2 * LIBOIL - Library of Optimized Inner Loops
3 * Copyright (c) 2005 David A. Schleef <ds@schleef.org>
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
19 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
20 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
23 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
24 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25 * POSSIBILITY OF SUCH DAMAGE.
32 #include <liboil/liboilrandom.h>
33 #include <liboil/liboilcolorspace.h>
37 * SECTION:liboilrandom
38 * @title: Random Number Generation
39 * @short_description: Random number generation
43 _oil_random_bits (void *dest, int n)
57 * Writes random values in the range [-(1<<31), (1<<31)-1] to the
61 oil_random_s32(oil_type_s32 *dest, int n)
63 _oil_random_bits (dest, n*4);
69 * Writes random values in the range [-(1<<63), (1<<63)-1] to the
73 oil_random_s64 (oil_type_s64 *dest, int n)
75 _oil_random_bits (dest, n*8);
81 * Writes random values in the range [-(1<<15), (1<<15)-1] to the
85 oil_random_s16 (oil_type_s16 *dest, int n)
87 _oil_random_bits (dest, n*2);
93 * Writes random values in the range [-(1<<7), (1<<7)-1] to the
97 oil_random_s8 (oil_type_s8 *dest, int n)
99 _oil_random_bits (dest, n);
105 * Writes random values in the range [0, (1<<32)-1] to the
109 oil_random_u32 (oil_type_u32 *dest, int n)
111 _oil_random_bits (dest, n*4);
117 * Writes random values in the range [0, (1<<64)-1] to the
121 oil_random_u64 (oil_type_u64 *dest, int n)
123 _oil_random_bits (dest, n*8);
129 * Writes random values in the range [0, (1<<16)-1] to the
133 oil_random_u16 (oil_type_u16 *dest, int n)
135 _oil_random_bits (dest, n*2);
141 * Writes random values in the range [0, (1<<8)-1] to the
145 oil_random_u8 (oil_type_u8 *dest, int n)
147 _oil_random_bits (dest, n);
153 * Writes random double-precision floating point values in the
154 * range [0, 1.0) to the destination array.
157 oil_random_f64 (oil_type_f64 *dest, int n)
161 dest[i] = (((rand()/(RAND_MAX+1.0))+rand())/(RAND_MAX+1.0));
168 * Writes random single-precision floating point values in the
169 * range [0, 1.0) to the destination array.
172 oil_random_f32 (oil_type_f32 *dest, int n)
176 dest[i] = (rand()/(RAND_MAX+1.0));
183 * Writes random values in the range [0, 255] to the destination
184 * array suitable for alpha values. This is similar to oil_random_u8(),
185 * except the values 0 and 255 are strongly favored.
188 oil_random_alpha(uint8_t *dest, int n)
193 x = ((rand()>>8) & 0x1ff) - 0x80;
202 * @dest: destination array.
203 * @n: number of values to write.
205 * Creates valid random RGBA values and places them in the destination
209 oil_random_argb(uint32_t *dest, int n)
214 x = ((rand()>>8) & 0x1ff) - 0x80;
217 dest[i] = oil_argb_noclamp(x,
218 oil_muldiv_255(x,oil_rand_u8()),
219 oil_muldiv_255(x,oil_rand_u8()),
220 oil_muldiv_255(x,oil_rand_u8()));