Code cleanup: remove old closure sampling code Cycles.

This was the original code to get things working on old GPUs, but now it is no
longer in use and various features in fact depend on this to work correctly to
the point that enabling this code is too buggy to be useful.

3 files changed, 5 insertions, 112 deletions

diff --git a/intern/cycles/kernel/svm/svm.h b/intern/cycles/kernel/svm/svm.h
index 49351d14443..dbf59c60cb0 100644
--- a/intern/cycles/kernel/svm/svm.h
+++ b/intern/cycles/kernel/svm/svm.h
@@ -182,10 +182,9 @@ CCL_NAMESPACE_BEGIN
 
 /* Main Interpreter Loop */
 
-ccl_device_noinline void svm_eval_nodes(KernelGlobals *kg, ShaderData *sd, ShaderType type, float randb, int path_flag)
+ccl_device_noinline void svm_eval_nodes(KernelGlobals *kg, ShaderData *sd, ShaderType type, int path_flag)
 {
 	float stack[SVM_STACK_SIZE];
-	float closure_weight = 1.0f;
 	int offset = sd->shader & SHADER_MASK;
 
 	while(1) {
@@ -200,7 +199,7 @@ ccl_device_noinline void svm_eval_nodes(KernelGlobals *kg, ShaderData *sd, Shade
 				break;
 			}
 			case NODE_CLOSURE_BSDF:
-				svm_node_closure_bsdf(kg, sd, stack, node, randb, path_flag, &offset);
+				svm_node_closure_bsdf(kg, sd, stack, node, path_flag, &offset);
 				break;
 			case NODE_CLOSURE_EMISSION:
 				svm_node_closure_emission(sd, stack, node);
@@ -227,10 +226,7 @@ ccl_device_noinline void svm_eval_nodes(KernelGlobals *kg, ShaderData *sd, Shade
 				svm_node_emission_weight(kg, sd, stack, node);
 				break;
 			case NODE_MIX_CLOSURE:
-				svm_node_mix_closure(sd, stack, node, &offset, &randb);
-				break;
-			case NODE_ADD_CLOSURE:
-				svm_node_add_closure(sd, stack, node.y, node.z, &offset, &randb, &closure_weight);
+				svm_node_mix_closure(sd, stack, node);
 				break;
 			case NODE_JUMP_IF_ZERO:
 				if(stack_load_float(stack, node.z) == 0.0f)
@@ -442,9 +438,6 @@ ccl_device_noinline void svm_eval_nodes(KernelGlobals *kg, ShaderData *sd, Shade
 #endif			
 			case NODE_END:
 			default:
-#ifndef __MULTI_CLOSURE__
-				sd->closure.weight *= closure_weight;
-#endif
 				return;
 		}
 	}
diff --git a/intern/cycles/kernel/svm/svm_closure.h b/intern/cycles/kernel/svm/svm_closure.h
index ab9927f569b..caae65487c4 100644
--- a/intern/cycles/kernel/svm/svm_closure.h
+++ b/intern/cycles/kernel/svm/svm_closure.h
@@ -51,7 +51,6 @@ ccl_device void svm_node_glass_setup(ShaderData *sd, ShaderClosure *sc, int type
 
 ccl_device_inline ShaderClosure *svm_node_closure_get_non_bsdf(ShaderData *sd, ClosureType type, float mix_weight)
 {
-#ifdef __MULTI_CLOSURE__
 	ShaderClosure *sc = &sd->closure[sd->num_closure];
 
 	if(sd->num_closure < MAX_CLOSURE) {
@@ -65,14 +64,10 @@ ccl_device_inline ShaderClosure *svm_node_closure_get_non_bsdf(ShaderData *sd, C
 	}
 
 	return NULL;
-#else
-	return &sd->closure;
-#endif
 }
 
 ccl_device_inline ShaderClosure *svm_node_closure_get_bsdf(ShaderData *sd, float mix_weight)
 {
-#ifdef __MULTI_CLOSURE__
 	ShaderClosure *sc = &sd->closure[sd->num_closure];
 	float3 weight = sc->weight * mix_weight;
 	float sample_weight = fabsf(average(weight));
@@ -88,14 +83,10 @@ ccl_device_inline ShaderClosure *svm_node_closure_get_bsdf(ShaderData *sd, float
 	}
 
 	return NULL;
-#else
-	return &sd->closure;
-#endif
 }
 
 ccl_device_inline ShaderClosure *svm_node_closure_get_absorption(ShaderData *sd, float mix_weight)
 {
-#ifdef __MULTI_CLOSURE__
 	ShaderClosure *sc = &sd->closure[sd->num_closure];
 	float3 weight = (make_float3(1.0f, 1.0f, 1.0f) - sc->weight) * mix_weight;
 	float sample_weight = fabsf(average(weight));
@@ -111,16 +102,12 @@ ccl_device_inline ShaderClosure *svm_node_closure_get_absorption(ShaderData *sd,
 	}
 
 	return NULL;
-#else
-	return &sd->closure;
-#endif
 }
 
-ccl_device void svm_node_closure_bsdf(KernelGlobals *kg, ShaderData *sd, float *stack, uint4 node, float randb, int path_flag, int *offset)
+ccl_device void svm_node_closure_bsdf(KernelGlobals *kg, ShaderData *sd, float *stack, uint4 node, int path_flag, int *offset)
 {
 	uint type, param1_offset, param2_offset;
 
