The Quake III Arena sources as originally released under the GPL license on August 20, 2005.

lcc/tst/struct.c

@@ -0,0 +1,69 @@
+typedef struct point { int x,y; } point;
+typedef struct rect { point pt1, pt2; } rect;
+
+point addpoint(point p1, point p2) {	/* add two points */
+	p1.x += p2.x;
+	p1.y += p2.y;
+	return p1;
+}
+
+#define min(a, b) ((a) < (b) ? (a) : (b))
+#define max(a, b) ((a) > (b) ? (a) : (b))
+
+rect canonrect(rect r) {		/* canonicalize rectangle coordinates */
+	rect temp;
+
+	temp.pt1.x = min(r.pt1.x, r.pt2.x);
+	temp.pt1.y = min(r.pt1.y, r.pt2.y);
+	temp.pt2.x = max(r.pt1.x, r.pt2.x);
+	temp.pt2.y = max(r.pt1.y, r.pt2.y);
+	return temp;
+}
+
+point makepoint(int x, int y) {		/* make a point from x and y components */
+	point p;
+
+	p.x = x;
+	p.y = y;
+	return p;
+}
+
+rect makerect(point p1, point p2) {	/* make a rectangle from two points */
+	rect r;
+
+	r.pt1 = p1;
+	r.pt2 = p2;
+	return canonrect(r);
+}
+
+int ptinrect(point p, rect r) {		/* is p in r? */
+	return p.x >= r.pt1.x && p.x < r.pt2.x
+		&& p.y >= r.pt1.y && p.y < r.pt2.y;
+}
+
+struct odd {char a[3]; } y = {'a', 'b', 0};
+
+odd(struct odd y) {
+	struct odd x = y;
+	printf("%s\n", x.a);
+}
+
+main() {
+	int i;
+	point x, origin = { 0, 0 }, maxpt = { 320, 320 };
+	point pts[] = { -1, -1, 1, 1, 20, 300, 500, 400 };
+	rect screen = makerect(addpoint(maxpt, makepoint(-10, -10)),
+		addpoint(origin, makepoint(10, 10)));
+
+	for (i = 0; i < sizeof pts/sizeof pts[0]; i++) {
+		printf("(%d,%d) is ", pts[i].x,
+			(x = makepoint(pts[i].x, pts[i].y)).y);
+		if (ptinrect(x, screen) == 0)
+			printf("not ");
+		printf("within [%d,%d; %d,%d]\n", screen.pt1.x, screen.pt1.y,
+			screen.pt2.x, screen.pt2.y);
+	}
+	odd(y);
+	exit(0);
+}
+