/*
 * Copyright (c) 2009-2021 jMonkeyEngine
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
 *   may be used to endorse or promote products derived from this software
 *   without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package jme3test.post;

import com.jme3.app.SimpleApplication;
import com.jme3.material.Material;
import com.jme3.math.ColorRGBA;
import com.jme3.math.FastMath;
import com.jme3.math.Quaternion;
import com.jme3.math.Vector3f;
import com.jme3.post.SceneProcessor;
import com.jme3.profile.AppProfiler;
import com.jme3.renderer.Camera;
import com.jme3.renderer.RenderManager;
import com.jme3.renderer.ViewPort;
import com.jme3.renderer.queue.RenderQueue;
import com.jme3.scene.Geometry;
import com.jme3.scene.shape.Box;
import com.jme3.system.AppSettings;
import com.jme3.system.JmeContext.Type;
import com.jme3.texture.FrameBuffer;
import com.jme3.texture.FrameBuffer.FrameBufferTarget;
import com.jme3.texture.Image.Format;
import com.jme3.util.BufferUtils;
import com.jme3.util.Screenshots;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.image.BufferedImage;
import java.nio.ByteBuffer;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

/**
 * This test renders a scene to an offscreen framebuffer, then copies
 * the contents to a Swing JFrame. Note that some parts are done inefficiently,
 * this is done to make the code more readable.
 */
public class TestRenderToMemory extends SimpleApplication implements SceneProcessor {

    private Geometry offBox;
    private float angle = 0;

    private FrameBuffer offBuffer;
    private ImageDisplay display;

    private static final int width = 800, height = 600;

    private final ByteBuffer cpuBuf = BufferUtils.createByteBuffer(width * height * 4);
    private final BufferedImage image = new BufferedImage(width, height,
                                            BufferedImage.TYPE_INT_BGR);

    private class ImageDisplay extends JPanel {

        private long t;
        private long total;
        private int frames;
        private int fps;

        @Override
        public void paintComponent(Graphics gfx) {
            super.paintComponent(gfx);
            Graphics2D g2d = (Graphics2D) gfx;

            if (t == 0)
                t = timer.getTime();

//            g2d.setBackground(Color.BLACK);
//            g2d.clearRect(0,0,width,height);

            synchronized (image){
                g2d.drawImage(image, null, 0, 0);
            }

            long t2 = timer.getTime();
            long dt = t2 - t;
            total += dt;
            frames ++;
            t = t2;

            if (total > timer.getResolution()) {
                fps = frames;
                total = 0;
                frames = 0;
            }

            g2d.setColor(Color.white);
            g2d.drawString("FPS: "+fps, 0, getHeight() - 100);
        }
    }

    public static void main(String[] args){
        TestRenderToMemory app = new TestRenderToMemory();
        app.setPauseOnLostFocus(false);
        AppSettings settings = new AppSettings(true);
        settings.setResolution(1, 1);
        app.setSettings(settings);
        app.start(Type.OffscreenSurface);
    }

    public void createDisplayFrame(){
        SwingUtilities.invokeLater(new Runnable(){
            @Override
            public void run(){
                JFrame frame = new JFrame("Render Display");
                display = new ImageDisplay();
                display.setPreferredSize(new Dimension(width, height));
                frame.getContentPane().add(display);
                frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
                frame.addWindowListener(new WindowAdapter(){
                    @Override
                    public void windowClosed(WindowEvent e){
                        stop();
                    }
                });
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setResizable(false);
                frame.setVisible(true);
            }
        });
    }

    public void updateImageContents(){
        cpuBuf.clear();
        renderer.readFrameBuffer(offBuffer, cpuBuf);

        synchronized (image) {
            Screenshots.convertScreenShot2(cpuBuf.asIntBuffer(), image);    
        }

        if (display != null)
            display.repaint();
    }

    public void setupOffscreenView(){
        Camera offCamera = new Camera(width, height);

        // create a pre-view. a view that is rendered before the main view
        ViewPort offView
                = renderManager.createPreView("Offscreen View", offCamera);
        offView.setBackgroundColor(ColorRGBA.DarkGray);
        offView.setClearFlags(true, true, true);
        
        // this will let us know when the scene has been rendered to the 
        // frame buffer
        offView.addProcessor(this);

        // create offscreen framebuffer
        offBuffer = new FrameBuffer(width, height, 1);

        //setup framebuffer's cam
        offCamera.setFrustumPerspective(45f, 1f, 1f, 1000f);
        offCamera.setLocation(new Vector3f(0f, 0f, -5f));
        offCamera.lookAt(new Vector3f(0f, 0f, 0f), Vector3f.UNIT_Y);

        //setup framebuffer's texture
//        offTex = new Texture2D(width, height, Format.RGBA8);

        //setup framebuffer to use renderbuffer
        // this is faster for gpu -> cpu copies
        offBuffer.setDepthTarget(FrameBufferTarget.newTarget(Format.Depth));
        offBuffer.addColorTarget(FrameBufferTarget.newTarget(Format.RGBA8));
        
        //set viewport to render to offscreen framebuffer
        offView.setOutputFrameBuffer(offBuffer);

        // setup framebuffer's scene
        Box boxMesh = new Box(1, 1, 1);
        Material material = assetManager.loadMaterial("Interface/Logo/Logo.j3m");
        offBox = new Geometry("box", boxMesh);
        offBox.setMaterial(material);

        // attach the scene to the viewport to be rendered
        offView.attachScene(offBox);
    }

    @Override
    public void simpleInitApp() {
        setupOffscreenView();
        createDisplayFrame();
    }

    @Override
    public void simpleUpdate(float tpf){
        Quaternion q = new Quaternion();
        angle += tpf;
        angle %= FastMath.TWO_PI;
        q.fromAngles(angle, 0, angle);

        offBox.setLocalRotation(q);
        offBox.updateLogicalState(tpf);
        offBox.updateGeometricState();
    }

    @Override
    public void initialize(RenderManager rm, ViewPort vp) {
    }

    @Override
    public void reshape(ViewPort vp, int w, int h) {
    }

    @Override
    public boolean isInitialized() {
        return true;
    }

    @Override
    public void preFrame(float tpf) {
    }

    @Override
    public void postQueue(RenderQueue rq) {
    }

    /**
     * Update the CPU image's contents after the scene has
     * been rendered to the framebuffer.
     */
    @Override
    public void postFrame(FrameBuffer out) {
        updateImageContents();
    }

    @Override
    public void cleanup() {
    }

    @Override
    public void setProfiler(AppProfiler profiler) {
        // not implemented
    }


}
