New version of the samples and tutorials based on KHR_ray_tracing

ray_tracing_jitter_cam/shaders/random.glsl

@@ -0,0 +1,34 @@
+// 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;
+}
+
+// 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 prev)
+{
+  return (float(lcg(prev)) / float(0x01000000));
+}