Barycentric Coordinates 2D

Problem

Compute the barycentric coordinates [u, v, w] of point p with respect to triangle abc, so that p = u*a + v*b + w*c and u + v + w = 1.

Use v0 = b - a, v1 = c - a, v2 = p - a and the standard dot-product formulas. Return None if the triangle is degenerate.

Hint

Compute v and w from dot products, then u = 1 - v - w.

case 1

in: [[0.5,0.5],[0,0],[1,0],[0,1]]

expected: [0,0.5,0.5]

case 2

in: [[0,0],[0,0],[1,0],[0,1]]

expected: [1,0,0]

case 3

in: [[1,1],[0,0],[1,0],[0,1]]

expected: [-1,1,1]

case 4

in: [[1,1],[0,0],[1,1],[2,2]]

expected: null

Starter codePython

def barycentric_2d(p, a, b, c):
    # Your code here
    pass

4 test cases · run your code against them in the editor