Advanced techniques for the development of 2D Windows 8 games using Direct X and C++ Markus Jost CEO, Lead Programmer, Codebox GmbH

Agenda

Cross-Device UI Design Chapter 1/4

Illustrating design thoughts by sample

Performance tuning Chapter 2/4

Texture Atlases © Gango Games <!--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 -->

Build-time processing media Pipeline Direct3D 11:

SpriteBatch Sample:

Sample optimization optimization

Advanced Techniques Chapter 3/4

Sprite-Level1 x:-150 y:-100 angle: 0 Sprite-Level1 x:100 y:-60 angle: 15

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

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

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

 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

Sample

Implementation S s = V h * S i * sqrt(1/(A + B * D e + C *( D e 2 ))) V h : Viewport height S i : Initial point size D e 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);

Box2D

Questions? Chapter 4/4