1 /*
2 * Adapted from Open Shading Language with this license:
3 *
4 * Copyright (c) 2009-2010 Sony Pictures Imageworks Inc., et al.
5 * All Rights Reserved.
6 *
7 * Modifications Copyright 2012, Blender Foundation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions are
11 * met:
12 * * Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * * Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * * Neither the name of Sony Pictures Imageworks nor the names of its
18 * contributors may be used to endorse or promote products derived from
19 * this software without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
24 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
25 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
26 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
30 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 #ifndef __BSDF_PHONG_RAMP_H__
34 #define __BSDF_PHONG_RAMP_H__
35
36 CCL_NAMESPACE_BEGIN
37
38 #ifdef __OSL__
39
40 typedef ccl_addr_space struct PhongRampBsdf {
41 SHADER_CLOSURE_BASE;
42
43 float exponent;
44 float3 *colors;
45 } PhongRampBsdf;
46
47 static_assert(sizeof(ShaderClosure) >= sizeof(PhongRampBsdf), "PhongRampBsdf is too large!");
48
bsdf_phong_ramp_get_color(const float3 colors[8],float pos)49 ccl_device float3 bsdf_phong_ramp_get_color(const float3 colors[8], float pos)
50 {
51 int MAXCOLORS = 8;
52
53 float npos = pos * (float)(MAXCOLORS - 1);
54 int ipos = float_to_int(npos);
55 if (ipos < 0)
56 return colors[0];
57 if (ipos >= (MAXCOLORS - 1))
58 return colors[MAXCOLORS - 1];
59 float offset = npos - (float)ipos;
60 return colors[ipos] * (1.0f - offset) + colors[ipos + 1] * offset;
61 }
62
bsdf_phong_ramp_setup(PhongRampBsdf * bsdf)63 ccl_device int bsdf_phong_ramp_setup(PhongRampBsdf *bsdf)
64 {
65 bsdf->type = CLOSURE_BSDF_PHONG_RAMP_ID;
66 bsdf->exponent = max(bsdf->exponent, 0.0f);
67 return SD_BSDF | SD_BSDF_HAS_EVAL;
68 }
69
bsdf_phong_ramp_eval_reflect(const ShaderClosure * sc,const float3 I,const float3 omega_in,float * pdf)70 ccl_device float3 bsdf_phong_ramp_eval_reflect(const ShaderClosure *sc,
71 const float3 I,
72 const float3 omega_in,
73 float *pdf)
74 {
75 const PhongRampBsdf *bsdf = (const PhongRampBsdf *)sc;
76 float m_exponent = bsdf->exponent;
77 float cosNI = dot(bsdf->N, omega_in);
78 float cosNO = dot(bsdf->N, I);
79
80 if (cosNI > 0 && cosNO > 0) {
81 // reflect the view vector
82 float3 R = (2 * cosNO) * bsdf->N - I;
83 float cosRI = dot(R, omega_in);
84 if (cosRI > 0) {
85 float cosp = powf(cosRI, m_exponent);
86 float common = 0.5f * M_1_PI_F * cosp;
87 float out = cosNI * (m_exponent + 2) * common;
88 *pdf = (m_exponent + 1) * common;
89 return bsdf_phong_ramp_get_color(bsdf->colors, cosp) * out;
90 }
91 }
92
93 return make_float3(0.0f, 0.0f, 0.0f);
94 }
95
bsdf_phong_ramp_eval_transmit(const ShaderClosure * sc,const float3 I,const float3 omega_in,float * pdf)96 ccl_device float3 bsdf_phong_ramp_eval_transmit(const ShaderClosure *sc,
97 const float3 I,
98 const float3 omega_in,
99 float *pdf)
100 {
101 return make_float3(0.0f, 0.0f, 0.0f);
102 }
103
bsdf_phong_ramp_sample(const ShaderClosure * sc,float3 Ng,float3 I,float3 dIdx,float3 dIdy,float randu,float randv,float3 * eval,float3 * omega_in,float3 * domega_in_dx,float3 * domega_in_dy,float * pdf)104 ccl_device int bsdf_phong_ramp_sample(const ShaderClosure *sc,
105 float3 Ng,
106 float3 I,
107 float3 dIdx,
108 float3 dIdy,
109 float randu,
110 float randv,
111 float3 *eval,
112 float3 *omega_in,
113 float3 *domega_in_dx,
114 float3 *domega_in_dy,
115 float *pdf)
116 {
117 const PhongRampBsdf *bsdf = (const PhongRampBsdf *)sc;
118 float cosNO = dot(bsdf->N, I);
119 float m_exponent = bsdf->exponent;
120
121 if (cosNO > 0) {
122 // reflect the view vector
123 float3 R = (2 * cosNO) * bsdf->N - I;
124
125 # ifdef __RAY_DIFFERENTIALS__
126 *domega_in_dx = (2 * dot(bsdf->N, dIdx)) * bsdf->N - dIdx;
127 *domega_in_dy = (2 * dot(bsdf->N, dIdy)) * bsdf->N - dIdy;
128 # endif
129
130 float3 T, B;
131 make_orthonormals(R, &T, &B);
132 float phi = M_2PI_F * randu;
133 float cosTheta = powf(randv, 1 / (m_exponent + 1));
134 float sinTheta2 = 1 - cosTheta * cosTheta;
135 float sinTheta = sinTheta2 > 0 ? sqrtf(sinTheta2) : 0;
136 *omega_in = (cosf(phi) * sinTheta) * T + (sinf(phi) * sinTheta) * B + (cosTheta)*R;
137 if (dot(Ng, *omega_in) > 0.0f) {
138 // common terms for pdf and eval
139 float cosNI = dot(bsdf->N, *omega_in);
140 // make sure the direction we chose is still in the right hemisphere
141 if (cosNI > 0) {
142 float cosp = powf(cosTheta, m_exponent);
143 float common = 0.5f * M_1_PI_F * cosp;
144 *pdf = (m_exponent + 1) * common;
145 float out = cosNI * (m_exponent + 2) * common;
146 *eval = bsdf_phong_ramp_get_color(bsdf->colors, cosp) * out;
147 }
148 }
149 }
150 return LABEL_REFLECT | LABEL_GLOSSY;
151 }
152
153 #endif /* __OSL__ */
154
155 CCL_NAMESPACE_END
156
157 #endif /* __BSDF_PHONG_RAMP_H__ */
158