source: trunk/gui/vizservers/nanovis/ParticleSystem.cpp @ 397

/*
 * ----------------------------------------------------------------------
 * ParticleSystem.cpp: particle system class
 *
 * ======================================================================
 *  AUTHOR:  Wei Qiao <qiaow@purdue.edu>
 *           Purdue Rendering and Perceptualization Lab (PURPL)
 *
 *  Copyright (c) 2004-2006  Purdue Research Foundation
 *
 *  See the file "license.terms" for information on usage and
 *  redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 * ======================================================================
 */

#include <stdio.h>
#include <assert.h>
#include <malloc.h>
#include <string.h>

#include "ParticleSystem.h"


ParticleSystem::ParticleSystem(int w, int h, CGcontext context, NVISid volume, float scale_x, 
                float scale_y, float scale_z){

  fprintf(stderr, "%f, %f, %f\n", scale_x, scale_y, scale_z);
  scale = Vector3(scale_x, scale_y, scale_z);
  
  psys_width = w;
  psys_height = h;

  psys_frame = 0;
  reborn = true;
  flip = true;
  max_life = 500;

  data = (Particle*) malloc(w*h*sizeof(Particle));

  m_vertex_array = new RenderVertexArray(psys_width*psys_height, 3, GL_FLOAT);
  assert(glGetError()==0);

  glGenFramebuffersEXT(2, psys_fbo);
  glGenTextures(2, psys_tex);

  glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, psys_fbo[0]);

  glBindTexture(GL_TEXTURE_RECTANGLE_NV, psys_tex[0]);
  glTexParameterf(GL_TEXTURE_RECTANGLE_NV, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  glTexParameterf(GL_TEXTURE_RECTANGLE_NV, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  glTexImage2D(GL_TEXTURE_RECTANGLE_NV, 0, GL_FLOAT_RGBA32_NV, psys_width, psys_height, 0, GL_RGBA, GL_FLOAT, NULL);
  glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_RECTANGLE_NV, psys_tex[0], 0);

  glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, psys_fbo[1]);

  glBindTexture(GL_TEXTURE_RECTANGLE_NV, psys_tex[1]);
  glTexParameterf(GL_TEXTURE_RECTANGLE_NV, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  glTexParameterf(GL_TEXTURE_RECTANGLE_NV, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  glTexImage2D(GL_TEXTURE_RECTANGLE_NV, 0, GL_FLOAT_RGBA32_NV, psys_width, psys_height, 0, GL_RGBA, GL_FLOAT, NULL);
  glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_RECTANGLE_NV, psys_tex[1], 0);

  CHECK_FRAMEBUFFER_STATUS();
  assert(glGetError()==0);

  //load related shaders
  m_g_context = context;

  m_pos_fprog = loadProgram(m_g_context, CG_PROFILE_FP30, CG_SOURCE, "./shaders/update_pos.cg");
  m_pos_timestep_param  = cgGetNamedParameter(m_pos_fprog, "timestep");
  m_vel_tex_param = cgGetNamedParameter(m_pos_fprog, "vel_tex");
  m_pos_tex_param = cgGetNamedParameter(m_pos_fprog, "pos_tex");
  m_scale_param = cgGetNamedParameter(m_pos_fprog, "scale");
  cgGLSetTextureParameter(m_vel_tex_param, volume);
  cgGLSetParameter3f(m_scale_param, scale_x, scale_y, scale_z);

  fprintf(stderr, "init_psys\n");
}


ParticleSystem::~ParticleSystem(){
  glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, psys_fbo[0]);
  glDeleteTextures(1, psys_tex);

  glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, psys_fbo[1]);
  glDeleteTextures(1, psys_tex+1);

  glDeleteFramebuffersEXT(2, psys_fbo);

  free(data);
}


void ParticleSystem::initialize(Particle* p){
  //also store the data on main memory for next initialization
  memcpy(data, p, psys_width*psys_height*sizeof(Particle));

  glBindTexture(GL_TEXTURE_RECTANGLE_NV, psys_tex[0]);
  glTexImage2D(GL_TEXTURE_RECTANGLE_NV, 0, GL_FLOAT_RGBA32_NV, psys_width, psys_height, 0, GL_RGBA, GL_FLOAT, (float*)p);
  
  assert(glGetError()==0);

  flip = true;
  reborn = false;

