Code refactor: Split __VOLUME__ defines in Cycles.

* __VOLUME__ is basic volume support with Emission and Absorption.
* __VOLUME_SCATTER__ enables volume Scattering support.
* __VOLUME_DECOUPLED__ enables Decoupled Ray Marching.

4 files changed, 29 insertions, 6 deletions

diff --git a/intern/cycles/kernel/kernel_path.h b/intern/cycles/kernel/kernel_path.h
index 7c06a895249..25c285e3def 100644
--- a/intern/cycles/kernel/kernel_path.h
+++ b/intern/cycles/kernel/kernel_path.h
@@ -90,6 +90,8 @@ ccl_device void kernel_path_indirect(KernelGlobals *kg, RNG *rng, Ray ray,
 
 			bool heterogeneous = volume_stack_is_heterogeneous(kg, state.volume_stack);
 			int sampling_method = volume_stack_sampling_method(kg, state.volume_stack);
+
+#ifdef __VOLUME_DECOUPLED__
 			bool decoupled = kernel_volume_use_decoupled(kg, heterogeneous, false, sampling_method);
 
 			if(decoupled) {
@@ -141,12 +143,15 @@ ccl_device void kernel_path_indirect(KernelGlobals *kg, RNG *rng, Ray ray,
 						break;
 				}
 			}
-			else {
+			else
+#endif
+			{
 				/* integrate along volume segment with distance sampling */
 				ShaderData volume_sd;
 				VolumeIntegrateResult result = kernel_volume_integrate(
 					kg, &state, &volume_sd, &volume_ray, L, &throughput, rng);
 
+#ifdef __VOLUME_SCATTER__
 				if(result == VOLUME_PATH_SCATTERED) {
 					/* direct lighting */
 					kernel_path_volume_connect_light(kg, rng, &volume_sd, throughput, &state, L, 1.0f);
@@ -157,6 +162,7 @@ ccl_device void kernel_path_indirect(KernelGlobals *kg, RNG *rng, Ray ray,
 					else
 						break;
 				}
+#endif
 			}
 		}
 #endif
@@ -471,6 +477,8 @@ ccl_device float4 kernel_path_integrate(KernelGlobals *kg, RNG *rng, int sample,
 
 			bool heterogeneous = volume_stack_is_heterogeneous(kg, state.volume_stack);
 			int sampling_method = volume_stack_sampling_method(kg, state.volume_stack);
+
+#ifdef __VOLUME_DECOUPLED__
 			bool decoupled = kernel_volume_use_decoupled(kg, heterogeneous, true, sampling_method);
 
 			if(decoupled) {
@@ -522,12 +530,15 @@ ccl_device float4 kernel_path_integrate(KernelGlobals *kg, RNG *rng, int sample,
 						break;
 				}
 			}
-			else {
+			else 
+#endif
+			{
 				/* integrate along volume segment with distance sampling */
 				ShaderData volume_sd;
 				VolumeIntegrateResult result = kernel_volume_integrate(
 					kg, &state, &volume_sd, &volume_ray, &L, &throughput, rng);
 
+#ifdef __VOLUME_SCATTER__
 				if(result == VOLUME_PATH_SCATTERED) {
 					/* direct lighting */
 					kernel_path_volume_connect_light(kg, rng, &volume_sd, throughput, &state, &L, 1.0f);
@@ -538,6 +549,7 @@ ccl_device float4 kernel_path_integrate(KernelGlobals *kg, RNG *rng, int sample,
 					else
 						break;
 				}
+#endif
 			}
 		}
 #endif
@@ -804,7 +816,7 @@ ccl_device float4 kernel_branched_path_integrate(KernelGlobals *kg, RNG *rng, in
 			Ray volume_ray = ray;
 			volume_ray.t = (hit)? isect.t: FLT_MAX;
 
-#ifdef __KERNEL_CPU__
+#ifdef __VOLUME_DECOUPLED__
 			/* decoupled ray marching only supported on CPU */
 			bool heterogeneous = volume_stack_is_heterogeneous(kg, state.volume_stack);
 
@@ -891,6 +903,7 @@ ccl_device float4 kernel_branched_path_integrate(KernelGlobals *kg, RNG *rng, in
 				VolumeIntegrateResult result = kernel_volume_integrate(
 					kg, &ps, &volume_sd, &volume_ray, &L, &tp, rng);
 				
