CODEWITHSUNDEEP
javaopengltexturesjogl
Ethan
Ethan

Reputation: 1266

Basic Texture drawing with JOGL, using a Texture object

I'm trying to give the user of my application the ability to load an image of their choice to make the background. Loading the image via Java is no problem, but I can't get the image into a texture....I just end up with a big grey box on my GLCanvas. This is the code I have so far:

  //if there's an image to overlay, render it
    if (renderImage) {

        gl.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);

        if (texture == null && img != null) {

            texture = TextureIO.newTexture(img, true);
            texture.enable();
            texture.bind();
        }

        gl.glBegin(GL.GL_POLYGON);
        gl.glNormal3f(0,0,1);
            gl.glTexCoord2d(-texture.getWidth(), -texture.getHeight());
            gl.glVertex2d(-25, -25);
            gl.glTexCoord2d(-texture.getWidth(), texture.getHeight());
            gl.glVertex2d(canvas.getWidth(),0);
            gl.glTexCoord2d(texture.getWidth(), texture.getHeight());
            gl.glVertex2d(canvas.getWidth(), canvas.getHeight());
            gl.glTexCoord2d(texture.getWidth(), -texture.getHeight());
            gl.glVertex2d(0, canvas.getHeight());
        gl.glEnd();
        gl.glFlush();
    }
    //otherwise, render "grass"
    else {

        gl.glClearColor(0.0f, 0.65f, 0.0f, 0.0f);

        //Clear buffer and set background color to green (the "grass" on the sides of the intersection)
        gl.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
    }

Upvotes: 2

Views: 8238

Answers (2)

Squiva
Squiva

Reputation: 21

I put

  if (texture == null && img != null) {

        texture = TextureIO.newTexture(img, true);
        texture.enable();
        texture.bind();
    }

in a try, catch statement.

Upvotes: 1

genpfault
genpfault

Reputation: 52167

Try this:

gl.glBegin(GL.GL_QUADS);
gl.glNormal3f(0,0,1);
gl.glTexCoord2d(0.0, 0.0);
gl.glVertex2d(0.0, 0.0);
gl.glTexCoord2d(1.0, 0.0);
gl.glVertex2d(canvas.getWidth(), 0.0);
gl.glTexCoord2d(1.0, 1.0);
gl.glVertex2d(canvas.getWidth(), canvas.getHeight());
gl.glTexCoord2d(0.0, 1.0);
gl.glVertex2d(0.0, canvas.getHeight());
gl.glEnd();

Non-repeating texture coordinates are in the 0.0 to 1.0 range by default.

Upvotes: 4

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