chronological order

mountain/origami-mountain-1a.c → 02-mountain/origami-mountain-1a.c

@@ -2,16 +2,17 @@
 #include <stdio.h>
 #include <string.h>
 #include <time.h>
+#include <math.h>
 
-#include "noise.c"
+#include "../common/noise.c"
 
 #define TWOPI 6.28318530718
 
 int main(int argc, char **argv){
 	time_t t;
 	srand((unsigned) time(&t));
 
-	float seed = rand()%100/100.0;
+	float seed = rand()%1000/100.0;
 
 	int width = 800;
 	int height = 800;

mountain/origami-mountain-1b.c → 02-mountain/origami-mountain-1b.c

@@ -2,16 +2,17 @@
 #include <stdio.h>
 #include <string.h>
 #include <time.h>
+#include <math.h>
 
-#include "noise.c"
+#include "../common/noise.c"
 
 #define TWOPI 6.28318530718
 
 int main(int argc, char **argv){
 	time_t t;
 	srand((unsigned) time(&t));
 
-	float seed = rand()%100/100.0;
+	float seed = rand()%1000/100.0;
 
 	int width = 800;
 	int height = 800;

mountain/origami-mountain-1c.c → 02-mountain/origami-mountain-1c.c

@@ -2,8 +2,9 @@
 #include <stdio.h>
 #include <string.h>
 #include <time.h>
+#include <math.h>
 
-#include "noise.c"
+#include "../common/noise.c"
 
 #define TWOPI 6.28318530718
 

mountain/origami-mountain-2a.c → 02-mountain/origami-mountain-2a.c

@@ -2,8 +2,9 @@
 #include <stdio.h>
 #include <string.h>
 #include <time.h>
+#include <math.h>
 
-#include "noise.c"
+#include "../common/noise.c"
 
 #define TWOPI 6.28318530718
 

mountain/origami-mountain-2b.c → 02-mountain/origami-mountain-2b.c

@@ -2,8 +2,9 @@
 #include <stdio.h>
 #include <string.h>
 #include <time.h>
+#include <math.h>
 
-#include "noise.c"
+#include "../common/noise.c"
 
 #define TWOPI 6.28318530718
 

mountain/origami-mountain-2c.c → 02-mountain/origami-mountain-2c.c

@@ -2,8 +2,9 @@
 #include <stdio.h>
 #include <string.h>
 #include <time.h>
+#include <math.h>
 
-#include "noise.c"
+#include "../common/noise.c"
 
 #define TWOPI 6.28318530718
 

mountain/origami-mountain-simple.c → 02-mountain/origami-mountain-simple.c

@@ -2,8 +2,9 @@
 #include <stdio.h>
 #include <string.h>
 #include <time.h>
+#include <math.h>
 
-#include "noise.c"
+#include "../common/noise.c"
 
 #define TWOPI 6.28318530718
 

mountain/origami-mountain.c → 02-mountain/origami-mountain.c

@@ -4,7 +4,7 @@
 #include <time.h>
 #include <math.h>
 
-#include "noise1234.c"
+#include "../common/noise1234.c"
 
