Cycles: Get rid of hardcoded enum values in the code

Still need to keep enum definition in sync with the python code,
but the code itself is a bit more clear to understand now.

2 files changed, 18 insertions, 6 deletions

diff --git a/intern/cycles/render/shader.cpp b/intern/cycles/render/shader.cpp
index b960dfa3861..2a3969b6188 100644
--- a/intern/cycles/render/shader.cpp
+++ b/intern/cycles/render/shader.cpp
@@ -138,8 +138,8 @@ Shader::Shader()
 	use_mis = true;
 	use_transparent_shadow = true;
 	heterogeneous_volume = true;
-	volume_sampling_method = 0;
-	volume_interpolation_method = 0;
+	volume_sampling_method = VOLUME_SAMPLING_DISTANCE;
+	volume_interpolation_method = VOLUME_INTERPOLATION_LINEAR;
 
 	has_surface = false;
 	has_surface_transparent = false;
@@ -353,11 +353,11 @@ void ShaderManager::device_update_common(Device *device, DeviceScene *dscene, Sc
 			flag |= SD_HAS_BSSRDF_BUMP;
 		if(shader->has_converter_blackbody)
 			has_converter_blackbody = true;
-		if(shader->volume_sampling_method == 1)
+		if(shader->volume_sampling_method == VOLUME_SAMPLING_EQUIANGULAR)
 			flag |= SD_VOLUME_EQUIANGULAR;
-		if(shader->volume_sampling_method == 2)
+		if(shader->volume_sampling_method == VOLUME_SAMPLING_MULTIPLE_IMPORTANCE)
 			flag |= SD_VOLUME_MIS;
-		if(shader->volume_interpolation_method == 1)
+		if(shader->volume_interpolation_method == VOLUME_INTERPOLATION_CUBIC)
 			flag |= SD_VOLUME_CUBIC;
 
 		/* regular shader */
diff --git a/intern/cycles/render/shader.h b/intern/cycles/render/shader.h
index 0eef62a1c61..b267731abe5 100644
--- a/intern/cycles/render/shader.h
+++ b/intern/cycles/render/shader.h
@@ -44,6 +44,18 @@ enum ShadingSystem {
 	SHADINGSYSTEM_SVM
 };
 
+/* Keep those in sync with the python-defined enum. */
+enum VolumeSampling {
+	VOLUME_SAMPLING_DISTANCE = 0,
+	VOLUME_SAMPLING_EQUIANGULAR = 1,
+	VOLUME_SAMPLING_MULTIPLE_IMPORTANCE = 2,
+};
+
+enum VolumeInterpolation {
+	VOLUME_INTERPOLATION_LINEAR = 0,
+	VOLUME_INTERPOLATION_CUBIC = 1,
+};
+
 /* Shader describing the appearance of a Mesh, Light or Background.
  *
  * While there is only a single shader graph, it has three outputs: surface,
@@ -68,7 +80,7 @@ public:
 	bool use_mis;
 	bool use_transparent_shadow;
 	bool heterogeneous_volume;
-	int volume_sampling_method;
+	VolumeSampling volume_sampling_method;
 	int volume_interpolation_method;
 
 	/* synchronization */