Java tutorial
/* * The MIT License * * Copyright 2015 Richard Coan. * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package main.java.com.YeAJG.game; import java.nio.FloatBuffer; import java.util.Iterator; import java.util.Map.Entry; import main.java.com.YeAJG.game.gfx.TextureHandler; import main.java.com.YeAJG.game.io.ConfigHandler; import main.java.com.YeAJG.game.io.InputHandler; import main.java.com.YeAJG.game.physics.Force; import main.java.com.YeAJG.game.utils.Conversions; import main.java.com.example.emitters.ExampleEmitter; import main.java.com.example.emitters.ExampleParticle; import main.java.com.example.primitives.Quad; import org.apache.logging.log4j.LogManager; import org.apache.logging.log4j.Logger; import org.lwjgl.BufferUtils; import org.lwjgl.LWJGLException; import org.lwjgl.opengl.ContextAttribs; import org.lwjgl.opengl.Display; import org.lwjgl.opengl.DisplayMode; import org.lwjgl.opengl.GL11; import org.lwjgl.opengl.PixelFormat; import org.lwjgl.util.glu.GLU; import org.lwjgl.util.vector.Matrix4f; import org.lwjgl.util.vector.Vector3f; /** * * @author Richard Coan */ public class Game implements Runnable { private static Game instance = null; private static final Logger logger = LogManager.getLogger(Game.class.getName()); public static final String Name = "YeAJGE: Demonstration"; protected ConfigHandler Config; protected InputHandler Input; private long lastFPS; private int fps; //Global Static Values public static int WINDOW_WIDTH; public static int WINDOW_HEIGHT; public static Vector3f cameraPos = null; public static FloatBuffer matrix44Buffer = null; //Moving Varibles public static Matrix4f projectionMatrix = null; public static Matrix4f viewMatrix = null; public static Game getInstance() { if (instance == null) instance = new Game(); return instance; } /** * Constructor - Singleton */ private Game() { Config = ConfigHandler.getInstance(); Input = InputHandler.getInstance(); //Load Screen Size WINDOW_WIDTH = Config.getSettings().getJsonObject("display").getInt("width"); WINDOW_HEIGHT = Config.getSettings().getJsonObject("display").getInt("height"); lastFPS = System.currentTimeMillis(); cameraPos = new Vector3f(0, 0, -1); setupOpenGL(); setupMatrices(); } /** * Set up for the projection matrix. */ private void setupMatrices() { // Setup projection matrix projectionMatrix = new Matrix4f(); float fieldOfView = 60f; float aspectRatio = (float) WINDOW_WIDTH / (float) WINDOW_HEIGHT; float near_plane = 0.1f; float far_plane = 100f; float y_scale = Conversions.coTangent(Conversions.degreesToRadians(fieldOfView / 2f)); float x_scale = y_scale / aspectRatio; float frustum_length = far_plane - near_plane; projectionMatrix.m00 = x_scale; projectionMatrix.m11 = y_scale; projectionMatrix.m22 = -((far_plane + near_plane) / frustum_length); projectionMatrix.m23 = -1; projectionMatrix.m32 = -((2 * near_plane * far_plane) / frustum_length); projectionMatrix.m33 = 0; // Setup view matrix viewMatrix = new Matrix4f(); // Create a FloatBuffer with the proper size to store our matrices later matrix44Buffer = BufferUtils.createFloatBuffer(16); } /** * Game Loop */ @Override public void run() { final int TICKS_PER_SECOND = 25; final int SKIP_TICKS = 1000 / TICKS_PER_SECOND; final int MAX_FRAMESKIP = 5; long next_game_tick = System.currentTimeMillis(); int loops; float interpolation; while (!Display.isCloseRequested()) { loops = 0; while (System.currentTimeMillis() > next_game_tick && loops < MAX_FRAMESKIP) { doTick(next_game_tick); next_game_tick += SKIP_TICKS; loops++; } interpolation = (float) (System.currentTimeMillis() + SKIP_TICKS - next_game_tick) / (float) SKIP_TICKS; render(interpolation); updateFPS(); } this.destroyGL(); } /** * Initiates Display and OpenGL, using OpenGL 3.2 */ private void setupOpenGL() { try { PixelFormat pixelFormat = new PixelFormat(); ContextAttribs contextAtrributes = new ContextAttribs(3, 2).withForwardCompatible(true) .withProfileCore(true); Display.setDisplayMode(new DisplayMode(WINDOW_WIDTH, WINDOW_HEIGHT)); Display.setTitle(Name + " " + ConfigHandler.getVersion()); Display.create(pixelFormat, contextAtrributes); } catch (LWJGLException e) { logger.fatal(e.getMessage()); System.exit(-1); } //Sets the Background color. GL11.glClearColor(0.4f, 0.6f, 0.9f, 0f); //Creates the Viewport. GL11.glViewport(0, 0, WINDOW_WIDTH, WINDOW_HEIGHT); //Enables Depth Testing. GL11.glEnable(GL11.GL_DEPTH_TEST); //Exit on Setup Error. Game.exitOnGLError("setupOpenGL"); } /** * Destroys OpenGL */ private void destroyGL() { //Deletes Textures for (Iterator<Entry<String, Integer>> it = TextureHandler.Textures.entrySet().iterator(); it.hasNext();) { Entry<String, Integer> set = it.next(); GL11.glDeleteTextures(set.getValue()); } Display.destroy(); } /** * Runs an number of work units (ticks). * @param next_game_tick */ private void doTick(long next_game_tick) { } /** * Renders the Scene. * @param interpolation */ private void render(float interpolation) { GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT); // Reset view and model matrices Game.viewMatrix = new Matrix4f(); // Translate camera Matrix4f.translate(Game.cameraPos, Game.viewMatrix, Game.viewMatrix); //TODO: Render Entites Display.sync(60); Display.update(); } /** * Calculate the FPS and set it in the title bar */ public void updateFPS() { if (System.currentTimeMillis() - lastFPS > 1000) { Display.setTitle(Name + " " + ConfigHandler.getVersion() + " (FPS: " + fps + ")"); fps = 0; //reset the FPS counter lastFPS += 1000; //add one second } fps++; } public static void exitOnGLError(String errorMessage) { int errorValue = GL11.glGetError(); if (errorValue != GL11.GL_NO_ERROR) { String errorString = GLU.gluErrorString(errorValue); logger.error(errorMessage + ": " + errorString); if (Display.isCreated()) Display.destroy(); System.exit(-1); } } }