Luke Crook wrote: >An SDL_Surface is basically a foreign array. Reading >and writing individual pixels involves calling MEM-AREF >to access an integer value ... >Can I use WITH-POINTER-TO-VECTOR-DATA to somehow speed this up?
Nope, WITH-POINTER-TO-VECTOR-DATA is not the right abstraction for this. As you said, you have a foreign array. Alas, CL does not allow to portably extend the built-in ARRAY type. Your best bet is to look at CFFI's proposed block transfer operations, which ought to be optimised for speed. http://cffi.common-lisp.net/project/cffi/darcs/cffi/doc/mem-vector.txt Outside of CFFI's scope, you may find that some implementations provide for means to have specialised Lisp arrays mapped at known (malloc'ed) locations. I believe Allegro features this. Then you can use all of CL's array and sequence functions on the foreign memory area. Regards, Jorg Hohle. _______________________________________________ cffi-devel mailing list cffi-devel@common-lisp.net http://common-lisp.net/cgi-bin/mailman/listinfo/cffi-devel
