Bringing Large Scale Console Game to iOS

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The Bard's Tale

Why?

Device are fast enough
Market segment is not as crowded
Hugh potential user base
Rich back data log of content
Potentially very low cost

Session1: port process
- application framework
 - development workflow
Session 2 port-port
- performance/memory opt.

OpenGL Cocoa Touch App

Bring it all together

Workflow: Data deployment

OpenAL
limit 32 active sources, DirectSound 256 channels on XBOX

-Sluggish
-5.8G -> 2Glimited on iOS

60Hz?
   - terriable for battery life
30 Hz
  - Game may depend on 60Hz

Hybrid
   -   60hz, functionsliity intact
  - 30hz : low GPU/ save energy
   -60hz, at 5th device is optional

VFP??

Candidate for NEON SIMD

SGX GPUs: a few stats

Render opt.
-minimal vertex format size
-texture size and mipmapping

Alpha test and SGX
- Fragment discard expensive
-huge impact on fill rate
-use alpha blend at all costs

Eliminating Alpha blending
-sorting issue
-automatic material separation
- evaluate polygon pixel coverage
-separate into: opaque/transparent

load time sorting
-resort all base on alpha
-sort alpha and write depth

per device opt.
-less effect, less polygon
-reduce RT
-shader LOD on low end
  - rigid/smooth skinning
  - less lights
-half native resolution


downsampling  and non power to texture


Bundle size
-OGG compression
-texture compression and reduction
-mipmap chain removal
-remove DVD-ROM redundant data

Adding iOS features:
- ObjC
-Require calls to be made on main thread

iCloud
- File system directly
 - new complications
-hybrid solution to iCloud client
 - use iCloud as a dropbox
 - game save data
- culled at high level