wp8 game development for beginners

Windows Phone 8 2D Game DevelopmentFor Beginners

Cao PhongDeveloper Tech Support ManagerNokia, Vietnam

Content

• Setting up a basic framework with XNA

• Setting up a basic framework with Direct3D:

DirectX TK

Direct3D (native)

Direct3D with XAML and XAML with Direct3D app

• Porting XNA to Asha Touch

XNA vs Direct3D

XNA

Pros:- Simple setup and easy to use- Legacy support- Can be quickly ported to Asha

Touch

Cons:- Unable to use WP8 APIs: In-app

purchase, NFC, Bluetooth…- Lack of native code support

Direct3D

Pros:- Best performance- Leverage on WP8 APIs: In-app

purchase, NFC, Bluetooth…- Native code support- Flexibility to add nice game

effects

Cons:- Requiring quite a lot steps to set

up at the beginning- Fairly complex to use

XNAChoose project template

Main loop

protected override void Update(GameTime gameTime){

// Allows the game to exitif (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)

this.Exit();

// TODO: Add your update logic herebase.Update(gameTime);

}

protected override void Draw(GameTime gameTime){

GraphicsDevice.Clear(Color.CornflowerBlue);

// TODO: Add your drawing code herebase.Draw(gameTime);

}

Fill RectangleTexture2D m_pRectTexture = null;Rectangle m_rect;Color m_color;

public void FillRect(int color, int x, int y, int w, int h){

if (m_pRectTexture == null){

m_pRectTexture = new Texture2D(GraphicsDevice, 1, 1);m_pRectTexture.SetData<Color>(new Color[] { Color.White });

}

m_rect.X = x;m_rect.Y = y;m_rect.Width = w;m_rect.Height = h;

m_color.A = (byte)((color & 0xFF000000) >> 24);m_color.R = (byte)((color & 0x00FF0000) >> 16);m_color.G = (byte)((color & 0x0000FF00) >> 8);m_color.B = (byte)((color & 0x000000FF));

spriteBatch.Begin(SpriteSortMode.Deferred, BlendState.Opaque);spriteBatch.Draw(m_pRectTexture, m_rect, m_color);spriteBatch.End();

}

Draw Image

protected override void Draw(GameTime gameTime){

GraphicsDevice.Clear(Color.CornflowerBlue);

// Draw a rectangle (color=red, x=50, y=100, w=100, h=50)FillRect(0xFF0000, 50, 100, 100, 50);

// Draw an image (x=10, y=10)spriteBatch.Begin(SpriteSortMode.Deferred, BlendState.NonPremultiplied);spriteBatch.Draw(imgGirl, new Vector2(10, 10), Color.White);spriteBatch.End();

base.Draw(gameTime);}

public Texture2D LoadImage(String file){

try{

Stream fs = TitleContainer.OpenStream(file);Texture2D img = Texture2D.FromStream(GraphicsDevice, fs);fs.Close();fs = null;return img;

}catch (Exception e){

// Handle errorreturn null;

}}

Direct3D

DirectX TK (Toolkit)There is a collection of helper classes united under the name of DirectX Tool Kit [4] - or in short DirectX TK - started by Shawn Hargreaves. This library contains convenience classes that help write code that uses Direct X. It also contains a tool called MakeSpriteFont that can create fonts to be used in game.

Download link: http://directxtk.codeplex.com/releases/view/98986

Direct3D Choose project template

Fill Rectanglevoid GameRenderer::FillRect(int color, int x, int y, int w, int h){

// Create TextureCD3D11_TEXTURE2D_DESC texDesc(

DXGI_FORMAT_R8G8B8A8_UNORM,// DXGI_FORMAT1,// width1,// height1,// arraySize1,// mipLevelsD3D11_BIND_SHADER_RESOURCE// bindFlags

);

D3D11_SUBRESOURCE_DATA colorData = { 0 };Microsoft::WRL::ComPtr<ID3D11Texture2D> texture;int a[] = {0xFF000000 | ((color & 0xFF) << 16) | (((color & 0xFF00) >> 8) << 8) | ((color & 0xFF0000) >> 16)}; // argb => abgrcolorData.pSysMem = &a;colorData.SysMemPitch = sizeof(a);colorData.SysMemSlicePitch = 0;m_d3dDevice->CreateTexture2D(&texDesc, &colorData, texture.GetAddressOf());Microsoft::WRL::ComPtr<ID3D11ShaderResourceView> view;m_d3dDevice->CreateShaderResourceView(texture.Get(), 0, &view);

