalRaw performance tuningHigh level abstractionRely on compiler and runtimeDeveloper productivity锐普PPT论坛chinakui首发：Why C# r0 x0rzPowerful and expressiveType safety reduces hard-to-track-down bugsReflectionInitializer syntaxGreat

3、 tooling (IntelliSense)Similar enough to C that learning and porting are easyBlazingly fast compilesC#锐普PPT论坛chinakui首发：.NET on WindowsUsually within a few percent of native performanceAwesome generational garbage collectionPerformance shootout: Raymond Chen vs. Rico Mariani锐普PPT论坛chinakui首发：.NET on

4、 Xbox 360360Significant delta between managed and native.NET Compact FrameworkSimplistic mark-and-sweep garbage collectionXbox is not a general purpose computerUnforgiving in-order CPU architectureRequires custom VMX instructions for optimal math perfSecurity architecture poses challenges for jitted

5、 code锐普PPT论坛chinakui首发：.NET on Windows Phone 7In between Windows and Xbox 360.NET Compact FrameworkKeep an eye on garbage collection!ARMv7 CPUMore forgiving toward jitted codeARM jitter is more mature than PPC锐普PPT论坛chinakui首发：Ways To Call CodeInstance methodInterfaceDelegate / eventReflectionVirtua

6、l method锐普PPT论坛chinakui首发：Choose Your Own AddressC+ allows independent choice of.NET types dictate their allocation and usage semanticsData typeThe memory in which a type lives (placement new)How a type instance is referenced (T, T*, T&, const T&)Value typesint, bool, struct, Vector3Reference typesc

7、lass, array, string, delegate, boxed value types锐普PPT论坛chinakui首发：A Popular MythOft-repeated wisdomValue types live on the stackReference types live on the heapValue types live wherever they are declaredReference types have two piecesMemory allocated from the heapA pointer to this heap memoryThat is

8、 subtly incorrect锐普PPT论坛chinakui首发：By default, prefer class over structureUse struct for things that areclass vs. structSmall (= 16 bytes)Short livedPass large structures by referenceMatrix a, b, c;c = Matrix.Multiply(a, b); / copies 192 bytes!Matrix.Multiply(ref a, ref b, out c);锐普PPT论坛chinakui首发：M

9、emory ManagementGarbage collection is not optionalCant have type safety without automatic memory management锐普PPT论坛chinakui首发：Mark and SweepTriggered per megabyte of allocation1Starts with root references (stack variables, statics)2Recursively follows all references to see what other objects can be r

10、eached3Anything we didnt reach must be garbage4Compacts the heap, sliding live objects down to fill holes5锐普PPT论坛chinakui首发：Frameworks designed for performanceFrameworks designed for performanceTwo Ways To Keep GC HappyMake it run Less OftenIf you never allocate, GC will never runMake it Finish Quic

11、klyCollection time is proportional to how many object references must be traversedUse object poolsSimple heap = fast collectionUse value types and integer handles锐普PPT论坛chinakui首发：GC.CollectExplicitly forces a garbage collectionUse wisely to give yourself more headroomAfter loadingDuring pauses in g

12、ameplayDont call every frame!锐普PPT论坛chinakui首发：Avoiding AllocationBeware of boxingstring vs. StringBuilderUse WeakReference to track GC frequencyUse CLR Profiler on WindowsSee MIX10 talk: “Development and Debugging Tools for Windows Phone 7 Series”Use .NET Reflector to peek behind the curtain锐普PPT论坛

13、chinakui首发：The GPU锐普PPT论坛chinakui首发：Plus hardware accelerated 2D sprite drawingFive Configurable EffectsBasicEffectSkinnedEffectEnvironmentMapEffectAlphaTestEffectDualTextureEffect锐普PPT论坛chinakui首发：BasicEffect0-3 directional lightsBlinn-Phong shadingOptional textureOptional fogOptional vertex colorB

14、asicEffect锐普PPT论坛chinakui首发：DualTextureEffectDualTextureEffectFor lightmaps, detail textures, decalsBlends two texturesSeparate texture coordinatesModulate 2X combine mode (A*B*2)Good visuals at low pixel cost锐普PPT论坛chinakui首发：AlphaTestEffectFor billboards and impostersAdds alpha test operations (pi

15、xel kill)Standard blending is free with all effectsOnly need alpha test if you want to disable depth/stencil writesAlphaTestEffect锐普PPT论坛chinakui首发：SkinnedEffectSkinnedEffectFor animated models and instancingGame code animates bones on CPUVertex skinning performed by GPUUp to 72 bonesOne, two, or fo

16、ur weights per vertex锐普PPT论坛chinakui首发：EnvironmentMapEffectEnvironmentMapEffectOooh, shiny!Diffuse texture + cube environment mapCheap way to fake many complex lightsFresnel term simulates behavior when light reaches a surface and some reflects, some penetrates锐普PPT论坛chinakui首发：锐普PPT论坛chinakui首发：A B

17、alancing ActFramerateNumberof PixelsPixel Cost锐普PPT论坛chinakui首发：Balancing FramerateFramerate30 hz refresh rateNo point updating faster than the display! Game.TargetElapsedTime = TimeSpan.FromSeconds(1f / 30);锐普PPT论坛chinakui首发：A Balancing ActPixel CostPrefer cheaper effectsMinimize overdrawMany known

18、 algorithms:Distance, frustum, BSP, sort front to backImplement “overdraw x-ray mode” Draw untextured with additive blendingBrighter areas indicate overdraw锐普PPT论坛chinakui首发：A Balancing ActNumberof Pixels800 x480 is 25% more pixels than Xbox 1Great for textToo many pixels for intensive games800 x480

19、 = 384,000 pixels600 x360 = 216,000 pixels (56%)Dedicated hardware scalerDoes not consume any GPUHigher quality than bilinear upsampling锐普PPT论坛chinakui首发：Scaler Demo锐普PPT论坛chinakui首发：XNA Framework API Cheat SheetAvoidPreferRenderTargetUsage.PreserveContentsRenderTargetUsage.DiscardContentsdevice.Ble

20、ndState = new BlendState .;/ At startupstatic BlendState myState = new BlendState .;/ Per frameDevice.BlendState = myState;VertexBuffer.SetData(.)device.DrawUserPrimitives(.);/ orDynamicVertexBuffer.SetData(., SetDataOptions.NoOverwrite);锐普PPT论坛chinakui首发：SummaryGreat performance comes from great kn

21、owledgeUnderstandActionsValue types vs. reference typesGarbage collectionC# compiler magic (foreach, iterator methods, closures)Cost of the different graphical effect optionsUse CLR Profiler and .NET ReflectorRender smaller than display resolution, rely on scaler锐普PPT论坛chinakui首发： 2010 Microsoft Corporation. All rights reserv