1 |
– |
/* Copyright (c) 1988 Regents of the University of California */ |
2 |
– |
|
1 |
|
#ifndef lint |
2 |
< |
static char SCCSid[] = "$SunId$ LBL"; |
2 |
> |
static const char RCSid[] = "$Id$"; |
3 |
|
#endif |
6 |
– |
|
4 |
|
/* |
5 |
|
* noise3.c - noise functions for random textures. |
6 |
|
* |
7 |
|
* Credit for the smooth algorithm goes to Ken Perlin. |
8 |
|
* (ref. SIGGRAPH Vol 19, No 3, pp 287-96) |
12 |
– |
* |
13 |
– |
* 4/15/86 |
14 |
– |
* 5/19/88 Added fractal noise function |
9 |
|
*/ |
10 |
|
|
11 |
+ |
#include "copyright.h" |
12 |
|
|
13 |
+ |
#include <math.h> |
14 |
+ |
|
15 |
+ |
#include "calcomp.h" |
16 |
+ |
#include "func.h" |
17 |
+ |
|
18 |
|
#define A 0 |
19 |
|
#define B 1 |
20 |
|
#define C 2 |
25 |
|
#define rand3c(x,y,z) frand(89*(x)+97*(y)+101*(z)) |
26 |
|
#define rand3d(x,y,z) frand(103*(x)+107*(y)+109*(z)) |
27 |
|
|
28 |
< |
#define hermite(p0,p1,r0,r1,t) ( p0*((2.0*t-3.0)*t*t+1.0) + \ |
29 |
< |
p1*(-2.0*t+3.0)*t*t + \ |
30 |
< |
r0*((t-2.0)*t+1.0)*t + \ |
31 |
< |
r1*(t-1.0)*t*t ) |
28 |
> |
#define hpoly1(t) ((2.0*t-3.0)*t*t+1.0) |
29 |
> |
#define hpoly2(t) (-2.0*t+3.0)*t*t |
30 |
> |
#define hpoly3(t) ((t-2.0)*t+1.0)*t |
31 |
> |
#define hpoly4(t) (t-1.0)*t*t |
32 |
|
|
33 |
< |
double *noise3(), noise3coef(), argument(), frand(); |
33 |
> |
#define hermite(p0,p1,r0,r1,t) ( p0*hpoly1(t) + \ |
34 |
> |
p1*hpoly2(t) + \ |
35 |
> |
r0*hpoly3(t) + \ |
36 |
> |
r1*hpoly4(t) ) |
37 |
|
|
38 |
+ |
static char noise_name[4][8] = {"noise3x", "noise3y", "noise3z", "noise3"}; |
39 |
+ |
static char fnoise_name[] = "fnoise3"; |
40 |
+ |
static char hermite_name[] = "hermite"; |
41 |
+ |
|
42 |
|
static long xlim[3][2]; |
43 |
|
static double xarg[3]; |
44 |
|
|
45 |
< |
#define EPSILON .0001 /* error allowed in fractal */ |
45 |
> |
#define EPSILON .001 /* error allowed in fractal */ |
46 |
|
|
47 |
< |
#define frand3(x,y,z) frand((long)((12.38*(x)-22.30*(y)-42.63*(z))/EPSILON)) |
47 |
> |
#define frand3(x,y,z) frand(17*(x)+23*(y)+29*(z)) |
48 |
|
|
49 |
< |
double fnoise3(); |
49 |
> |
static double l_noise3(char *nam); |
50 |
> |
static double l_hermite(char *nm); |
51 |
> |
static double * noise3(double xnew[3]); |
52 |
> |
static void interpolate(double f[4], int i, int n); |
53 |
> |
static double frand(long s); |
54 |
> |
static double fnoise3(double p[3]); |
55 |
|
|
56 |
|
|
57 |
< |
double |
58 |
< |
l_noise3() /* compute 3-dimensional noise function */ |
57 |
> |
static double |
58 |
> |
l_noise3( /* compute a noise function */ |
