Brecht Van Lommel
f6107af4cf
These are used for randomization, so it's convenient if the index is already hashed and consistent with the Object Info node.
73 lines
1.4 KiB
C
73 lines
1.4 KiB
C
/*
|
|
* 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.
|
|
*/
|
|
|
|
#ifndef __UTIL_HASH_H__
|
|
#define __UTIL_HASH_H__
|
|
|
|
#include "util/util_types.h"
|
|
|
|
CCL_NAMESPACE_BEGIN
|
|
|
|
ccl_device_inline uint hash_int_2d(uint kx, uint ky)
|
|
{
|
|
#define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k))))
|
|
|
|
uint a, b, c;
|
|
|
|
a = b = c = 0xdeadbeef + (2 << 2) + 13;
|
|
a += kx;
|
|
b += ky;
|
|
|
|
c ^= b; c -= rot(b,14);
|
|
a ^= c; a -= rot(c,11);
|
|
b ^= a; b -= rot(a,25);
|
|
c ^= b; c -= rot(b,16);
|
|
a ^= c; a -= rot(c,4);
|
|
b ^= a; b -= rot(a,14);
|
|
c ^= b; c -= rot(b,24);
|
|
|
|
return c;
|
|
|
|
#undef rot
|
|
}
|
|
|
|
ccl_device_inline uint hash_int(uint k)
|
|
{
|
|
return hash_int_2d(k, 0);
|
|
}
|
|
|
|
#ifndef __KERNEL_GPU__
|
|
static inline uint hash_string(const char *str)
|
|
{
|
|
uint i = 0, c;
|
|
|
|
while((c = *str++))
|
|
i = i * 37 + c;
|
|
|
|
return i;
|
|
}
|
|
#endif
|
|
|
|
ccl_device_inline float hash_int_01(uint k)
|
|
{
|
|
return (float)hash_int(k) * (1.0f/(float)0xFFFFFFFF);
|
|
}
|
|
|
|
CCL_NAMESPACE_END
|
|
|
|
#endif /* __UTIL_HASH_H__ */
|
|
|