cuda-samples/Samples/2_Concepts_and_Techniques/particles/particles.cpp

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/*
    Particle system example with collisions using uniform grid

    CUDA 2.1 SDK release 12/2008
    - removed atomic grid method, some optimization, added demo mode.

    CUDA 2.2 release 3/2009
    - replaced sort function with latest radix sort, now disables v-sync.
    - added support for automated testing and comparison to a reference value.
*/

// OpenGL Graphics includes
#include <helper_gl.h>
#if defined(WIN32)
#include <GL/wglew.h>
#endif
#if defined(__APPLE__) || defined(__MACOSX)
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
#include <GLUT/glut.h>
#ifndef glutCloseFunc
#define glutCloseFunc glutWMCloseFunc
#endif
#else
#include <GL/freeglut.h>
#endif

// CUDA runtime
#include <cuda_runtime.h>

// CUDA utilities and system includes
#include <helper_functions.h>
#include <helper_cuda.h>  // includes cuda.h and cuda_runtime_api.h

// Includes
#include <stdlib.h>
#include <cstdlib>
#include <cstdio>
#include <algorithm>

#include "particleSystem.h"
#include "render_particles.h"
#include "paramgl.h"

#define MAX_EPSILON_ERROR 5.00f
#define THRESHOLD 0.30f

#define GRID_SIZE 64
#define NUM_PARTICLES 16384

const uint width = 640, height = 480;

// view params
int ox, oy;
int buttonState = 0;
float camera_trans[] = {0, 0, -3};
float camera_rot[] = {0, 0, 0};
float camera_trans_lag[] = {0, 0, -3};
float camera_rot_lag[] = {0, 0, 0};
const float inertia = 0.1f;
ParticleRenderer::DisplayMode displayMode = ParticleRenderer::PARTICLE_SPHERES;

int mode = 0;
bool displayEnabled = true;
bool bPause = false;
bool displaySliders = false;
bool wireframe = false;
bool demoMode = false;
int idleCounter = 0;
int demoCounter = 0;
const int idleDelay = 2000;

enum { M_VIEW = 0, M_MOVE };

uint numParticles = 0;
uint3 gridSize;
int numIterations = 0;  // run until exit

// simulation parameters
float timestep = 0.5f;
float damping = 1.0f;
float gravity = 0.0003f;
int iterations = 1;
int ballr = 10;

float collideSpring = 0.5f;
;
float collideDamping = 0.02f;
;
float collideShear = 0.1f;
float collideAttraction = 0.0f;

ParticleSystem *psystem = 0;

// fps
static int fpsCount = 0;
static int fpsLimit = 1;
StopWatchInterface *timer = NULL;

ParticleRenderer *renderer = 0;

float modelView[16];

ParamListGL *params;

// Auto-Verification Code
const int frameCheckNumber = 4;
unsigned int frameCount = 0;
unsigned int g_TotalErrors = 0;
char *g_refFile = NULL;

const char *sSDKsample = "CUDA Particles Simulation";

extern "C" void cudaInit(int argc, char **argv);
extern "C" void cudaGLInit(int argc, char **argv);
extern "C" void copyArrayFromDevice(void *host, const void *device,
                                    unsigned int vbo, int size);

// initialize particle system
void initParticleSystem(int numParticles, uint3 gridSize, bool bUseOpenGL) {
  psystem = new ParticleSystem(numParticles, gridSize, bUseOpenGL);
  psystem->reset(ParticleSystem::CONFIG_GRID);

  if (bUseOpenGL) {
    renderer = new ParticleRenderer;
    renderer->setParticleRadius(psystem->getParticleRadius());
    renderer->setColorBuffer(psystem->getColorBuffer());
  }

  sdkCreateTimer(&timer);
}

void cleanup() {
  sdkDeleteTimer(&timer);

  if (psystem) {
    delete psystem;
  }
  return;
}

// initialize OpenGL
void initGL(int *argc, char **argv) {
  glutInit(argc, argv);
  glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
  glutInitWindowSize(width, height);
  glutCreateWindow("CUDA Particles");

  if (!isGLVersionSupported(2, 0) ||
      !areGLExtensionsSupported(
          "GL_ARB_multitexture GL_ARB_vertex_buffer_object")) {
    fprintf(stderr, "Required OpenGL extensions missing.");
    exit(EXIT_FAILURE);
  }

