Posted by gouessej on Feb 08, 2024; 9:07am
URL: https://forum.jogamp.org/What-s-the-relation-between-GLCanvas-setsize-JFrame-setsize-JFrame-getLocationOnScreen-and-gl-glView-tp4043298p4043299.html

Hello

Don't make a confusion between the size of the canvas/frame/window (it becomes even more complicated with HiDPI) and the size of the viewport, these are distinct concepts.

Moreover, OpenGL and Swing/AWT can have distinct point of references.

You can implement this method to set the viewport when the canvas has just been resized:
https://jogamp.org/deployment/jogamp-next/javadoc/jogl/javadoc/com/jogamp/opengl/GLEventListener.html#reshape(com.jogamp.opengl.GLAutoDrawable,int,int,int,int)