1 /*
2 * GStreamer
3 * Copyright (C) 2010 Thiago Santos <thiago.sousa.santos@collabora.co.uk>
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be included in
13 * all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 *
23 * Alternatively, the contents of this file may be used under the
24 * GNU Lesser General Public License Version 2.1 (the "LGPL"), in
25 * which case the following provisions apply instead of the ones
26 * mentioned above:
27 *
28 * This library is free software; you can redistribute it and/or
29 * modify it under the terms of the GNU Library General Public
30 * License as published by the Free Software Foundation; either
31 * version 2 of the License, or (at your option) any later version.
32 *
33 * This library is distributed in the hope that it will be useful,
34 * but WITHOUT ANY WARRANTY; without even the implied warranty of
35 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
36 * Library General Public License for more details.
37 *
38 * You should have received a copy of the GNU Library General Public
39 * License along with this library; if not, write to the
40 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
41 * Boston, MA 02110-1301, USA.
42 */
43
44 /*
45 * Thanks to Jerry Huxtable <http://www.jhlabs.com> work on its java
46 * image editor and filters. The algorithms here were extracted from
47 * his code.
48 */
49
50 #include "geometricmath.h"
51 #include <math.h>
52
53 #define N 0x1000
54 #define B 0x100
55 #define BM 0xff
56
57 struct _GstGMNoise
58 {
59 gdouble p[2 * B + 2];
60 gdouble g2[2 * B + 2][2];
61 };
62
63 static void
normalize_2(gdouble * v)64 normalize_2 (gdouble * v)
65 {
66 gdouble s = sqrt (v[0] * v[0] + v[1] * v[1]);
67
68 v[0] = v[0] / s;
69 v[1] = v[1] / s;
70 }
71
72 GstGMNoise *
gst_gm_noise_new(void)73 gst_gm_noise_new (void)
74 {
75 GstGMNoise *noise = g_new0 (GstGMNoise, 1);
76 gint i, j, k;
77
78 for (i = 0; i < B; i++) {
79 noise->p[i] = i;
80 for (j = 0; j < 2; j++) {
81 noise->g2[i][j] = ((g_random_int () % (2 * B))
82 - B) / (gdouble) B;
83 }
84 normalize_2 (noise->g2[i]);
85 }
86
87 for (i = B - 1; i >= 0; i--) {
88 k = noise->p[i];
89 j = g_random_int () % B;
90 noise->p[i] = noise->p[j];
91 noise->p[j] = k;
92 }
93
94 for (i = 0; i < B + 2; i++) {
95 noise->p[B + i] = noise->p[i];
96 for (j = 0; j < 2; j++) {
97 noise->g2[B + i][j] = noise->g2[i][j];
98 }
99 }
100
101 return noise;
102 }
103
104 void
gst_gm_noise_free(GstGMNoise * noise)105 gst_gm_noise_free (GstGMNoise * noise)
106 {
107 g_free (noise);
108 }
109
110 static gdouble
s_curve(gdouble x)111 s_curve (gdouble x)
112 {
113 return x * x * (3.0 - 2.0 * x);
114 }
115
116 static gdouble
lerp(gdouble t,gdouble a,gdouble b)117 lerp (gdouble t, gdouble a, gdouble b)
118 {
119 return a + t * (b - a);
120 }
121
122 gdouble
gst_gm_noise_2(GstGMNoise * noise,gdouble x,gdouble y)123 gst_gm_noise_2 (GstGMNoise * noise, gdouble x, gdouble y)
124 {
125 gint bx0, bx1, by0, by1, b00, b10, b01, b11;
126 gdouble rx0, rx1, ry0, ry1, sx, sy, a, b, t, u, v;
127 gdouble *q;
128 gint i, j;
129
130 t = x + N;
131 bx0 = ((gint) t) & BM;
132 bx1 = (bx0 + 1) & BM;
133 rx0 = t - (gint) t;
134 rx1 = rx0 - 1.0;
135
136 t = y + N;
137 by0 = ((gint) t) & BM;
138 by1 = (by0 + 1) & BM;
139 ry0 = t - (gint) t;
140 ry1 = ry0 - 1.0;
141
142 i = noise->p[bx0];
143 j = noise->p[bx1];
144
145 b00 = noise->p[i + by0];
146 b10 = noise->p[j + by0];
147 b01 = noise->p[i + by1];
148 b11 = noise->p[j + by1];
149
150 sx = s_curve (rx0);
151 sy = s_curve (ry0);
152
153 q = noise->g2[b00];
154 u = rx0 * q[0] + ry0 * q[1];
155 q = noise->g2[b10];
156 v = rx1 * q[0] + ry0 * q[1];
157 a = lerp (sx, u, v);
158
159 q = noise->g2[b01];
160 u = rx0 * q[0] + ry1 * q[1];
161 q = noise->g2[b11];
162 v = rx1 * q[0] + ry1 * q[1];
163 b = lerp (sx, u, v);
164
165 return 1.5 * lerp (sy, a, b);
166 }
167
168 /*
169 * This differs from the % operator with respect to negative numbers
170 */
171 gdouble
gst_gm_mod_float(gdouble a,gdouble b)172 gst_gm_mod_float (gdouble a, gdouble b)
173 {
174 gint n = (gint) (a / b);
175
176 a -= n * b;
177 if (a < 0)
178 return a + b;
179 return a;
180 }
181
182 /*
183 * Returns a repeating triangle shape in the range 0..1 with wavelength 1.0
184 */
185 gdouble
gst_gm_triangle(gdouble x)186 gst_gm_triangle (gdouble x)
187 {
188 gdouble r = gst_gm_mod_float (x, 1.0);
189
190 return 2.0 * (r < 0.5 ? r : 1 - r);
191 }
192
193 /*
194 * Hermite interpolation
195 */
196 gdouble
gst_gm_smoothstep(gdouble edge0,gdouble edge1,gdouble x)197 gst_gm_smoothstep (gdouble edge0, gdouble edge1, gdouble x)
198 {
199 gdouble t = CLAMP ((x - edge0) / (edge1 - edge0), 0.0, 1.0);
200 return t * t * (3.0 - 2.0 * t);
201 }
202