 #define TWOPI 6.28318530718
 

common/noise.c

@@ -0,0 +1,201 @@
+/* coherent noise function over 1, 2 or 3 dimensions */
+/* (copyright Ken Perlin) */
+
+#include "noise.h"
+
+#define B 0x100
+#define BM 0xff
+
+#define N 0x1000
+#define NP 12   /* 2^N */
+#define NM 0xfff
+
+static int p[B + B + 2];
+static float g3[B + B + 2][3];
+static float g2[B + B + 2][2];
+static float g1[B + B + 2];
+static int start = 1;
+
+static void init(void);
+
+#define s_curve(t) ( t * t * (3. - 2. * t) )
+
+#define lerp(t, a, b) ( a + t * (b - a) )
+
+#define setup(i,b0,b1,r0,r1)\
+t = vec[i] + N;\
+b0 = ((int)t) & BM;\
+b1 = (b0+1) & BM;\
+r0 = t - (int)t;\
+r1 = r0 - 1.;
+
+double peach()
+{
+    return 0.5;
+}
+
+double noise1(double arg)
+{
+	int bx0, bx1;
+	float rx0, rx1, sx, t, u, v, vec[1];
+
+	vec[0] = arg;
+	if (start) {
+		start = 0;
+		init();
+	}
+
+	setup(0, bx0,bx1, rx0,rx1);
+
+	sx = s_curve(rx0);
+
+	u = rx0 * g1[ p[ bx0 ] ];
+	v = rx1 * g1[ p[ bx1 ] ];
+
+	return lerp(sx, u, v);
+}
+
+float noise2(float vec[2])
+{
+	int bx0, bx1, by0, by1, b00, b10, b01, b11;
+	float rx0, rx1, ry0, ry1, *q, sx, sy, a, b, t, u, v;
+	int i;
+    int j;
+
+	if (start) {
+		start = 0;
+		init();
+	}
+
+	setup(0, bx0,bx1, rx0,rx1);
+	setup(1, by0,by1, ry0,ry1);
+
+	i = p[ bx0 ];
+	j = p[ bx1 ];
+
+	b00 = p[ i + by0 ];
+	b10 = p[ j + by0 ];
+	b01 = p[ i + by1 ];
+	b11 = p[ j + by1 ];
+
+	sx = s_curve(rx0);
+	sy = s_curve(ry0);
+
+#define at2(rx,ry) ( rx * q[0] + ry * q[1] )
+
+	q = g2[ b00 ] ; u = at2(rx0,ry0);
+	q = g2[ b10 ] ; v = at2(rx1,ry0);
+	a = lerp(sx, u, v);
+
+	q = g2[ b01 ] ; u = at2(rx0,ry1);
+	q = g2[ b11 ] ; v = at2(rx1,ry1);
+	b = lerp(sx, u, v);
+
+	return lerp(sy, a, b);
+}
+
+float noise3(float vec[3])
+{
+	int bx0, bx1, by0, by1, bz0, bz1, b00, b10, b01, b11;
+	float rx0, rx1, ry0, ry1, rz0, rz1, *q, sy, sz, a, b, c, d, t, u, v;
+    int i;
+    int j;
+
+	if (start) {
+		start = 0;
+		init();
+	}
+
+	setup(0, bx0,bx1, rx0,rx1);
+	setup(1, by0,by1, ry0,ry1);
+	setup(2, bz0,bz1, rz0,rz1);
+
+	i = p[ bx0 ];
+	j = p[ bx1 ];
+
+	b00 = p[ i + by0 ];
+	b10 = p[ j + by0 ];
+	b01 = p[ i + by1 ];
+	b11 = p[ j + by1 ];
+
+	t  = s_curve(rx0);
+	sy = s_curve(ry0);
+	sz = s_curve(rz0);
+
+#define at3(rx,ry,rz) ( rx * q[0] + ry * q[1] + rz * q[2] )
+
+	q = g3[ b00 + bz0 ] ; u = at3(rx0,ry0,rz0);
+	q = g3[ b10 + bz0 ] ; v = at3(rx1,ry0,rz0);
+	a = lerp(t, u, v);
+
+	q = g3[ b01 + bz0 ] ; u = at3(rx0,ry1,rz0);
+	q = g3[ b11 + bz0 ] ; v = at3(rx1,ry1,rz0);
+	b = lerp(t, u, v);
+
+	c = lerp(sy, a, b);
+
+	q = g3[ b00 + bz1 ] ; u = at3(rx0,ry0,rz1);
+	q = g3[ b10 + bz1 ] ; v = at3(rx1,ry0,rz1);
+	a = lerp(t, u, v);
+
+	q = g3[ b01 + bz1 ] ; u = at3(rx0,ry1,rz1);
+	q = g3[ b11 + bz1 ] ; v = at3(rx1,ry1,rz1);
+	b = lerp(t, u, v);
+
+	d = lerp(sy, a, b);
+
+	return lerp(sz, c, d);
+}
+
+static void normalize2(float v[2])
+{
+	float s;
+
+	s = sqrt(v[0] * v[0] + v[1] * v[1]);
+	v[0] = v[0] / s;
+	v[1] = v[1] / s;
+}
+
+static void normalize3(float v[3])
+{
+	float s;
+
+	s = sqrt(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]);
+	v[0] = v[0] / s;
+	v[1] = v[1] / s;
+	v[2] = v[2] / s;
+}
+
+static void init(void)
+{
+	int i, j, k;
+
+	for (i = 0 ; i < B ; i++) {
+		p[i] = i;
+
+		g1[i] = (float)((random() % (B + B)) - B) / B;
+
+		for (j = 0 ; j < 2 ; j++)
+			g2[i][j] = (float)((random() % (B + B)) - B) / B;
+		normalize2(g2[i]);
+
+		for (j = 0 ; j < 3 ; j++)
+			g3[i][j] = (float)((random() % (B + B)) - B) / B;
+		normalize3(g3[i]);
+	}
+
+	while (--i) {
+		k = p[i];
+		p[i] = p[j = random() % B];
+		p[j] = k;
+	}
+
+	for (i = 0 ; i < B + 2 ; i++) {
+		p[B + i] = p[i];
+		g1[B + i] = g1[i];
+		for (j = 0 ; j < 2 ; j++)
+			g2[B + i][j] = g2[i][j];
+		for (j = 0 ; j < 3 ; j++)
+			g3[B + i][j] = g3[i][j];
+	}
+}

common/noise.h

@@ -0,0 +1,12 @@
+#ifndef Perlin_noise_h
+#define Perlin_noise_h
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+
+double noise1(double arg);
+float noise2(float vec[2]);
+float noise3(float vec[3]);
+
+#endif