Fur: add domain warping

1 files changed, 52 insertions, 2 deletions

diff --git a/math.cginc b/math.cginc
index 3112418..cbf162c 100644
--- a/math.cginc
+++ b/math.cginc
@@ -307,7 +307,57 @@ float2 hex_to_cart(float3 cart) {
       (cart[1] - cart[2]) * SQRT_3_OVER_2);

 }

 

-// Rotate 45 degrees.

-float2 rot45(float2 v) { return float2(v.x - v.y, v.x + v.y) * RCP_SQRT_2; }

+// Rotate 45 degrees.
+float2 rot45(float2 v) { return float2(v.x - v.y, v.x + v.y) * RCP_SQRT_2; }
+
+// p = point to get noise for
+float valueNoise2D(
+    float2 p) {
+  // quantized part
+  float2 q = floor(p);
+  // fractional part
+  float2 f = frac(p);
+
+  float l00 = rand2(q);
+  float l01 = rand2(q + float2(0, 1));
+  float l10 = rand2(q + float2(1, 0));
+  float l11 = rand2(q + float2(1, 1));
+
+  // Cubic interpolation.
+  f = f * f * (3.0f - 2.0f * f);
+
+  float l0 = lerp(l00, l01, f.y);
+  float l1 = lerp(l10, l11, f.y);
+  return lerp(l0, l1, f.x);
+}
+
+// p = point to get noise for
+float valueNoise3D(
+    float3 p) {
+  // quantized part

+  float3 q = floor(p);

+  // fractional part

+  float3 f = frac(p);

+

+  float l000 = rand3(q);

+  float l001 = rand3(q + float3(0, 0, 1));

+  float l010 = rand3(q + float3(0, 1, 0));

+  float l011 = rand3(q + float3(0, 1, 1));

+  float l100 = rand3(q + float3(1, 0, 0));

+  float l101 = rand3(q + float3(1, 0, 1));

+  float l110 = rand3(q + float3(1, 1, 0));

+  float l111 = rand3(q + float3(1, 1, 1));

+

+  // Cubic interpolation.

+  f = f * f * (3.0f - 2.0f * f);

+

+  float l00 = lerp(l000, l001, f.z);

+  float l01 = lerp(l010, l011, f.z);

+  float l10 = lerp(l100, l101, f.z);

+  float l11 = lerp(l110, l111, f.z);

+  float l0 = lerp(l00, l01, f.y);

+  float l1 = lerp(l10, l11, f.y);

+  return lerp(l0, l1, f.x);

+}

 

 #endif  // __MATH_INC