Division by zero in QuickCompressDXT.cpp, line 452

[GoogleCodeExporter]

What steps will reproduce the problem?
1.Compress an image such that in optimizeAlpha8(..) the terms beta2_sum and 
alphabeta_sum are both zero
2. Then the computation of factor = 1.0f / (...) causes division by zero
3.

What is the expected output? What do you see instead?
The factor term should never be INF, it causes some problems with MSVC 2013

What version of the product are you using? On what operating system?
Latest from SVN.  OS is Win7 64-bit.

Please provide any additional information below.

Original issue reported on code.google.com by [email protected] on 28 Apr 2014 at 7:03