mmp/pbrt-v2 — pull request #8 by kysucix (2012-12-03 12:55:51+00:00)
Title: Fix pfm file writer

Small patch to fix WriteImagePFM() function.

In the original it did not take into consideration that the pfm file format assume the image to be stored from bottom to top row and not viceversa.

Compare specification as in http://netpbm.sourceforge.net/doc/pfm.html