import org.lwjgl.LWJGLException;
import org.lwjgl.Sys;
import org.lwjgl.input.Keyboard;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import org.lwjgl.opengl.GL11;
import org.lwjgl.util.glu.GLU;

/**
  * NeHe Lesson 05 - 3D Shapes
  *  
  * @author Tim Biedert
  * @author kappaOne
  */
public class Lesson05 {

  String windowTitle = "NeHe Lesson 05 - 3D Shapes";
  public boolean closeRequested = false;

  long lastFrameTime; // used to calculate delta
   
  float triangleAngle; // Angle of rotation for the triangles
  float quadAngle; // Angle of rotation for the quads

  public void run() {

   createWindow();
   getDelta(); // Initialise delta timer
   initGL();
    
   while (!closeRequested) {
    pollInput();
    updateLogic(getDelta());
    renderGL();

    Display.update();
   }
    
   cleanup();
  }
   
  private void initGL() {

   /* OpenGL */
   int width = Display.getDisplayMode().getWidth();
   int height = Display.getDisplayMode().getHeight();

   GL11.glViewport(0, 0, width, height); // Reset The Current Viewport
   GL11.glMatrixMode(GL11.GL_PROJECTION); // Select The Projection Matrix
   GL11.glLoadIdentity(); // Reset The Projection Matrix
   GLU.gluPerspective(45.0f, ((float) width / (float) height), 0.1f, 100.0f); // Calculate The Aspect Ratio Of The Window
   GL11.glMatrixMode(GL11.GL_MODELVIEW); // Select The Modelview Matrix
   GL11.glLoadIdentity(); // Reset The Modelview Matrix

   GL11.glShadeModel(GL11.GL_SMOOTH); // Enables Smooth Shading
   GL11.glClearColor(0.0f, 0.0f, 0.0f, 0.0f); // Black Background
   GL11.glClearDepth(1.0f); // Depth Buffer Setup
   GL11.glEnable(GL11.GL_DEPTH_TEST); // Enables Depth Testing
   GL11.glDepthFunc(GL11.GL_LEQUAL); // The Type Of Depth Test To Do
   GL11.glHint(GL11.GL_PERSPECTIVE_CORRECTION_HINT, GL11.GL_NICEST); // Really Nice Perspective Calculations

  }
   
  private void updateLogic(int delta) {
   triangleAngle += 0.1f * delta; // Increase The Rotation Variable For The Triangles
   quadAngle -= 0.05f * delta; // Decrease The Rotation Variable For The Quads
  }

  private void renderGL() {

   GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT); // Clear The Screen And The Depth Buffer
   GL11.glLoadIdentity(); // Reset The View
   GL11.glTranslatef(-1.5f, 0.0f, -6.0f); // Move Left And Into The Screen

   GL11.glRotatef(triangleAngle, 0.0f, 1.0f, 0.0f); // Rotate The Pyramid On It's Y Axis

   GL11.glBegin(GL11.GL_TRIANGLES); // Start Drawing The Pyramid
   GL11.glColor3f(1.0f, 0.0f, 0.0f); // Red
   GL11.glVertex3f(0.0f, 1.0f, 0.0f); // Top Of Triangle (Front)
   GL11.glColor3f(0.0f, 1.0f, 0.0f); // Green
   GL11.glVertex3f(-1.0f, -1.0f, 1.0f); // Left Of Triangle (Front)
   GL11.glColor3f(0.0f, 0.0f, 1.0f); // Blue
   GL11.glVertex3f(1.0f, -1.0f, 1.0f); // Right Of Triangle (Front)

   GL11.glColor3f(1.0f, 0.0f, 0.0f); // Red
   GL11.glVertex3f(0.0f, 1.0f, 0.0f); // Top Of Triangle (Right)
   GL11.glColor3f(0.0f, 0.0f, 1.0f); // Blue
   GL11.glVertex3f(1.0f, -1.0f, 1.0f); // Left Of Triangle (Right)
   GL11.glColor3f(0.0f, 1.0f, 0.0f); // Green
   GL11.glVertex3f(1.0f, -1.0f, -1.0f); // Right Of Triangle (Right)

   GL11.glColor3f(1.0f, 0.0f, 0.0f); // Red
   GL11.glVertex3f(0.0f, 1.0f, 0.0f); // Top Of Triangle (Back)
   GL11.glColor3f(0.0f, 1.0f, 0.0f); // Green
   GL11.glVertex3f(1.0f, -1.0f, -1.0f); // Left Of Triangle (Back)
   GL11.glColor3f(0.0f, 0.0f, 1.0f); // Blue
   GL11.glVertex3f(-1.0f, -1.0f, -1.0f); // Right Of Triangle (Back)

   GL11.glColor3f(1.0f, 0.0f, 0.0f); // Red
   GL11.glVertex3f(0.0f, 1.0f, 0.0f); // Top Of Triangle (Left)
   GL11.glColor3f(0.0f, 0.0f, 1.0f); // Blue
   GL11.glVertex3f(-1.0f, -1.0f, -1.0f); // Left Of Triangle (Left)
   GL11.glColor3f(0.0f, 1.0f, 0.0f); // Green
   GL11.glVertex3f(-1.0f, -1.0f, 1.0f); // Right Of Triangle (Left)
   GL11.glEnd(); // Done Drawing The Pyramid

