Function InsertPolygon

roomedit/source/objects.cpp:3272–3335

*/

void InsertPolygon (SHORT xpos, SHORT ypos, SHORT nsides, SHORT radius)
{
	SHORT sector;
	SHORT n;

	// are we inside a Sector?
	sector = GetCurObject (OBJ_SECTORS, xpos, ypos, xpos, ypos);

	if (nsides < 3)		nsides = 3;
	if (radius < 8)		radius = 8;

	// Insert vertices (and new sector)
	InsertPolygonVertices (xpos, ypos, nsides, radius);
	if (sector < 0)
		InsertObject (OBJ_SECTORS, -1, 0, 0);

	// Insert the LineDefs
	for (n = 0; n < nsides; n++)
	{
		// Insert LineDef
		InsertObject (OBJ_LINEDEFS, -1, 0, 0);

		// Insert SideDef1
		InsertObject (OBJ_SIDEDEFS, -1, 0, 0);
		LineDefs[NumLineDefs - 1].sidedef1 = NumSideDefs-1;
		if (sector >= 0)
			SideDefs[NumSideDefs - 1].sector = sector;
	}

	// If inside a sector, join LineDef clockwise
	if (sector >= 0)
	{
		LineDef *pLineDef = &LineDefs[NumLineDefs-1];

		// Close polygon with last LineDef
		pLineDef->start = NumVertexes - 1;
		pLineDef->end   = NumVertexes - nsides;

		// Build polygon with LineDefs
		for (n = 2; n <= nsides; n++)
		{
			pLineDef = &LineDefs[NumLineDefs-n];

			pLineDef->start = NumVertexes - n;
			pLineDef->end   = NumVertexes - n + 1;
		}
	}
	// If outside a sector, join LineDef anti-clockwise
	else
	{
		LineDef *pLineDef = &LineDefs[NumLineDefs-1];

		pLineDef->start = NumVertexes - nsides;
		pLineDef->end   = NumVertexes - 1;

		for (n = 2; n <= nsides; n++)
		{
			pLineDef = &LineDefs[NumLineDefs-n];