imageworks/OpenShadingLanguage — pull request #76 by lgritz (2011-10-11 21:14:19+00:00)
Title: Review: blackbody and luminance improvements.

Improve performance of blackbody by interpolating from a precomputed table
rather than doing the full computation every time. Also fix a minor bug
where very low temperature values produced out-of-gamut reds that resulted
in negative color values (needed a clamp).

Also fix luminance() to give the correct result for whichever colorspace we
are using; the previous implementation was always assuming sRGB/Rec709.