// Draw In a RectangleRECT rect = {x, y, x + w, y + h}; // left, top, right, bottomspriteBatch->Begin();spriteBatch->Draw(view.Get(), rect, Colors::White);spriteBatch->End();

}

DirectDraw Surface (DDS)DirectDraw Surface file format• Filename extension: DDS• Data compressed with the lossy S3 Texture Compression (S3TC) algorithm• Support phone GPUs and consoles (PSP, PS3, Xbox 360…)

Converting images to .dds files• DirectXTex library:

http://directxtex.codeplex.com/SourceControl/changeset/22746

• NVIDIA Texture Tools:https://developer.nvidia.com/nvidia-texture-tools-adobe-photoshophttps://developer.nvidia.com/content/texture-tools-208-64-bit

• Easy2Convert PNG to DDS:http://www.easy2convert.com/png2dds/

Draw Image

Load resource

1. Declare texture in GameRenderer.h:

ID3D11ShaderResourceView* m_catTexture;

2. Include DDS loader header in GameRenderer.cpp:

#include <DDSTextureLoader.h>

3. Load texture in CreateDeviceResources method:

void GameRenderer::CreateDeviceResources(){Direct3DBase::CreateDeviceResources();spriteBatch = std::shared_ptr<SpriteBatch>(new SpriteBatch(m_d3dContext.Get()));DX::ThrowIfFailed(CreateDDSTextureFromFile(m_d3dDevice.Get(),

L"Assets\\CatTexture.dds", NULL, &m_catTexture, NULL));m_loadingComplete = true;

}

Draw Imagevoid GameRenderer::Render(float timeTotal, float timeDelta){

const float midnightBlue[] = { 0.098f, 0.098f, 0.439f, 1.000f };

m_d3dContext->ClearRenderTargetView(m_renderTargetView.Get(), midnightBlue);m_d3dContext->ClearDepthStencilView(m_depthStencilView.Get(), D3D11_CLEAR_DEPTH,

1.0f, 0);

// Only draw once the resources are loaded (loading is asynchronous).if (!m_loadingComplete){

return;}

m_d3dContext->OMSetRenderTargets(1, m_renderTargetView.GetAddressOf(),m_depthStencilView.Get());

// Fill a rectangleFillRect(0xFF0000, 50, 100, 100, 50);

// Draw an image (x=10, y=10)spriteBatch->Begin();spriteBatch->Draw(m_catTexture, XMFLOAT2(10, 10));spriteBatch->End();

}

Direct3D App Choose project template

3D Coordinate Systems

Left-handed versus Right-handed

• DirectX: usually uses Left-handed coordinate system

• OpenGL: usually uses Right-handed coordinate system

HLSL (High Level Shader Language) The language used to write shaders for GPUs in DirectX

SimpleVertexShader.hlsl

VertexShaderOutput main(VertexShaderInput input){

VertexShaderOutput output;float4 pos = float4(input.pos, 1.0f);

// Transform the vertex position into projected space.pos = mul(pos, model);pos = mul(pos, view);pos = mul(pos, projection);output.pos = pos;

// Pass through the color without modification.output.color = input.color;

return output;}

SimplePixelShader.hlsl

float4 main(PixelShaderInput input) : SV_TARGET{

return float4(input.color,1.0f);}

DirectX Math and HLSLMatrix Vector

OpenGL Column-major Column vectors

GLSL Column-major Column vectors

DirectX Math Row-major Row vectors

HLSL (by default) Column-major Row vectors

Solutions:

• Transpose matrices before sending to HLSL

• Use the #pragma pack_matrix directive in shaders:

#pragma pack_matrix( row_major )

DirectX PrimitivesPoint Lists Line Lists Line Strips

Triangle Lists Triangle Strips

Face and Vertex Normal Vectors

• Each face in a mesh has a perpendicular unit normal vector

• The vector's direction is determined by the order in which the vertices are defined and by whether the coordinate system is right- or left-handed

• The face normal points away from the front side of the face

• In Direct3D, only the front of a face is visible

• A front face is one in which vertices are defined in clockwise order.

Use row-major in HLSL so that you don’t need to transpose matrices from DirectX Math

1. Add directive in vertex shader:

Direct3D App (Cont.)

