Написал 10ю задачу по Геометрии

ComputationalGeometry/10Ex/polygon.c

@@ -0,0 +1,122 @@
+#include "polygon.h"
+
+line getLine(point pt1, point pt2) {
+	return (line){.start=pt1, .direction=(point){pt2.x - pt1.x, pt2.y - pt1.y}}; 
+}	
+
+lines getLines(points pts) {
+	line * lns = (line *)malloc(pts.len * sizeof(line));
+	int len = pts.len;
+
+	for (int i = 0; i < len; ++i) {
+		lns[i] = getLine(pts.arr[i], pts.arr[(i + 1) % len]);
+	}
+
+	return (lines){lns, len};
+}
+
+points getVectors(points pts) {
+	point * vectors = (point *)malloc(pts.len * sizeof(point));
+	int len = pts.len;
+	point vector;
+	double vlen;
+
+	for (int i = 0; i < len; ++i) {
+		vector = normal(getLine(pts.arr[i], pts.arr[(i + 1) % len]));
+		vlen = vector_len(vector);
+
+		vector.x /= vlen, vector.y /= vlen;
+		
+		vectors[i] = vector;
+	}
+
+	return (points){vectors, len};
+}
+
+point normal(line ln) {
+	return (point){ln.direction.y, -ln.direction.x};
+}
+
+double vector_len(point vector) {
+	return sqrt(qpow(vector.x) + qpow(vector.y));
+}
+
+double qpow(double number) {
+	return number * number;
+}
+
+void repairPolygon(polygon * plgn) {
+	lines lns = getLines(plgn -> pts);
+	int len = lns.len;
+
+	for (int i = 0; i < len; ++i) { 
+		point fdirect = lns.arr[i].direction;
+		point sdirect = lns.arr[(i + 1) % len].direction;
+		
+		if (isNull(fdirect)) {
+			polygonDelPoint(plgn, i), --len;
+			delLine(&lns, i--);
+			fdirect = sdirect, sdirect = lns.arr[(i + 1) % len].direction;
+		}
+		
+		if (isCollinear(fdirect, sdirect)) {
+			polygonDelPoint(plgn, i), --len;
+			delLine(&lns, i--);
+		}
+	}
+}       
+
+bool isNull(point vector) {
+	return (fabs(vector.x) < eps && fabs(vector.y) < eps);
+}
+
+void polygonDelPoint(polygon * plgn, int index) {
+	delVector(&(plgn -> pts), index);
+}
+
+bool isCollinear(point fvec, point svec) {
+	return fabs(fabs(fvec.x * svec.x + fvec.y * svec.y) - (vector_len(fvec) * vector_len(svec))) < eps;
+}
+
+DELFUNC(Vector, points)
+
+DELFUNC(Line, lines)
+
+//void delVector(points * vectors, int index) {
+//	DEL(vectors -> arr, index, vectors -> len)
+//	vectors -> len--;
+//}
+//
+//void delLine(lines * lns, int index) {
+//	for (int i = index + 1; i < lns -> len; ++i) {
+//		lns -> arr[i] = lns -> arr[i - 1];
+//	}
+//	
+//	lns -> len--;
+//}
+
+polygon getPolygon(polygon * plgn, double shift) {
+	points vectors = getVectors(plgn -> pts);
+	int secind, len = plgn -> pts.len;
+	point * pts = (point *)malloc(len * sizeof(point));
+
+	memcpy(pts, plgn -> pts.arr, len * sizeof(point));
+
+	for (int i = 0; i < len; ++i) {
+		vectors.arr[i].x *= shift;
+		vectors.arr[i].y *= shift;
+
+		secind = ((i + 1) % len);
+			
+		pts[i].x += vectors.arr[i].x;
+		pts[secind].x += vectors.arr[i].x;
+		
+		pts[i].y += vectors.arr[i].y;
+		pts[secind].y += vectors.arr[i].y;
+	}
+
+	free(vectors.arr);
+
+	return (polygon){(points){pts, len}};
+}
+