xlib_playground

commit c30d1d25cd402a1fda5dc4fe5a44db49b3fbce45
parent 7f1318fb2cb94a2c782910b1d6c7e7ff3ccf8068
Author: Matsuda Kenji <info@mtkn.jp>
Date:   Sat, 24 Dec 2022 10:23:30 +0900

implement simple collision detection

Diffstat:
M
ex4/ex4.c
 | 
52
+++++++++++++++++++++++++++++++++++-----------------

1 file changed, 35 insertions(+), 17 deletions(-)
diff --git a/ex4/ex4.c b/ex4/ex4.c
@@ -47,7 +47,7 @@ struct square {
 Display      *display;
 Window        window;
 unsigned int  win_width = INIT_WIDTH, win_height = INIT_HEIGHT;
-GC            gc;
+GC            gc, sgc[NUM_SQUARE];
 Atom          wm_delete_window;
 struct square square[NUM_SQUARE];
 int           next_menu = START_MENU;
@@ -60,7 +60,8 @@ void start_menu(void);
 void game_play(void);
 void receive_events(int[]);
 void handle_inputs(int[]);
-void next_tick(long);
+void next_tick(struct square *, long);
+int  test_collision(struct square *, struct square*);
 void game_over(void);
 
 
@@ -80,6 +81,11 @@ setup(void)
 						0);
 	XStoreName(display, window, "UNKO");
 	gc = XCreateGC(display, window, 0, NULL);
+	XSetForeground(display, gc, 0x00FFFF);
+	for (int i = 0; i < NUM_SQUARE; i++){
+		sgc[i] = XCreateGC(display, window, 0, NULL);
+		XSetForeground(display, sgc[i], 0x00FF00);
+	}
 
 	wm_delete_window = XInternAtom(display,
 	                               "WM_DELETE_WINDOW", False);
@@ -88,7 +94,6 @@ setup(void)
 	XSelectInput(display, window,
 	             ExposureMask | KeyPressMask | KeyReleaseMask);
 
-	XSetForeground(display, gc, 0x00FFFF);
 	XMapWindow(display, window);
 }
 
@@ -234,19 +239,27 @@ handle_inputs(int key_state[])
 }
 
 void
-next_tick(long ndt) // nano second
+next_tick(struct square *s, long ndt) // nano second
 {
-	square[0].px = square[0].px + square[0].vx * ndt / 1000 / 1000 / 1000;
-	square[0].py = square[0].py + square[0].vy * ndt / 1000 / 1000 / 1000;
+	s->px = s->px + s->vx * ndt / 1000 / 1000 / 1000;
+	s->py = s->py + s->vy * ndt / 1000 / 1000 / 1000;
+
 	// bind within the window
-	if (square[0].px < 0)
-		square[0].px = 0;
-	if (win_width < square[0].px + square[0].w)
-		square[0].px = win_width - square[0].w;
-	if (square[0].py < 0)
-		square[0].py = 0;
-	if (win_height < square[0].py + square[0].h)
-		square[0].py = win_height - square[0].h;
+	if (s->px < 0)
+		s->px = 0;
+	if (win_width < s->px + s->w)
+		s->px = win_width - s->w;
+	if (s->py < 0)
+		s->py = 0;
+	if (win_height < s->py + s->h)
+		s->py = win_height - s->h;
+}
+
+int
+test_collision(struct square *s1, struct square* s2)
+{
+	return s1->px < s2->px + s2->w && s2->px < s1->px + s1->w &&
+	       s2->py < s1->py + s1->h && s1->py < s2->py + s2->h;
 }
 
 void
@@ -293,15 +306,20 @@ game_play(void)
 		clock_gettime(CLOCK_MONOTONIC, &ts);
 		t0 = ts.tv_nsec;
 
-		next_tick(1000 * 1000 * 1000 / FPS);
+		for (int i = 0; i < NUM_SQUARE; i++)
+			next_tick(&square[i], 1000 * 1000 * 1000 / FPS);
+
+		if (test_collision(&square[0], &square[1]))
+			XSetForeground(display, sgc[1], 0xFF0000);
+		else
+			XSetForeground(display, sgc[1], 0x00FF00);
 
 		XClearArea(display, window,
 				   0, 0,                  // position
 				   win_width, win_height, // width and height
 				   False);
 		for (int i = 0; i < NUM_SQUARE; i++) {
-			XSetForeground(display, gc, 0x000FFF << i * 12);
-			XFillRectangle(display, window, gc,
+			XFillRectangle(display, window, sgc[i],
 						   square[i].px, square[i].py,    // position
 						   square[i].w, square[i].h);   // width and height
 		}