1// Copyright 2009-2021 Intel Corporation
2// SPDX-License-Identifier: Apache-2.0
3
4#pragma once
5
6#include "../common/geometry.h"
7
8namespace embree
9{
10 static const size_t MAX_PATCH_VALENCE = 16; //!< maximum number of vertices of a patch
11 static const size_t MAX_RING_FACE_VALENCE = 64; //!< maximum number of faces per ring
12 static const size_t MAX_RING_EDGE_VALENCE = 2*64; //!< maximum number of edges per ring
13
14 class CatmullClarkPrecomputedCoefficients
15 {
16 private:
17
18 float table_cos_2PI_div_n[MAX_RING_FACE_VALENCE+1];
19
20 float* table_limittangent_a[MAX_RING_FACE_VALENCE+1];
21 float* table_limittangent_b[MAX_RING_FACE_VALENCE+1];
22 float table_limittangent_c[MAX_RING_FACE_VALENCE+1];
23
24 __forceinline float set_cos_2PI_div_n(const size_t n) {
25 if (unlikely(n == 0)) return 1.0f;
26 return cosf(2.0f*float(pi)/(float)n);
27 }
28
29 __forceinline float set_limittangent_a(const size_t i, const size_t n)
30 {
31 if (unlikely(n == 0)) return 1.0f;
32 const float c0 = 1.0f/(float)n * 1.0f / sqrtf(4.0f + cosf(float(pi)/(float)n)*cosf(float(pi)/(float)n));
33 const float c1 = (1.0f/(float)n + cosf(float(pi)/(float)n) * c0);
34 return cosf(2.0f*float(pi)*(float)i/(float)n) * c1;
35 }
36
37 __forceinline float set_limittangent_b(const size_t i, const size_t n)
38 {
39 if (unlikely(n == 0)) return 1.0f;
40 const float c0 = 1.0f/(float)n * 1.0f / sqrtf(4.0f + cosf(float(pi)/(float)n)*cosf(float(pi)/(float)n));
41 return cosf((2.0f*float(pi)*i+float(pi))/(float)n) * c0;
42 }
43
44 __forceinline float set_limittangent_c(const size_t n)
45 {
46 if (unlikely(n == 0)) return 1.0f;
47 return 2.0f/16.0f * (5.0f + cosf(2.0f*float(pi)/(float)n) + cosf(float(pi)/(float)n) * sqrtf(18.0f+2.0f*cosf(2.0f*float(pi)/(float)n)));
48 }
49
50 public:
51
52 __forceinline float cos_2PI_div_n(const size_t n)
53 {
54 if (likely(n <= MAX_RING_FACE_VALENCE))
55 return table_cos_2PI_div_n[n];
56 else
57 return set_cos_2PI_div_n(n);
58 }
59
60 __forceinline float limittangent_a(const size_t i, const size_t n)
61 {
62 assert(n <= MAX_RING_FACE_VALENCE);
63 assert(i < n);
64 return table_limittangent_a[n][i];
65 }
66
67 __forceinline float limittangent_b(const size_t i, const size_t n)
68 {
69 assert(n <= MAX_RING_FACE_VALENCE);
70 assert(i < n);
71 return table_limittangent_b[n][i];
72 }
73
74 __forceinline float limittangent_c(const size_t n)
75 {
76 assert(n <= MAX_RING_FACE_VALENCE);
77 return table_limittangent_c[n];
78 }
79
80 static CatmullClarkPrecomputedCoefficients table;
81
82 CatmullClarkPrecomputedCoefficients();
83 ~CatmullClarkPrecomputedCoefficients();
84 };
85}
86