Backport r8827: Potential fix for Runtime Check Failures with VC 2003 by setting default values of a couple alpha_op_ex arguments.
Backport r8827: Potential fix for Runtime Check Failures with VC 2003 by setting default values of a couple alpha_op_ex arguments.

vbudovski/ogre,vbudovski/ogre,vbudovski/ogre,vbudovski/ogre,vbudovski/ogre