blob: 92cfff639b4b789cef5c926ca73ef6433d75b7e4 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
|
/*
* Copyright 2011-2013 Blender Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
CCL_NAMESPACE_BEGIN
/* Linear Congruential Generator */
ccl_device uint lcg_step_uint(uint *rng)
{
/* implicit mod 2^32 */
*rng = (1103515245 * (*rng) + 12345);
return *rng;
}
ccl_device float lcg_step_float(uint *rng)
{
/* implicit mod 2^32 */
*rng = (1103515245 * (*rng) + 12345);
return (float)*rng * (1.0f / (float)0xFFFFFFFF);
}
ccl_device uint lcg_init(uint seed)
{
uint rng = seed;
lcg_step_uint(&rng);
return rng;
}
ccl_device_inline uint lcg_state_init(const uint rng_hash,
const uint rng_offset,
const uint sample,
const uint scramble)
{
return lcg_init(rng_hash + rng_offset + sample * scramble);
}
CCL_NAMESPACE_END
|
