// if the 4th field is 0.0, this specifies a direction ...
GLfloat white[4] = { 1.0, 1.0, 1.0, 1.0 };
// base sky color
+#if defined (sgi)
GLfloat base_sky_color[4] = { 0.20, 0.32, 0.50, 1.0 };
+#else // PC
+ GLfloat base_sky_color[4] = { 0.38, 0.57, 0.82, 1.0 };
+#endif
// base fog color
GLfloat base_fog_color[4] = { 0.65, 0.62, 0.70, 1.0 };
double deg, ambient, diffuse, specular, sky_brightness;