59 |
> |
register char *nam |
60 |
> |
) |
61 |
|
{ |
62 |
< |
return(noise3coef(D)); |
49 |
< |
} |
50 |
< |
|
51 |
< |
|
52 |
< |
double |
53 |
< |
l_noise3a() /* compute x slope of noise function */ |
54 |
< |
{ |
55 |
< |
return(noise3coef(A)); |
56 |
< |
} |
57 |
< |
|
58 |
< |
|
59 |
< |
double |
60 |
< |
l_noise3b() /* compute y slope of noise function */ |
61 |
< |
{ |
62 |
< |
return(noise3coef(B)); |
63 |
< |
} |
64 |
< |
|
65 |
< |
|
66 |
< |
double |
67 |
< |
l_noise3c() /* compute z slope of noise function */ |
68 |
< |
{ |
69 |
< |
return(noise3coef(C)); |
70 |
< |
} |
71 |
< |
|
72 |
< |
|
73 |
< |
double |
74 |
< |
l_fnoise3() /* compute fractal noise function */ |
75 |
< |
{ |
62 |
> |
register int i; |
63 |
|
double x[3]; |
64 |
< |
|
64 |
> |
/* get point */ |
65 |
|
x[0] = argument(1); |
66 |
|
x[1] = argument(2); |
67 |
|
x[2] = argument(3); |
68 |
< |
|
69 |
< |
return(fnoise3(x)); |
68 |
> |
/* make appropriate call */ |
69 |
> |
if (nam == fnoise_name) |
70 |
> |
return(fnoise3(x)); |
71 |
> |
i = 4; |
72 |
> |
while (i--) |
73 |
> |
if (nam == noise_name[i]) |
74 |
> |
return(noise3(x)[i]); |
75 |
> |
eputs(nam); |
76 |
> |
eputs(": called l_noise3!\n"); |
77 |
> |
quit(1); |
78 |
> |
return 1; /* pro forma return */ |
79 |
|
} |
80 |
|
|
81 |
|
|
82 |
|
static double |
83 |
< |
noise3coef(coef) /* return coefficient of noise function */ |
88 |
< |
int coef; |
83 |
> |
l_hermite(char *nm) /* library call for hermite interpolation */ |
84 |
|
{ |
85 |
< |
double x[3]; |
85 |
> |
double t; |
86 |
> |
|
87 |
> |
t = argument(5); |
88 |
> |
return( hermite(argument(1), argument(2), |
89 |
> |
argument(3), argument(4), t) ); |
90 |
> |
} |
91 |
|
|
92 |
– |
x[0] = argument(1); |
93 |
– |
x[1] = argument(2); |
94 |
– |
x[2] = argument(3); |
92 |
|
|
93 |
< |
return(noise3(x)[coef]); |
93 |
> |
extern void |
94 |
> |
setnoisefuncs(void) /* add noise functions to library */ |
95 |
> |
{ |
96 |
> |
register int i; |
97 |
> |
|
98 |
> |
funset(hermite_name, 5, ':', l_hermite); |
99 |
> |
funset(fnoise_name, 3, ':', l_noise3); |
100 |
> |
i = 4; |
101 |
> |
while (i--) |
102 |
> |
funset(noise_name[i], 3, ':', l_noise3); |
103 |
|
} |
104 |
|
|
105 |
|
|
106 |
< |
double * |
107 |
< |
noise3(xnew) /* compute the noise function */ |
108 |
< |
register double xnew[3]; |
106 |
> |
static double * |
107 |
> |
noise3( /* compute the noise function */ |
108 |
> |
register double xnew[3] |
109 |
> |
) |
110 |
|
{ |
104 |
– |
extern double floor(); |
111 |
|
