Optimisations and debugging

Hi All,

This is just a quick update to mention that debugging and optimisation of the next release of L3DT is proceeding well. The most recent change was an optimisation to the linear interpolation algorithm that has increased the speed of the resizing calculation by 60% [1] and the shadow casting algorithm by 70% [2]. I aim to have a developmental release available in the next fortnight, but I have a few bugs to iron out first.

Cheers, Aaron.

[1] Time taken to resize a heightfield from 512×512 to 2048×2048.

[2] Time taken to cast shadows at 15 degree elevation sun angle on 512×512 pixel heightfield with 8x light map resolution.