Windows scaling causes blank spaces in JOGL

Question

Im using Java OpenGL binding (JOGL 2.3.2) and the problem is my canvas is stuck in lower left corner of my form, so no matter what i write, theres black spaces on the top and right of canvas.

I figured out that this is because the scaling in my windows settings is set to 125%, and if i set it to 100%, the problem goes away. But, i feel like this is not the right way to solve such problems. Here is my code for creating a frame:

//FrameMain class just adds listener to frame so it can be closed by pressing cross button
final FrameMain frame = new FrameMain("Form 1");
frame.setSize(720, 720);

final GLProfile profile = GLProfile.get(GLProfile.GL2);
GLCapabilities capabilities = new GLCapabilities(profile);

// The canvas
final GLCanvas glcanvas = new GLCanvas(capabilities);
AppMain b = new AppMain();
glcanvas.addGLEventListener(b);
glcanvas.setSize(720, 720);
frame.add(glcanvas);
frame.setVisible(true);

And my display and reshape methods:

public void display(GLAutoDrawable drawable) {
    GL2 gl = drawable.getGL().getGL2();
    gl.glBegin(GL2.GL_QUADS);
    gl.glVertex3f(-1, 1, 0);
    gl.glVertex3f(1, 1, 0);
    gl.glVertex3f(1, -1, 0);
    gl.glVertex3f(-1, -1, 0);
    gl.glEnd();
}

public void reshape(GLAutoDrawable drawable, int x, int y, int width, int height) {
    GL2 gl = drawable.getGL().getGL2();

    gl.glLoadIdentity();
    gl.glViewport(0, 0, width, height);
}

The result i am getting:

How do i make so canvas occupy full form, and not like it is now?

PS: i cant change technologies used, it should be JOGL and something that creates window without external libraries. Yes, i know that swing is outdated and ugly

You probably get the scaled size in the `reshape` callback. So the viewport is set with the wrong size (`gl.glViewport(0, 0, width, height);`) — Rabbid76, Nov 06 '22 at 19:32
Hm, you are right, adding 25% to width and height in viewport fixes the problem, but only with case when it scaled 125%. I might think about how to make it universal for every scaling percentage and post the answer with that — StreakerOne, Nov 06 '22 at 20:53

score 1 · Accepted Answer · edited Nov 07 '22 at 19:20

1

So, using Rabbid76's advice, I came up with this solution: I added this to my class, using this answer https://stackoverflow.com/a/70119734/20433881 :

    private static JFrame frame = null;
    private static float scalingFactor;
    
    private static float getScalingFactor() {
        return (float) getWindow(frame).getGraphicsConfiguration().getDefaultTransform().getScaleX();
    }

Added this line to main(), after creation of a frame:

scalingFactor = getScalingFactor();

And also I changed line with viewport like this:

gl.glViewport(0, 0, (int) (width * scalingFactor), (int) (height * scalingFactor));

edited Nov 07 '22 at 19:20

gouessej

3,640
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answered Nov 06 '22 at 21:43

StreakerOne

73
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Your workaround is correct but if you want to give us a chance to fix it within JOGL, rather post on our official forum and indicate at least which version of Java you use. – gouessej Nov 07 '22 at 19:20
I use this workaround: https://jogamp.org/cgit/ardor3d.git/tree/ardor3d-jogl-awt/src/main/java/com/ardor3d/framework/jogl/awt/JoglAwtCanvas.java#n67 – gouessej Nov 07 '22 at 19:24

Windows scaling causes blank spaces in JOGL

1 Answers1