Circuit draw does not differentiate between different control values

[Mayank447]

from qutip_qip.circuit import QubitCircuit
from qutip_qip.operations import gates, get_controlled_gate

qc = QubitCircuit(2)
qc.add_gate(gates.CX, 0, 1)
qc.draw()

modified_CX = get_controlled_gate(gates.X, n_ctrl_qubits=1, control_value=0)
qc2 = QubitCircuit(2)
qc2.add_gate(modified_CX, 0, 1)
qc2.draw()

Both render the control bit the same, although in the first case the control value is 1, while in the second case control value is 0. Also in case of custom controlled gates, target_gate name should be used while rendering not the controlled gate's name.

[BoxiLi]

True, we don't distinguish them. How should they look like then with a different control value? Is there any convention?

[Mayank447]

Standard convention is a filled circle for control value 1 and a hollow circle in case of control value being 0. This is how qiskit does it