Bulk update NvPro-Samples 03/18/21

ray_tracing_ao/shaders/raycommon.glsl

@@ -0,0 +1,190 @@
+/* Copyright (c) 2014-2018, NVIDIA CORPORATION. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *  * Neither the name of NVIDIA CORPORATION nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+//-
+// This utility compresses a normal(x,y,z) to a uint and decompresses it
+
+
+#define C_Stack_Max 3.402823466e+38f
+uint CompressUnitVec(vec3 nv)
+{
+  // map to octahedron and then flatten to 2D (see 'Octahedron Environment Maps' by Engelhardt & Dachsbacher)
+  if((nv.x < C_Stack_Max) && !isinf(nv.x))
+  {
+    const float d = 32767.0f / (abs(nv.x) + abs(nv.y) + abs(nv.z));
+    int         x = int(roundEven(nv.x * d));
+    int         y = int(roundEven(nv.y * d));
+    if(nv.z < 0.0f)
+    {
+      const int maskx = x >> 31;
+      const int masky = y >> 31;
+      const int tmp   = 32767 + maskx + masky;
+      const int tmpx  = x;
+      x               = (tmp - (y ^ masky)) ^ maskx;
+      y               = (tmp - (tmpx ^ maskx)) ^ masky;
+    }
+    uint packed = (uint(y + 32767) << 16) | uint(x + 32767);
+    if(packed == ~0u)
+      return ~0x1u;
+    return packed;
+  }
+  else
+  {
+    return ~0u;
+  }
+}
+
+float ShortToFloatM11(const int v)  // linearly maps a short 32767-32768 to a float -1-+1 //!! opt.?
+{
+  return (v >= 0) ? (uintBitsToFloat(0x3F800000u | (uint(v) << 8)) - 1.0f) :
+                    (uintBitsToFloat((0x80000000u | 0x3F800000u) | (uint(-v) << 8)) + 1.0f);
+}
+vec3 DecompressUnitVec(uint packed)
+{
+  if(packed != ~0u)  // sanity check, not needed as isvalid_unit_vec is called earlier
+  {
+    int       x     = int(packed & 0xFFFFu) - 32767;
+    int       y     = int(packed >> 16) - 32767;
+    const int maskx = x >> 31;
+    const int masky = y >> 31;
+    const int tmp0  = 32767 + maskx + masky;
+    const int ymask = y ^ masky;
+    const int tmp1  = tmp0 - (x ^ maskx);
+    const int z     = tmp1 - ymask;
+    float     zf;
+    if(z < 0)
+    {
+      x  = (tmp0 - ymask) ^ maskx;
+      y  = tmp1 ^ masky;
+      zf = uintBitsToFloat((0x80000000u | 0x3F800000u) | (uint(-z) << 8)) + 1.0f;
+    }
+    else
+    {
+      zf = uintBitsToFloat(0x3F800000u | (uint(z) << 8)) - 1.0f;
+    }
+    return normalize(vec3(ShortToFloatM11(x), ShortToFloatM11(y), zf));
+  }
+  else
+  {
+    return vec3(C_Stack_Max);
+  }
+}
+
+
+//-------------------------------------------------------------------------------------------------
+// Avoiding self intersections (see Ray Tracing Gems, Ch. 6)
+//
+vec3 OffsetRay(in vec3 p, in vec3 n)
+{
+  const float intScale   = 256.0f;
+  const float floatScale = 1.0f / 65536.0f;
+  const float origin     = 1.0f / 32.0f;
+
+  ivec3 of_i = ivec3(intScale * n.x, intScale * n.y, intScale * n.z);
+
+  vec3 p_i = vec3(intBitsToFloat(floatBitsToInt(p.x) + ((p.x < 0) ? -of_i.x : of_i.x)),
+                  intBitsToFloat(floatBitsToInt(p.y) + ((p.y < 0) ? -of_i.y : of_i.y)),
+                  intBitsToFloat(floatBitsToInt(p.z) + ((p.z < 0) ? -of_i.z : of_i.z)));
+
+  return vec3(abs(p.x) < origin ? p.x + floatScale * n.x : p_i.x,  //
+              abs(p.y) < origin ? p.y + floatScale * n.y : p_i.y,  //
+              abs(p.z) < origin ? p.z + floatScale * n.z : p_i.z);
+}
+
+
+//////////////////////////// AO //////////////////////////////////////
+#define EPS 0.05
+const float M_PI = 3.141592653589;
+
+void ComputeDefaultBasis(const vec3 normal, out vec3 x, out vec3 y)
+{
+  // ZAP's default coordinate system for compatibility
+  vec3        z  = normal;
+  const float yz = -z.y * z.z;
+  y              = normalize(((abs(z.z) > 0.99999f) ? vec3(-z.x * z.y, 1.0f - z.y * z.y, yz) :
+                                         vec3(-z.x * z.z, yz, 1.0f - z.z * z.z)));
+
+  x = cross(y, z);
+}
+
+//-------------------------------------------------------------------------------------------------
+// Random
+//-------------------------------------------------------------------------------------------------
+
+
+// Generate a random unsigned int from two unsigned int values, using 16 pairs
+// of rounds of the Tiny Encryption Algorithm. See Zafar, Olano, and Curtis,
+// "GPU Random Numbers via the Tiny Encryption Algorithm"
+uint tea(uint val0, uint val1)
+{
+  uint v0 = val0;
+  uint v1 = val1;
+  uint s0 = 0;
+
+  for(uint n = 0; n < 16; n++)
+  {
+    s0 += 0x9e3779b9;
+    v0 += ((v1 << 4) + 0xa341316c) ^ (v1 + s0) ^ ((v1 >> 5) + 0xc8013ea4);
+    v1 += ((v0 << 4) + 0xad90777d) ^ (v0 + s0) ^ ((v0 >> 5) + 0x7e95761e);
+  }
+
+  return v0;
+}
+
+uvec2 pcg2d(uvec2 v)
+{
+  v = v * 1664525u + 1013904223u;
+
+  v.x += v.y * 1664525u;
+  v.y += v.x * 1664525u;
+
+  v = v ^ (v >> 16u);
+
+  v.x += v.y * 1664525u;
+  v.y += v.x * 1664525u;
+
+  v = v ^ (v >> 16u);
+
+  return v;
+}
+
+// Generate a random unsigned int in [0, 2^24) given the previous RNG state
+// using the Numerical Recipes linear congruential generator
+uint lcg(inout uint prev)
+{
+  uint LCG_A = 1664525u;
+  uint LCG_C = 1013904223u;
+  prev       = (LCG_A * prev + LCG_C);
+  return prev & 0x00FFFFFF;
+}
+
+// Generate a random float in [0, 1) given the previous RNG state
+float rnd(inout uint seed)
+{
+  return (float(lcg(seed)) / float(0x01000000));
+}