| 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); |
| } |
| |