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