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Diffstat (limited to 'intern/cycles/kernel/sample/sample_mis.h')
-rw-r--r-- | intern/cycles/kernel/sample/sample_mis.h | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/intern/cycles/kernel/sample/sample_mis.h b/intern/cycles/kernel/sample/sample_mis.h new file mode 100644 index 00000000000..0878b3aac36 --- /dev/null +++ b/intern/cycles/kernel/sample/sample_mis.h @@ -0,0 +1,64 @@ +/* + * Parts adapted from Open Shading Language with this license: + * + * Copyright (c) 2009-2010 Sony Pictures Imageworks Inc., et al. + * All Rights Reserved. + * + * Modifications Copyright 2011, Blender Foundation. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * * Neither the name of Sony Pictures Imageworks nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#pragma once + +CCL_NAMESPACE_BEGIN + +/* Multiple importance sampling utilities. */ + +ccl_device float balance_heuristic(float a, float b) +{ + return (a) / (a + b); +} + +ccl_device float balance_heuristic_3(float a, float b, float c) +{ + return (a) / (a + b + c); +} + +ccl_device float power_heuristic(float a, float b) +{ + return (a * a) / (a * a + b * b); +} + +ccl_device float power_heuristic_3(float a, float b, float c) +{ + return (a * a) / (a * a + b * b + c * c); +} + +ccl_device float max_heuristic(float a, float b) +{ + return (a > b) ? 1.0f : 0.0f; +} + +CCL_NAMESPACE_END |