#pragma pack_matrix( row_major )

SimpleVertexShader.hlsl

2. Remove all transpose matrices in CubeRenderer.cpp:

void CubeRenderer::CreateWindowSizeDependentResources(){

Direct3DBase::CreateWindowSizeDependentResources();

float aspectRatio = m_windowBounds.Width / m_windowBounds.Height;float fovAngleY = 70.0f * XM_PI / 180.0f;if (aspectRatio < 1.0f){

fovAngleY /= aspectRatio;}

XMStoreFloat4x4(&m_constantBufferData.projection,XMMatrixTranspose(XMMatrixPerspectiveFovRH(fovAngleY,

aspectRatio,0.01f,100.0f)));}

void CubeRenderer::Update(float timeTotal, float timeDelta){

(void) timeDelta; // Unused parameter.

XMVECTOR eye = XMVectorSet(0.0f, 0.7f, 1.5f, 0.0f);XMVECTOR at = XMVectorSet(0.0f, -0.1f, 0.0f, 0.0f);XMVECTOR up = XMVectorSet(0.0f, 1.0f, 0.0f, 0.0f);

XMStoreFloat4x4(&m_constantBufferData.view,XMMatrixTranspose(XMMatrixLookAtRH(eye, at, up)));

XMStoreFloat4x4(&m_constantBufferData.model,XMMatrixTranspose(XMMatrixRotationY(timeTotal * XM_PIDIV4)));

}

Apply orthographic projection for our 2D game framework with Left-handed coordinate system

Direct3D App

void CubeRenderer::CreateWindowSizeDependentResources(){

Direct3DBase::CreateWindowSizeDependentResources();

XMStoreFloat4x4(&m_constantBufferData.projection,XMMatrixOrthographicOffCenterLH(

0, // ViewLeftm_windowBounds.Width, // ViewRightm_windowBounds.Height, // ViewBottom0, // ViewTop-1.0f, // NearZ1.0f // FarZ

);

}

Update view matrix with Left-handed coordinate system

Direct3D App

void CubeRenderer::Update(float timeTotal, float timeDelta){

(void) timeDelta; // Unused parameter.

XMVECTOR eye = XMVectorSet(0.0f, 0.0f, -1.0f, 0.0f);XMVECTOR at = XMVectorSet(0.0f, 0.0f, 1.0f, 0.0f);XMVECTOR up = XMVectorSet(0.0f, 1.0f, 0.0f, 0.0f);

XMStoreFloat4x4(&m_constantBufferData.view, XMMatrixLookAtLH(eye, at, up));XMStoreFloat4x4(&m_constantBufferData.model, XMMatrixIdentity());

}

Disabling Z buffer in 2D mode to enable back-to-front rendering

Direct3D App

// Initialize the Direct3D resources required to run.void Direct3DBase::Initialize(CoreWindow^ window){

m_window = window;

CreateDeviceResources();CreateWindowSizeDependentResources();

D3D11_DEPTH_STENCIL_DESC depthDisabledStencilDesc;ID3D11DepthStencilState* depthDisabledStencilState;

depthDisabledStencilDesc.DepthEnable = false;depthDisabledStencilDesc.DepthWriteMask = D3D11_DEPTH_WRITE_MASK_ALL;depthDisabledStencilDesc.DepthFunc = D3D11_COMPARISON_LESS;depthDisabledStencilDesc.StencilEnable = true;depthDisabledStencilDesc.StencilReadMask = 0xFF;depthDisabledStencilDesc.StencilWriteMask = 0xFF;depthDisabledStencilDesc.FrontFace.StencilFailOp = D3D11_STENCIL_OP_KEEP;depthDisabledStencilDesc.FrontFace.StencilDepthFailOp = D3D11_STENCIL_OP_INCR;depthDisabledStencilDesc.FrontFace.StencilPassOp = D3D11_STENCIL_OP_KEEP;depthDisabledStencilDesc.FrontFace.StencilFunc = D3D11_COMPARISON_ALWAYS;depthDisabledStencilDesc.BackFace.StencilFailOp = D3D11_STENCIL_OP_KEEP;depthDisabledStencilDesc.BackFace.StencilDepthFailOp = D3D11_STENCIL_OP_DECR;depthDisabledStencilDesc.BackFace.StencilPassOp = D3D11_STENCIL_OP_KEEP;depthDisabledStencilDesc.BackFace.StencilFunc = D3D11_COMPARISON_ALWAYS;

