forked from bartvdbraak/blender
75 lines
2.2 KiB
C
75 lines
2.2 KiB
C
/*
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* Copyright 2011-2013 Blender Foundation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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CCL_NAMESPACE_BEGIN
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/* Fresnel Node */
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ccl_device void svm_node_fresnel(ShaderData *sd, float *stack, uint ior_offset, uint ior_value, uint node)
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{
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uint normal_offset, out_offset;
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decode_node_uchar4(node, &normal_offset, &out_offset, NULL, NULL);
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float eta = (stack_valid(ior_offset))? stack_load_float(stack, ior_offset): __uint_as_float(ior_value);
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float3 normal_in = stack_valid(normal_offset)? stack_load_float3(stack, normal_offset): sd->N;
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eta = fmaxf(eta, 1e-5f);
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eta = (sd->flag & SD_BACKFACING)? 1.0f/eta: eta;
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float f = fresnel_dielectric_cos(dot(sd->I, normal_in), eta);
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stack_store_float(stack, out_offset, f);
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}
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/* Layer Weight Node */
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ccl_device void svm_node_layer_weight(ShaderData *sd, float *stack, uint4 node)
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{
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uint blend_offset = node.y;
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uint blend_value = node.z;
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uint type, normal_offset, out_offset;
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decode_node_uchar4(node.w, &type, &normal_offset, &out_offset, NULL);
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float blend = (stack_valid(blend_offset))? stack_load_float(stack, blend_offset): __uint_as_float(blend_value);
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float3 normal_in = (stack_valid(normal_offset))? stack_load_float3(stack, normal_offset): sd->N;
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float f;
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if(type == NODE_LAYER_WEIGHT_FRESNEL) {
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float eta = fmaxf(1.0f - blend, 1e-5f);
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eta = (sd->flag & SD_BACKFACING)? eta: 1.0f/eta;
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f = fresnel_dielectric_cos(dot(sd->I, normal_in), eta);
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}
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else {
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f = fabsf(dot(sd->I, normal_in));
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if(blend != 0.5f) {
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blend = clamp(blend, 0.0f, 1.0f-1e-5f);
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blend = (blend < 0.5f)? 2.0f*blend: 0.5f/(1.0f - blend);
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f = powf(f, blend);
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}
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f = 1.0f - f;
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}
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stack_store_float(stack, out_offset, f);
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}
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CCL_NAMESPACE_END
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