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package jme3test.terrain;

import jme3tools.converters.ImageToAwt;
import com.jme3.app.SimpleApplication;
import com.jme3.font.BitmapText;
import com.jme3.input.KeyInput;
import com.jme3.input.controls.ActionListener;
import com.jme3.input.controls.KeyTrigger;
import com.jme3.light.DirectionalLight;
import com.jme3.light.PointLight;
import com.jme3.material.Material;
import com.jme3.math.ColorRGBA;
import com.jme3.math.Vector3f;
import com.jme3.scene.Geometry;
import com.jme3.terrain.geomipmap.TerrainLodControl;
import com.jme3.terrain.heightmap.AbstractHeightMap;
import com.jme3.terrain.heightmap.ImageBasedHeightMap;
import com.jme3.terrain.geomipmap.TerrainQuad;
import com.jme3.terrain.geomipmap.lodcalc.DistanceLodCalculator;
import com.jme3.terrain.geomipmap.lodcalc.SimpleLodThreshold;
import com.jme3.texture.Texture;
import com.jme3.texture.Texture.WrapMode;

/**
 * Demonstrates how to use terrain.
 * The base terrain class it uses is TerrainQuad, which is a quad tree of actual
 * meshes called TerainPatches.
 * There are a couple options for the terrain in this test:
 * The first is wireframe mode. Here you can see the underlying trianglestrip structure.
 * You will notice some off lines; these are degenerate triangles and are part of the
 * trianglestrip. They are only noticeable in wireframe mode.
 * Second is Tri-Planar texture mode. Here the textures are rendered on all 3 axes and
 * then blended together to reduce distortion and stretching.
 * Third, which you have to modify the code to see, is Entropy LOD calculations.
 * In the constructor for the TerrainQuad, un-comment the final parameter that is
 * the LodPerspectiveCalculatorFactory. Then you will see the terrain flicker to start
 * while it calculates the entropies. Once it is done, it will pick the best LOD value
 * based on entropy. This method reduces "popping" of terrain greatly when LOD levels
 * change. It is highly suggested you use it in your app.
 *
 * @author bowens
 */
public class TerrainTest extends SimpleApplication {

    private TerrainQuad terrain;
    Material matRock;
    Material matWire;
    boolean wireframe = false;
    boolean triPlanar = false;
    protected BitmapText hintText;
    PointLight pl;
    Geometry lightMdl;
    private float grassScale = 64;
    private float dirtScale = 16;
    private float rockScale = 128;

    public static void main(String[] args) {
        TerrainTest app = new TerrainTest();
        app.start();
    }

    @Override
    public void initialize() {
        super.initialize();

        loadHintText();
    }

    @Override
    public void simpleInitApp() {
        setupKeys();

        // First, we load up our textures and the heightmap texture for the terrain

        // TERRAIN TEXTURE material
        matRock = new Material(assetManager, "Common/MatDefs/Terrain/Terrain.j3md");
        matRock.setBoolean("useTriPlanarMapping", false);

        // ALPHA map (for splat textures)
        matRock.setTexture("Alpha", assetManager.loadTexture("Textures/Terrain/splat/alphamap.png"));

        // HEIGHTMAP image (for the terrain heightmap)
        Texture heightMapImage = assetManager.loadTexture("Textures/Terrain/splat/mountains512.png");

        // GRASS texture
        Texture grass = assetManager.loadTexture("Textures/Terrain/splat/grass.jpg");
        grass.setWrap(WrapMode.Repeat);
        matRock.setTexture("Tex1", grass);
        matRock.setFloat("Tex1Scale", grassScale);

        // DIRT texture
        Texture dirt = assetManager.loadTexture("Textures/Terrain/splat/dirt.jpg");
        dirt.setWrap(WrapMode.Repeat);
        matRock.setTexture("Tex2", dirt);
        matRock.setFloat("Tex2Scale", dirtScale);

        // ROCK texture
        Texture rock = assetManager.loadTexture("Textures/Terrain/splat/road.jpg");
        rock.setWrap(WrapMode.Repeat);
        matRock.setTexture("Tex3", rock);
        matRock.setFloat("Tex3Scale", rockScale);

