1 files changed, 85 insertions, 0 deletions
diff --git a/thirdparty/embree/kernels/subdiv/catmullclark_coefficients.h b/thirdparty/embree/kernels/subdiv/catmullclark_coefficients.h
new file mode 100644
index 0000000000..46959797bf
--- /dev/null
+++ b/thirdparty/embree/kernels/subdiv/catmullclark_coefficients.h
@@ -0,0 +1,85 @@
+// Copyright 2009-2021 Intel Corporation
+// SPDX-License-Identifier: Apache-2.0
+
+#pragma once
+
+#include "../common/geometry.h"
+
+namespace embree
+{
+  static const size_t MAX_PATCH_VALENCE = 16;         //!< maximum number of vertices of a patch
+  static const size_t MAX_RING_FACE_VALENCE = 64;     //!< maximum number of faces per ring
+  static const size_t MAX_RING_EDGE_VALENCE = 2*64;   //!< maximum number of edges per ring
+
+  class CatmullClarkPrecomputedCoefficients 
+  {
+  private:
+    
+    float table_cos_2PI_div_n[MAX_RING_FACE_VALENCE+1];
+
+    float* table_limittangent_a[MAX_RING_FACE_VALENCE+1];
+    float* table_limittangent_b[MAX_RING_FACE_VALENCE+1];
+    float table_limittangent_c[MAX_RING_FACE_VALENCE+1];
+
+    __forceinline float set_cos_2PI_div_n(const size_t n) { 
+      if (unlikely(n == 0)) return 1.0f;
+      return cosf(2.0f*float(pi)/(float)n); 
+    }
+
+    __forceinline float set_limittangent_a(const size_t i, const size_t n)  
+    { 
+      if (unlikely(n == 0)) return 1.0f;
+      const float c0 = 1.0f/(float)n * 1.0f / sqrtf(4.0f + cosf(float(pi)/(float)n)*cosf(float(pi)/(float)n));
+      const float c1 = (1.0f/(float)n + cosf(float(pi)/(float)n) * c0); 
+      return cosf(2.0f*float(pi)*(float)i/(float)n) * c1;
+    }
+
+    __forceinline float set_limittangent_b(const size_t i, const size_t n)  
+    { 
+      if (unlikely(n == 0)) return 1.0f;
+      const float c0 = 1.0f/(float)n * 1.0f / sqrtf(4.0f + cosf(float(pi)/(float)n)*cosf(float(pi)/(float)n));
+      return cosf((2.0f*float(pi)*i+float(pi))/(float)n) * c0;
+    }
+
+    __forceinline float set_limittangent_c(const size_t n)  
+    { 
+      if (unlikely(n == 0)) return 1.0f;
+      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)));
+    }
+
+  public:
+
+    __forceinline float cos_2PI_div_n(const size_t n)
+    {
+      if (likely(n <= MAX_RING_FACE_VALENCE))
+        return table_cos_2PI_div_n[n];
+      else
+        return set_cos_2PI_div_n(n);
+    }
+
+    __forceinline float limittangent_a(const size_t i, const size_t n)
+    {
+      assert(n <= MAX_RING_FACE_VALENCE);
+      assert(i < n);
+      return table_limittangent_a[n][i];
+    }
+
+    __forceinline float limittangent_b(const size_t i, const size_t n)
+    {
+      assert(n <= MAX_RING_FACE_VALENCE);
+      assert(i < n);
+      return table_limittangent_b[n][i];
+    }
+
+    __forceinline float limittangent_c(const size_t n)
+    {
+      assert(n <= MAX_RING_FACE_VALENCE);
+      return table_limittangent_c[n];
+    }
+
+    static CatmullClarkPrecomputedCoefficients table;
+ 
+    CatmullClarkPrecomputedCoefficients();    
+    ~CatmullClarkPrecomputedCoefficients();    
+  };
+}