[LWJGL] Problem with Viewport and Windows Aero vs. Basic

OpenGL Development
#1

Hello,

today I used a different PC than I’m usually using for my OpenGL development. On my standard PC I run Win7 with Windows Aero … everything works just fine. But on this new maschine I get a different result using Viewports:

Normal PC / different PC with basic (intended):

different PC with Aero (problem):

It appears that for same reason the glViewport(5, 5, widht, height) gets transformed to glViewport(10, 0, width, height) … or something like that. I checked the glViewport call and the values are correct but the result stays flawed.
Also interesting: as soon as I change the displayMode or manually resize the window the viewport gets applyed correctly.

Can someone explain why this problem occurs?
Thanks!

#2

Ooof…this might be an LWJGL bug. Are you using the latest version?

#3

I’m using 2.8.5 which should be the latest version. If someone has an idea feel free to post here. I think I might post it in the lwjgl forums as well an see if I get an answer there.

#4

Give us code, so we can actually make some informed suggestions. :point:

#5

Sorry this comes two days late, had lots of work to do. Here some code:

glInit (Display)

	private void glInitContext() {
		DisplayMode displayMode = new DisplayMode(main.getWidth(), main.getHeight());
		windowDimensions = new int[] { 0, 0, main.getWidth(), main.getHeight() };
		PixelFormat pixelFormat = new PixelFormat().withSamples(8);
		try {
			Display.setDisplayMode(displayMode);
			Display.create(pixelFormat);
			Display.setTitle(title);
			Display.setResizable(resizable);
		} catch (LWJGLException e) {
			e.printStackTrace();
		}
		glEnable(GL_DEPTH_TEST);
		glDepthFunc(GL_LEQUAL);
		glDepthMask(true);
		glDepthRange(0.0f, 1.0f);
		glEnable(GL_BLEND);
		glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
		glEnable(GL_MULTISAMPLE);
		glEnable(GL_SCISSOR_TEST);
		glViewport(0, 0, Display.getWidth(), Display.getHeight());
		glScissor(0, 0, Display.getWidth(), Display.getHeight());
		EPHVertexArrayObject.glInitShaderProgramPool(shaderParentPath);
		glInitialized = true;
		synchronized (glInitMonitor) {
			glInitMonitor.notifyAll();
		}
	}

glDraw (VAO)

public synchronized void glRender() {
		if (handle < 0 || !updated) glInit();
		if (size > 0 && hasVisibleEntries()) {
			glBindVertexArray(handle);
			glViewport(viewPortRect[0], viewPortRect[1], viewPortRect[2], viewPortRect[3]); // viewportRect is set correctly
			glScissor(scissorRect[0], scissorRect[1], scissorRect[2], scissorRect[3]); // scissorRect is also set correctly
                        // Binding the Program
                        // upload the uniforms
                        // glDrawElements(...)
                        // unbind the Program
			glBindVertexArray(0);
		}
	}

I’m not too sure what kind of code you’d like to see … I thought this are the parts where the viewport is important .

#6

I know this comes late, but I finally managed to resolve the problem and for further reference here the solution (that worked for me):
For some reason the LWJGL Display bugs out if you issue Display.create(…) before the Display.setResizable(true). So the solution for me was changing

//...
Display.setDisplayMode(displayMode);
Display.create(pixelFormat);
Display.setResizable(resizable); // true
// ...

to

// ...
Display.setDisplayMode(displayMode);
Display.setResizable(resizable); // true
Display.create(pixelFormat);
// ...