// Create the state using the device.m_d3dDevice->CreateDepthStencilState(&depthDisabledStencilDesc, &depthDisabledStencilState);m_d3dContext->OMSetDepthStencilState(depthDisabledStencilState, 1);

}

Direct3DBase.cpp

Render 3 rectangles using Triangle Lists

Direct3D App

VertexPositionColor cubeVertices[] = {

{XMFLOAT3(0.0f, 0.0f, 0.0f), XMFLOAT3(0.0f, 0.0f, 1.0f)},{XMFLOAT3(100.0f, 0.0f, 0.0f), XMFLOAT3(0.0f, 0.0f, 1.0f)},{XMFLOAT3(100.0f, 100.0f, 0.0f), XMFLOAT3(0.0f, 0.0f, 1.0f)},{XMFLOAT3(0.0f, 100.0f, 0.0f), XMFLOAT3(0.0f, 0.0f, 1.0f)},{XMFLOAT3(50.0f, 50.0f, 0.0f), XMFLOAT3(0.0f, 1.0f, 0.0f)},{XMFLOAT3(150.0f, 50.0f, 0.0f), XMFLOAT3(0.0f, 1.0f, 0.0f)},{XMFLOAT3(150.0f, 150.0f, 0.0f), XMFLOAT3(0.0f, 1.0f, 0.0f)},{XMFLOAT3(50.0f, 150.0f, 0.0f), XMFLOAT3(0.0f, 1.0f, 0.0f)},{XMFLOAT3(100.0f, 100.0f, 0.0f), XMFLOAT3(1.0f, 0.0f, 0.0f)},{XMFLOAT3(200.0f, 100.0f, 0.0f), XMFLOAT3(1.0f, 0.0f, 0.0f)},{XMFLOAT3(200.0f, 200.0f, 0.0f), XMFLOAT3(1.0f, 0.0f, 0.0f)},{XMFLOAT3(100.0f, 200.0f, 0.0f), XMFLOAT3(1.0f, 0.0f, 0.0f)},

};

unsigned short cubeIndices[] = {

0,1,2,0,2,3,4,5,6,4,6,7,8,9,10,8,10,11,

};

CubeRenderer.cpp

Direct3D App

0 (0,0) 1 (100,0)

2 (100,100)3 (0,100)

Texture Mapping0 (0,0) 1 (300,0)

2 (300,300)3 (0,300)

0.0 1.0

1.0

U

V

• Texturing allows adding photographs and other images onto polygon faces

• The format of the textures are Direct Draw Surface (.dds) files

• In the texel coordinate system, the width value is named "U" and the height value is named "V“:• The width goes from 0.0 on the left to 1.0 on the right• The height goes from 0.0 on the top to 1.0 on the bottom

Texel Coordinate System

Update texture coordinates and render

VertexPositionTexture cubeVertices[] = {

{XMFLOAT3(0.0f, 0.0f, 0.0f), XMFLOAT3(0.0f, 0.0f, 0.0f)},{XMFLOAT3(300.0f, 0.0f, 0.0f), XMFLOAT3(1.0f, 0.0f, 0.0f)},{XMFLOAT3(300.0f, 300.0f, 0.0f), XMFLOAT3(1.0f, 1.0f, 0.0f)},{XMFLOAT3(0.0f, 300.0f, 0.0f), XMFLOAT3(0.0f, 1.0f, 0.0f)},

};

Map texture to a square having width=300, height=300 and render it at (0, 0):

Choosing the right project template for your game

Direct3DDirect3D with XAML

XAML with Direct3D

UI (XAML) No Yes Yes

Exclusive Features No Yes Yes

Acts as a XAML control (can be placed anywhere on the screen, above or next to other XAML controls)

No No Yes

Features

Exclusive Features:• Background Agents• Browser Control• Map Control• Background Transfer Service• Live Tiles• Push Notifications• The Windows Phone Ad Control• Localized resources• XAML controls

Choosing the right project template for your game for WP8

Direct3DDirect3D with XAML

XAML with Direct3D

Startup time 2 1 1

Rendering 3 2 1

Performance

Unofficial tests:• Direct3D with XAML app is 18 – 20%

slower than Direct3D app• XAML with Direct3D app is 5 – 7%

slower than Direct3D with XAML app

* Note: higher number means faster performance

Direct3D with XAML appChoose project template

Direct3D with XAML appUses the DrawingSurfaceBackgroundGrid control• Render graphics that are displayed across the entire background of your app, behind any XAML

controls in your UI• Must be the root element of the XAML tree and is always the full size of the screen

