95 lines
2.7 KiB
C
95 lines
2.7 KiB
C
/* SPDX-FileCopyrightText: 2009-2010 Sony Pictures Imageworks Inc., et al. All Rights Reserved.
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* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
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*
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* SPDX-License-Identifier: BSD-3-Clause
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*
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* Adapted code from Open Shading Language. */
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#pragma once
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#include "kernel/types.h"
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#include "kernel/sample/mapping.h"
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#include "kernel/util/colorspace.h"
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CCL_NAMESPACE_BEGIN
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#ifdef __OSL__
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struct DiffuseRampBsdf {
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SHADER_CLOSURE_BASE;
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ccl_private float3 *colors;
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};
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static_assert(sizeof(ShaderClosure) >= sizeof(DiffuseRampBsdf), "DiffuseRampBsdf is too large!");
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ccl_device float3 bsdf_diffuse_ramp_get_color(const float3 colors[8], float pos)
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{
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const int MAXCOLORS = 8;
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const float npos = pos * (float)(MAXCOLORS - 1);
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const int ipos = float_to_int(npos);
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if (ipos < 0) {
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return colors[0];
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}
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if (ipos >= (MAXCOLORS - 1)) {
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return colors[MAXCOLORS - 1];
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}
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const float offset = npos - (float)ipos;
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return colors[ipos] * (1.0f - offset) + colors[ipos + 1] * offset;
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}
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ccl_device int bsdf_diffuse_ramp_setup(DiffuseRampBsdf *bsdf)
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{
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bsdf->type = CLOSURE_BSDF_DIFFUSE_RAMP_ID;
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return SD_BSDF | SD_BSDF_HAS_EVAL;
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}
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ccl_device void bsdf_diffuse_ramp_blur(ccl_private ShaderClosure *sc, const float roughness) {}
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ccl_device Spectrum bsdf_diffuse_ramp_eval(const ccl_private ShaderClosure *sc,
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const float3 wi,
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const float3 wo,
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ccl_private float *pdf)
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{
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const DiffuseRampBsdf *bsdf = (const DiffuseRampBsdf *)sc;
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const float3 N = bsdf->N;
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const float cosNO = fmaxf(dot(N, wo), 0.0f);
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if (cosNO >= 0.0f) {
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*pdf = cosNO * M_1_PI_F;
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return rgb_to_spectrum(bsdf_diffuse_ramp_get_color(bsdf->colors, cosNO) * M_1_PI_F);
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}
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*pdf = 0.0f;
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return zero_spectrum();
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}
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ccl_device int bsdf_diffuse_ramp_sample(const ccl_private ShaderClosure *sc,
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const float3 Ng,
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const float3 wi,
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const float2 rand,
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ccl_private Spectrum *eval,
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ccl_private float3 *wo,
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ccl_private float *pdf)
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{
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const DiffuseRampBsdf *bsdf = (const DiffuseRampBsdf *)sc;
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const float3 N = bsdf->N;
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// distribution over the hemisphere
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sample_cos_hemisphere(N, rand, wo, pdf);
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if (dot(Ng, *wo) > 0.0f) {
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*eval = rgb_to_spectrum(bsdf_diffuse_ramp_get_color(bsdf->colors, *pdf * M_PI_F) * M_1_PI_F);
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}
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else {
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*pdf = 0.0f;
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*eval = zero_spectrum();
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}
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return LABEL_REFLECT | LABEL_DIFFUSE;
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}
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#endif /* __OSL__ */
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CCL_NAMESPACE_END
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