Utilities2D.py 文件源码

def getBarycentricCoords(A, B, C, X, checkValidity = True):
    T = np.array( [ [A.x - C.x, B.x - C.x ], [A.y - C.y, B.y - C.y] ] )
    y = np.array( [ [X.x - C.x], [X.y - C.y] ] )
    lambdas = linalg.solve(T, y)
    lambdas = lambdas.flatten()
    lambdas = np.append(lambdas, 1 - (lambdas[0] + lambdas[1]))
    if checkValidity:
        if (lambdas[0] < 0 or lambdas[1] < 0 or lambdas[2] < 0):
            print "ERROR: Not a convex combination; lambda = %s"%lambdas
            print "pointInsideConvexPolygon2D = %s"%pointInsideConvexPolygon2D([A, B, C], X, 0)
            plt.plot([A.x, B.x, C.x, A.x], [A.y, B.y, C.y, A.y], 'r')
            plt.hold(True)
            plt.plot([X.x], [X.y], 'b.')
            plt.show()
        assert (lambdas[0] >= 0 and lambdas[1] >= 0 and lambdas[2] >= 0)
    else:
        lambdas[0] = max(lambdas[0], 0)
        lambdas[1] = max(lambdas[1], 0)
        lambdas[2] = max(lambdas[2], 0)
    return lambdas