   GL11.glLoadIdentity(); // Reset The View
   GL11.glTranslatef(1.5f, 0.0f, -7.0f); // Move Right And Into The Screen

   GL11.glRotatef(quadAngle, 1.0f, 1.0f, 1.0f); // Rotate The Cube On X, Y & Z

   GL11.glBegin(GL11.GL_QUADS); // Start Drawing The Cube
   GL11.glColor3f(0.0f, 1.0f, 0.0f); // Set The Color To Green
   GL11.glVertex3f(1.0f, 1.0f, -1.0f); // Top Right Of The Quad (Top)
   GL11.glVertex3f(-1.0f, 1.0f, -1.0f); // Top Left Of The Quad (Top)
   GL11.glVertex3f(-1.0f, 1.0f, 1.0f); // Bottom Left Of The Quad (Top)
   GL11.glVertex3f(1.0f, 1.0f, 1.0f); // Bottom Right Of The Quad (Top)

   GL11.glColor3f(1.0f, 0.5f, 0.0f); // Set The Color To Orange
   GL11.glVertex3f(1.0f, -1.0f, 1.0f); // Top Right Of The Quad (Bottom)
   GL11.glVertex3f(-1.0f, -1.0f, 1.0f); // Top Left Of The Quad (Bottom)
   GL11.glVertex3f(-1.0f, -1.0f, -1.0f); // Bottom Left Of The Quad (Bottom)
   GL11.glVertex3f(1.0f, -1.0f, -1.0f); // Bottom Right Of The Quad (Bottom)

   GL11.glColor3f(1.0f, 0.0f, 0.0f); // Set The Color To Red
   GL11.glVertex3f(1.0f, 1.0f, 1.0f); // Top Right Of The Quad (Front)
   GL11.glVertex3f(-1.0f, 1.0f, 1.0f); // Top Left Of The Quad (Front)
   GL11.glVertex3f(-1.0f, -1.0f, 1.0f); // Bottom Left Of The Quad (Front)
   GL11.glVertex3f(1.0f, -1.0f, 1.0f); // Bottom Right Of The Quad (Front)

   GL11.glColor3f(1.0f, 1.0f, 0.0f); // Set The Color To Yellow
   GL11.glVertex3f(1.0f, -1.0f, -1.0f); // Bottom Left Of The Quad (Back)
   GL11.glVertex3f(-1.0f, -1.0f, -1.0f); // Bottom Right Of The Quad (Back)
   GL11.glVertex3f(-1.0f, 1.0f, -1.0f); // Top Right Of The Quad (Back)
   GL11.glVertex3f(1.0f, 1.0f, -1.0f); // Top Left Of The Quad (Back)

   GL11.glColor3f(0.0f, 0.0f, 1.0f); // Set The Color To Blue
   GL11.glVertex3f(-1.0f, 1.0f, 1.0f); // Top Right Of The Quad (Left)
   GL11.glVertex3f(-1.0f, 1.0f, -1.0f); // Top Left Of The Quad (Left)
   GL11.glVertex3f(-1.0f, -1.0f, -1.0f); // Bottom Left Of The Quad (Left)
   GL11.glVertex3f(-1.0f, -1.0f, 1.0f); // Bottom Right Of The Quad (Left)

   GL11.glColor3f(1.0f, 0.0f, 1.0f); // Set The Color To Violet
   GL11.glVertex3f(1.0f, 1.0f, -1.0f); // Top Right Of The Quad (Right)
   GL11.glVertex3f(1.0f, 1.0f, 1.0f); // Top Left Of The Quad (Right)
   GL11.glVertex3f(1.0f, -1.0f, 1.0f); // Bottom Left Of The Quad (Right)
   GL11.glVertex3f(1.0f, -1.0f, -1.0f); // Bottom Right Of The Quad (Right)
   GL11.glEnd(); // Done Drawing The Quad

  }

  /**
   * Poll Input
   */
  public void pollInput() {

   // scroll through key events
   while (Keyboard.next()) {
    if (Keyboard.getEventKeyState()) {
     if (Keyboard.getEventKey() == Keyboard.KEY_ESCAPE)
      closeRequested = true;
    }
   }

   if (Display.isCloseRequested()) {
    closeRequested = true;
   }
  }
   
  /**  
   * Calculate how many milliseconds have passed  
   * since last frame.
   *  
   * @return milliseconds passed since last frame  
   */
  public int getDelta() {
      long time = (Sys.getTime() * 1000) / Sys.getTimerResolution();
      int delta = (int) (time - lastFrameTime);
      lastFrameTime = time;
    
      return delta;
  }

  private void createWindow() {
   try {
    Display.setDisplayMode(new DisplayMode(640, 480));
    Display.setVSyncEnabled(true);
    Display.setTitle(windowTitle);
    Display.create();
   } catch (LWJGLException e) {
    Sys.alert("Error", "Initialization failed!\n\n" + e.getMessage());
    System.exit(0);
   }
  }
   
  /**
   * Destroy and clean up resources
   */
  private void cleanup() {
   Display.destroy();
  }
   
  public static void main(String[] args) {
   Lesson05 lesson = new Lesson05();
   lesson.run();
  }
}