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texturesbindlwjgl

Trying to bind a texture to a quad in LWJGL


I'm trying to bind a simple texture to a quad with LWJGL.

So far i've made a quad, which i can move around with my arrow keys, but when i'm trying to add a texture to it with the .bind() method, nothing happens.

Here's my code :

    import java.io.*;
    import org.lwjgl.LWJGLException;
    import org.lwjgl.input.Keyboard;
    import org.lwjgl.opengl.Display;
    import org.lwjgl.opengl.DisplayMode;
    import org.lwjgl.opengl.GL11;
    import org.newdawn.slick.Color;
    import org.newdawn.slick.opengl.Texture;
    import org.newdawn.slick.opengl.TextureLoader;
    import org.newdawn.slick.util.ResourceLoader;


    public class Test {

        Texture texture;

        boolean stop;

        float x = 400;
        float y = 300;

        public Test(){
            stop = false;
        }

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

        public void start(){
            try{
                Display.setDisplayMode(new DisplayMode(800, 600));
                Display.setTitle("Jepla");
                Display.create();
                Display.setVSyncEnabled(true);
            }
            catch(LWJGLException e){
                System.out.println(e);
            }

            initGL();

            while(!Display.isCloseRequested()){
                updateGL();
                renderGL();

                Display.update();
                Display.sync(120);
            }

            Display.destroy();
        }

        public void initGL(){
            GL11.glMatrixMode(GL11.GL_PROJECTION);
            GL11.glLoadIdentity();
            GL11.glOrtho(0, 800, 0, 600, 1, -1);
            GL11.glMatrixMode(GL11.GL_MODELVIEW);

            try{
                texture = TextureLoader.getTexture("PNG", ResourceLoader.getResourceAsStream("men.png"));

                System.out.println("Texture loaded: "+texture);
                System.out.println(">> Image width: "+texture.getImageWidth());
                System.out.println(">> Image height: "+texture.getImageHeight());
                System.out.println(">> Texture width: "+texture.getTextureWidth());
                System.out.println(">> Texture height: "+texture.getTextureHeight());
                System.out.println(">> Texture ID: "+texture.getTextureID());

            }
            catch(IOException ioe){
                System.out.println(ioe);
            }
        }

        public void renderGL(){

            GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT);

            GL11.glColor3f(0.5f,0.5f,0.2f);

            GL11.glBindTexture(GL11.GL_TEXTURE_2D, texture.getTextureID());

            GL11.glPushMatrix();

                GL11.glBegin(GL11.GL_QUADS);
                    GL11.glVertex2f(x,y);
                    GL11.glVertex2f(x+texture.getTextureWidth(),y);
                    GL11.glVertex2f(x+texture.getTextureWidth(),y+texture.getTextureHeight());
                    GL11.glVertex2f(x,y+texture.getTextureHeight());
                GL11.glEnd();
            GL11.glPopMatrix();



        }

        public void updateGL(){

            if (Keyboard.isKeyDown(Keyboard.KEY_LEFT)) x = x-1;
            if (Keyboard.isKeyDown(Keyboard.KEY_RIGHT)) x = x+1;

            if (Keyboard.isKeyDown(Keyboard.KEY_UP)) y = y+1;
            if (Keyboard.isKeyDown(Keyboard.KEY_DOWN)) y = y-1;

            if (x < 0) x = 0;
            if (x > 800) x = 800;
            if (y < 0) y = 0;
            if (y > 600) y = 600;
        }

    }

Solution

  • You need to enable textures

    glEnable(GL_TEXTURE_2D);
    

    Also you need to tell opengl where to pin the texture on what ever you are drawing on like this

    texture.bind();
    glBegin(GL11.GL_QUADS);
                    glTexCoord2f(0, 0); // top left
                    glVertex2f(x,y);
    
                    glTexCoord2f(0, 1); // bottom left 
                    glVertex2f(x, y + objects_Y_size);
    
                    glTexCoord2f(1, 1); // bottom right
                    glVertex2f(x + objects_X_size,y + objects_Y_size);
    
                    glTexCoord2f(1, 0); // top right
                    glVertex2f(x + objects_X_size, y);
                glEnd();
    

    Im no pro at opengl or LWJGL but i always bind textures in the way you see in the above code

    You can also avoid using GL11. for every call if you import opengl like this

    import static org.lwjgl.opengl.GL11.*;
    

    gl buddy