Added function to randomize permutation table at runtime

.gitignore

@@ -8,3 +8,4 @@ env
 *.egg
 *.egg-info
 .coverage
+/PKG-INFO

CHANGES.txt

@@ -1,3 +1,9 @@
+1.2.3 -- August 8, 2018
+
+  - Added randomize function to get a new permuation table
+
+  - Fixed lacunarity not settable for 4d simplex noise
+
 1.2.2 -- March 26, 2015
 
   - AppVeyor support for Windows builds (Thanks to Federico Tomassetti)

__init__.py

@@ -7,10 +7,11 @@
 Copyright (c) 2008, Casey Duncan (casey dot duncan at gmail dot com)
 """
 
-__version__ = "1.2.1"
+__version__ = "1.2.3"
 
 from . import _perlin, _simplex
 
+randomize = _simplex.randomize
 snoise2 = _simplex.noise2
 snoise3 = _simplex.noise3
 snoise4 = _simplex.noise4

_noise.h

@@ -26,7 +26,10 @@ const float GRAD4[][4] = {
 
 // At the possible cost of unaligned access, we use char instead of
 // int here to try to ensure that this table fits in L1 cache
-const unsigned char PERM[] = {
+#define DEFAULTPERIOD 256
+int period = DEFAULTPERIOD;
+unsigned char *PERM;
+unsigned char DEFAULTPERM[] = {
   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,

_perlin.c

@@ -28,8 +28,8 @@ noise1(float x, const int repeat, const int base)
 	float fx;
 	int i = (int)floorf(x) % repeat;
 	int ii = (i + 1) % repeat;
-	i = (i & 255) + base;
-	ii = (ii & 255) + base;
+	i = (i % period) + base;
+	ii = (ii % period) + base;
 
 	x -= floorf(x);
 	fx = x*x*x * (x * (x * 6 - 15) + 10);
@@ -92,10 +92,10 @@ noise2(float x, float y, const float repeatx, const float repeaty, const int bas
 	int j = (int)floorf(fmodf(y, repeaty));
 	int ii = (int)fmodf(i + 1, repeatx);
 	int jj = (int)fmodf(j + 1, repeaty);
-	i = (i & 255) + base;
-	j = (j & 255) + base;
-	ii = (ii & 255) + base;
-	jj = (jj & 255) + base;
+	i = (i % period) + base;
+	j = (j % period) + base;
+	ii = (ii % period) + base;
+	jj = (jj % period) + base;
 
 	x -= floorf(x); y -= floorf(y);
 	fx = x*x*x * (x * (x * 6 - 15) + 10);
@@ -173,12 +173,12 @@ noise3(float x, float y, float z, const int repeatx, const int repeaty, const in
 	int ii = (int)fmodf(i + 1,  repeatx);
 	int jj = (int)fmodf(j + 1, repeaty);
 	int kk = (int)fmodf(k + 1, repeatz);
-	i = (i & 255) + base;
-	j = (j & 255) + base;
-	k = (k & 255) + base;
-	ii = (ii & 255) + base;
-	jj = (jj & 255) + base;
-	kk = (kk & 255) + base;
+	i = (i % period) + base;
+	j = (j % period) + base;
+	k = (k % period) + base;
+	ii = (ii % period) + base;
+	jj = (jj % period) + base;
+	kk = (kk % period) + base;
 
 	x -= floorf(x); y -= floorf(y); z -= floorf(z);
 	fx = x*x*x * (x * (x * 6 - 15) + 10);
@@ -254,7 +254,7 @@ static PyMethodDef perlin_functions[] = {
 		"noise2(x, y, octaves=1, persistence=0.5, lacunarity=2.0, repeatx=1024, repeaty=1024, base=0.0)\n\n"
 		"2 dimensional perlin improved noise function (see noise3 for more info)"},
 	{"noise3", (PyCFunction) py_noise3, METH_VARARGS | METH_KEYWORDS, 
-		"noise3(x, y, z, octaves=1, persistence=0.5, lacunarity=2.0, "
+		"noise3(x, y, z, octaves=1, persistence=0.5, lacunarity=2.0"
 			"repeatx=1024, repeaty=1024, repeatz=1024, base=0.0)\n\n"
 		"return perlin \"improved\" noise value for specified coordinate\n\n"
 		"octaves -- specifies the number of passes for generating fBm noise,\n"
@@ -291,6 +291,7 @@ static struct PyModuleDef moduledef = {
 PyObject *
 PyInit__perlin(void)
 {
+    PERM = &DEFAULTPERM;
     return PyModule_Create(&moduledef);
 }
 
@@ -299,6 +300,7 @@ PyInit__perlin(void)
 void
 init_perlin(void)
 {
+	PERM = &DEFAULTPERM;
 	Py_InitModule3("_perlin", perlin_functions, module_doc);
 }
 

_simplex.c

@@ -5,6 +5,7 @@
 #include "Python.h"
 #include <math.h>
 #include <float.h>
+#include <stdlib.h>
 #include "_noise.h"
 
 // 2D simplex skew factors
@@ -35,8 +36,8 @@ noise2(float x, float y)
 	xx[1] = xx[0] - i1 + G2;
 	yy[1] = yy[0] - j1 + G2;
 
-	I = (int) i & 255;
-	J = (int) j & 255;
+	I = (int) i % period;
+	J = (int) j % period;
 	g[0] = PERM[I + PERM[J]] % 12;
 	g[1] = PERM[I + i1 + PERM[J + j1]] % 12;
 	g[2] = PERM[I + 1 + PERM[J + 1]] % 12;
@@ -105,9 +106,9 @@ noise3(float x, float y, float z)
 		pos[1][c] = pos[0][c] - o1[c] + G3;
 	}
 
