Cycles: refactor kernel closure storage to use structs per closure type.

Reviewed By: dingto, sergey

Differential Revision: https://developer.blender.org/D2127

intern/cycles/kernel/closure/alloc.h

@@ -0,0 +1,90 @@
+/*
+ * Copyright 2011-2016 Blender Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+CCL_NAMESPACE_BEGIN
+
+ccl_device ShaderClosure *closure_alloc(ShaderData *sd, int size, ClosureType type, float3 weight)
+{
+	kernel_assert(size <= sizeof(ShaderClosure));
+
+	int num_closure = ccl_fetch(sd, num_closure);
+	int num_closure_extra = ccl_fetch(sd, num_closure_extra);
+	if(num_closure + num_closure_extra >= MAX_CLOSURE)
+		return NULL;
+
+	ShaderClosure *sc = &ccl_fetch(sd, closure)[num_closure];
+
+	sc->type = type;
+	sc->weight = weight;
+
+	ccl_fetch(sd, num_closure)++;
+
+	return sc;
+}
+
+ccl_device ccl_addr_space void *closure_alloc_extra(ShaderData *sd, int size)
+{
+	/* Allocate extra space for closure that need more parameters. We allocate
+	 * in chunks of sizeof(ShaderClosure) starting from the end of the closure
+	 * array.
+	 *
+	 * This lets us keep the same fast array iteration over closures, as we
+	 * found linked list iteration and iteration with skipping to be slower. */
+	int num_extra = ((size + sizeof(ShaderClosure) - 1) / sizeof(ShaderClosure));
+	int num_closure = ccl_fetch(sd, num_closure);
+	int num_closure_extra = ccl_fetch(sd, num_closure_extra) + num_extra;
+
+	if(num_closure + num_closure_extra > MAX_CLOSURE) {
+		/* Remove previous closure. */
+		ccl_fetch(sd, num_closure)--;
+		ccl_fetch(sd, num_closure_extra)++;
+		return NULL;
+	}
+
+	ccl_fetch(sd, num_closure_extra) = num_closure_extra;
+	return (ccl_addr_space void*)(ccl_fetch(sd, closure) + MAX_CLOSURE - num_closure_extra);
+}
+
+ccl_device_inline ShaderClosure *bsdf_alloc(ShaderData *sd, int size, float3 weight)
+{
+	ShaderClosure *sc = closure_alloc(sd, size, CLOSURE_NONE_ID, weight);
+
+	if(!sc)
+		return NULL;
+
+	float sample_weight = fabsf(average(weight));
+	sc->sample_weight = sample_weight;
+	return (sample_weight >= CLOSURE_WEIGHT_CUTOFF) ? sc : NULL;
+}
+
+#ifdef __OSL__
+ccl_device_inline ShaderClosure *bsdf_alloc_osl(ShaderData *sd, int size, float3 weight, void *data)
+{
+	ShaderClosure *sc = closure_alloc(sd, size, CLOSURE_NONE_ID, weight);
+
+	if(!sc)
+		return NULL;
+
+	memcpy(sc, data, size);
+
+	float sample_weight = fabsf(average(weight));
+	sc->weight = weight;
+	sc->sample_weight = sample_weight;
+	return (sample_weight >= CLOSURE_WEIGHT_CUTOFF) ? sc : NULL;
+}
+#endif
+
+CCL_NAMESPACE_END