Brecht Van Lommel
9cfc7967dd
* Replace license text in headers with SPDX identifiers. * Remove specific license info from outdated readme.txt, instead leave details to the source files. * Add list of SPDX license identifiers used, and corresponding license texts. * Update copyright dates while we're at it. Ref D14069, T95597
41 lines
803 B
C++
41 lines
803 B
C++
/* SPDX-License-Identifier: BSD-3-Clause
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*
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* Adapted from Open Shading Language
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* Copyright (c) 2009-2010 Sony Pictures Imageworks Inc., et al.
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* All Rights Reserved.
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*
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* Modifications Copyright 2011-2022 Blender Foundation. */
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#pragma once
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CCL_NAMESPACE_BEGIN
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/* Multiple importance sampling utilities. */
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ccl_device float balance_heuristic(float a, float b)
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{
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return (a) / (a + b);
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}
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ccl_device float balance_heuristic_3(float a, float b, float c)
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{
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return (a) / (a + b + c);
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}
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ccl_device float power_heuristic(float a, float b)
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{
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return (a * a) / (a * a + b * b);
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}
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ccl_device float power_heuristic_3(float a, float b, float c)
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{
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return (a * a) / (a * a + b * b + c * c);
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}
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ccl_device float max_heuristic(float a, float b)
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{
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return (a > b) ? 1.0f : 0.0f;
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}
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CCL_NAMESPACE_END
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