From fc9521874ca3dcbc8dfd7237b9b3f2420250b351 Mon Sep 17 00:00:00 2001
From: kwolekr <kwolekr@minetest.net>
Date: Wed, 12 Nov 2014 23:49:45 -0500
Subject: [PATCH] Add eased 3d point-value noise functions

---
 src/noise.cpp | 25 ++++++++++++++++---------
 src/noise.h   | 11 ++++++++---
 2 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/src/noise.cpp b/src/noise.cpp
index c30e1570d..c0249a437 100644
--- a/src/noise.cpp
+++ b/src/noise.cpp
@@ -215,7 +215,7 @@ float noise2d_gradient(float x, float y, int seed)
 }
 
 
-float noise3d_gradient(float x, float y, float z, int seed)
+float noise3d_gradient(float x, float y, float z, int seed, bool eased)
 {
 	// Calculate the integer coordinates
 	int x0 = myfloor(x);
@@ -235,10 +235,17 @@ float noise3d_gradient(float x, float y, float z, int seed)
 	float v011 = noise3d(x0,     y0 + 1, z0 + 1, seed);
 	float v111 = noise3d(x0 + 1, y0 + 1, z0 + 1, seed);
 	// Interpolate
-	return triLinearInterpolationNoEase(
-		v000, v100, v010, v110,
-		v001, v101, v011, v111,
-		xl, yl, zl);
+	if (eased) {
+		return triLinearInterpolation(
+			v000, v100, v010, v110,
+			v001, v101, v011, v111,
+			xl, yl, zl);
+	} else {
+		return triLinearInterpolationNoEase(
+			v000, v100, v010, v110,
+			v001, v101, v011, v111,
+			xl, yl, zl);
+	}
 }
 
 
@@ -275,14 +282,14 @@ float noise2d_perlin_abs(float x, float y, int seed,
 
 
 float noise3d_perlin(float x, float y, float z, int seed,
-		int octaves, float persistence)
+		int octaves, float persistence, bool eased)
 {
 	float a = 0;
 	float f = 1.0;
 	float g = 1.0;
 	for (int i = 0; i < octaves; i++)
 	{
-		a += g * noise3d_gradient(x * f, y * f, z * f, seed + i);
+		a += g * noise3d_gradient(x * f, y * f, z * f, seed + i, eased);
 		f *= 2.0;
 		g *= persistence;
 	}
@@ -291,14 +298,14 @@ float noise3d_perlin(float x, float y, float z, int seed,
 
 
 float noise3d_perlin_abs(float x, float y, float z, int seed,
-		int octaves, float persistence)
+		int octaves, float persistence, bool eased)
 {
 	float a = 0;
 	float f = 1.0;
 	float g = 1.0;
 	for (int i = 0; i < octaves; i++)
 	{
-		a += g * fabs(noise3d_gradient(x * f, y * f, z * f, seed + i));
+		a += g * fabs(noise3d_gradient(x * f, y * f, z * f, seed + i, eased));
 		f *= 2.0;
 		g *= persistence;
 	}
diff --git a/src/noise.h b/src/noise.h
index aa489b2c0..00d3612af 100644
--- a/src/noise.h
+++ b/src/noise.h
@@ -134,7 +134,7 @@ float noise2d(int x, int y, int seed);
 float noise3d(int x, int y, int z, int seed);
 
 float noise2d_gradient(float x, float y, int seed);
-float noise3d_gradient(float x, float y, float z, int seed);
+float noise3d_gradient(float x, float y, float z, int seed, bool eased=false);
 
 float noise2d_perlin(float x, float y, int seed,
 		int octaves, float persistence);
@@ -143,10 +143,10 @@ float noise2d_perlin_abs(float x, float y, int seed,
 		int octaves, float persistence);
 
 float noise3d_perlin(float x, float y, float z, int seed,
-		int octaves, float persistence);
+		int octaves, float persistence, bool eased=false);
 
 float noise3d_perlin_abs(float x, float y, float z, int seed,
-		int octaves, float persistence);
+		int octaves, float persistence, bool eased=false);
 
 inline float easeCurve(float t) {
 	return t * t * t * (t * (6.f * t - 15.f) + 10.f);
@@ -182,5 +182,10 @@ float contour(float v);
 		noise3d_perlin((float)(x) / (np)->spread.X, (float)(y) / (np)->spread.Y, \
 		(float)(z) / (np)->spread.Z, (s) + (np)->seed, (np)->octaves, (np)->persist))
 
+#define NoisePerlin3DEased(np, x, y, z, s) ((np)->offset + (np)->scale * \
+		noise3d_perlin((float)(x) / (np)->spread.X, (float)(y) / (np)->spread.Y, \
+		(float)(z) / (np)->spread.Z, (s) + (np)->seed, (np)->octaves, \
+		(np)->persist), true)
+
 #endif