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/*
* Example program for the Allegro library, by Shawn Hargreaves.
*
* This program demonstrates how to use the timer routines.
* These can be a bit of a pain, because you have to be sure you lock
* all the memory that is used inside your interrupt handlers.
*/
#include "allegro.h"
/* these must be declared volatile so the optimiser doesn't mess up */
volatile int x = 0;
volatile int y = 0;
volatile int z = 0;
/* timer interrupt handler */
void inc_x(void)
{
x++;
}
END_OF_FUNCTION(inc_x);
/* timer interrupt handler */
void inc_y(void)
{
y++;
}
END_OF_FUNCTION(inc_y);
/* timer interrupt handler */
void inc_z(void)
{
z++;
}
END_OF_FUNCTION(inc_z);
int main()
{
int c;
allegro_init();
install_keyboard();
install_timer();
if (set_gfx_mode(GFX_SAFE, 320, 200, 0, 0) != 0) {
set_gfx_mode(GFX_TEXT, 0, 0, 0, 0);
allegro_message("Unable to set any graphic mode\n%s\n", allegro_error);
return 1;
}
set_palette(desktop_palette);
clear_to_color(screen, makecol(255, 255, 255));
text_mode(makecol(255, 255, 255));
textprintf_centre(screen, font, SCREEN_W/2, 8, makecol(0, 0, 0),"Driver: %s", timer_driver->name);
/* use rest() to delay for a specified number of milliseconds */
textprintf_centre(screen, font, SCREEN_W/2, 48, makecol(0, 0, 0),"Timing five seconds:");
for (c=1; c<=5; c++) {
textprintf_centre(screen, font, SCREEN_W/2, 62+c*10, makecol(0, 0, 0),"%d", c);
rest(1000);
}
textprintf_centre(screen, font, SCREEN_W/2, 142, makecol(0, 0, 0),"Press a key to set up interrupts");
readkey();
/* all variables and code used inside interrupt handlers must be locked */
LOCK_VARIABLE(x);
LOCK_VARIABLE(y);
LOCK_VARIABLE(z);
LOCK_FUNCTION(inc_x);
LOCK_FUNCTION(inc_y);
LOCK_FUNCTION(inc_z);
/* the speed can be specified in milliseconds (this is once a second) */
install_int(inc_x, 1000);
/* or in beats per second (this is 10 ticks a second) */
install_int_ex(inc_y, BPS_TO_TIMER(10));
/* or in seconds (this is 10 ticks a second) */
install_int_ex(inc_z, SECS_TO_TIMER(10));
/* the interrupts are now active... */
while (!keypressed())
textprintf_centre(screen, font, SCREEN_W/2, 176, makecol(0, 0, 0),"x=%d, y=%d, z=%d", x, y, z);
return 0;
}
END_OF_MAIN();
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