#if defined(WIN32)

  if (wglewIsSupported("WGL_EXT_swap_control")) {
    // disable vertical sync
    wglSwapIntervalEXT(0);
  }

#endif

  glEnable(GL_DEPTH_TEST);
  glClearColor(0.25, 0.25, 0.25, 1.0);

  glutReportErrors();
}

void runBenchmark(int iterations, char *exec_path) {
  printf("Run %u particles simulation for %d iterations...\n\n", numParticles,
         iterations);
  cudaDeviceSynchronize();
  sdkStartTimer(&timer);

  for (int i = 0; i < iterations; ++i) {
    psystem->update(timestep);
  }

  cudaDeviceSynchronize();
  sdkStopTimer(&timer);
  float fAvgSeconds =
      ((float)1.0e-3 * (float)sdkGetTimerValue(&timer) / (float)iterations);

  printf(
      "particles, Throughput = %.4f KParticles/s, Time = %.5f s, Size = %u "
      "particles, NumDevsUsed = %u, Workgroup = %u\n",
      (1.0e-3 * numParticles) / fAvgSeconds, fAvgSeconds, numParticles, 1, 0);

  if (g_refFile) {
    printf("\nChecking result...\n\n");
    float *hPos =
        (float *)malloc(sizeof(float) * 4 * psystem->getNumParticles());
    copyArrayFromDevice(hPos, psystem->getCudaPosVBO(), 0,
                        sizeof(float) * 4 * psystem->getNumParticles());

    sdkDumpBin((void *)hPos, sizeof(float) * 4 * psystem->getNumParticles(),
               "particles.bin");

    if (!sdkCompareBin2BinFloat("particles.bin", g_refFile,
                                4 * psystem->getNumParticles(),
                                MAX_EPSILON_ERROR, THRESHOLD, exec_path)) {
      g_TotalErrors++;
    }
  }
}

void computeFPS() {
  frameCount++;
  fpsCount++;

  if (fpsCount == fpsLimit) {
    char fps[256];
    float ifps = 1.f / (sdkGetAverageTimerValue(&timer) / 1000.f);
    sprintf(fps, "CUDA Particles (%d particles): %3.1f fps", numParticles,
            ifps);

    glutSetWindowTitle(fps);
    fpsCount = 0;

    fpsLimit = (int)MAX(ifps, 1.f);
    sdkResetTimer(&timer);
  }
}

void display() {
  sdkStartTimer(&timer);

  // update the simulation
  if (!bPause) {
    psystem->setIterations(iterations);
    psystem->setDamping(damping);
    psystem->setGravity(-gravity);
    psystem->setCollideSpring(collideSpring);
    psystem->setCollideDamping(collideDamping);
    psystem->setCollideShear(collideShear);
    psystem->setCollideAttraction(collideAttraction);

    psystem->update(timestep);

    if (renderer) {
      renderer->setVertexBuffer(psystem->getCurrentReadBuffer(),
                                psystem->getNumParticles());
    }
  }

  // render
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  // view transform
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();

  for (int c = 0; c < 3; ++c) {
    camera_trans_lag[c] += (camera_trans[c] - camera_trans_lag[c]) * inertia;
    camera_rot_lag[c] += (camera_rot[c] - camera_rot_lag[c]) * inertia;
  }

  glTranslatef(camera_trans_lag[0], camera_trans_lag[1], camera_trans_lag[2]);
  glRotatef(camera_rot_lag[0], 1.0, 0.0, 0.0);
  glRotatef(camera_rot_lag[1], 0.0, 1.0, 0.0);

  glGetFloatv(GL_MODELVIEW_MATRIX, modelView);

  // cube
  glColor3f(1.0, 1.0, 1.0);
  glutWireCube(2.0);

