DragonFly On-Line Manual Pages
fixacos(3) Allegro manual fixacos(3)
NAME
fixacos - Fixed point inverse cosine lookup table. Allegro game
programming library.
SYNOPSIS
#include <allegro.h>
fixed fixacos(fixed x);
DESCRIPTION
This function finds the inverse cosine of a value using a lookup table.
The input value must be a fixed point radian. The inverse cosine is
defined only in the domain from `-1' to `1'. Outside of this input
range, the function will set `errno' to EDOM and return zero. Example:
fixed result;
/* Sets `result' to binary angle 128. */
result = fixacos(itofix(-1));
RETURN VALUE
Returns the inverse sine of a fixed point value, measured as fixed
point binary format angle, or zero if the input was out of range. All
return values of this function will be in the range `0' to `128'.
SEE ALSO
Allegro version 4.4.2 fixacos(3)