-	I = (int) i & 255; 
-	J = (int) j & 255; 
-	K = (int) k & 255;
+	I = (int) i % period;
+	J = (int) j % period;
+	K = (int) k % period;
 	g[0] = PERM[I + PERM[J + PERM[K]]] % 12;
 	g[1] = PERM[I + o1[0] + PERM[J + o1[1] + PERM[o1[2] + K]]] % 12;
 	g[2] = PERM[I + o2[0] + PERM[J + o2[1] + PERM[o2[2] + K]]] % 12;
@@ -195,10 +196,10 @@ noise4(float x, float y, float z, float w) {
     float z4 = z0 - 1.0f + 4.0f*G4;
     float w4 = w0 - 1.0f + 4.0f*G4;
 
-    int I = (int)i & 255;
-    int J = (int)j & 255;
-    int K = (int)k & 255;
-    int L = (int)l & 255;
+    int I = (int)i % period;
+    int J = (int)j % period;
+    int K = (int)k % period;
+    int L = (int)l % period;
     int gi0 = PERM[I + PERM[J + PERM[K + PERM[L]]]] & 0x1f;
     int gi1 = PERM[I + i1 + PERM[J + j1 + PERM[K + k1 + PERM[L + l1]]]] & 0x1f; 
     int gi2 = PERM[I + i2 + PERM[J + j2 + PERM[K + k2 + PERM[L + l2]]]] & 0x1f; 
@@ -353,12 +354,12 @@ py_noise4(PyObject *self, PyObject *args, PyObject *kwargs)
 	float x, y, z, w;
 	int octaves = 1;
 	float persistence = 0.5f;
-    float lacunarity = 2.0f;
+	float lacunarity = 2.0f;
 
 	static char *kwlist[] = {"x", "y", "z", "w", "octaves", "persistence", "lacunarity", NULL};
 
 	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "ffff|iff:snoise4", kwlist,
-		&x, &y, &z, &w, &octaves, &persistence))
+		&x, &y, &z, &w, &octaves, &persistence, &lacunarity))
 		return NULL;
 
 	if (octaves == 1) {
@@ -373,6 +374,41 @@ py_noise4(PyObject *self, PyObject *args, PyObject *kwargs)
 	}
 }
 
+static PyObject *
+randomize(PyObject *self, PyObject *args, PyObject *kwargs)
+{
+        int pperiod=DEFAULTPERIOD;
+        int pseed=0;
+
+        static char *kwlist[] = {"period", "seed", NULL};
+
+        if (!PyArg_ParseTupleAndKeywords(args, kwargs, "ii:randomize", kwlist,
+		&pperiod, &pseed))
+            return NULL;
+
+        period=pperiod;
+
+        if(PERM != &DEFAULTPERM)
+            free(PERM);
+        PERM = malloc(period*2*sizeof(unsigned char));
+        if(PERM==NULL)
+        {    
+            period=DEFAULTPERIOD;
+            PERM = &DEFAULTPERM;
+            PyErr_SetString(PyExc_ValueError, "Failed to allocate memory");
+            return NULL;
+        }
+
+        srand(pseed);
+
+        for(int i=0; i < period; i++){
+            PERM[i]=(unsigned char)(rand() / (RAND_MAX / 255 + 1));
+            PERM[i+period]=PERM[i];
+        }
+
+        Py_RETURN_TRUE;
+}
+
 static PyMethodDef simplex_functions[] = {
 	{"noise2", (PyCFunction)py_noise2, METH_VARARGS | METH_KEYWORDS, 
 		"noise2(x, y, octaves=1, persistence=0.5, lacunarity=2.0, repeatx=None, repeaty=None, base=0.0) "
@@ -406,6 +442,9 @@ static PyMethodDef simplex_functions[] = {
 		"is halved). Note the amplitude of the first pass is always 1.0.\n\n"
         "lacunarity -- specifies the frequency of each successive octave relative\n"
         "to the one below it, similar to persistence. Defaults to 2.0."},
+	{"randomize", (PyCFunction)randomize, METH_VARARGS | METH_KEYWORDS, 
+		"randomize(period, seed) creates a new random permutation with period "
+		"and specified random seed"},
 	{NULL}
 };
 
@@ -428,6 +467,7 @@ static struct PyModuleDef moduledef = {
 PyObject *
 PyInit__simplex(void)
 {
+    PERM = &DEFAULTPERM;
     return PyModule_Create(&moduledef);
 }
 
@@ -436,6 +476,7 @@ PyInit__simplex(void)
 void
 init_simplex(void)
 {
+	PERM = &DEFAULTPERM;
 	Py_InitModule3("_simplex", simplex_functions, module_doc);
 }
 

setup.py

@@ -12,7 +12,7 @@
 
 setup(
     name='noise',
-    version='1.2.2',
+    version='1.2.3',
     description='Perlin noise for Python',
     long_description='''\
 Perlin noise is ubiquitous in modern CGI. Used for procedural texturing,
@@ -30,6 +30,8 @@
 motion) noise by combining multiple octaves of Perlin noise. Shader functions
 for convenient generation of turbulent noise are also included.
 
+- 1.2.3 Adds ability to randomize permutation table to the C implementations
+
 - 1.2.2 AppVeyor support for Windows builds (Thanks to Federico Tomassetti)
 
 - 1.2.1 Fixes MSVC compatibility (Thanks to Christoph Gohlke)

test.py

@@ -76,6 +76,9 @@ def test_perlin_3d_base(self):
 
 
 class SimplexTestCase(unittest.TestCase):
+    def test_randomize(self):
+        from noise import randomize
+        self.assertTrue(randomize(4096,23490))
 
     def test_simplex_2d_range(self):
         from noise import snoise2