Of course, messing around with pixel formats wouldn't be at all necessary if convert-image works properly with GL windows... Does it?
On Sun, Jul 12, 2009 at 12:39 AM, Elliott Slaughter < elliottslaugh...@gmail.com> wrote: > Another question along the lines of my first question: > > A lot of the C++ tutorials have code to deal with the pixel format and bit > depth of surfaces loaded from files [1]. For example, > > surface->format->BytesPerPixel > > might be used to get the bit depth, or > > surface->format->Rmask > > might be used to get the position of the red byte in the pixel format (to > determine if the image is RGB or BGR). > > The lisp equivalent (that I found) seems to be: > > (cffi:foreign-slot-value (sdl-base::pixel-format (sdl:fp surface)) > 'sdl-cffi::sdl-pixel-format 'sdl-cffi::bytesperpixel) > > (cffi:foreign-slot-value (sdl-base::pixel-format (sdl:fp surface)) > 'sdl-cffi::sdl-pixel-format 'sdl-cffi::rmask) > > Is there (rather, _isn't_ there) a better way to do this? > > Thanks. > > [1] http://gpwiki.org/index.php/C:SDL_OGL > > > On Sat, Jul 11, 2009 at 9:59 PM, Elliott Slaughter < > elliottslaugh...@gmail.com> wrote: > >> Hi, >> >> I'm trying to use lispbuilder with cl-opengl. Specifically, I'm trying to >> convert a texture example from C++ into lisp [1]. >> >> I ran into a little trouble when the example got the pixels from the >> surface: >> >> surface->pixels >> >> What I eventually got working in lisp is: >> >> (sdl-base::with-pixels (pixels (sdl:fp surface)) >> (sdl-base::pixel-data pixels)) >> >> Which seems to work ok. (But I'd still like confirmation that this is the >> best way to do it. It seems like too much code to do something so simple.) >> >> >> My second question is about how to free the texture after I'm done. I know >> this isn't really an SDL thing, but I figured you dealt with this when you >> created lisp wrappers around SDL surfaces. >> >> My intuition would be to create a finalizer for the wrapper, and free the >> texture then. But according to trivial-garbage [2], in some lisps it isn't >> safe to use an object when the finalizer is called. (Or does CFFI do this >> automatically for me?) >> >> >> Thanks. Any advice would be appreciated. >> >> [1] http://anomtech.uuuq.com/glTextures.php >> [2] http://www.cliki.net/trivial-garbage >> >> -- >> Elliott Slaughter >> >> "Don't worry about what anybody else is going to do. The best way to >> predict the future is to invent it." - Alan Kay >> > > > > -- > Elliott Slaughter > > "Don't worry about what anybody else is going to do. The best way to > predict the future is to invent it." - Alan Kay > -- Elliott Slaughter "Don't worry about what anybody else is going to do. The best way to predict the future is to invent it." - Alan Kay
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