Method from_regular

pygorithm/geometry/polygon2.py:168–269

Create a new regular polygon. .. hint:: If no rotation is specified there is always a point at ``(length, 0)`` If no center is specified, the center will be calculated such that all the vertexes positive and the bounding box inc

(cls, sides, length, start_rads = None, start_degs = None, center = None)

            
    @classmethod
    def from_regular(cls, sides, length, start_rads = None, start_degs = None, center = None):
        """
        Create a new regular polygon.
        
        .. hint::
        
            If no rotation is specified there is always a point at ``(length, 0)``
        
        If no center is specified, the center will be calculated such that
        all the vertexes positive and the bounding box includes (0, 0). This
        operation requires O(n) time (where n is the number if sides)
        
        May specify the angle of the first point. For example, if the coordinate
        system is x to the right and y upward, then if the starting offset is 0
        then the first point will be at the right and the next point counter-clockwise.
        
        This would make for the regular quad (sides=4) to look like a diamond. To make
        the bottom side a square, the whole polygon needs to be rotated 45 degrees, like
        so:
        
        .. code-block:: python
        
            from pygorithm.geometry import (vector2, polygon2)
            import math
            
            # This is a diamond shape (rotated square) (0 degree rotation assumed)
            diamond = polygon2.Polygon2.from_regular(4, 1)
            
            # This is a flat square
            square = polygon2.Polygon2.from_regular(4, 1, start_degs = 45)
            
            # Creating a flat square with radians 
            square2 = polygon2.Polygon2.from_regular(4, 1, math.pi / 4)
        
        Uses the `definition of a regular polygon <https://en.wikipedia.org/wiki/Regular_polygon>`
        to find the angle between each vertex in the polygon. Then converts the side
        length to circumradius using the formula explained `here <http://mathworld.wolfram.com/RegularPolygon.html>`
        
        Finally, each vertex is found using ``<radius * cos(angle), radius * sin(angle)>``
        
        If the center is not specified, the minimum of the bounding box of the 
        polygon is calculated while the vertices are being found, and the inverse
        of that value is offset to the rest of the points in the polygon. 
        
        :param sides: the number of sides in the polygon
        :type sides: :class:`numbers.Number`
        :param length: the length of any side of the polygon
        :type length: :class:`numbers.Number`
        :param start_rads: the starting radians or None 
        :type start_rads: :class:`numbers.Number` or None
        :param start_degs: the starting degrees or None 
        :type start_degs: :class:`numbers.Number` or None
        :param center: the center of the polygon
        :type center: :class:`pygorithm.geometry.vector2.Vector2`
        :returns: the new regular polygon
        :rtype: :class:`pygorithm.geometry.polygon2.Polygon2`
        
        :raises ValueError: if ``sides < 3`` or ``length <= 0``