/*
 * ----------------------------------------------------------------------
 * NvParticleRenderer.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 <R2/R2FilePath.h>
#include "NvParticleRenderer.h"
#include <Trace.h>


#define NV_32

NvParticleRenderer::NvParticleRenderer(int w, int h, CGcontext context)
    : scale(1, 1, 1), _activate(false), origin(0, 0, 0)
{
    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);

#ifdef NV_32
    glTexImage2D(GL_TEXTURE_RECTANGLE_NV, 0, GL_FLOAT_RGBA32_NV, psys_width, psys_height, 0, GL_RGBA, GL_FLOAT, NULL);
#else
    glTexImage2D(GL_TEXTURE_RECTANGLE_NV, 0, GL_RGBA, psys_width, psys_height, 0, GL_RGBA, GL_FLOAT, NULL);
#endif
    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);
#ifdef NV_32
    glTexImage2D(GL_TEXTURE_RECTANGLE_NV, 0, GL_FLOAT_RGBA32_NV, psys_width, psys_height, 0, GL_RGBA, GL_FLOAT, NULL);
#else
    glTexImage2D(GL_TEXTURE_RECTANGLE_NV, 0, GL_RGBA, psys_width, psys_height, 0, GL_RGBA, GL_FLOAT, NULL);
#endif
    glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_RECTANGLE_NV, psys_tex[1], 0);

    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);

    CHECK_FRAMEBUFFER_STATUS();

    //load related shaders
    /*
      m_g_context = context;

      m_pos_fprog = LoadCgSourceProgram(m_g_context, "update_pos.cg", 
	CG_PROFILE_FP30, NULL);
      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);
    */

    _advectionShader = new NvParticleAdvectionShader();

}

NvParticleRenderer::~NvParticleRenderer()
{
    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 NvParticleRenderer::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]);
    // I need to find out why GL_FLOAT_RGBA32_NV doesn't work
#ifdef NV_32
    glTexImage2D(GL_TEXTURE_RECTANGLE_NV, 0, GL_FLOAT_RGBA32_NV, psys_width, psys_height, 0, GL_RGBA, GL_FLOAT, (float*)p);
#else
    glTexImage2D(GL_TEXTURE_RECTANGLE_NV, 0, GL_RGBA, psys_width, psys_height, 0, GL_RGBA, GL_FLOAT, (float*)p);
#endif
    glBindTexture(GL_TEXTURE_RECTANGLE_NV, 0);
  
    flip = true;
    reborn = false;

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

void NvParticleRenderer::reset()
{
    glBindTexture(GL_TEXTURE_RECTANGLE_NV, psys_tex[0]);

#ifdef NV_32
    glTexImage2D(GL_TEXTURE_RECTANGLE_NV, 0, GL_FLOAT_RGBA32_NV, psys_width, psys_height, 0, GL_RGBA, GL_FLOAT, (float*)data);
#else
    glTexImage2D(GL_TEXTURE_RECTANGLE_NV, 0, GL_RGBA, psys_width, psys_height, 0, GL_RGBA, GL_FLOAT, (float*)data);#
#endif
                                                                                                                       glBindTexture(GL_TEXTURE_RECTANGLE_NV, 0);
  
    flip = true;
    reborn = false;
    psys_frame = 0;
}

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

    glDisable(GL_BLEND);
    glDisable(GL_DEPTH_TEST);
   
    if (flip) 
        {
            glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, psys_fbo[1]);
            glEnable(GL_TEXTURE_RECTANGLE_NV);
            glBindTexture(GL_TEXTURE_RECTANGLE_NV, psys_tex[0]);

            glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
            //glClear(GL_COLOR_BUFFER_BIT);

            glViewport(0, 0, psys_width, psys_height);
            glMatrixMode(GL_PROJECTION);
            glLoadIdentity();
            //gluOrtho2D(0, psys_width, 0, psys_height);
            glOrtho(0, psys_width, 0, psys_height, -10.0f, 10.0f);
            glMatrixMode(GL_MODELVIEW);
            glLoadIdentity();

            _advectionShader->bind(psys_tex[0]);
     
            //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);
            glDisable(GL_TEXTURE_RECTANGLE_NV);
        }
    else
        {
            glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, psys_fbo[0]);
            glBindTexture(GL_TEXTURE_RECTANGLE_NV, psys_tex[1]);

            glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
            //glClear(GL_COLOR_BUFFER_BIT);

            glViewport(0, 0, psys_width, psys_height);
            glMatrixMode(GL_PROJECTION);
            glLoadIdentity();
            //gluOrtho2D(0, psys_width, 0, psys_height);
            glOrtho(0, psys_width, 0, psys_height, -10.0f, 10.0f);
            glMatrixMode(GL_MODELVIEW);
            glLoadIdentity();

            _advectionShader->bind(psys_tex[1]);

            //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);
            //draw_quad(psys_width, psys_height, 1.0f, 1.0f);

            //cgGLDisableProfile(CG_PROFILE_FP30);
            //cgGLDisableTextureParameter(m_vel_tex_param);
            //cgGLDisableTextureParameter(m_pos_tex_param);
        }

    _advectionShader->unbind();

    //soft_read_verts();
   
    update_vertex_buffer();

    flip = (!flip);

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

    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
}

void NvParticleRenderer::update_vertex_buffer()
{
    m_vertex_array->Read(psys_width, psys_height);

    //m_vertex_array->LoadData(vert);     //does not work??
    //assert(glGetError()==0);
}

void NvParticleRenderer::render()
{ 
    display_vertices(); 
}

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

    glEnable(GL_COLOR_MATERIAL);

    glPointSize(1.2);
    glColor4f(.2,.2,.8,1.);
  
    glPushMatrix();

    glTranslatef(origin.x, origin.y, origin.z);
    glScaled(scale.x, scale.y, scale.z);

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

    glPopMatrix();
  
    glDisable(GL_DEPTH_TEST);

    //assert(glGetError()==0);
}

void NvParticleRenderer::setVectorField(unsigned int texID, const Vector3& ori, float scaleX, float scaleY, float scaleZ, float max)
{
    origin = ori;
    scale.set(scaleX, scaleY, scaleZ);
    _advectionShader->setScale(scale);
    _advectionShader->setVelocityVolume(texID, max);
}