Hans Goudey
c9f8f7915f
Currently, the random attribute node doesn't work well for most workflows because for any change in the input data it outputs completely different results. This patch adds an implicit seed attribute input to the node, referred to by "id". The attribute is hashed for each element using the CPPType system's hash method, meaning the attribute can have any data type. Supporting any data type is also important so any attribute can be copied into the "id" attribute and used as a seed. The "id" attribute is an example of a "reserved name" attribute, meaning attributes with this name can be used implicitly by nodes like the random attribute node. Although it makes it a bit more difficult to dig deeper, using the name implicitly rather than exposing it as an input should make the system more accessible and predictable. Differential Revision: https://developer.blender.org/D9832
117 lines
2.5 KiB
C++
117 lines
2.5 KiB
C++
/*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version 2
|
|
* of the License, or (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software Foundation,
|
|
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
/** \file
|
|
* \ingroup bli
|
|
*/
|
|
|
|
#include "BLI_utildefines.h"
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
/**
|
|
* Jenkins Lookup3 Hash Functions.
|
|
* Source: http://burtleburtle.net/bob/c/lookup3.c
|
|
*/
|
|
|
|
#define rot(x, k) (((x) << (k)) | ((x) >> (32 - (k))))
|
|
#define final(a, b, c) \
|
|
{ \
|
|
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); \
|
|
} \
|
|
((void)0)
|
|
|
|
BLI_INLINE unsigned int BLI_hash_int_3d(unsigned int kx, unsigned int ky, unsigned int kz)
|
|
{
|
|
unsigned int a, b, c;
|
|
a = b = c = 0xdeadbeef + (3 << 2) + 13;
|
|
|
|
c += kz;
|
|
b += ky;
|
|
a += kx;
|
|
final(a, b, c);
|
|
|
|
return c;
|
|
}
|
|
|
|
BLI_INLINE unsigned int BLI_hash_int_2d(unsigned int kx, unsigned int ky)
|
|
{
|
|
unsigned int a, b, c;
|
|
|
|
a = b = c = 0xdeadbeef + (2 << 2) + 13;
|
|
a += kx;
|
|
b += ky;
|
|
|
|
final(a, b, c);
|
|
|
|
return c;
|
|
}
|
|
|
|
#undef final
|
|
#undef rot
|
|
|
|
BLI_INLINE unsigned int BLI_hash_string(const char *str)
|
|
{
|
|
unsigned int i = 0, c;
|
|
|
|
while ((c = *str++)) {
|
|
i = i * 37 + c;
|
|
}
|
|
return i;
|
|
}
|
|
|
|
BLI_INLINE unsigned int BLI_hash_int(unsigned int k)
|
|
{
|
|
return BLI_hash_int_2d(k, 0);
|
|
}
|
|
|
|
BLI_INLINE float BLI_hash_int_01(unsigned int k)
|
|
{
|
|
return (float)BLI_hash_int(k) * (1.0f / (float)0xFFFFFFFF);
|
|
}
|
|
|
|
BLI_INLINE void BLI_hash_pointer_to_color(const void *ptr, int *r, int *g, int *b)
|
|
{
|
|
size_t val = (size_t)ptr;
|
|
const size_t hash_a = BLI_hash_int(val & 0x0000ffff);
|
|
const size_t hash_b = BLI_hash_int((uint)((val & 0xffff0000) >> 16));
|
|
const size_t hash = hash_a ^ (hash_b + 0x9e3779b9 + (hash_a << 6) + (hash_a >> 2));
|
|
*r = (hash & 0xff0000) >> 16;
|
|
*g = (hash & 0x00ff00) >> 8;
|
|
*b = hash & 0x0000ff;
|
|
}
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|