Source code for svgen.cartesian.mutate

"""
A module implementing cartesian object mutations.
"""

# built-in
import math
from typing import NamedTuple, Union




class Angle(NamedTuple):
    """A definition of angle attributes."""

    degrees: float
    radians: float
    sin: float
    cos: float



    @staticmethod
    def from_degrees(val: float) -> "Angle":
        """Create an angle from a degree value."""
        return Angle.from_radians(math.radians(val))




    @staticmethod
    def from_radians(val: float) -> "Angle":
        """Create an angle from a radian value."""
        return Angle(math.degrees(val), val, math.sin(val), math.cos(val))




ANGLES = {
    "quarter": Angle.from_degrees(90),
    "half": Angle.from_degrees(180),
    "three_quarter": Angle.from_degrees(270),
}




class Translation(NamedTuple):
    """A definition of a translation in a Cartesian coordinate system."""

    dx: float = 0.0
    dy: float = 0.0

    def __eq__(self, other) -> bool:
        """Test if two translations are equivalent."""
        return math.isclose(self.dx, other.dx, abs_tol=1e-12) and math.isclose(
            self.dy, other.dy, abs_tol=1e-12
        )



    def rotate(self, angle: Angle = ANGLES["quarter"]) -> "Translation":
        """Rotate this translation vector by some angle."""
        return Translation(
            self.dx * angle.cos - self.dy * angle.sin,
            self.dx * angle.sin + self.dy * angle.cos,
        )




    @staticmethod
    def normalize(
        dx: Union["Translation", float], *args, **kwargs
    ) -> "Translation":
        """Normalize input data into a translation."""
        if isinstance(dx, Translation):
            return dx
        return Translation(dx, *args, **kwargs)




    @staticmethod
    def polar(
        count: float,
        radius: float = 1.0,
        degrees: bool = True,
        ccw: bool = True,
    ) -> "Translation":
        """Create a polar translation based on provided parameters."""

        if degrees:
            count = math.radians(count)
        if not ccw:
            count *= -1

        return Translation(math.cos(count) * radius, math.sin(count) * radius)




# Common translations.
UP = Translation(0.0, -1.0)
DOWN = Translation(0.0, 1.0)
LEFT = Translation(-1.0, 0.0)
RIGHT = Translation(1.0, 0.0)
VECTORS = {"up": UP, "down": DOWN, "left": LEFT, "right": RIGHT}