  // collider
  glPushMatrix();
  float3 p = psystem->getColliderPos();
  glTranslatef(p.x, p.y, p.z);
  glColor3f(1.0, 0.0, 0.0);
  glutSolidSphere(psystem->getColliderRadius(), 20, 10);
  glPopMatrix();

  if (renderer && displayEnabled) {
    renderer->display(displayMode);
  }

  if (displaySliders) {
    glDisable(GL_DEPTH_TEST);
    glBlendFunc(GL_ONE_MINUS_DST_COLOR, GL_ZERO);  // invert color
    glEnable(GL_BLEND);
    params->Render(0, 0);
    glDisable(GL_BLEND);
    glEnable(GL_DEPTH_TEST);
  }

  sdkStopTimer(&timer);

  glutSwapBuffers();
  glutReportErrors();

  computeFPS();
}

inline float frand() { return rand() / (float)RAND_MAX; }

void addSphere() {
  // inject a sphere of particles
  float pr = psystem->getParticleRadius();
  float tr = pr + (pr * 2.0f) * ballr;
  float pos[4], vel[4];
  pos[0] = -1.0f + tr + frand() * (2.0f - tr * 2.0f);
  pos[1] = 1.0f - tr;
  pos[2] = -1.0f + tr + frand() * (2.0f - tr * 2.0f);
  pos[3] = 0.0f;
  vel[0] = vel[1] = vel[2] = vel[3] = 0.0f;
  psystem->addSphere(0, pos, vel, ballr, pr * 2.0f);
}

void reshape(int w, int h) {
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluPerspective(60.0, (float)w / (float)h, 0.1, 100.0);

  glMatrixMode(GL_MODELVIEW);
  glViewport(0, 0, w, h);

  if (renderer) {
    renderer->setWindowSize(w, h);
    renderer->setFOV(60.0);
  }
}

void mouse(int button, int state, int x, int y) {
  int mods;

  if (state == GLUT_DOWN) {
    buttonState |= 1 << button;
  } else if (state == GLUT_UP) {
    buttonState = 0;
  }

  mods = glutGetModifiers();

  if (mods & GLUT_ACTIVE_SHIFT) {
    buttonState = 2;
  } else if (mods & GLUT_ACTIVE_CTRL) {
    buttonState = 3;
  }

  ox = x;
  oy = y;

  demoMode = false;
  idleCounter = 0;

  if (displaySliders) {
    if (params->Mouse(x, y, button, state)) {
      glutPostRedisplay();
      return;
    }
  }

  glutPostRedisplay();
}

// transform vector by matrix
void xform(float *v, float *r, GLfloat *m) {
  r[0] = v[0] * m[0] + v[1] * m[4] + v[2] * m[8] + m[12];
  r[1] = v[0] * m[1] + v[1] * m[5] + v[2] * m[9] + m[13];
  r[2] = v[0] * m[2] + v[1] * m[6] + v[2] * m[10] + m[14];
}

// transform vector by transpose of matrix
void ixform(float *v, float *r, GLfloat *m) {
  r[0] = v[0] * m[0] + v[1] * m[1] + v[2] * m[2];
  r[1] = v[0] * m[4] + v[1] * m[5] + v[2] * m[6];
  r[2] = v[0] * m[8] + v[1] * m[9] + v[2] * m[10];
}

void ixformPoint(float *v, float *r, GLfloat *m) {
  float x[4];
  x[0] = v[0] - m[12];
  x[1] = v[1] - m[13];
  x[2] = v[2] - m[14];
  x[3] = 1.0f;
  ixform(x, r, m);
}

void motion(int x, int y) {
  float dx, dy;
  dx = (float)(x - ox);
  dy = (float)(y - oy);

  if (displaySliders) {
    if (params->Motion(x, y)) {
      ox = x;
      oy = y;
      glutPostRedisplay();
      return;
    }
  }

  switch (mode) {
    case M_VIEW:
      if (buttonState == 3) {
        // left+middle = zoom
        camera_trans[2] += (dy / 100.0f) * 0.5f * fabs(camera_trans[2]);
      } else if (buttonState & 2) {
        // middle = translate
        camera_trans[0] += dx / 100.0f;
        camera_trans[1] -= dy / 100.0f;
      } else if (buttonState & 1) {
        // left = rotate
        camera_rot[0] += dy / 5.0f;
        camera_rot[1] += dx / 5.0f;
      }

      break;

    case M_MOVE: {
      float translateSpeed = 0.003f;
      float3 p = psystem->getColliderPos();

      if (buttonState == 1) {
        float v[3], r[3];
        v[0] = dx * translateSpeed;
        v[1] = -dy * translateSpeed;
        v[2] = 0.0f;
        ixform(v, r, modelView);
        p.x += r[0];
        p.y += r[1];
        p.z += r[2];
      } else if (buttonState == 2) {
        float v[3], r[3];
        v[0] = 0.0f;
        v[1] = 0.0f;
        v[2] = dy * translateSpeed;
        ixform(v, r, modelView);
        p.x += r[0];
        p.y += r[1];
        p.z += r[2];
      }

