commit 908b28bb971310e20d375f941df806e1dcf63e19
parent 958f1257971888e9786f27a75f1c9a439a982149
Author: Christian Ermann <christianermann@gmail.com>
Date: Mon, 16 Aug 2021 14:49:39 -0500
3d perlin noise
Diffstat:
2 files changed, 116 insertions(+), 0 deletions(-)
diff --git a/include/perlin.h b/include/perlin.h
@@ -0,0 +1,6 @@
+#ifndef PERLIN_H
+#define PERLIN_H
+
+float perlin(float x, float y, float z);
+
+#endif
diff --git a/src/perlin.c b/src/perlin.c
@@ -0,0 +1,110 @@
+#include "perlin.h"
+
+#include <math.h>
+
+const static int p[512] = {
+ 151, 160, 137, 91, 90, 15, 131, 13, 201, 95, 96, 53, 194, 233, 7,
+ 225, 140, 36, 103, 30, 69, 142, 8, 99, 37, 240, 21, 10, 23, 190,
+ 6, 148, 247, 120, 234, 75, 0, 26, 197, 62, 94, 252, 219, 203, 117,
+ 35, 11, 32, 57, 177, 33, 88, 237, 149, 56, 87, 174, 20, 125, 136,
+ 171, 168, 68, 175, 74, 165, 71, 134, 139, 48, 27, 166, 77, 146, 158,
+ 231, 83, 111, 229, 122, 60, 211, 133, 230, 220, 105, 92, 41, 55, 46,
+ 245, 40, 244, 102, 143, 54, 65, 25, 63, 161, 1, 216, 80, 73, 209,
+ 76, 132, 187, 208, 89, 18, 169, 200, 196, 135, 130, 116, 188, 159, 86,
+ 164, 100, 109, 198, 173, 186, 3, 64, 52, 217, 226, 250, 124, 123, 5,
+ 202, 38, 147, 118, 126, 255, 82, 85, 212, 207, 206, 59, 227, 47, 16,
+ 58, 17, 182, 189, 28, 42, 223, 183, 170, 213, 119, 248, 152, 2, 44,
+ 154, 163, 70, 221, 153, 101, 155, 167, 43, 172, 9, 129, 22, 39, 253,
+ 19, 98, 108, 110, 79, 113, 224, 232, 178, 185, 112, 104, 218, 246, 97,
+ 228, 251, 34, 242, 193, 238, 210, 144, 12, 191, 179, 162, 241, 81, 51,
+ 145, 235, 249, 14, 239, 107, 49, 192, 214, 31, 181, 199, 106, 157, 184,
+ 84, 204, 176, 115, 121, 50, 45, 127, 4, 150, 254, 138, 236, 205, 93,
+ 222, 114, 67, 29, 24, 72, 243, 141, 128, 195, 78, 66, 215, 61, 156,
+ 180,
+ 151, 160, 137, 91, 90, 15, 131, 13, 201, 95, 96, 53, 194, 233, 7,
+ 225, 140, 36, 103, 30, 69, 142, 8, 99, 37, 240, 21, 10, 23, 190,
+ 6, 148, 247, 120, 234, 75, 0, 26, 197, 62, 94, 252, 219, 203, 117,
+ 35, 11, 32, 57, 177, 33, 88, 237, 149, 56, 87, 174, 20, 125, 136,
+ 171, 168, 68, 175, 74, 165, 71, 134, 139, 48, 27, 166, 77, 146, 158,
+ 231, 83, 111, 229, 122, 60, 211, 133, 230, 220, 105, 92, 41, 55, 46,
+ 245, 40, 244, 102, 143, 54, 65, 25, 63, 161, 1, 216, 80, 73, 209,
+ 76, 132, 187, 208, 89, 18, 169, 200, 196, 135, 130, 116, 188, 159, 86,
+ 164, 100, 109, 198, 173, 186, 3, 64, 52, 217, 226, 250, 124, 123, 5,
+ 202, 38, 147, 118, 126, 255, 82, 85, 212, 207, 206, 59, 227, 47, 16,
+ 58, 17, 182, 189, 28, 42, 223, 183, 170, 213, 119, 248, 152, 2, 44,
+ 154, 163, 70, 221, 153, 101, 155, 167, 43, 172, 9, 129, 22, 39, 253,
+ 19, 98, 108, 110, 79, 113, 224, 232, 178, 185, 112, 104, 218, 246, 97,
+ 228, 251, 34, 242, 193, 238, 210, 144, 12, 191, 179, 162, 241, 81, 51,
+ 145, 235, 249, 14, 239, 107, 49, 192, 214, 31, 181, 199, 106, 157, 184,
+ 84, 204, 176, 115, 121, 50, 45, 127, 4, 150, 254, 138, 236, 205, 93,
+ 222, 114, 67, 29, 24, 72, 243, 141, 128, 195, 78, 66, 215, 61, 156,
+ 180
+};
+
+static float fade(float t)
+{
+ return t * t * t * (t * (t * 6 - 15) + 10);
+}
+
+static float lerp(float t, float a, float b)
+{
+ return a + t * (b - a);
+}
+
+const static float g[16][3] = {
+ { 1, 1, 0 },
+ { -1, 1, 0 },
+ { 1, -1, 0 },
+ { -1, -1, 0 },
+ { 1, 0, 1 },
+ { -1, 0, 1 },
+ { 1, 0, -1 },
+ { -1, 0, -1 },
+ { 0, 1, 1 },
+ { 0, -1, 1 },
+ { 0, 1, -1 },
+ { 0, -1, -1 },
+ { 1, 1, 0 },
+ { 0, -1, 1 },
+ { -1, 1, 0 },
+ { 0, -1, -1 }
+};
+
+static float grad(int hash, float x, float y, float z)
+{
+ int h = hash & 15;
+ return g[h][0] * x + g[h][1] * y + g[h][2] * z;
+}
+
+float perlin(float x, float y, float z)
+{
+ int X = (int)floorf(x) & 255;
+ int Y = (int)floorf(y) & 255;
+ int Z = (int)floorf(z) & 255;
+
+ x -= floorf(x);
+ y -= floorf(y);
+ z -= floorf(z);
+
+ float u = fade(x);
+ float v = fade(y);
+ float w = fade(z);
+
+ int a = p[p[p[X ] + Y ] + Z];
+ int b = p[p[p[X + 1] + Y ] + Z];
+ int c = p[p[p[X ] + Y + 1] + Z];
+ int d = p[p[p[X + 1] + Y + 1] + Z];
+ int e = p[p[p[X ] + Y ] + Z + 1];
+ int f = p[p[p[X + 1] + Y ] + Z + 1];
+ int g = p[p[p[X ] + Y + 1] + Z + 1];
+ int h = p[p[p[X + 1] + Y + 1] + Z + 1];
+
+ return lerp(w, lerp(v, lerp(u, grad(a, x , y , z ),
+ grad(b, x - 1, y , z )),
+ lerp(u, grad(c, x , y - 1, z ),
+ grad(d, x - 1, y - 1, z ))),
+ lerp(v, lerp(u, grad(e, x , y , z - 1),
+ grad(f, x - 1, y , z - 1)),
+ lerp(u, grad(g, x , y - 1, z - 1),
+ grad(h, x - 1, y - 1, z - 1))));
+}
