// Simple main loop
void mainLoop()
{
// Window is not minimized
bool active = true;
for(;;)// Infinite loop
{
SDL_Event event;
// Wait for event
if(SDL_WaitEvent(&event) == 0) throw SDL_Exception();
// Screen needs redraw
bool redraw = false;
// Handle all waiting events
do
{
camera += cam_velocity;
// Call proper event handlers
switch(event.type)
{
case SDL_ACTIVEEVENT : // Stop redraw when minimized
if(event.active.state == SDL_APPACTIVE)
active = event.active.gain;
break;
case SDL_KEYDOWN :
onKeyDown(event.key.keysym.sym, event.key.keysym.mod);
break;
case SDL_KEYUP :
onKeyUp(event.key.keysym.sym, event.key.keysym.mod);
break;
case SDL_MOUSEMOTION :
onMouseMove(event.motion.x, event.motion.y, event.motion.xrel, event.motion.yrel, event.motion.state);
break;
case SDL_MOUSEBUTTONDOWN :
onMouseDown(event.button.button, event.button.x, event.button.y);
break;
case SDL_MOUSEBUTTONUP :
onMouseUp(event.button.button, event.button.x, event.button.y);
break;
case SDL_QUIT :
return; // End main loop
case SDL_VIDEORESIZE :
onWindowResized(event.resize.w, event.resize.h);
break;
case SDL_VIDEOEXPOSE :
redraw = true;
break;
default : // Do nothing
break;
}
} while(SDL_PollEvent(&event) == 1);
// Optionally redraw window
if(active && redraw) onWindowRedraw();
}
}
// Animation main loop
// period - maximum time between redraws in ms
void mainLoop(unsigned period)
{
// This main loop requires timer support
if(SDL_InitSubSystem(SDL_INIT_TIMER) < 0) throw SDL_Exception();
// Create redraw timer
class RedrawTimer
{
private :
SDL_TimerID id;
static Uint32 callback(Uint32 interval, void *)
{
redraw();
return interval;
}
public :
RedrawTimer(unsigned interval)
: id(SDL_AddTimer(interval, callback, NULL))
{
if(id == NULL) throw SDL_Exception();
}
~RedrawTimer()
{
if(id != NULL) SDL_RemoveTimer(id);
}
} redrawTimer(period);
// Window is not minimized
bool active = true;
for(;;)// Infinite loop
{
SDL_Event event;
// Wait for event
if(SDL_WaitEvent(&event) == 0) throw SDL_Exception();
// Screen needs redraw
bool redraw = false;
// Handle all waiting events
do
{
// Call proper event handlers
switch(event.type)
{
case SDL_ACTIVEEVENT :// Stop redraw when minimized
if(event.active.state == SDL_APPACTIVE)
active = event.active.gain;
break;
case SDL_KEYDOWN :
onKeyDown(event.key.keysym.sym, event.key.keysym.mod);
break;
case SDL_KEYUP :
onKeyUp(event.key.keysym.sym, event.key.keysym.mod);
break;
case SDL_MOUSEMOTION :
onMouseMove(event.motion.x, event.motion.y, event.motion.xrel, event.motion.yrel, event.motion.state);
break;
case SDL_MOUSEBUTTONDOWN :
onMouseDown(event.button.button, event.button.x, event.button.y);
break;
case SDL_MOUSEBUTTONUP :
onMouseUp(event.button.button, event.button.x, event.button.y);
break;
case SDL_QUIT :
return;// End main loop
case SDL_VIDEORESIZE :
onWindowResized(event.resize.w, event.resize.h);
break;
case SDL_VIDEOEXPOSE :
redraw = true;
break;
default :// Do nothing
break;
}
} while(SDL_PollEvent(&event) == 1);
// Optionally redraw window
if(active && redraw) onWindowRedraw();
}
}