static double x[3] = {-100000.0, -100000.0, -100000.0}; |
112 |
|
static double f[4]; |
113 |
|
|
125 |
|
} |
126 |
|
|
127 |
|
|
128 |
< |
static |
129 |
< |
interpolate(f, i, n) |
130 |
< |
double f[4]; |
131 |
< |
register int i, n; |
128 |
> |
static void |
129 |
> |
interpolate( |
130 |
> |
double f[4], |
131 |
> |
register int i, |
132 |
> |
register int n |
133 |
> |
) |
134 |
|
{ |
135 |
< |
double f0[4], f1[4]; |
135 |
> |
double f0[4], f1[4], hp1, hp2; |
136 |
|
|
137 |
|
if (n == 0) { |
138 |
|
f[A] = rand3a(xlim[0][i&1],xlim[1][i>>1&1],xlim[2][i>>2]); |
143 |
|
n--; |
144 |
|
interpolate(f0, i, n); |
145 |
|
interpolate(f1, i | 1<<n, n); |
146 |
< |
f[A] = (1.0-xarg[n])*f0[A] + xarg[n]*f1[A]; |
147 |
< |
f[B] = (1.0-xarg[n])*f0[B] + xarg[n]*f1[B]; |
148 |
< |
f[C] = (1.0-xarg[n])*f0[C] + xarg[n]*f1[C]; |
149 |
< |
f[D] = hermite(f0[D], f1[D], f0[n], f1[n], xarg[n]); |
146 |
> |
hp1 = hpoly1(xarg[n]); hp2 = hpoly2(xarg[n]); |
147 |
> |
f[A] = f0[A]*hp1 + f1[A]*hp2; |
148 |
> |
f[B] = f0[B]*hp1 + f1[B]*hp2; |
149 |
> |
f[C] = f0[C]*hp1 + f1[C]*hp2; |
150 |
> |
f[D] = f0[D]*hp1 + f1[D]*hp2 + |
151 |
> |
f0[n]*hpoly3(xarg[n]) + f1[n]*hpoly4(xarg[n]); |
152 |
|
} |
153 |
|
} |
154 |
|
|
155 |
|
|
156 |
< |
double |
157 |
< |
frand(s) /* get random number from seed */ |
158 |
< |
register long s; |
156 |
> |
static double |
157 |
> |
frand( /* get random number from seed */ |
158 |
> |
register long s |
159 |
> |
) |
160 |
|
{ |
161 |
|
s = s<<13 ^ s; |
162 |
|
return(1.0-((s*(s*s*15731+789221)+1376312589)&0x7fffffff)/1073741824.0); |
163 |
|
} |
164 |
|
|
165 |
|
|
166 |
< |
double |
167 |
< |
l_hermite() /* library call for hermite interpolation */ |
166 |
> |
static double |
167 |
> |
fnoise3( /* compute fractal noise function */ |
168 |
> |
double p[3] |
169 |
> |
) |
170 |
|
{ |
171 |
< |
double t; |
172 |
< |
|
173 |
< |
t = argument(5); |
174 |
< |
return( hermite(argument(1), argument(2), |
162 |
< |
argument(3), argument(4), t) ); |
163 |
< |
} |
164 |
< |
|
165 |
< |
|
166 |
< |
double |
167 |
< |
fnoise3(p) /* compute fractal noise function */ |
168 |
< |
register double p[3]; |
169 |
< |
{ |
170 |
< |
double floor(); |
171 |
< |
double v[3], beg[3], fval[8], s, fc; |
172 |
< |
int closing, branch; |
171 |
> |
long t[3], v[3], beg[3]; |
172 |
> |
double fval[8], fc; |
173 |
> |
int branch; |
174 |
> |
register long s; |
175 |
|
register int i, j; |
176 |
|
/* get starting cube */ |
177 |
< |
for (i = 0; i < 3; i++) |
178 |
< |
beg[i] = floor(p[i]); |
177 |