-#ifdef __MULTI_CLOSURE__
 	uint mix_weight_offset;
 	decode_node_uchar4(node.y, &type, &param1_offset, &param2_offset, &mix_weight_offset);
 	float mix_weight = (stack_valid(mix_weight_offset)? stack_load_float(stack, mix_weight_offset): 1.0f);
@@ -132,13 +119,6 @@ ccl_device void svm_node_closure_bsdf(KernelGlobals *kg, ShaderData *sd, float *
 		return;
 
 	float3 N = stack_valid(data_node.x)? stack_load_float3(stack, data_node.x): sd->N; 
-#else
-	decode_node_uchar4(node.y, &type, &param1_offset, &param2_offset, NULL);
-	float mix_weight = 1.0f;
-
-	uint4 data_node = read_node(kg, offset);
-	float3 N = stack_valid(data_node.x)? stack_load_float3(stack, data_node.x): sd->N; 
-#endif
 
 	float param1 = (stack_valid(param1_offset))? stack_load_float(stack, param1_offset): __uint_as_float(node.z);
 	float param2 = (stack_valid(param2_offset))? stack_load_float(stack, param2_offset): __uint_as_float(node.w);
@@ -255,7 +235,6 @@ ccl_device void svm_node_closure_bsdf(KernelGlobals *kg, ShaderData *sd, float *
 			float fresnel = fresnel_dielectric_cos(cosNO, eta);
 			float roughness = param1;
 
-#ifdef __MULTI_CLOSURE__
 			/* reflection */
 			ShaderClosure *sc = &sd->closure[sd->num_closure];
 			float3 weight = sc->weight;
@@ -279,15 +258,6 @@ ccl_device void svm_node_closure_bsdf(KernelGlobals *kg, ShaderData *sd, float *
 				sc->N = N;
 				svm_node_glass_setup(sd, sc, type, eta, roughness, true);
 			}
-#else
-			ShaderClosure *sc = svm_node_closure_get_bsdf(sd, mix_weight);
-
-			if(sc) {
-				sc->N = N;
-				bool refract = (randb > fresnel);
-				svm_node_glass_setup(sd, sc, type, eta, roughness, refract);
-			}
-#endif
 
 			break;
 		}
@@ -484,17 +454,12 @@ ccl_device void svm_node_closure_volume(KernelGlobals *kg, ShaderData *sd, float
 #ifdef __VOLUME__
 	uint type, param1_offset, param2_offset;
 
-#ifdef __MULTI_CLOSURE__
 	uint mix_weight_offset;
 	decode_node_uchar4(node.y, &type, &param1_offset, &param2_offset, &mix_weight_offset);
 	float mix_weight = (stack_valid(mix_weight_offset)? stack_load_float(stack, mix_weight_offset): 1.0f);
 
 	if(mix_weight == 0.0f)
 		return;
-#else
-	decode_node_uchar4(node.y, &type, &param1_offset, &param2_offset, NULL);
-	float mix_weight = 1.0f;
-#endif
 
 	float param1 = (stack_valid(param1_offset))? stack_load_float(stack, param1_offset): __uint_as_float(node.z);
 	float param2 = (stack_valid(param2_offset))? stack_load_float(stack, param2_offset): __uint_as_float(node.w);
@@ -527,7 +492,6 @@ ccl_device void svm_node_closure_volume(KernelGlobals *kg, ShaderData *sd, float
 
 ccl_device void svm_node_closure_emission(ShaderData *sd, float *stack, uint4 node)
 {
-#ifdef __MULTI_CLOSURE__
 	uint mix_weight_offset = node.y;
 
 	if(stack_valid(mix_weight_offset)) {
@@ -540,17 +504,12 @@ ccl_device void svm_node_closure_emission(ShaderData *sd, float *stack, uint4 no
 	}
 	else
 		svm_node_closure_get_non_bsdf(sd, CLOSURE_EMISSION_ID, 1.0f);
-#else
-	ShaderClosure *sc = &sd->closure;
-	sc->type = CLOSURE_EMISSION_ID;
-#endif
 
 	sd->flag |= SD_EMISSION;
 }
 
 ccl_device void svm_node_closure_background(ShaderData *sd, float *stack, uint4 node)
 {
-#ifdef __MULTI_CLOSURE__
 	uint mix_weight_offset = node.y;
 
 	if(stack_valid(mix_weight_offset)) {
@@ -563,15 +522,10 @@ ccl_device void svm_node_closure_background(ShaderData *sd, float *stack, uint4
 	}
 	else
 		svm_node_closure_get_non_bsdf(sd, CLOSURE_BACKGROUND_ID, 1.0f);
-#else
-	ShaderClosure *sc = &sd->closure;
-	sc->type = CLOSURE_BACKGROUND_ID;
-#endif
 }
 