+#ifdef __VOLUME_SCATTER__
 				if(result == VOLUME_PATH_SCATTERED) {
 					/* todo: support equiangular, MIS and all light sampling.
 					 * alternatively get decoupled ray marching working on the GPU */
@@ -905,6 +918,7 @@ ccl_device float4 kernel_branched_path_integrate(KernelGlobals *kg, RNG *rng, in
 						path_radiance_reset_indirect(&L);
 					}
 				}
+#endif
 			}
 
 			/* todo: avoid this calculation using decoupled ray marching */
diff --git a/intern/cycles/kernel/kernel_path_volume.h b/intern/cycles/kernel/kernel_path_volume.h
index e7047f0ab85..4d6bf47ef9e 100644
--- a/intern/cycles/kernel/kernel_path_volume.h
+++ b/intern/cycles/kernel/kernel_path_volume.h
@@ -16,7 +16,7 @@
 
 CCL_NAMESPACE_BEGIN
 
-#ifdef __VOLUME__
+#ifdef __VOLUME_SCATTER__
 
 ccl_device void kernel_path_volume_connect_light(KernelGlobals *kg, RNG *rng,
 	ShaderData *sd, float3 throughput, PathState *state, PathRadiance *L,
diff --git a/intern/cycles/kernel/kernel_types.h b/intern/cycles/kernel/kernel_types.h
index 0ee7e60f4f6..8a99dbbbb90 100644
--- a/intern/cycles/kernel/kernel_types.h
+++ b/intern/cycles/kernel/kernel_types.h
@@ -66,6 +66,8 @@ CCL_NAMESPACE_BEGIN
 #define __SUBSURFACE__
 #define __CMJ__
 #define __VOLUME__
+#define __VOLUME_DECOUPLED__
+#define __VOLUME_SCATTER__
 #define __SHADOW_RECORD_ALL__
 #endif
 
@@ -76,6 +78,7 @@ CCL_NAMESPACE_BEGIN
 
 /* Experimental on GPU */
 //#define __VOLUME__
+//#define __VOLUME_SCATTER__
 //#define __SUBSURFACE__
 #endif
 
diff --git a/intern/cycles/kernel/kernel_volume.h b/intern/cycles/kernel/kernel_volume.h
index 49e5f5099d1..402867fa00c 100644
--- a/intern/cycles/kernel/kernel_volume.h
+++ b/intern/cycles/kernel/kernel_volume.h
@@ -334,6 +334,7 @@ ccl_device VolumeIntegrateResult kernel_volume_integrate_homogeneous(KernelGloba
 	float t = ray->t;
 	float3 new_tp;
 
+#ifdef __VOLUME_SCATTER__
 	/* randomly scatter, and if we do t is shortened */
 	if(closure_flag & SD_SCATTER) {
 		/* extinction coefficient */
@@ -387,7 +388,9 @@ ccl_device VolumeIntegrateResult kernel_volume_integrate_homogeneous(KernelGloba
 			new_tp = *throughput * transmittance / pdf;
 		}
 	}
-	else if(closure_flag & SD_ABSORPTION) {
+	else 
+#endif
+	if(closure_flag & SD_ABSORPTION) {
 		/* absorption only, no sampling needed */
 		float3 transmittance = volume_color_transmittance(coeff.sigma_a, t);
 		new_tp = *throughput * transmittance;
@@ -464,6 +467,7 @@ ccl_device VolumeIntegrateResult kernel_volume_integrate_heterogeneous_distance(
 			bool scatter = false;
 
 			/* distance sampling */
+#ifdef __VOLUME_SCATTER__
 			if((closure_flag & SD_SCATTER) || (has_scatter && (closure_flag & SD_ABSORPTION))) {
 				has_scatter = true;
 
@@ -499,7 +503,9 @@ ccl_device VolumeIntegrateResult kernel_volume_integrate_heterogeneous_distance(
 					xi = 1.0f - (1.0f - xi)/sample_transmittance;
 				}
 			}
-			else if(closure_flag & SD_ABSORPTION) {
+			else 
+#endif
+			if(closure_flag & SD_ABSORPTION) {
 				/* absorption only, no sampling needed */
 				float3 sigma_a = coeff.sigma_a;