Re: Problems with C floats
- Posted by mattlewis (admin) Jan 31, 2010
- 2340 views
irv said...
Your tests work. This is a different problem - many GTK routines return 2 or more values, as follows:
void gtk_window_get_default_size (GtkWindow *window,
gint *width,
gint *height);
By allocating variables and passing them to the routine, they get filled in with the current values. This works fine as long as the vars are integers, pointers, or doubles, but when they are floats, I get an machine exception. I tried using safe.e, but can't see anything there to help. Perhaps this is related to the previous problem when passing floats to a c routine?
Not sure what you're doing as far as passing floats:
// irv.c
// build with $ gcc -shared -fPIC -ldl irv.c -o irv.so
#include <stdio.h>
void pbr_float( float * pf ){
*pf += 5.5f;
}
...and then...
-- irv.ex include std/dll.e include std/machine.e include std/convert.e constant irv = open_dll( "./irv.so" ), pbr_float = define_c_proc( irv, "pbr_float", {C_POINTER} ) atom ptr = allocate( 4 ) poke( ptr, atom_to_float32( 1.5 ) ) c_proc( pbr_float, {ptr} ) ? float32_to_atom( peek( ptr & 4 ) )
From that, I get:
$ eui irv 7
...which is correct.
Matt
