6.2

Author: Heatwave

chapter-6-structures/1.structures-and-functions.c

@@ -0,0 +1,113 @@
+#include <stdio.h>
+
+#define XMAX 100
+#define YMAX 100
+
+#define min(a, b) ((a) < (b) ? (a) : (b))
+#define max(a, b) ((a) > (b) ? (a) : (b))
+
+struct point {
+	int x;
+	int y;
+};
+
+struct rect {
+	struct point pt1;
+	struct point pt2;
+};
+
+main()
+{
+	struct rect screen;
+	struct point middle;
+	struct point makepoint(int, int);
+	struct point addpoint(struct point, struct point);
+	int ptinrect(struct point, struct rect);
+	struct rect canonrect(struct rect);
+
+	screen.pt1 = makepoint(0, 0);
+	screen.pt2 = makepoint(XMAX, YMAX);
+	middle = makepoint((screen.pt1.x + screen.pt2.x) / 2,
+						(screen.pt1.y + screen.pt2.y) /2);
+	
+	printf("middle.x: %d, middle.y: %d\n", middle.x, middle.y);
+
+	struct point p1 = { 5, 5 };
+
+	p1 = addpoint(p1, middle);
+
+	printf("p1.x: %d, p1.y: %d\n", p1.x, p1.y);
+
+	int p1inscreen = ptinrect(p1, screen);
+
+	printf("p1inscreen: %d\n", p1inscreen);
+
+	struct point p2;
+
+	printf("p2.x: %d, p2.y: %d\n", p2.x, p2.y);
+
+
+	struct rect r1 = { 10, 10, 0, 0 };
+
+	printf("r1.pt1.x: %d, r1.pt1.y: %d, r1.pt2.x: %d, r1.pt2.y: %d\n",
+			r1.pt1.x, r1.pt1.y, r1.pt2.x, r1.pt2.y);
+
+	r1 = canonrect(r1);
+
+	printf("r1.pt1.x: %d, r1.pt1.y: %d, r1.pt2.x: %d, r1.pt2.y: %d\n",
+			r1.pt1.x, r1.pt1.y, r1.pt2.x, r1.pt2.y);
+
+	struct rect r2 = { { 20, 0 }, { 0, 20 } };
+
+	printf("r2.pt1.x: %d, r2.pt1.y: %d, r2.pt2.x: %d, r2.pt2.y: %d\n",
+			r2.pt1.x, r2.pt1.y, r2.pt2.x, r2.pt2.y);
+
+	r2 = canonrect(r2);
+
+	printf("r2.pt1.x: %d, r2.pt1.y: %d, r2.pt2.x: %d, r2.pt2.y: %d\n",
+			r2.pt1.x, r2.pt1.y, r2.pt2.x, r2.pt2.y);
+
+	
+	struct point origin = { 15, 20 };
+	struct point *pp;
+
+	pp = &origin;
+	printf("origin is (%d, %d)\n", (*pp).x, (*pp).y);
+	printf("origin is (%d, %d)\n", pp->x, pp->y);
+
+	return 0;
+}
+
+struct point makepoint(int x, int y)
+{
+	struct point temp;
+
+	temp.x = x;
+	temp.y = y;
+	return temp;
+}
+
+struct point addpoint(struct point p1, struct point p2)
+{
+	p1.x += p2.x;
+	p1.y += p2.y;
+	return p1;
+}
+
+int ptinrect(struct point p, struct rect r)
+{
+	return p.x >= r.pt1.x && p.x < r.pt2.x
+		&& p.y >= r.pt1.y && p.y < r.pt2.y;
+}
+
+struct rect canonrect(struct rect r)
+{
+	struct 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;
+}
+