Allow reuse of texture units

In case where we have used all other texture units previously

Change-Id: I341c5d1442640e64323b145a05a84d3b6f01663c
Removed debug messages

Change-Id: Id75fe70bf5fb1a80cc5d46ecf24bc6e563c9c12a
Fixing MIP issues

Change-Id: I23a5e2443fe115c1e397282974ba9b70be2fa6b7