The document outlines advanced techniques for developing 2D games on Windows 8 using DirectX and C++. It covers topics such as cross-device UI design, performance tuning, sprite animation methods, and optimizations for game graphics. Additionally, it includes code examples for implementing techniques like sprite-batching and particle systems.

1. Advanced techniques for the development of 2D
Windows 8 games using Direct X and C++
Markus Jost
CEO, Lead Programmer, Codebox GmbH
markus.jost@codebox.ch

2. Agenda
Recap first Session 5’
Cross-Device UI Design 5’
Performance tuning 15’
Advanced Techniques 15’
Questions 5’

3. Cross-Device UI Design
Chapter 1/4

4. The Problem:
The Solution:

5. The Problem:
The Solution:

6. Illustrating design thoughts by sample

7. Performance tuning
Chapter 2/4

9. Texture Atlases
© Gango Games
<?xml version="1.0" encoding="UTF-8"?>
<!-- Created with TexturePacker http://texturepacker.com-->
<!-- $TexturePacker:SmartUpdate:963678140e0adc4acab0c90e39ea3d54$ -->
<!--Format:
n => name of the sprite
x => sprite x pos in texture
y => sprite y pos in texture
w => sprite width (may be trimmed)
h => sprite height (may be trimmed)
oX => sprite's x-corner offset (only available if trimmed)
oY => sprite's y-corner offset (only available if trimmed)
oW => sprite's original width (only available if trimmed)
oH => sprite's original height (only available if trimmed)
r => 'y' only set if sprite is rotated
-->
<TextureAtlas imagePath="FlySplash.png" width="512" height="1024">
<sprite n="fly_mouth_frame1.png" x="416" y="210" w="56" h="102" r="y"/>
<sprite n="fly_mouth_frame2.png" x="416" y="106" w="56" h="102" r="y"/>
<sprite n="fly_mouth_frame3.png" x="416" y="2" w="56" h="102" r="y"/>
<sprite n="fly_splash_solid.png" x="2" y="2" w="412" h="298"/>
<sprite n="fly_wings_frame1.png" x="2" y="412" w="228" h="108"/>
<sprite n="fly_wings_frame2.png" x="232" y="314" w="228" h="108"/>
<sprite n="fly_wings_frame3.png" x="2" y="302" w="228" h="108"/>
</TextureAtlas>

10. Build-time processing media
Pipeline Direct3D 11: http://code.msdn.microsoft.com/windowsapps/Direct3D-Resource-Loading-25406148

12. Sprite-Batching
SpriteBatch Sample: http://code.msdn.microsoft.com/windowsapps/Direct3D-sprite-sample-97ae6262

13. The Problem:
The Solution:

14. Sample optimization
optimization

15. Advanced Techniques
Chapter 3/4

16. Sample Pseudo Code for setting Transform:
Vector<Sprite*> parents = getParentSprites();
Matrix translation = Matrix.Identity;
foreach(Sprite *s in parents)
{
translation *= s.getTranslationMatrix();
}
translation *= getTranslationMatrix();
SetTranslation(translation);

17. SpriteSheet Animation
Create animation sequences from an Atlas
 Pros:
 High level of detail
 Easy to implement
 Cons:
 Very High Memory use
 Low FPS resolution
 Hand drawn frames take time

18. Bone Animations
Create animations using a tool (e.g. Flash) combining
body parts
 Pros:
 Way less memory consumption
 Allows many many animations to reuse same
texture parts
 Runs at max FPS
 Artists are used to using Flash
 Fast creation
 Cons:
 Low level of details
 Restrictions in design
 More work to implement

19. 3D Animations
Use 3D Animations made with 3DSMax or any other 3D
Animation Tool
 Pros:
 Smooth Animations
 High Level of Details
 Depending on LOD, fast production
 Cons:
 Doesn’t mix well with 2D
 GPU intense
 Also Memory intense due to Animation data

20.  Used for example for smoke, fire, dust, snow, rain etc.
 Lots of tiny textures that face the camera
 Each particle has its own state
 Position
 Rotation
 Scale
 Color
 1 Texture…
 Using PointSprites, particles have only 1 vertex
 Usually alpha blended -> performance
 Avoid filling Particle Sytsems
 Supported by most GPUs

21. Sample

22. Implementation
Ss = Vh * Si * sqrt(1/(A + B * De + C *( De
2 )))
Vh : Viewport height
Si : Initial point size
De
2 : The Distance from eye to position
A, B, C : User defined values
float fPointSize = 1.0f, fPointScaleB = 1.0f;
m_d3dDevice->SetRenderState(D3DRS_POINTSPRITEENABLE, true); //create vertices?
m_d3dDevice->SetRenderState(D3DRS_POINTSCALEENABLE, true); //use scale function?
m_d3dDevice->SetRenderState(D3DRS_POINTSIZE, *((DWORD*)&fPointSize));
m_d3dDevice->SetRenderState(D3DRS_POINTSCALE_B, *((DWORD*)&fPointScaleB));
m_d3dDevice->SetRenderState(D3DRS_ALPHABLENDENABLE,true);
m_d3dDevice->SetRenderState(D3DRS_SRCBLEND,D3DBLEND_ONE);
m_d3dDevice->SetRenderState(D3DRS_DESTBLEND,D3DBLEND_ONE);
#define D3DFVF_CUSTOMVERTEX (D3DFVF_XYZ | D3DFVF_PSIZE | D3DFVF_DIFFUSE) struct
D3DVERTEX { float fX, fY, fZ, fSize; DWORD dwColor; };
D3DXCreateTextureFromFile(m_d3dDevice,"texture.png",&pTex);
m_d3dDevice->SetTexture(0,pTex);
m_d3dDevice->SetStreamSource(0,pVB,0,sizeof(D3DVERTEX));
m_d3dDevice->DrawPrimitive(D3DPT_POINTLIST, 0, numPoints);

23. Box2D
http://www.box2d.org/manual.html

24. On Windows 8
http://code.msdn.microsoft.com/windowsapps/DWriteHelloWorld-760793d2
On Windows Phone 8
Or use BitmapFonts
http://directxtk.codeplex.com/
http://www.71squared.com/en/glyphdesigner

26. Questions?
Chapter 4/4