121 lines
3.7 KiB
C++
121 lines
3.7 KiB
C++
/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
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*
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* SPDX-License-Identifier: Apache-2.0 */
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#pragma once
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#include "kernel/types.h"
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CCL_NAMESPACE_BEGIN
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ccl_device ccl_private ShaderClosure *closure_alloc(ccl_private ShaderData *sd,
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const uint size,
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ClosureType type,
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Spectrum weight)
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{
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kernel_assert(size <= sizeof(ShaderClosure));
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(void)size;
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if (sd->num_closure_left == 0) {
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return nullptr;
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}
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ccl_private ShaderClosure *sc = &sd->closure[sd->num_closure];
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sc->type = type;
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sc->weight = weight;
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sd->num_closure++;
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sd->num_closure_left--;
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return sc;
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}
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ccl_device ccl_private void *closure_alloc_extra(ccl_private ShaderData *sd, const int size)
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{
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/* Allocate extra space for closure that need more parameters. We allocate
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* in chunks of sizeof(ShaderClosure) starting from the end of the closure
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* array.
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*
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* This lets us keep the same fast array iteration over closures, as we
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* found linked list iteration and iteration with skipping to be slower. */
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const int num_extra = ((size + sizeof(ShaderClosure) - 1) / sizeof(ShaderClosure));
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if (num_extra > sd->num_closure_left) {
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/* Remove previous closure if it was allocated. */
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sd->num_closure--;
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sd->num_closure_left++;
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return nullptr;
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}
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sd->num_closure_left -= num_extra;
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return (ccl_private void *)(sd->closure + sd->num_closure + sd->num_closure_left);
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}
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ccl_device_inline float closure_sample_weight(const int flag, ccl_private Spectrum &weight)
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{
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kernel_assert(isfinite_safe(weight));
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/* No negative weights allowed. */
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weight = max(weight, zero_float3());
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const float sample_weight = fabsf(average(weight));
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/* Do not perform weight cutoff for volume shaders, because large volume with low density could
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* still contribute significantly to the scene. It should be up to the volume shader to decide
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* the cutoff. */
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/* Use comparison this way to help dealing with non-finite weight: if the average is not finite
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* we will not allocate new closure. */
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if ((sample_weight >= CLOSURE_WEIGHT_CUTOFF) || (flag & SD_IS_VOLUME_SHADER_EVAL)) {
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return sample_weight;
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}
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return 0.0f;
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}
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ccl_device_inline ccl_private ShaderClosure *bsdf_alloc(ccl_private ShaderData *sd,
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const int size,
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Spectrum weight)
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{
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const float sample_weight = closure_sample_weight(sd->flag, weight);
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if (!(sample_weight > 0.0f)) {
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return nullptr;
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}
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ccl_private ShaderClosure *sc = closure_alloc(sd, size, CLOSURE_NONE_ID, weight);
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if (!sc) {
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return nullptr;
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}
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sc->sample_weight = sample_weight;
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return sc;
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}
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/* Allocate BSDF closures that are possibly used for emission. */
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template<class Bsdf>
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ccl_device_inline ccl_private Bsdf *bsdf_alloc_maybe_emission(ccl_private ShaderData *sd,
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ccl_private Bsdf *bsdf,
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const uint32_t path_flag,
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Spectrum weight)
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{
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if (path_flag & PATH_RAY_EMISSION) {
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/* When evaluating emission we don't allocate closures, but we still need a valid closure to
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* compute the weight. */
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const float sample_weight = closure_sample_weight(sd->flag, weight);
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if (!(sample_weight > 0.0f)) {
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return nullptr;
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}
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bsdf->weight = weight;
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bsdf->sample_weight = sample_weight;
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}
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else {
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bsdf = (ccl_private Bsdf *)bsdf_alloc(sd, sizeof(Bsdf), weight);
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}
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return bsdf;
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}
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CCL_NAMESPACE_END
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