package com.luciad.view.opengl.binding.jogl2;

import org.junit.Assert;
import org.junit.Test;

import javax.media.opengl.DefaultGLCapabilitiesChooser;
import javax.media.opengl.GL2;
import javax.media.opengl.GLAutoDrawable;
import javax.media.opengl.GLCapabilities;
import javax.media.opengl.GLDrawableFactory;
import javax.media.opengl.GLEventListener;
import javax.media.opengl.GLProfile;
import javax.media.opengl.awt.GLCanvas;
import javax.swing.JFrame;
import java.awt.BorderLayout;

/**
 * Tests whether GL context sharing with a pbuffer can prevent a GLCanvas's
 * texture objects from being lost when the canvas is moved to a new parent.
 *
 * @author tomn
 */
public class GLCanvasContextSharingFullscreenTest {

  @Test
  public void testContextSharing() throws InterruptedException {
    // Create a canvas and add a listener that performs the tests.
    GLCanvas canvas = new GLCanvas();
    canvas.setSize( 500, 500 );
    canvas.addGLEventListener( new MyEventListener() );

    // Show the canvas in windowed mode
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation( JFrame.DISPOSE_ON_CLOSE );
    frame.getContentPane().setLayout( new BorderLayout() );
    frame.getContentPane().add( canvas, BorderLayout.CENTER );
    frame.pack();
    frame.setVisible( true );

    canvas.display();
    Thread.sleep( 2000 );

    // Switch the canvas to "fullscreen" mode
    JFrame fullscreen = new JFrame();
    fullscreen.setUndecorated( true );
    fullscreen.setExtendedState( JFrame.MAXIMIZED_BOTH );
    frame.getContentPane().remove( canvas );
    frame.setVisible( false );
    fullscreen.getContentPane().setLayout( new BorderLayout() );
    fullscreen.getContentPane().add( canvas, BorderLayout.CENTER );
    fullscreen.setVisible( true );

    canvas.display();
    Thread.sleep( 2000 );
  }

  private static class MyEventListener implements GLEventListener {
    private int fTextureObject = -1;
    private GLAutoDrawable fSharing;

    @Override
    public void init( GLAutoDrawable aGLAutoDrawable ) {
      System.out.println( "Canvas init" );
      if ( fSharing != null ) {
        fSharing.display();
        return;
      }

      // When canvas is inited, share its context with a pbuffer
      System.out.println( "Creating sharing context" );
      GLProfile profile = aGLAutoDrawable.getGLProfile();
      fSharing = GLDrawableFactory.getFactory( profile ).createGLPbuffer(
          null,
          new GLCapabilities( profile ),
          new DefaultGLCapabilitiesChooser(),
          16, 16,
          aGLAutoDrawable.getContext()
      );
      // Let pbuffer check if it actually shares textures with the canvas
      fSharing.addGLEventListener( new GLEventListener() {
        @Override
        public void init( GLAutoDrawable aGLAutoDrawable ) {
        }

        @Override
        public void dispose( GLAutoDrawable aGLAutoDrawable ) {
        }

        @Override
        public void display( GLAutoDrawable aGLAutoDrawable ) {
          System.out.println( "Pbuffer display" );
          if ( fTextureObject != -1 ) {
            GL2 gl = aGLAutoDrawable.getGL().getGL2();
            Assert.assertTrue( "Texture object lost in pbuffer", gl.glIsTexture( fTextureObject ) );
          }
        }

        @Override
        public void reshape( GLAutoDrawable aGLAutoDrawable, int i, int i1, int i2, int i3 ) {
        }
      } );
      fSharing.display();
    }

    @Override
    public void dispose( GLAutoDrawable aGLAutoDrawable ) {
      System.out.println( "Canvas destroy" );
      fSharing.display();
    }

    @Override
    public void display( GLAutoDrawable aGLAutoDrawable ) {
      System.out.println( "Canvas display" );

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

      // Initialize a texture object if necessary
      if ( fTextureObject == -1 ) {
        int[] t = new int[ 1 ];
        gl.glGenTextures( 1, t, 0 );
        fTextureObject = t[ 0 ];
        gl.glClearColor( 0f, 1f, 0f, 1f );
        gl.glClear( GL2.GL_COLOR_BUFFER_BIT );
        gl.glBindTexture( GL2.GL_TEXTURE_2D, fTextureObject );
        gl.glCopyTexImage2D( GL2.GL_TEXTURE_2D, 0, GL2.GL_RGB8, 0, 0, 256, 256, 0 );
      }

      // Check if the texture object is valid. This fails after going full screen.
      Assert.assertTrue( "Texture object lost in canvas", gl.glIsTexture( fTextureObject ) );

      gl.glClearColor( 1f, 0f, 0f, 1f );
      gl.glClear( GL2.GL_COLOR_BUFFER_BIT );

      // Use the texture for visual verification
      gl.glBindTexture( GL2.GL_TEXTURE_2D, fTextureObject );
      gl.glTexParameteri( GL2.GL_TEXTURE_2D, GL2.GL_TEXTURE_MAG_FILTER, GL2.GL_LINEAR );
      gl.glTexParameteri( GL2.GL_TEXTURE_2D, GL2.GL_TEXTURE_MIN_FILTER, GL2.GL_LINEAR );

      gl.glEnable( GL2.GL_TEXTURE_2D );
      gl.glBegin( GL2.GL_QUADS );
      gl.glTexCoord2f( 0, 0 );
      gl.glVertex2f( -1, -1 );
      gl.glTexCoord2f( 1, 0 );
      gl.glVertex2f( 0, -1 );
      gl.glTexCoord2f( 1, 1 );
      gl.glVertex2f( 0, 0 );
      gl.glTexCoord2f( 0, 1 );
      gl.glVertex2f( -1, 0 );
      gl.glEnd();

      fSharing.display();
    }

    @Override
    public void reshape( GLAutoDrawable aGLAutoDrawable, int i, int i1, int i2, int i3 ) {
      System.out.println( "Canvas reshape" );
    }
  }
}