#include <u.h>
#include <libc.h>
#include <draw.h>
#include <event.h>
#include "graphics.h"

enum {
	framems = 20,
	Kdel = 0x7f
};

/* TODO: move these sorts of things to something like state.c/.h. */
extern Point screenRes; /* TODO: ew, coupling. */
extern int r; /* TODO: also coupling. */
Point ballPos = {40, 40};
double ballXDelta = 10;
double ballYDelta = 10;
int killgame = 0;

void changeState(void) {
	if (ballPos.x > screenRes.x - (r*3) || ballPos.x < -r) {
		ballXDelta *= -1;
	}
	if (ballPos.y > screenRes.y - (r*3) || ballPos.y < -r) {
		ballYDelta *= -1;
	}

	ballPos.x = ballPos.x + ballXDelta;
	ballPos.y = ballPos.y + ballYDelta;
}

void main(void)
{
	if(initdraw(nil, nil, "Another Plan") < 0) {
		sysfatal("initdraw failed: %r");
	}
	resizewin(Pt(SCREEN_WIDTH * DEFAULT_SCALE, SCREEN_HEIGHT * DEFAULT_SCALE));

	initGraphics(&ballPos);
	einit(Emouse | Ekeyboard);

	int child = rfork(RFPROC|RFMEM);
	if (child) {
		vlong startms = nsec()/1000000LL;
		for(;;) {
			changeState();
			render();
			flushimage(display, 1);
			if (killgame) {
				exits(0);
			}
			vlong endms = nsec()/1000000LL;
			sleep (framems - (endms-startms));
			startms = endms;
		}
	} else {
		for(;;) {
			if( ecankbd() ) {
				switch(ekbd()) {
					case 'q': case Kdel: killgame = 1; exits(0); break;
				}
			}
		}
	}
}