mirror of
https://github.com/NVIDIA/cuda-samples.git
synced 2024-11-24 19:09:14 +08:00
281 lines
7.1 KiB
C++
281 lines
7.1 KiB
C++
/* Copyright (c) 2021, NVIDIA CORPORATION. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* * Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* * Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* * Neither the name of NVIDIA CORPORATION nor the names of its
|
|
* contributors may be used to endorse or promote products derived
|
|
* from this software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
|
|
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
|
|
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
|
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
|
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
|
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
|
|
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#include "bodysystemcpu.h"
|
|
|
|
#include <assert.h>
|
|
#include <memory.h>
|
|
#include <math.h>
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <helper_cuda.h>
|
|
#include <algorithm>
|
|
#include "tipsy.h"
|
|
|
|
#ifdef OPENMP
|
|
#include <omp.h>
|
|
#endif
|
|
|
|
template <typename T>
|
|
BodySystemCPU<T>::BodySystemCPU(int numBodies)
|
|
: m_numBodies(numBodies),
|
|
m_bInitialized(false),
|
|
m_force(0),
|
|
m_softeningSquared(.00125f),
|
|
m_damping(0.995f) {
|
|
m_pos = 0;
|
|
m_vel = 0;
|
|
|
|
_initialize(numBodies);
|
|
}
|
|
|
|
template <typename T>
|
|
BodySystemCPU<T>::~BodySystemCPU() {
|
|
_finalize();
|
|
m_numBodies = 0;
|
|
}
|
|
|
|
template <typename T>
|
|
void BodySystemCPU<T>::_initialize(int numBodies) {
|
|
assert(!m_bInitialized);
|
|
|
|
m_numBodies = numBodies;
|
|
|
|
m_pos = new T[m_numBodies * 4];
|
|
m_vel = new T[m_numBodies * 4];
|
|
m_force = new T[m_numBodies * 3];
|
|
|
|
memset(m_pos, 0, m_numBodies * 4 * sizeof(T));
|
|
memset(m_vel, 0, m_numBodies * 4 * sizeof(T));
|
|
memset(m_force, 0, m_numBodies * 3 * sizeof(T));
|
|
|
|
m_bInitialized = true;
|
|
}
|
|
|
|
template <typename T>
|
|
void BodySystemCPU<T>::_finalize() {
|
|
assert(m_bInitialized);
|
|
|
|
delete[] m_pos;
|
|
delete[] m_vel;
|
|
delete[] m_force;
|
|
|
|
m_bInitialized = false;
|
|
}
|
|
|
|
template <typename T>
|
|
void BodySystemCPU<T>::loadTipsyFile(const std::string &filename) {
|
|
if (m_bInitialized) _finalize();
|
|
|
|
vector<typename vec4<T>::Type> positions;
|
|
vector<typename vec4<T>::Type> velocities;
|
|
vector<int> ids;
|
|
|
|
int nBodies = 0;
|
|
int nFirst = 0, nSecond = 0, nThird = 0;
|
|
|
|
read_tipsy_file(positions, velocities, ids, filename, nBodies, nFirst,
|
|
nSecond, nThird);
|
|
|
|
_initialize(nBodies);
|
|
|
|
memcpy(m_pos, &positions[0], sizeof(vec4<T>) * nBodies);
|
|
memcpy(m_vel, &velocities[0], sizeof(vec4<T>) * nBodies);
|
|
}
|
|
|
|
template <typename T>
|
|
void BodySystemCPU<T>::update(T deltaTime) {
|
|
assert(m_bInitialized);
|
|
|
|
_integrateNBodySystem(deltaTime);
|
|
|
|
// std::swap(m_currentRead, m_currentWrite);
|
|
}
|
|
|
|
template <typename T>
|
|
T *BodySystemCPU<T>::getArray(BodyArray array) {
|
|
assert(m_bInitialized);
|
|
|
|
T *data = 0;
|
|
|
|
switch (array) {
|
|
default:
|
|
case BODYSYSTEM_POSITION:
|
|
data = m_pos;
|
|
break;
|
|
|
|
case BODYSYSTEM_VELOCITY:
|
|
data = m_vel;
|
|
break;
|
|
}
|
|
|
|
return data;
|
|
}
|
|
|
|
template <typename T>
|
|
void BodySystemCPU<T>::setArray(BodyArray array, const T *data) {
|
|
assert(m_bInitialized);
