LWJGL adds line above my texture

Question

EDIT - I fixed it while I was waiting for this to be answered. I will leave this here for others who will run into thsi problem.

The problem was that the image i was loading was 1280 x 100, and that was not a proper aspect ratio, so when I changed it to 1280 x 720, it fixed itself.

When I render the ground-layer quad, it draws a textured line above it. It is the only texture that does that.

It is the only one of my textures that does that. And I even checked if maybe I drew an extra line in PAINT.NET but no, it looks normal outside the game.

    //Ground
    GL11.glPushMatrix();

    Color.white.bind();
    TextureBuffer.Level_TutorialGround.bind();

    GL11.glBegin(GL11.GL_QUADS);

    GL11.glTexCoord2f(0, 0);
    GL11.glVertex2f(-100, 650);
    GL11.glTexCoord2f(1, 0);
    GL11.glVertex2f(1950, 650);
    GL11.glTexCoord2f(1, 1);
    GL11.glVertex2f(1950, 500);
    GL11.glTexCoord2f(0, 1);
    GL11.glVertex2f(-100, 500);

    GL11.glEnd();

    GL11.glPopMatrix();

That is my rendering code, in case it matters.

And a weird thing is that when I first placed the quad in the scene it looked fine, but after I re-positioned it via Hot Code swap(Debug mode in eclipse) it added the line.

EDIT: My texture loading stuff: (I removed the other texture's loading stuff for the sake of space)

public static void loadTextures() throws IOException {
    try {
    Level_TutorialGround = TextureLoader.getTexture("PNG", ResourceLoader.getResourceAsStream("res/textures/Level_TutorialGround.png"));
        System.out.println("Texture loaded: " + "Level_TutorialGround");
        System.out.println(">> Image width: " + Level_TutorialGround.getImageWidth());
        System.out.println(">> Image height: " + Level_TutorialGround.getImageHeight());
        System.out.println(">> Texture width: " + Level_TutorialGround.getTextureWidth());
        System.out.println(">> Texture height: " + Level_TutorialGround.getTextureHeight());
        System.out.println(">> Texture ID: " + Level_TutorialGround.getTextureID());
    } finally {
        doneLoading = true;
    }

Is your texture repeating? If it is it may be the way you load the texture. Can you post your texture loading code. — Jesse Laning
I actually considered whether or not it was repeating, i'm just using slick2d to load textures. — mcmonkeyninja
GL's default texture wrap state is GL_REPEAT, and the texture coordinates (1.0) and (0.0) are actually on the boundary between the edge/border of your image. This means that if you use a linear texture filter, your texels will be partially sampled from the other side. There are a couple of ways to solve this, but if you just want to stretch this texture over your quad a single time the absolute easiest way is simply to use GL_CLAMP_TO_EDGE for GL_TEXTURE_WRAP_S and GL_TEXTURE_WRAP_T. — Andon M. Coleman
@mcmonkeyninja When you load your image replace your texture line with this Level_TutorialGround = TextureLoader.getTexture("PNG", ResourceLoader.getResourceAsStream("res/textures/Level_TutorialGround.png"), GL11.GL_NEAREST); — Jesse Laning
Thanks, I will use ya'lls suggestions for when I run into this problem again, but I found an easier way to fix it for this situation. Thanks for your help — mcmonkeyninja

Andon M. Coleman Andon M. Coleman · Accepted Answer · 2013-12-24T19:19:20

GL's default texture wrap state is GL_REPEAT, and the texture coordinates (1.0) and (0.0) are actually on the boundary between the edge/border of your image.

This means that if you use a linear texture filter (also default), your texels will be partially sampled from the other side (hence the term repeat) at the edges of your quad. There are a couple of ways to solve this, but if you just want to stretch this texture over your quad a single time the absolute easiest way is simply to use GL_CLAMP_TO_EDGE for GL_TEXTURE_WRAP_S and GL_TEXTURE_WRAP_T.

You can fix this by setting your texture's wrap state like so:

TextureBuffer.Level_TutorialGround.bind ();

GL11.glTexParameteri (GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_S, GL12.GL_CLAMP_TO_EDGE);
GL11.glTexParameteri (GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_T, GL12.GL_CLAMP_TO_EDGE);

However, texture objects track this state persistently so you would only need to do this when you first load your texture.

LWJGL adds line above my texture

The problem was that the image i was loading was 1280 x 100, and that was not a proper aspect ratio, so when I changed it to 1280 x 720, it fixed itself.

1 Answers