105 lines
3.5 KiB
Plaintext
105 lines
3.5 KiB
Plaintext
// Filename: randomizer.I
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// Created by: drose (18Jan07)
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//
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////////////////////////////////////////////////////////////////////
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//
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// PANDA 3D SOFTWARE
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// Copyright (c) Carnegie Mellon University. All rights reserved.
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//
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// All use of this software is subject to the terms of the revised BSD
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// license. You should have received a copy of this license along
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// with this source code in a file named "LICENSE."
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//
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////////////////////////////////////////////////////////////////////
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////////////////////////////////////////////////////////////////////
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// Function: Randomizer::Constructor
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// Access: Public
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// Description: If seed is nonzero, it is used to define the tables;
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// if it is zero a random seed is generated.
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////////////////////////////////////////////////////////////////////
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Randomizer::
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Randomizer(unsigned long seed) :
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_mersenne(seed != 0 ? seed : get_next_seed())
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{
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}
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////////////////////////////////////////////////////////////////////
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// Function: Randomizer::Copy Constructor
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// Access: Public
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// Description:
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////////////////////////////////////////////////////////////////////
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Randomizer::
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Randomizer(const Randomizer ©) :
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_mersenne(copy._mersenne)
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{
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}
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////////////////////////////////////////////////////////////////////
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// Function: Randomizer::Copy Assignment Operator
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// Access: Public
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// Description:
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////////////////////////////////////////////////////////////////////
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void Randomizer::
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operator = (const Randomizer ©) {
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_mersenne = copy._mersenne;
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}
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////////////////////////////////////////////////////////////////////
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// Function: Randomizer::random_int
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// Access: Public
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// Description: Returns a random integer in the range [0, range).
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////////////////////////////////////////////////////////////////////
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INLINE int Randomizer::
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random_int(int range) {
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return (int)floor(random_real((double)range));
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}
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////////////////////////////////////////////////////////////////////
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// Function: Randomizer::random_real
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// Access: Public
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// Description: Returns a random double in the range [0, range).
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////////////////////////////////////////////////////////////////////
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INLINE double Randomizer::
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random_real(double range) {
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return (range * _mersenne.get_uint31()) / ((double)0x80000000);
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}
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////////////////////////////////////////////////////////////////////
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// Function: Randomizer::random_real_unit
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// Access: Public
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// Description: Returns a random double in the range [-0.5, 0.5).
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////////////////////////////////////////////////////////////////////
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INLINE double Randomizer::
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random_real_unit() {
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return random_real(1.0f) - 0.5f;
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}
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////////////////////////////////////////////////////////////////////
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// Function: Randomizer::get_next_seed
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// Access: Public, Static
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// Description: Returns a random seed value for the next global
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// Randomizer object.
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////////////////////////////////////////////////////////////////////
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INLINE unsigned long Randomizer::
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get_next_seed() {
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if (!_got_first_seed) {
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_next_seed = Mersenne((unsigned long)time(NULL));
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_got_first_seed = true;
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}
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return _next_seed.get_uint31();
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}
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////////////////////////////////////////////////////////////////////
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// Function: Randomizer::get_seed
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// Access: Public
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// Description: Returns a unique seed value based on the seed value
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// passed to this Randomizer object (and on its current
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// state).
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////////////////////////////////////////////////////////////////////
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INLINE unsigned long Randomizer::
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get_seed() {
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return _mersenne.get_uint31();
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}
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