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/*
* Example program for the Allegro library, by Shawn Hargreaves.
*
* This program demonstrates how to use fixed point numbers.
*/
#include <stdio.h>
#include "allegro.h"
int main()
{
/* declare three 32 bit (16.16) fixed point variables */
fixed x, y, z;
allegro_init();
/* convert integers to fixed point like this */
x = itofix(10);
/* convert floating point to fixed point like this */
y = ftofix(3.14);
/* fixed point variables can be assigned, added, subtracted, negated,
* and compared just like integers, eg:
*/
z = x + y;
allegro_message("%f + %f = %f\n", fixtof(x), fixtof(y), fixtof(z));
/* you can't add integers or floating point to fixed point, though:
* z = x + 3;
* would give the wrong result.
*/
/* fixed point variables can be multiplied or divided by integers or
* floating point numbers, eg:
*/
z = y * 2;
allegro_message("%f * 2 = %f\n", fixtof(y), fixtof(z));
/* you can't multiply or divide two fixed point numbers, though:
* z = x * y;
* would give the wrong result. Use fixmul() and fixdiv() instead, eg:
*/
z = fixmul(x, y);
allegro_message("%f * %f = %f\n", fixtof(x), fixtof(y), fixtof(z));
/* fixed point trig and square root are also available, eg: */
z = fixsqrt(x);
allegro_message("fixsqrt(%f) = %f\n", fixtof(x), fixtof(z));
return 0;
}
END_OF_MAIN();
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