      psystem->setColliderPos(p);
    } break;
  }

  ox = x;
  oy = y;

  demoMode = false;
  idleCounter = 0;

  glutPostRedisplay();
}

// commented out to remove unused parameter warnings in Linux
void key(unsigned char key, int /*x*/, int /*y*/) {
  switch (key) {
    case ' ':
      bPause = !bPause;
      break;

    case 13:
      psystem->update(timestep);

      if (renderer) {
        renderer->setVertexBuffer(psystem->getCurrentReadBuffer(),
                                  psystem->getNumParticles());
      }

      break;

    case '\033':
    case 'q':
#if defined(__APPLE__) || defined(MACOSX)
      exit(EXIT_SUCCESS);
#else
      glutDestroyWindow(glutGetWindow());
      return;
#endif
    case 'v':
      mode = M_VIEW;
      break;

    case 'm':
      mode = M_MOVE;
      break;

    case 'p':
      displayMode = (ParticleRenderer::DisplayMode)(
          (displayMode + 1) % ParticleRenderer::PARTICLE_NUM_MODES);
      break;

    case 'd':
      psystem->dumpGrid();
      break;

    case 'u':
      psystem->dumpParticles(0, numParticles - 1);
      break;

    case 'r':
      displayEnabled = !displayEnabled;
      break;

    case '1':
      psystem->reset(ParticleSystem::CONFIG_GRID);
      break;

    case '2':
      psystem->reset(ParticleSystem::CONFIG_RANDOM);
      break;

    case '3':
      addSphere();
      break;

    case '4': {
      // shoot ball from camera
      float pr = psystem->getParticleRadius();
      float vel[4], velw[4], pos[4], posw[4];
      vel[0] = 0.0f;
      vel[1] = 0.0f;
      vel[2] = -0.05f;
      vel[3] = 0.0f;
      ixform(vel, velw, modelView);

      pos[0] = 0.0f;
      pos[1] = 0.0f;
      pos[2] = -2.5f;
      pos[3] = 1.0;
      ixformPoint(pos, posw, modelView);
      posw[3] = 0.0f;

      psystem->addSphere(0, posw, velw, ballr, pr * 2.0f);
    } break;

    case 'w':
      wireframe = !wireframe;
      break;

    case 'h':
      displaySliders = !displaySliders;
      break;
  }

  demoMode = false;
  idleCounter = 0;
  glutPostRedisplay();
}

void special(int k, int x, int y) {
  if (displaySliders) {
    params->Special(k, x, y);
  }

  demoMode = false;
  idleCounter = 0;
}

void idle(void) {
  if ((idleCounter++ > idleDelay) && (demoMode == false)) {
    demoMode = true;
    printf("Entering demo mode\n");
  }

  if (demoMode) {
    camera_rot[1] += 0.1f;

    if (demoCounter++ > 1000) {
      ballr = 10 + (rand() % 10);
      addSphere();
      demoCounter = 0;
    }
  }

  glutPostRedisplay();
}

void initParams() {
  if (g_refFile) {
    timestep = 0.0f;
    damping = 0.0f;
    gravity = 0.0f;
    ballr = 1;
    collideSpring = 0.0f;
    collideDamping = 0.0f;
    collideShear = 0.0f;
    collideAttraction = 0.0f;
  } else {
    // create a new parameter list
    params = new ParamListGL("misc");
    params->AddParam(
        new Param<float>("time step", timestep, 0.0f, 1.0f, 0.01f, &timestep));
    params->AddParam(
        new Param<float>("damping", damping, 0.0f, 1.0f, 0.001f, &damping));
    params->AddParam(
        new Param<float>("gravity", gravity, 0.0f, 0.001f, 0.0001f, &gravity));
    params->AddParam(new Param<int>("ball radius", ballr, 1, 20, 1, &ballr));

    params->AddParam(new Param<float>("collide spring", collideSpring, 0.0f,
                                      1.0f, 0.001f, &collideSpring));
    params->AddParam(new Param<float>("collide damping", collideDamping, 0.0f,
                                      0.1f, 0.001f, &collideDamping));
    params->AddParam(new Param<float>("collide shear", collideShear, 0.0f, 0.1f,
                                      0.001f, &collideShear));
    params->AddParam(new Param<float>("collide attract", collideAttraction,
                                      0.0f, 0.1f, 0.001f, &collideAttraction));
  }
}

