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Diffstat (limited to 'source/blender/freestyle/intern/system/RandGen.cpp')
-rwxr-xr-x | source/blender/freestyle/intern/system/RandGen.cpp | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/source/blender/freestyle/intern/system/RandGen.cpp b/source/blender/freestyle/intern/system/RandGen.cpp new file mode 100755 index 00000000000..a328cb7f583 --- /dev/null +++ b/source/blender/freestyle/intern/system/RandGen.cpp @@ -0,0 +1,86 @@ + +// +// Copyright (C) : Please refer to the COPYRIGHT file distributed +// with this source distribution. +// +// 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. +// +/////////////////////////////////////////////////////////////////////////////// + +#include "RandGen.h" + +// +// Macro definitions +// +/////////////////////////////////////////////////////////////////////////////// + +#define N 16 +#define MASK ((unsigned)(1 << (N - 1)) + (1 << (N - 1)) - 1) +#define X0 0x330E +#define X1 0xABCD +#define X2 0x1234 +#define A0 0xE66D +#define A1 0xDEEC +#define A2 0x5 +#define C 0xB +#define HI_BIT (1L << (2 * N - 1)) + +#define LOW(x) ((unsigned)(x) & MASK) +#define HIGH(x) LOW((x) >> N) +#define MUL(x, y, z) { long l = (long)(x) * (long)(y); \ + (z)[0] = LOW(l); (z)[1] = HIGH(l); } +#define CARRY(x, y) ((unsigned long)((long)(x) + (long)(y)) > MASK) +#define ADDEQU(x, y, z) (z = CARRY(x, (y)), x = LOW(x + (y))) +#define SET3(x, x0, x1, x2) ((x)[0] = (x0), (x)[1] = (x1), (x)[2] = (x2)) +#define SETLOW(x, y, n) SET3(x, LOW((y)[n]), LOW((y)[(n)+1]), LOW((y)[(n)+2])) +#define SEED(x0, x1, x2) (SET3(x, x0, x1, x2), SET3(a, A0, A1, A2), c = C) +#define REST(v) for (i = 0; i < 3; i++) { xsubi[i] = x[i]; x[i] = temp[i]; } \ + return (v); +#define NEST(TYPE, f, F) TYPE f(register unsigned short *xsubi) { \ + register int i; register TYPE v; unsigned temp[3]; \ + for (i = 0; i < 3; i++) { temp[i] = x[i]; x[i] = LOW(xsubi[i]); } \ + v = F(); REST(v); } + +static unsigned x[3] = { X0, X1, X2 }, a[3] = { A0, A1, A2 }, c = C; + +// +// Methods implementation +// +/////////////////////////////////////////////////////////////////////////////// + +real RandGen::drand48() { + static real two16m = 1.0 / (1L << N); + next(); + return (two16m * (two16m * (two16m * x[0] + x[1]) + x[2])); +} + +void RandGen::srand48(long seedval) { + SEED(X0, LOW(seedval), HIGH(seedval)); +} + +void RandGen::next() { + unsigned p[2], q[2], r[2], carry0, carry1; + + MUL(a[0], x[0], p); + ADDEQU(p[0], c, carry0); + ADDEQU(p[1], carry0, carry1); + MUL(a[0], x[1], q); + ADDEQU(p[1], q[0], carry0); + MUL(a[1], x[0], r); + x[2] = LOW(carry0 + carry1 + CARRY(p[1], r[0]) + q[1] + r[1] + + a[0] * x[2] + a[1] * x[1] + a[2] * x[0]); + x[1] = LOW(p[1] + r[0]); + x[0] = LOW(p[0]); +} |