Cycles: add new Spectrum and PackedSpectrum types

These replace float3 and packed_float3 in various places in the kernel where a
spectral color representation will be used in the future. That representation
will require more than 3 channels and conversion to from/RGB. The kernel code
was refactored to remove the assumption that Spectrum and RGB colors are the
same thing.

There are no functional changes, Spectrum is still a float3 and the conversion
functions are no-ops.

Differential Revision: https://developer.blender.org/D15535

1 files changed, 4 insertions, 3 deletions

diff --git a/intern/cycles/kernel/light/sample.h b/intern/cycles/kernel/light/sample.h
index 2e309cee43f..4195675dd13 100644
--- a/intern/cycles/kernel/light/sample.h
+++ b/intern/cycles/kernel/light/sample.h
@@ -14,7 +14,7 @@
 CCL_NAMESPACE_BEGIN
 
 /* Evaluate shader on light. */
-ccl_device_noinline_cpu float3
+ccl_device_noinline_cpu Spectrum
 light_sample_shader_eval(KernelGlobals kg,
                          IntegratorState state,
                          ccl_private ShaderData *ccl_restrict emission_sd,
@@ -22,7 +22,7 @@ light_sample_shader_eval(KernelGlobals kg,
                          float time)
 {
   /* setup shading at emitter */
-  float3 eval = zero_float3();
+  Spectrum eval = zero_spectrum();
 
   if (shader_constant_emission_eval(kg, ls->shader, &eval)) {
     if ((ls->prim != PRIM_NONE) && dot(ls->Ng, ls->D) > 0.0f) {
@@ -82,7 +82,8 @@ light_sample_shader_eval(KernelGlobals kg,
 
   if (ls->lamp != LAMP_NONE) {
     ccl_global const KernelLight *klight = &kernel_data_fetch(lights, ls->lamp);
-    eval *= make_float3(klight->strength[0], klight->strength[1], klight->strength[2]);
+    eval *= rgb_to_spectrum(
+        make_float3(klight->strength[0], klight->strength[1], klight->strength[2]));
   }
 
   return eval;