void mainMenu(int i) { key((unsigned char)i, 0, 0); }

void initMenus() {
  glutCreateMenu(mainMenu);
  glutAddMenuEntry("Reset block [1]", '1');
  glutAddMenuEntry("Reset random [2]", '2');
  glutAddMenuEntry("Add sphere [3]", '3');
  glutAddMenuEntry("View mode [v]", 'v');
  glutAddMenuEntry("Move cursor mode [m]", 'm');
  glutAddMenuEntry("Toggle point rendering [p]", 'p');
  glutAddMenuEntry("Toggle animation [ ]", ' ');
  glutAddMenuEntry("Step animation [ret]", 13);
  glutAddMenuEntry("Toggle sliders [h]", 'h');
  glutAddMenuEntry("Quit (esc)", '\033');
  glutAttachMenu(GLUT_RIGHT_BUTTON);
}

////////////////////////////////////////////////////////////////////////////////
// Program main
////////////////////////////////////////////////////////////////////////////////
int main(int argc, char **argv) {
#if defined(__linux__)
  setenv("DISPLAY", ":0", 0);
#endif

  printf("%s Starting...\n\n", sSDKsample);

  printf(
      "NOTE: The CUDA Samples are not meant for performance measurements. "
      "Results may vary when GPU Boost is enabled.\n\n");

  numParticles = NUM_PARTICLES;
  uint gridDim = GRID_SIZE;
  numIterations = 0;

  if (argc > 1) {
    if (checkCmdLineFlag(argc, (const char **)argv, "n")) {
      numParticles = getCmdLineArgumentInt(argc, (const char **)argv, "n");
    }

    if (checkCmdLineFlag(argc, (const char **)argv, "grid")) {
      gridDim = getCmdLineArgumentInt(argc, (const char **)argv, "grid");
    }

    if (checkCmdLineFlag(argc, (const char **)argv, "file")) {
      getCmdLineArgumentString(argc, (const char **)argv, "file", &g_refFile);
      fpsLimit = frameCheckNumber;
      numIterations = 1;
    }
  }

  gridSize.x = gridSize.y = gridSize.z = gridDim;
  printf("grid: %d x %d x %d = %d cells\n", gridSize.x, gridSize.y, gridSize.z,
         gridSize.x * gridSize.y * gridSize.z);
  printf("particles: %d\n", numParticles);

  bool benchmark =
      checkCmdLineFlag(argc, (const char **)argv, "benchmark") != 0;

  if (checkCmdLineFlag(argc, (const char **)argv, "i")) {
    numIterations = getCmdLineArgumentInt(argc, (const char **)argv, "i");
  }

  if (benchmark || g_refFile) {
    cudaInit(argc, argv);
  } else {
    if (checkCmdLineFlag(argc, (const char **)argv, "device")) {
      printf("[%s]\n", argv[0]);
      printf("   Does not explicitly support -device=n in OpenGL mode\n");
      printf("   To use -device=n, the sample must be running w/o OpenGL\n\n");
      printf(" > %s -device=n -file=<*.bin>\n", argv[0]);
      printf("exiting...\n");
      exit(EXIT_SUCCESS);
    }

    initGL(&argc, argv);
    cudaInit(argc, argv);
  }

  initParticleSystem(numParticles, gridSize, !benchmark && g_refFile == NULL);
  initParams();

  if (benchmark || g_refFile) {
    if (numIterations <= 0) {
      numIterations = 300;
    }

    runBenchmark(numIterations, argv[0]);
  } else {
    if (!g_refFile) {
      initMenus();
    }

    glutDisplayFunc(display);
    glutReshapeFunc(reshape);
    glutMouseFunc(mouse);
    glutMotionFunc(motion);
    glutKeyboardFunc(key);
    glutSpecialFunc(special);
    glutIdleFunc(idle);

    glutCloseFunc(cleanup);

    glutMainLoop();
  }

  if (psystem) {
    delete psystem;
  }

  exit(g_TotalErrors > 0 ? EXIT_FAILURE : EXIT_SUCCESS);
}