 ccl_device void svm_node_closure_holdout(ShaderData *sd, float *stack, uint4 node)
 {
-#ifdef __MULTI_CLOSURE__
 	uint mix_weight_offset = node.y;
 
 	if(stack_valid(mix_weight_offset)) {
@@ -584,17 +538,12 @@ ccl_device void svm_node_closure_holdout(ShaderData *sd, float *stack, uint4 nod
 	}
 	else
 		svm_node_closure_get_non_bsdf(sd, CLOSURE_HOLDOUT_ID, 1.0f);
-#else
-	ShaderClosure *sc = &sd->closure;
-	sc->type = CLOSURE_HOLDOUT_ID;
-#endif
 
 	sd->flag |= SD_HOLDOUT;
 }
 
 ccl_device void svm_node_closure_ambient_occlusion(ShaderData *sd, float *stack, uint4 node)
 {
-#ifdef __MULTI_CLOSURE__
 	uint mix_weight_offset = node.y;
 
 	if(stack_valid(mix_weight_offset)) {
@@ -607,10 +556,6 @@ ccl_device void svm_node_closure_ambient_occlusion(ShaderData *sd, float *stack,
 	}
 	else
 		svm_node_closure_get_non_bsdf(sd, CLOSURE_AMBIENT_OCCLUSION_ID, 1.0f);
-#else
-	ShaderClosure *sc = &sd->closure;
-	sc->type = CLOSURE_AMBIENT_OCCLUSION_ID;
-#endif
 
 	sd->flag |= SD_AO;
 }
@@ -619,12 +564,8 @@ ccl_device void svm_node_closure_ambient_occlusion(ShaderData *sd, float *stack,
 
 ccl_device_inline void svm_node_closure_store_weight(ShaderData *sd, float3 weight)
 {
-#ifdef __MULTI_CLOSURE__
 	if(sd->num_closure < MAX_CLOSURE)
 		sd->closure[sd->num_closure].weight = weight;
-#else
-	sd->closure.weight = weight;
-#endif
 }
 
 ccl_device void svm_node_closure_set_weight(ShaderData *sd, uint r, uint g, uint b)
@@ -665,10 +606,8 @@ ccl_device void svm_node_emission_weight(KernelGlobals *kg, ShaderData *sd, floa
 	svm_node_closure_store_weight(sd, weight);
 }
 
-ccl_device void svm_node_mix_closure(ShaderData *sd, float *stack,
-	uint4 node, int *offset, float *randb)
+ccl_device void svm_node_mix_closure(ShaderData *sd, float *stack, uint4 node)
 {
-#ifdef __MULTI_CLOSURE__
 	/* fetch weight from blend input, previous mix closures,
 	 * and write to stack to be used by closure nodes later */
 	uint weight_offset, in_weight_offset, weight1_offset, weight2_offset;
@@ -683,44 +622,6 @@ ccl_device void svm_node_mix_closure(ShaderData *sd, float *stack,
 		stack_store_float(stack, weight1_offset, in_weight*(1.0f - weight));
 	if(stack_valid(weight2_offset))
 		stack_store_float(stack, weight2_offset, in_weight*weight);
-#else
-	/* pick a closure and make the random number uniform over 0..1 again.
-	 * closure 1 starts on the next node, for closure 2 the start is at an
-	 * offset from the current node, so we jump */
-	uint weight_offset = node.y;
-	uint node_jump = node.z;
-	float weight = stack_load_float(stack, weight_offset);
-	weight = clamp(weight, 0.0f, 1.0f);
-
-	if(*randb < weight) {
-		*offset += node_jump;
-		*randb = *randb/weight;
-	}
-	else
-		*randb = (*randb - weight)/(1.0f - weight);
-#endif
-}
-
-ccl_device void svm_node_add_closure(ShaderData *sd, float *stack, uint unused,
-	uint node_jump, int *offset, float *randb, float *closure_weight)
-{
-#ifdef __MULTI_CLOSURE__
-	/* nothing to do, handled in compiler */
-#else
-	/* pick one of the two closures with probability 0.5. sampling quality
-	 * is not going to be great, for that we'd need to evaluate the weights
-	 * of the two closures being added */
-	float weight = 0.5f;
-
-	if(*randb < weight) {
-		*offset += node_jump;
-		*randb = *randb/weight;
-	}
-	else
-		*randb = (*randb - weight)/(1.0f - weight);
-	
-	*closure_weight *= 2.0f;
-#endif
 }
 
 /* (Bump) normal */
diff --git a/intern/cycles/kernel/svm/svm_types.h b/intern/cycles/kernel/svm/svm_types.h
index 86bb3f048dc..a7deb0bb913 100644
--- a/intern/cycles/kernel/svm/svm_types.h
+++ b/intern/cycles/kernel/svm/svm_types.h
@@ -72,7 +72,6 @@ typedef enum NodeType {
 	NODE_TEX_COORD,
 	NODE_TEX_COORD_BUMP_DX,
 	NODE_TEX_COORD_BUMP_DY,
-	NODE_ADD_CLOSURE,
 	NODE_EMISSION_SET_WEIGHT_TOTAL,
 	NODE_ATTR_BUMP_DX,
 	NODE_ATTR_BUMP_DY,