# Geometry Computations#

## Ellipse#

colour.geometry

 ellipse_coefficients_general_form(coefficients) Return the general form ellipse coefficients from given canonical form ellipse coefficients. ellipse_coefficients_canonical_form(coefficients) Return the canonical form ellipse coefficients from given general form ellipse coefficients. point_at_angle_on_ellipse(phi, coefficients) Return the coordinates of the point at angle $$\phi$$ in degrees on the ellipse with given canonical form coefficients. ELLIPSE_FITTING_METHODS Supported ellipse fitting methods. ellipse_fitting(a[, method]) Return the coefficients of the implicit second-order polynomial/quadratic curve that fits given point array $$a$$ using given method.

Ancillary Objects

colour.geometry

 Return the coefficients of the implicit second-order polynomial/quadratic curve that fits given point array $$a$$ using Halir and Flusser (1998) method.

## Intersection#

colour.geometry

 extend_line_segment(a, b[, distance]) Extend the line segment defined by point arrays $$a$$ and $$b$$ by given distance and return the new end point. intersect_line_segments(l_1, l_2) Compute $$l_1$$ line segments intersections with $$l_2$$ line segments.

Ancillary Objects

colour.geometry

 Define the specification for intersection of line segments $$l_1$$ and $$l_2$$ returned by colour.algebra.intersect_line_segments() definition.

## Primitives#

colour

 PRIMITIVE_METHODS Supported geometry primitive generation methods. primitive([method]) Return a geometry primitive using given method.

Ancillary Objects

colour.geometry

 MAPPING_PLANE_TO_AXIS Plane to axis mapping. primitive_grid([width, height, ...]) Generate vertices and indexes for a filled and outlined grid primitive. primitive_cube([width, height, depth, ...]) Generate vertices and indexes for a filled and outlined cube primitive.

## Primitive Vertices#

colour

 PRIMITIVE_VERTICES_METHODS Supported geometry primitive vertices generation methods. primitive_vertices([method]) Return the vertices of a geometry primitive using given method.

colour.geometry

 primitive_vertices_quad_mpl([width, height, ...]) Return the vertices of a quad primitive for use with Matplotlib mpl_toolkits.mplot3d.art3d.Poly3DCollection class. primitive_vertices_grid_mpl([width, height, ...]) Return the vertices of a grid primitive made of quad primitives for use with Matplotlib mpl_toolkits.mplot3d.art3d.Poly3DCollection class. primitive_vertices_cube_mpl([width, height, ...]) Return the vertices of a cube primitive made of grid primitives for use with Matplotlib mpl_toolkits.mplot3d.art3d.Poly3DCollection class. primitive_vertices_sphere([radius, ...]) Return the vertices of a latitude-longitude sphere primitive.

## Hull Section#

colour.geometry

 hull_section(hull[, axis, origin, normalise]) Compute the hull section for given axis at given origin.