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* Adapted from Open Shading Language with this license:
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* Copyright (c) 2009-2010 Sony Pictures Imageworks Inc., et al.
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* Modifications Copyright 2011, Blender Foundation.
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* * Neither the name of Sony Pictures Imageworks nor the names of its
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* contributors may be used to endorse or promote products derived from
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* this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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/* EMISSION CLOSURE */
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/* return the probability distribution function in the direction I,
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* given the parameters and the light's surface normal. This MUST match
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* the PDF computed by sample(). */
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__device float emissive_pdf(const float3 Ng, const float3 I)
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float cosNO = fabsf(dot(Ng, I));
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return (cosNO > 0.0f)? 1.0f: 0.0f;
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__device void emissive_sample(const float3 Ng, float randu, float randv,
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float3 *omega_out, float *pdf)
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/* todo: not implemented and used yet */
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__device float3 emissive_simple_eval(const float3 Ng, const float3 I)
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float res = emissive_pdf(Ng, I);
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return make_float3(res, res, res);