[cffi-devel] WITH-POINTER-TO-VECTOR-DATA ?

[Luke Crook]

I'm trying to optimize memory access to an SDL_Surface in the lispbuilder-sdl 
project. An SDL_Surface is basically a foreign array. Reading and writing 
individual pixels involves calling MEM-AREF to access an integer value at a 
specific offset in the SDL_Surface array. This is fine for individual pixel 
reads and writes but sub-optimal for a rotation function where there is a read 
and corresponding write for each pixel in the surface (For example a 320x240 
resolution surface requires a total of 153,600 calls to MEM-AREF in order to 
perform a rotation.)

Can I use WITH-POINTER-TO-VECTOR-DATA to somehow speed this up? 

Thanks,
- Luke