convexhullPolygon

gistfile1.txt

Polygon convexhullPolygon(Polygon inpoly)
{

	Polygon outpoly = createPolygon();
	Polygon outpolyref = createPolygon();
	int i,j;

	printf("\ninpoly original :\n");

	for(j=0;j<inpoly.size;j++)
	{

		printf("\n\nx %de point : %f", j+1, inpoly.head->value.x);
		printf("\ny %de point : %f\n\n", j+1, inpoly.head->value.y);
		inpoly.head=inpoly.head->next;

	}

	outpoly = addPoint(outpoly, inpoly.head->value);
	outpolyref.head = outpoly.head;
	outpoly.size++;
	inpoly.head = inpoly.head->next;
	outpoly = addPoint(outpoly, inpoly.head->value);
	outpoly.size++;

	for (i = 3; i < inpoly.size; i++)
	{

		inpoly.head = inpoly.head->next;

		printf("\nboucle numero : %d\n====================================\n\ninpoly :\n", i-2);

		for(j=0;j<inpoly.size;j++)
		{

			printf("\n\nx %de point : %f", j+1, inpoly.head->value.x);
			printf("\ny %de point : %f\n\n", j+1, inpoly.head->value.y);
			inpoly.head=inpoly.head->next;

		}

		/*Vectorial product of the first point, the sign should be positive to continue (it would mean that the polygon turn always in the same direction)*/

		printf("Produit vectoriel sur z = %f", (outpoly.head->next->value.x - outpoly.head->value.x) * (inpoly.head->value.y - outpoly.head->next->value.y) - (inpoly.head->value.x - outpoly.head->next->value.x) * (outpoly.head->next->value.y - outpoly.head->value.y));

		while (outpoly.size >= 2 && ((outpoly.head->next->value.x - outpoly.head->value.x) * (inpoly.head->value.y - outpoly.head->next->value.y) - (inpoly.head->value.x - outpoly.head->next->value.x) * (outpoly.head->next->value.y - outpoly.head->value.y) < 0))
		{
			
			outpoly.head = outpoly.head->prev;
			outpoly = removePoint(outpoly,3);
			outpolyref.size--;

			printf("\noutpoly :\n");

			for(j=0;j<outpoly.size;j++)
			{

				printf("\n\nx %de point : %f", j+1, outpoly.head->value.x);
				printf("\ny %de point : %f\n\n", j+1, outpoly.head->value.y);
				outpoly.head=outpoly.head->next;

			}

			printf("Produit vectoriel sur z = %f", (outpoly.head->next->value.x - outpoly.head->value.x) * (inpoly.head->value.y - outpoly.head->next->value.y) - (inpoly.head->value.x - outpoly.head->next->value.x) * (outpoly.head->next->value.y - outpoly.head->value.y));

		}

		outpolyref = addPoint(outpolyref, inpoly.head->value);
		outpoly.size++;
		outpoly.head = outpoly.head->next;

			printf("\noutpoly :\n");

			for(j=0;j<outpoly.size;j++)
			{

				printf("\n\nx %de point : %f", j+1, outpoly.head->value.x);
				printf("\ny %de point : %f\n\n", j+1, outpoly.head->value.y);
				outpoly.head=outpoly.head->next;

			}

	}

	return outpoly;

}