> |
s = (long)(1.0/EPSILON); |
178 |
> |
for (i = 0; i < 3; i++) { |
179 |
> |
t[i] = s*p[i]; |
180 |
> |
beg[i] = s*floor(p[i]); |
181 |
> |
} |
182 |
|
for (j = 0; j < 8; j++) { |
183 |
|
for (i = 0; i < 3; i++) { |
184 |
|
v[i] = beg[i]; |
185 |
|
if (j & 1<<i) |
186 |
< |
v[i] += 1.0; |
186 |
> |
v[i] += s; |
187 |
|
} |
188 |
|
fval[j] = frand3(v[0],v[1],v[2]); |
189 |
|
} |
185 |
– |
s = 1.0; |
190 |
|
/* compute fractal */ |
191 |
|
for ( ; ; ) { |
192 |
< |
s *= 0.5; |
192 |
> |
fc = 0.0; |
193 |
> |
for (j = 0; j < 8; j++) |
194 |
> |
fc += fval[j]; |
195 |
> |
fc *= 0.125; |
196 |
> |
if ((s >>= 1) == 0) |
197 |
> |
return(fc); /* close enough */ |
198 |
|
branch = 0; |
190 |
– |
closing = 0; |
199 |
|
for (i = 0; i < 3; i++) { /* do center */ |
200 |
|
v[i] = beg[i] + s; |
201 |
< |
if (p[i] > v[i]) { |
201 |
> |
if (t[i] > v[i]) { |
202 |
|
branch |= 1<<i; |
203 |
< |
if (p[i] - v[i] > EPSILON) |
196 |
< |
closing++; |
197 |
< |
} else if (v[i] - p[i] > EPSILON) |
198 |
< |
closing++; |
203 |
> |
} |
204 |
|
} |
205 |
< |
fc = 0.0; |
201 |
< |
for (j = 0; j < 8; j++) |
202 |
< |
fc += fval[j]; |
203 |
< |
fc = 0.125*fc + s*frand3(v[0],v[1],v[2]); |
204 |
< |
if (closing == 0) |
205 |
< |
return(fc); /* close enough */ |
205 |
> |
fc += s*EPSILON*frand3(v[0],v[1],v[2]); |
206 |
|
fval[~branch & 7] = fc; |
207 |
|
for (i = 0; i < 3; i++) { /* do faces */ |
208 |
|
if (branch & 1<<i) |
213 |
|
for (j = 0; j < 8; j++) |
214 |
|
if (~(j^branch) & 1<<i) |
215 |
|
fc += fval[j]; |
216 |
< |
fc = 0.25*fc + s*frand3(v[0],v[1],v[2]); |
216 |
> |
fc = 0.25*fc + s*EPSILON*frand3(v[0],v[1],v[2]); |
217 |
|
fval[~(branch^1<<i) & 7] = fc; |
218 |
|
v[i] = beg[i] + s; |
219 |
|
} |
220 |
|
for (i = 0; i < 3; i++) { /* do edges */ |
221 |
< |
j = (i+1)%3; |
221 |
> |
if ((j = i+1) == 3) j = 0; |
222 |
|
if (branch & 1<<j) |
223 |
|
v[j] += s; |
224 |
|
else |
225 |
|
v[j] -= s; |
226 |
< |
j = (i+2)%3; |
226 |
> |
if (++j == 3) j = 0; |
227 |
|
if (branch & 1<<j) |
228 |
|
v[j] += s; |
229 |
|
else |
230 |
|
v[j] -= s; |
231 |
|
fc = fval[branch & ~(1<<i)]; |
232 |
|
fc += fval[branch | 1<<i]; |
233 |
< |
fc = 0.5*fc + s*frand3(v[0],v[1],v[2]); |
233 |
> |
fc = 0.5*fc + s*EPSILON*frand3(v[0],v[1],v[2]); |
234 |
|
fval[branch^1<<i] = fc; |
235 |
< |
j = (i+1)%3; |
235 |
> |
if ((j = i+1) == 3) j = 0; |
236 |
|
v[j] = beg[j] + s; |
237 |
< |
j = (i+2)%3; |
237 |
> |
if (++j == 3) j = 0; |
238 |
|
v[j] = beg[j] + s; |
239 |
|
} |
240 |
|
for (i = 0; i < 3; i++) /* new cube */ |