  //fprintf(stderr, "init particles\n");
}

void ParticleSystem::reset(){
  glBindTexture(GL_TEXTURE_RECTANGLE_NV, psys_tex[0]);
  glTexImage2D(GL_TEXTURE_RECTANGLE_NV, 0, GL_FLOAT_RGBA32_NV, psys_width, psys_height, 0, GL_RGBA, GL_FLOAT, (float*)data);
  
  assert(glGetError()==0);

  flip = true;
  reborn = false;
  psys_frame = 0;
}


void ParticleSystem::advect(){
   if(reborn) reset();

   glDisable(GL_BLEND);
   
   if(flip){

     glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, psys_fbo[1]);
     glBindTexture(GL_TEXTURE_RECTANGLE_NV, psys_tex[0]);

     glClear(GL_COLOR_BUFFER_BIT);

     glViewport(0, 0, psys_width, psys_height);
     glMatrixMode(GL_PROJECTION);
     glLoadIdentity();
     gluOrtho2D(0, psys_width, 0, psys_height);
     glMatrixMode(GL_MODELVIEW);
     glLoadIdentity();

     cgGLBindProgram(m_pos_fprog);
     cgGLSetParameter1f(m_pos_timestep_param, 0.05);
     cgGLEnableTextureParameter(m_vel_tex_param);
     cgGLSetTextureParameter(m_pos_tex_param, psys_tex[0]);
     cgGLEnableTextureParameter(m_pos_tex_param);

     cgGLEnableProfile(CG_PROFILE_FP30);
     draw_quad(psys_width, psys_height, psys_width, psys_height);
     cgGLDisableProfile(CG_PROFILE_FP30);
   
     cgGLDisableTextureParameter(m_vel_tex_param);
     cgGLDisableTextureParameter(m_pos_tex_param);
   }
   else
   {

     glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, psys_fbo[0]);
     glBindTexture(GL_TEXTURE_RECTANGLE_NV, psys_tex[1]);

     glClear(GL_COLOR_BUFFER_BIT);

     glViewport(0, 0, psys_width, psys_height);
     glMatrixMode(GL_PROJECTION);
     glLoadIdentity();
     gluOrtho2D(0, psys_width, 0, psys_height);
     glMatrixMode(GL_MODELVIEW);
     glLoadIdentity();

     cgGLBindProgram(m_pos_fprog);
     cgGLSetParameter1f(m_pos_timestep_param, 0.05);
     cgGLEnableTextureParameter(m_vel_tex_param);
     cgGLSetTextureParameter(m_pos_tex_param, psys_tex[1]);
     cgGLEnableTextureParameter(m_pos_tex_param);

     cgGLEnableProfile(CG_PROFILE_FP30);
     draw_quad(psys_width, psys_height, psys_width, psys_height);
     cgGLDisableProfile(CG_PROFILE_FP30);
   
     cgGLDisableTextureParameter(m_vel_tex_param);
     cgGLDisableTextureParameter(m_pos_tex_param);
   }

   assert(glGetError()==0);

   //soft_read_verts();
   update_vertex_buffer();

   flip = (!flip);

   psys_frame++;
   if(psys_frame==max_life){
     psys_frame=0;
     reborn = true;
   }

   //fprintf(stderr, "advect: %d ", psys_frame);
}


void ParticleSystem::update_vertex_buffer(){
  m_vertex_array->Read(psys_width, psys_height);
  //m_vertex_array->LoadData(vert);     //does not work??
  assert(glGetError()==0);
}


void ParticleSystem::display_vertices(){
  glDisable(GL_TEXTURE_2D);
  glDisable(GL_BLEND);
  glEnable(GL_DEPTH_TEST);

  glPointSize(1.2);
  glColor4f(.2,.2,.8,1.);
  
  glPushMatrix();
  glScaled(1./scale.x, 1./scale.y, 1./scale.z);

  m_vertex_array->SetPointer(0);
  //glEnableVertexAttribArray(0);
  glEnableClientState(GL_VERTEX_ARRAY);
  glDrawArrays(GL_POINTS, 0, psys_width*psys_height);
  //glDisableVertexAttribArray(0);
  glDisableClientState(GL_VERTEX_ARRAY);

  glPopMatrix();
  
  glDisable(GL_DEPTH_TEST);
  assert(glGetError()==0);
}