import java.awt.AlphaComposite;
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.font.GlyphVector;
import java.awt.font.FontRenderContext;
import java.awt.font.TextLayout;
import java.awt.image.BufferedImage;
import java.io.File;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;

import com.jogamp.opengl.util.texture.Texture;
import com.jogamp.opengl.util.texture.awt.AWTTextureIO;
import javax.media.opengl.GL2;
import javax.media.opengl.GLAutoDrawable;
import javax.media.opengl.GLCapabilities;
import javax.media.opengl.GLDrawable;
import javax.media.opengl.GLEventListener;
import javax.media.opengl.GLProfile;
import javax.media.opengl.awt.GLCanvas;
import static javax.media.opengl.GL2.*;

import java.awt.Frame;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.media.opengl.*;
import javax.media.opengl.awt.GLCanvas;
import com.jogamp.opengl.util.*;

public class test implements GLEventListener {

    private double theta = 0;
    private double s = 0;
    private double c = 0;

    public static void main(String[] args) {
        GLProfile glp = GLProfile.getDefault();
        GLCapabilities caps = new GLCapabilities(glp);
        GLCanvas canvas = new GLCanvas(caps);

        Frame frame = new Frame("AWT Window Test");
        frame.setSize(300, 300);
        frame.add(canvas);
        frame.setVisible(true);

        frame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });

        canvas.addGLEventListener(new test());

        FPSAnimator animator = new FPSAnimator(canvas, 60);
        animator.start();
    }

  public static long oldTime;

  public static long renderTime;

  private final int screenW = 800 , screenH = 600;

  /**
   * Serial version ID
   */
  static final long serialVersionUID = 20090529;

  public static final String[] fragShader = new String[] {
    "#version 330 core\n" +
    "in vec4 fragColor;\n" +
    "out vec4 color;\n" +
    "void main(void)\n" +
    "{\n" +
    "  color = fragColor;\n" +
    "}"};
  public static final String[] vertexShader = new String[] {
    "#version 330 core\n" +
    "layout (location = 0) in vec2 p0;\n" +
    "layout (location = 1) in vec2 p1;\n" +
    "layout (location = 2) in vec2 p2;\n" +
    "layout (location = 3) in vec4 color;\n" +
    "out vec4 fragColor;\n" +
    "void main(void)\n" +
    "{\n" +
    "  if(gl_VertexID == 0)\n" +
    "    gl_Position.xy = p0;\n" +
    "  else if(gl_VertexID == 1)\n" +
    "    gl_Position.xy = p1;\n" +
    "  else if(gl_VertexID == 2)\n" +
    "    gl_Position.xy = p2;\n" +
    "  gl_Position.z = 0;\n" +
    "  gl_Position.w = 1;\n" +
    "  fragColor = color;\n" +
    "}"};

  private int shader;

  public static final Font font = new Font("Arial" , Font.PLAIN , 40);
  private double fps;
  private Texture text;
  private long cycle;

  public void display(GLAutoDrawable drawable)
  {
    System.out.println("Fps: " + fps + " " + cycle);
    cycle++;
      renderTime = System.nanoTime();
      if(oldTime != 0 && renderTime != oldTime)
        fps = fps*0.9 + 100000000/(renderTime - oldTime);
      oldTime = renderTime;

    GL2 gl = drawable.getGL().getGL2();

    gl.glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    gl.glDisable(GL_TEXTURE_2D);
    float[] color = new float[]{0, 0.5f + cycle%100/200f ,0.5f + cycle%100/200f,1};
    gl.glClearBufferfv(GL_COLOR , 0 , color , 0);

    gl.glUseProgram(shader);

    gl.glVertexAttrib2fv(0, new float[]{0 , 0} , 0);
    gl.glVertexAttrib2fv(1, new float[]{0.25f + (cycle%2)*0.25f, 0} , 0);
    gl.glVertexAttrib2fv(2, new float[]{0 , 0.5f} , 0);
    gl.glVertexAttrib4fv(3, new float[]{0 , 1.0f*(cycle%256)/256f , 1.0f*(cycle%256)/256f , 1} , 0);


// Draw one triangle
gl.glDrawArrays(GL_TRIANGLES, 0, 3);
          gl.glScalef(2.0f,-0.5f,1.0f);
  }

  //Invoked when canvas is destroyed i.e. system exit. Nothing needing done.
  public void dispose(GLAutoDrawable drawable)
  {
    drawable.getGL().getGL2().glDeleteProgram(shader);
  }

  public void init(GLAutoDrawable drawable)
  {
    //Force v-sync.
    drawable.getGL().setSwapInterval(1);

    //disable 3D
    drawable.getGL().glDisable(GL_DEPTH_TEST);

    GL2 gl = drawable.getGL().getGL2();

    System.out.println(gl.glGetString(GL_SHADING_LANGUAGE_VERSION));

    //enable graphics space
    gl.glEnable(GL_BLEND);
    gl.glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

    //set screen size
    gl.glViewport(0 , 0 , screenW , screenH);
    gl.glMatrixMode(GL_PROJECTION);
    gl.glLoadIdentity();

    //set ortho view
    gl.glOrtho(0 , screenW , 0 , screenH , -1 , 1);
    gl.glMatrixMode(GL_MODELVIEW);
    gl.glLoadIdentity();

    //set screen default color
    //gl.glClearColor(0.25f,0.25f,0.25f,1);

    int v = gl.glCreateShader(GL_VERTEX_SHADER);
    gl.glShaderSource(v , vertexShader.length , vertexShader , new int[] { vertexShader[0].length() } , 0);
    gl.glCompileShader(v);

    {
      int[] compiled = new int[1];
      gl.glGetShaderiv(v , GL_COMPILE_STATUS , compiled , 0);
      if(compiled[0]!=0)
        System.out.println("Horray! vertex shader compiled");
      else
      {
        int[] logLength = new int[1];
        gl.glGetShaderiv(v , GL_INFO_LOG_LENGTH, logLength , 0);

        byte[] log = new byte[logLength[0]];
        gl.glGetShaderInfoLog(v , logLength[0] , (int[])null , 0 , log , 0);

        System.err.println("Error compiling the vertex shader: " + new String(log));
        System.exit(1);
      }
    }

    int f = gl.glCreateShader(GL_FRAGMENT_SHADER);
    gl.glShaderSource(f , fragShader.length , fragShader , new int[] { fragShader[0].length() } , 0);
    gl.glCompileShader(f);

    {
      int[] compiled = new int[1];
      gl.glGetShaderiv(f , GL_COMPILE_STATUS , compiled , 0);
      if(compiled[0]!=0)
        System.out.println("Horray! frag shader compiled");
      else
      {
        int[] logLength = new int[1];
        gl.glGetShaderiv(f , GL_INFO_LOG_LENGTH, logLength , 0);

        byte[] log = new byte[logLength[0]];
        gl.glGetShaderInfoLog(f , logLength[0] , (int[])null , 0 , log , 0);

        System.err.println("Error compiling the vertex shader: " + new String(log));
        System.exit(1);
      }
    }


    shader = gl.glCreateProgram();
    gl.glAttachShader(shader , v);
    gl.glAttachShader(shader , f);

    gl.glLinkProgram(shader);
    gl.glValidateProgram(shader);

    gl.glDeleteShader(v);
    gl.glDeleteShader(f);
  }

  // called when user resizes the window. Never happen.
  public void reshape(GLAutoDrawable drawable , int x , int y ,
                      int width , int height) {}
}