        // WIREFRAME material
        matWire = new Material(assetManager, "Common/MatDefs/Misc/Unshaded.j3md");
        matWire.getAdditionalRenderState().setWireframe(true);
        matWire.setColor("Color", ColorRGBA.Green);

        // CREATE HEIGHTMAP
        AbstractHeightMap heightmap = null;
        try {
            //heightmap = new HillHeightMap(1025, 1000, 50, 100, (byte) 3);

            heightmap = new ImageBasedHeightMap(ImageToAwt.convert(heightMapImage.getImage(), false, true, 0), 1f);
            heightmap.load();

        } catch (Exception e) {
            e.printStackTrace();
        }

        /*
         * Here we create the actual terrain. The tiles will be 65x65, and the total size of the
         * terrain will be 513x513. It uses the heightmap we created to generate the height values.
         */
        /**
         * Optimal terrain patch size is 65 (64x64).
         * The total size is up to you. At 1025 it ran fine for me (200+FPS), however at
         * size=2049, it got really slow. But that is a jump from 2 million to 8 million triangles...
         */
        terrain = new TerrainQuad("terrain", 65, 513, heightmap.getHeightMap());
        TerrainLodControl control = new TerrainLodControl(terrain, getCamera());
        control.setLodCalculator( new DistanceLodCalculator(65, 2.7f) ); // patch size, and a multiplier
        terrain.addControl(control);
        terrain.setMaterial(matRock);
        terrain.setLocalTranslation(0, -100, 0);
        terrain.setLocalScale(2f, 1f, 2f);
        rootNode.attachChild(terrain);

        DirectionalLight light = new DirectionalLight();
        light.setDirection((new Vector3f(-0.5f, -1f, -0.5f)).normalize());
        rootNode.addLight(light);

        cam.setLocation(new Vector3f(0, 10, -10));
        cam.lookAtDirection(new Vector3f(0, -1.5f, -1).normalizeLocal(), Vector3f.UNIT_Y);
    }

    public void loadHintText() {
        hintText = new BitmapText(guiFont, false);
        hintText.setSize(guiFont.getCharSet().getRenderedSize());
        hintText.setLocalTranslation(0, getCamera().getHeight(), 0);
        hintText.setText("Hit T to switch to wireframe,  P to switch to tri-planar texturing");
        guiNode.attachChild(hintText);
    }

    private void setupKeys() {
        flyCam.setMoveSpeed(50);
        inputManager.addMapping("wireframe", new KeyTrigger(KeyInput.KEY_T));
        inputManager.addListener(actionListener, "wireframe");
        inputManager.addMapping("triPlanar", new KeyTrigger(KeyInput.KEY_P));
        inputManager.addListener(actionListener, "triPlanar");
    }
    private ActionListener actionListener = new ActionListener() {

        public void onAction(String name, boolean pressed, float tpf) {
            if (name.equals("wireframe") && !pressed) {
                wireframe = !wireframe;
                if (!wireframe) {
                    terrain.setMaterial(matWire);
                } else {
                    terrain.setMaterial(matRock);
                }
            } else if (name.equals("triPlanar") && !pressed) {
                triPlanar = !triPlanar;
                if (triPlanar) {
                    matRock.setBoolean("useTriPlanarMapping", true);
                    // planar textures don't use the mesh's texture coordinates but real world coordinates,
                    // so we need to convert these texture coordinate scales into real world scales so it looks
                    // the same when we switch to/from tr-planar mode
                    matRock.setFloat("Tex1Scale", 1f / (float) (512f / grassScale));
                    matRock.setFloat("Tex2Scale", 1f / (float) (512f / dirtScale));
                    matRock.setFloat("Tex3Scale", 1f / (float) (512f / rockScale));
                } else {
                    matRock.setBoolean("useTriPlanarMapping", false);
                    matRock.setFloat("Tex1Scale", grassScale);
                    matRock.setFloat("Tex2Scale", dirtScale);
                    matRock.setFloat("Tex3Scale", rockScale);
                }
            }
        }
    };
}
