#include "explosion.h"
#include <GL/glut.h>
#include <iostream.h>
#include "m4x4.h"

typedef struct materialStruct {
  GLfloat ambient[4];
  GLfloat diffuse[4];
  GLfloat specular[4];
  GLfloat shininess;
} materialStruct;

extern materialStruct brassMaterials;

Explosion::Explosion(Math3d::M3d position, int size) {
  _numParticles = size;
  _particles = new Particle[_numParticles];

  srand((unsigned) time(0));

  for (int i=0; i<_numParticles; i++) {
    _particles[i].position = position;
    _particles[i].direction = Math3d::M3d((((float) rand() / RAND_MAX) - 0.5) * 2.0, 
					  (((float) rand() / RAND_MAX) - 0.5) * 2.0, 
					  (((float) rand() / RAND_MAX) - 0.5) * 2.0); 
    
    _particles[i].direction.normalize();
    //    cout << i << ": " << _particles[i].direction << endl;
    //    _particles[i].orientation = Math3d::MQuat((float)(rand()%3 - 1), (float)(rand()%3 - 1), 
    //					      (float)(rand()%3 - 1), (float)(rand()%3 - 1));
    _particles[i].orientation = Math3d::MQuat((((float) rand() / RAND_MAX) - 0.5) * 2.0, 
					      (((float) rand() / RAND_MAX) - 0.5) * 2.0, 
					      (((float) rand() / RAND_MAX) - 0.5) * 2.0,
					      (((float) rand() / RAND_MAX) - 0.5) * 2.0);
    _particles[i].orientation.normalize();
    
    _particles[i].size = (float) (rand() % 6) + 1.0;
    _particles[i].speed = ((float) rand() / RAND_MAX) * 200.0;
    
  }

  _timeAlive = 0.0;
}

void Explosion::Render() {
  glDisable(GL_TEXTURE_2D);

  glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, brassMaterials.ambient);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, brassMaterials.diffuse);
  glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, brassMaterials.specular);
  glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, brassMaterials.shininess);

  for (int i=0; i<_numParticles; i++) {
    glPushMatrix();

    glTranslatef(_particles[i].position[0], _particles[i].position[1], _particles[i].position[2]);

    Math3d::M4x4 rotMat;
    rotMat.loadRotate(_particles[i].orientation);
    glMultMatrixd(rotMat);

    glBegin(GL_TRIANGLES);
    glVertex3f(0.0, 0.0, 0.0);
    glVertex3f(0.0, _particles[i].size, 0.0);
    glVertex3f(_particles[i].size, _particles[i].size, 0.0);
    glEnd();

    glPopMatrix();
  }

  glEnable(GL_TEXTURE_2D);
}

void Explosion::UpdateState(float timeElapsed) {
  for (int i=0; i<_numParticles; i++) {
    _particles[i].position += _particles[i].direction * timeElapsed * _particles[i].speed;
  }

  _timeAlive += timeElapsed;
}