|
|
|
|
T *target = 0;
|
|
|
|
switch (array) {
|
|
default:
|
|
case BODYSYSTEM_POSITION:
|
|
target = m_pos;
|
|
break;
|
|
|
|
case BODYSYSTEM_VELOCITY:
|
|
target = m_vel;
|
|
break;
|
|
}
|
|
|
|
memcpy(target, data, m_numBodies * 4 * sizeof(T));
|
|
}
|
|
|
|
template <typename T>
|
|
T sqrt_T(T x) {
|
|
return sqrt(x);
|
|
}
|
|
|
|
template <>
|
|
float sqrt_T<float>(float x) {
|
|
return sqrtf(x);
|
|
}
|
|
|
|
template <typename T>
|
|
void bodyBodyInteraction(T accel[3], T posMass0[4], T posMass1[4],
|
|
T softeningSquared) {
|
|
T r[3];
|
|
|
|
// r_01 [3 FLOPS]
|
|
r[0] = posMass1[0] - posMass0[0];
|
|
r[1] = posMass1[1] - posMass0[1];
|
|
r[2] = posMass1[2] - posMass0[2];
|
|
|
|
// d^2 + e^2 [6 FLOPS]
|
|
T distSqr = r[0] * r[0] + r[1] * r[1] + r[2] * r[2];
|
|
distSqr += softeningSquared;
|
|
|
|
// invDistCube =1/distSqr^(3/2) [4 FLOPS (2 mul, 1 sqrt, 1 inv)]
|
|
T invDist = (T)1.0 / (T)sqrt((double)distSqr);
|
|
T invDistCube = invDist * invDist * invDist;
|
|
|
|
// s = m_j * invDistCube [1 FLOP]
|
|
T s = posMass1[3] * invDistCube;
|
|
|
|
// (m_1 * r_01) / (d^2 + e^2)^(3/2) [6 FLOPS]
|
|
accel[0] += r[0] * s;
|
|
accel[1] += r[1] * s;
|
|
accel[2] += r[2] * s;
|
|
}
|
|
|
|
template <typename T>
|
|
void BodySystemCPU<T>::_computeNBodyGravitation() {
|
|
#ifdef OPENMP
|
|
#pragma omp parallel for
|
|
#endif
|
|
|
|
for (int i = 0; i < m_numBodies; i++) {
|
|
int indexForce = 3 * i;
|
|
|
|
T acc[3] = {0, 0, 0};
|
|
|
|
// We unroll this loop 4X for a small performance boost.
|
|
int j = 0;
|
|
|
|
while (j < m_numBodies) {
|
|
bodyBodyInteraction<T>(acc, &m_pos[4 * i], &m_pos[4 * j],
|
|
m_softeningSquared);
|
|
j++;
|
|
bodyBodyInteraction<T>(acc, &m_pos[4 * i], &m_pos[4 * j],
|
|
m_softeningSquared);
|
|
j++;
|
|
bodyBodyInteraction<T>(acc, &m_pos[4 * i], &m_pos[4 * j],
|
|
m_softeningSquared);
|
|
j++;
|
|
bodyBodyInteraction<T>(acc, &m_pos[4 * i], &m_pos[4 * j],
|
|
m_softeningSquared);
|
|
j++;
|
|
}
|
|
|
|
m_force[indexForce] = acc[0];
|
|
m_force[indexForce + 1] = acc[1];
|
|
m_force[indexForce + 2] = acc[2];
|
|
}
|
|
}
|
|
|
|
template <typename T>
|
|
void BodySystemCPU<T>::_integrateNBodySystem(T deltaTime) {
|
|
_computeNBodyGravitation();
|
|
|
|
#ifdef OPENMP
|
|
#pragma omp parallel for
|
|
#endif
|
|
|
|
for (int i = 0; i < m_numBodies; ++i) {
|
|
int index = 4 * i;
|
|
int indexForce = 3 * i;
|
|
|
|
T pos[3], vel[3], force[3];
|
|
pos[0] = m_pos[index + 0];
|
|
pos[1] = m_pos[index + 1];
|
|
pos[2] = m_pos[index + 2];
|
|
T invMass = m_pos[index + 3];
|
|
|
|
vel[0] = m_vel[index + 0];
|
|
vel[1] = m_vel[index + 1];
|
|
vel[2] = m_vel[index + 2];
|
|
|
|
force[0] = m_force[indexForce + 0];
|
|
force[1] = m_force[indexForce + 1];
|
|
force[2] = m_force[indexForce + 2];
|
|
|
|
// acceleration = force / mass;
|
|
// new velocity = old velocity + acceleration * deltaTime
|
|
vel[0] += (force[0] * invMass) * deltaTime;
|
|
vel[1] += (force[1] * invMass) * deltaTime;
|
|
vel[2] += (force[2] * invMass) * deltaTime;
|
|
|
|
vel[0] *= m_damping;
|
|
vel[1] *= m_damping;
|
|
vel[2] *= m_damping;
|
|
|
|
// new position = old position + velocity * deltaTime
|
|
pos[0] += vel[0] * deltaTime;
|
|
pos[1] += vel[1] * deltaTime;
|
|
pos[2] += vel[2] * deltaTime;
|
|
|
|
m_pos[index + 0] = pos[0];
|
|
m_pos[index + 1] = pos[1];
|
|
m_pos[index + 2] = pos[2];
|
|
|
|
m_vel[index + 0] = vel[0];
|
|
m_vel[index + 1] = vel[1];
|
|
m_vel[index + 2] = vel[2];
|
|
}
|
|
}
|