Structure• Made up of two components: a XAML-based Windows Phone app and a component that’s based on

the Windows Phone Runtime• The XAML engine creates and maintains a Direct3D graphics device. Once per frame, the XAML

engine passes the graphics device and an associated render target to the Windows Phone Runtime component

Main classes• MainPage: hosts your XAML-based UI and your managed code• CubeRenderer: where the actual drawing to the shared texture is performed• PhoneDirect3DXamlAppComponent: contains touch input handling

XAML with Direct3D appChoose project template

XAML with Direct3D appUses the DrawingSurface control• Render graphics that are displayed behind or inline with XAML controls and content• The size and layout of your DrawingSurface are handled just as they are with other XAML controls

Structure• Made up of two components: a XAML-based Windows Phone app and a component that’s based on

the Windows Phone Runtime• The Windows Phone Runtime component creates a Direct3D graphics device, which it uses to create

a Texture that is shared with the XAML app. The Windows Phone Runtime component uses Direct3D to draw onto the Texture. The XAML engine maintains a swap chain that copies the texture to the screen within the bounds of the DrawingSurface control

Main classes• MainPage: hosts your XAML-based UI and your managed code• CubeRenderer: where the actual drawing to the shared texture is performed• Direct3DInterop: contains touch input handling

35

Porting 2D XNA Games to Asha Full Touch

• Minimal porting effort: 1 – 5 working days

• Leverage on Nokia Store payment system to maximize revenue:

In-app purchasing with 145 operator billing integrations

In-app advertising with Nokia Ad Exchange (NAX): 120 ad networks in over 200 countries

Why porting to Asha Full Touch?

Screen Resolution

480x800 240x400

All images are scaled down by half

All coordinates are divided by half

Images

68x74 34x37

Coordinates and Alignment

(x, y) (x / 2, y / 2)

XNA & J2ME - C# and Java language

C# Java

namespace package

const final

bool boolean

override N/A

XNA and Java ME Frameworks

XNA Java ME

Microsoft.Xna.Framework.Game javax.microedition.lcdui.Canvasjava.lang.Runnable

GraphicsDeviceManagerGraphicsDeviceSpriteBatchRenderTarget2D

Graphics

protected override void Update(GameTimegameTime)protected override void Draw(GameTimegameTime)

public void run()public void paint(Graphics g)

Color int color

Texture2D Image

XNA and Java ME Frameworks

Rule #1 – All coordinates divided by half

k_Factor:

• 1: Windows Phone

• 2: AshaFT

Rule #2 – Do relative alignment, no hard code

DON'T's DO’s

Rule #3 – Use J2ME wrapper classes in XNA

Rule #3 – Use J2ME wrapper classes in XNA

1. Develop or modify XNA source code with J2ME wrapper classes:

• Graphics

• Image

• Touch input and media related classes

2. Resize all images to one half and copy to AshaFT project

3. Update all coordinates with scale factor = ½

4. Replace Microsoft.Xna.Framework.Game by Javax.microedition.lcdui.Canvasand java.lang.Runnable

5. Remove all wrapper classes, go with the ones in MIDP such as javax.microedition.lcdui.Graphics…

6. Optimize memory and performance

Porting Steps

mcpp preprocessorhttp://mcpp.sourceforge.net/

• Implements all of C90, C99 and C++98 specifications.

• Provides a validation suite to test C/C++ preprocessor's conformance and quality comprehensively. When this validation suite is applied, mcppdistinguishes itself among many existing preprocessors.

• Has plentiful and on-target diagnostics to check all the preprocessing problems such as latent bug or lack of portability in source code.

• Has #pragma directives to output debugging information.

• Is portable and has been ported to many compiler-systems, including GCC and Visual C++, on UNIX-like systems and Windows.

• Has various behavior modes.

• Can be built either as a compiler-specific preprocessor to replace the resident preprocessor of a particular compiler system, or as a compiler-independent command, or even as a subroutine called from some other main program.

• Provides comprehensive documents both in Japanese and in English.

• Is an open source software released under BSD-style-license.

Develop a game fully in XNA

Building jar and jad automatically

Launch the file with Nokia Java Emulator

Thank you!

https://www.facebook.com/groups/viet.nok.devLet’s discuss more: