initial commit, 4.5 stable

thirdparty/embree/kernels/subdiv/gridrange.h

@@ -0,0 +1,96 @@
+// Copyright 2009-2021 Intel Corporation
+// SPDX-License-Identifier: Apache-2.0
+
+#pragma once
+
+#include "../common/default.h"
+
+namespace embree
+{
+  struct __aligned(16) GridRange
+  {
+    unsigned int u_start;
+    unsigned int u_end;
+    unsigned int v_start;
+    unsigned int v_end;
+
+    __forceinline GridRange() {}
+
+    __forceinline GridRange(unsigned int u_start, unsigned int u_end, unsigned int v_start, unsigned int v_end) 
+      : u_start(u_start), u_end(u_end), v_start(v_start), v_end(v_end) {}
+
+    __forceinline unsigned int width() const {
+      return u_end-u_start+1;
+    }
+
+    __forceinline unsigned int height() const {
+      return v_end-v_start+1;
+    }
+
+    __forceinline bool hasLeafSize() const
+    {
+      const unsigned int u_size = u_end-u_start+1;
+      const unsigned int v_size = v_end-v_start+1;
+      assert(u_size >= 1);
+      assert(v_size >= 1);
+      return u_size <= 3 && v_size <= 3;
+    }
+
+    static __forceinline unsigned int split(unsigned int start,unsigned int end)
+    {
+      const unsigned int center = (start+end)/2;
+      assert (center > start);
+      assert (center < end);
+      return center;
+    }
+
+    __forceinline void split(GridRange& r0, GridRange& r1) const
+    {
+      assert( hasLeafSize() == false );
+      const unsigned int u_size = u_end-u_start+1;
+      const unsigned int v_size = v_end-v_start+1;
+      r0 = *this;
+      r1 = *this;
+
+      if (u_size >= v_size)
+      {
+        const unsigned int u_mid = split(u_start,u_end);
+        r0.u_end   = u_mid;
+        r1.u_start = u_mid;
+      }
+      else
+      {
+        const unsigned int v_mid = split(v_start,v_end);
+        r0.v_end   = v_mid;
+        r1.v_start = v_mid;
+      }
+    }
+
+    __forceinline unsigned int splitIntoSubRanges(GridRange r[4]) const
+    {
+      assert( !hasLeafSize() );
+      unsigned int children = 0;
+      GridRange first,second;
+      split(first,second);
+
+      if (first.hasLeafSize()) {
+        r[0] = first;
+        children++;
+      } 
+      else {
+        first.split(r[0],r[1]);
+        children += 2;
+      }
+
+      if (second.hasLeafSize())	{
+        r[children] = second;
+        children++;
+      }
+      else {
+        second.split(r[children+0],r[children+1]);
+        children += 2;
+      }
+      return children;      
+    }
+  };
+}