Fixes for OSL implementation of blackbody node (AcademySoftwareFounda…

…tion#1423)

Fix a few syntactical mistakes causing compile errors in blackbody implementation.

libraries/pbrlib/genosl/mx_blackbody.osl

@@ -1,10 +1,10 @@
-void mx_blackbody(float temperature, output color color_value)
+void mx_blackbody(float temp, output color color_value)
 {
  float xc, yc;
  float t, t2, t3, xc2, xc3;
 
  // if value outside valid range of approximation clamp to accepted temperature range
- temperature = clamp(temperature, 1667.0, 25000.0);
+ float temperature = clamp(temp, 1667.0, 25000.0);
 
  t = 1000.0 / temperature;
  t2 = t * t;
@@ -39,9 +39,10 @@ void mx_blackbody(float temperature, output color color_value)
  vector XYZ = vector(xc / yc, 1.0, (1 - xc - yc) / yc);
 
  /// XYZ to Rec.709 RGB colorspace conversion
- matrix XYZ_to_RGB = matrix( 3.2406, -0.9689, 0.0557,
- -1.5372, 1.8758, -0.2040,
- -0.4986, 0.0415, 1.0570);
+ matrix XYZ_to_RGB = matrix( 3.2406, -0.9689, 0.0557, 0.0,
+ -1.5372, 1.8758, -0.2040, 0.0,
+ -0.4986, 0.0415, 1.0570, 0.0,
+ 0.0, 0.0, 0.0, 1.0);
 
  color_value = transform(XYZ_to_RGB, XYZ);
  color_value = max(color_value, vector(0.0));