#include "Spiral.h"
#include <cmath>
#include "vgl.h"

#include <iostream>
using namespace std;

Spiral::Spiral() {
  int i;
  float r = 0;
  float angle = 0;

  theta = 0;
  display = true;

  for(i=0;i<MAX_POINTS;i++) {
      points[i][0] = r * cos(angle);
      points[i][1] = r * sin(angle);
      r += 1.0/float(MAX_POINTS+3);
      angle += 2*M_PI / TURNS;
  }
  return;
}

Spiral::~Spiral() {
   glDeleteBuffers(1, &bufferID);
   glDeleteVertexArrays(1, &VAONumber);
   return;
}

void Spiral::BindSpiral(GLuint prog) {

  glGenVertexArrays(1, &VAONumber);

  glBindVertexArray(VAONumber);
  glGenBuffers(1,&bufferID);

  glBindBuffer(GL_ARRAY_BUFFER, bufferID);
  glBufferData(GL_ARRAY_BUFFER, sizeof(points), points, GL_STATIC_DRAW);


  glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
  glEnableVertexAttribArray(0);

  // unbind the array
  glBindVertexArray(0);

  program = prog;
  thetaLocation = glGetUniformLocation(program, "theta");

  return;
}

void Spiral::NextTheta() {
   theta += 0.1;
   if (theta > 360) {
      theta = 0;
   }
}

void Spiral::ToggleDisplay() {
   display = !display;
   return;
}


void Spiral::Display() {

  if (display) {
      glUniform1f(thetaLocation, theta*M_PI/180.0);

      glBindVertexArray(VAONumber);
      glDrawArrays(GL_LINE_STRIP, 0, MAX_POINTS);
      glBindVertexArray(0);
  }

  return;
}