Initial note: You do not need to have knowledge of LWJGL or OpenGL to review this code. The only parts of the code that require LWJGL knowledge are the Game class, and the rest, although it may contain some LWJGL/OpenGL/Slick-util code, it is rather self explanatory for anybody who's worked in Java before.
So I've built this simple game in Java using LWJGL. It's a relatively simple platformer, and I would like some opinions on my code so that I can correct it. Feel free to leave any constructive criticism or thoughts that you may have. Any and all opinions are appreciated. This is my first game, so it's bound to be a bit rough. This is also still early in development. I'll post all the classes that I've written code for so far.
Game class:
import static org.lwjgl.opengl.GL11.*;
import org.lwjgl.LWJGLException;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import org.newdawn.slick.opengl.Texture;
import com.hasherr.platformer.entity.Player;
public class Game { // starts game & manages display/init OpenGL
public Game() {
initDisplay(800, 500, "Komo"); // Temporary game name - KOMO
}
// initiate necessary classes
Player player = new Player(); // user-representation
InputHandler inputHandler = new InputHandler(player);
SpriteHandler spriteHandler = new SpriteHandler();
TextureHandler textureHandler = new TextureHandler();
private void initDisplay(int width, int height, String title) {
try {
Display.setDisplayMode(new DisplayMode(width, height));
Display.setTitle(title);
Display.create();
} catch (LWJGLException e) {
e.printStackTrace();
System.exit(0);
}
grabAllTextures();
while (!Display.isCloseRequested()) {
Display.update();
Display.sync(60); // 60 FPS
inputHandler.handleInput();
initGL(width, height);
spriteHandler.drawSprite(playerTexture, player.xPos, player.yPos);
}
Display.destroy();
}
private void initGL(int width, int height) {
glClear(GL_COLOR_BUFFER_BIT); // clear screen for efficient rendering
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, width, 0, height, 1, -1); // set orthographic view
glMatrixMode(GL_MODELVIEW);
glEnable(GL_TEXTURE_2D); // enable 2d rendering for textures & sprites
}
// Textures (only one so far)
Texture playerTexture;
private void grabAllTextures() { // basically TextHandler in one method.
playerTexture = textureHandler.grabTexture("Png", "scary_monster"); // on tex so far
}
public static void main(String[] args) { // start yer engines
new Game(); // start the show, ready go
}
}
InputHandler Class:
import org.lwjgl.input.Keyboard;
import org.lwjgl.input.Mouse;
import com.hasherr.platformer.entity.Player;
public class InputHandler { // handles all input
Player player;
public InputHandler(Player targetToHandle) {
player = targetToHandle;
}
public void handleInput() {
// keyboard input
if (!Keyboard.isKeyDown(Keyboard.KEY_D) && !Keyboard.isKeyDown( // no
Keyboard.KEY_A) && !Keyboard.isKeyDown(Keyboard.KEY_SPACE)) { // input
player.moveSpeed = 10.0f;
}
if (Keyboard.isKeyDown(Keyboard.KEY_D)) {
player.moveRight(); // move right
}
if (Keyboard.isKeyDown(Keyboard.KEY_A)) {
player.moveLeft(); // move left
}
if (Keyboard.isKeyDown(Keyboard.KEY_SPACE)) {
// jump
}
// mouse input
if (Mouse.isButtonDown(0)) {
}
}
}
SpriteHandler class:
import org.newdawn.slick.opengl.Texture;
import static org.lwjgl.opengl.GL11.*;
public class SpriteHandler { // draws all textures onto quads & handles importing of textures
public void drawSprite(Texture texture, float x, float y) {
float width = texture.getImageWidth();
float height = texture.getImageHeight();
texture.bind(); // wrap it before you tap it. (bind it)
glBegin(GL_QUADS);
glTexCoord2f(0, 1);
glVertex2f(x, y);
glTexCoord2f(1, 1);
glVertex2f(x + width, y);
glTexCoord2f(1, 0);
glVertex2f(x + width, y + height);
glTexCoord2f(0, 0);
glVertex2f(x, y + height);
glEnd();
}
}
TextureHandler class:
import java.io.IOException;
import org.newdawn.slick.opengl.Texture;
import org.newdawn.slick.opengl.TextureLoader;
import org.newdawn.slick.util.ResourceLoader;
public class TextureHandler {
Texture texture;
public Texture grabTexture(String ext, String name) {
try {
texture = TextureLoader.getTexture(
ext.toUpperCase(), ResourceLoader.getResourceAsStream(
"/res/textures/" + name + "." + ext.toLowerCase()));
} catch (IOException e) {
e.printStackTrace();
}
return texture;
}
}
And last but not least, the Player class:
public class Player { // controls Player & player physics
// velocity & physics fields
private float angle = 30.0f;
private float acceleration = 3.0f;
private float scaleX = (float) Math.cos(angle);
private float scaleY = (float) Math.sin(angle);
public float moveSpeed = 16.0f; // initial value, obv. set to move
private final static int MAX_MOVE_SPEED = 150;
private float xVelocity = scaleX * moveSpeed;
private float yVelocity = scaleY * moveSpeed;
// position fields
public float xPos = 0; // init
public float yPos = 0; // init
private void printPos() {
System.out.println("Movespeed: " + moveSpeed + ", X-Velocity: "
+ xVelocity);
}
private void handleAcceleration(float force) {
if (moveSpeed < MAX_MOVE_SPEED && moveSpeed > -MAX_MOVE_SPEED) {
moveSpeed += force;
xVelocity = scaleX * moveSpeed;
} else if (moveSpeed >= MAX_MOVE_SPEED) {
moveSpeed = MAX_MOVE_SPEED;
xVelocity = scaleX * moveSpeed;
} else if (moveSpeed <= -MAX_MOVE_SPEED) {
moveSpeed = -MAX_MOVE_SPEED;
xVelocity = scaleX * moveSpeed;
}
xPos += xVelocity;
}
public void moveRight() {
handleAcceleration(acceleration);
printPos();
}
public void moveLeft() {
handleAcceleration(-acceleration);
printPos();
}
public void jump() {
// jump (spacebar)
}
public void shoot() {
// shoot (mouse)
}
}
Like I said, these are only the classes that I've coded so far. All my code is open-source, so if you want to view the whole repository, you can view it here. Let me know if you guys need anything else, as I'll be glad to help anybody who is willing to help me.
