# Add the igl library to the modules search path
import sys, os
sys.path.insert(0, os.getcwd() + "/../")

import igl

b = igl.eigen.MatrixXi()
B = igl.eigen.MatrixXd()
bc = igl.eigen.MatrixXd()
lx = igl.eigen.MatrixXd()
ux = igl.eigen.MatrixXd()
Beq = igl.eigen.MatrixXd()
Bieq = igl.eigen.MatrixXd()
Z = igl.eigen.MatrixXd()

Q = igl.eigen.SparseMatrixd()
Aeq = igl.eigen.SparseMatrixd()
Aieq = igl.eigen.SparseMatrixd()

def solve(viewer):
    global Q,B,b,bc,Aeq,Beq,Aieq,Bieq,lx,ux,Z
    params = igl.active_set_params()
    params.max_iter = 8

    igl.active_set(Q,B,b,bc,Aeq,Beq,Aieq,Bieq,lx,ux,params,Z)

    C = igl.eigen.MatrixXd()
    igl.jet(Z,0,1,C)
    viewer.data.set_colors(C)

def key_down(viewer, key, mod):
    global Beq,solve
    if key == ord('.'):
         Beq[0,0] = Beq[0,0] * 2.0
         solve(viewer)
         return True
    elif key == ord(','):
         Beq[0,0] = Beq[0,0] / 2.0
         solve(viewer)
         return True
    elif key == ord(' '):
         solve(viewer)
         return True
    return False;


V = igl.eigen.MatrixXd()
F = igl.eigen.MatrixXi()

igl.readOFF("../../tutorial/shared/cheburashka.off",V,F)

# Plot the mesh
viewer = igl.viewer.Viewer()
viewer.data.set_mesh(V, F)
viewer.core.show_lines = False
viewer.callback_key_down = key_down

# One fixed point on belly
b  = igl.eigen.MatrixXi([[2556]])
bc = igl.eigen.MatrixXd([[1]])

# Construct Laplacian and mass matrix
L = igl.eigen.SparseMatrixd()
M = igl.eigen.SparseMatrixd()
Minv = igl.eigen.SparseMatrixd()

igl.cotmatrix(V,F,L)
igl.massmatrix(V,F,igl.MASSMATRIX_TYPE_VORONOI,M);
igl.invert_diag(M,Minv)

# Bi-Laplacian
Q = L.transpose() * (Minv * L)

# Zero linear term
B = igl.eigen.MatrixXd.Zero(V.rows(),1)

# Lower and upper bound
lx = igl.eigen.MatrixXd.Zero(V.rows(),1)
ux = igl.eigen.MatrixXd.Ones(V.rows(),1)

# Equality constraint constrain solution to sum to 1
Beq = igl.eigen.MatrixXd([[0.08]])
Aeq = M.diagonal().transpose().sparseView()

# (Empty inequality constraints)
solve(viewer)
print("Press '.' to increase scale and resolve.")
print("Press ',' to decrease scale and resolve.")

viewer.launch()
