hello there!
i'm having some problems with my opengl app (2D). Basically it is working without any problems, but when i start to move my character the whole screen starts to flicker (see image from a screenshot). Without moving everything is rendered properly!
I read about this issue using scissorstest, but i don't use any scissors...
I also read that this might happen if i'm not rendering to the backbuffer. How can i check where i render, or do i have to setup opengl in a different way to use backbuffer?
does someone have a useful advice or do you need some more infos?
thx prich
(http://img692.imageshack.us/img692/8168/testhf.png)
You may show how you initialize your screen and how you paint on the screen.
I had a similar issue when putting the GL screen into a ScrollPane... the 2D components caused the texture to overlap like shown on the shot...
Display.setTitle(title);
Display.setFullscreen(false);
if (!DEBUG)
Display.setVSyncEnabled(true);
Display.setDisplayMode(new DisplayMode(w, h));
Display.create();
GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glLoadIdentity();
GL11.glOrtho(0.0, Display.getDisplayMode().getWidth(), Display
.getDisplayMode().getHeight(), 0.0, Integer.MIN_VALUE,
Integer.MAX_VALUE);
GL11.glMatrixMode(GL11.GL_MODELVIEW);
GL11.glLoadIdentity();
GL11.glViewport(0, 0, Display.getDisplayMode().getWidth(), Display
.getDisplayMode().getHeight());
// GL11.glFrustum(0, Display.getDisplayMode().getWidth(),
// Display.getDisplayMode().getHeight(), 0 , 1, 2);
GL11.glEnable(GL11.GL_TEXTURE_2D);
GL11.glShadeModel(GL11.GL_SMOOTH);
GL11.glDisable(GL11.GL_LIGHTING);
GL11.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
GL11.glClearDepth(1);
I paint using VBOs and deathbuffer. A frame is like this:
first i fill my VBO with ts coordinats + xyz + color + normals and save it in the context with the texture (so i have to bind every texture only once).
Then i bind my texture and render quads in my vbo.
you need more?
it's funny because flushing the rendering pipeline (GL11.glFlush(); ) seems to fix all problems :)
but i still do not know why...
Quote from: prich on November 02, 2009, 18:13:09
it's funny because flushing the rendering pipeline (GL11.glFlush(); ) seems to fix all problems :)
but i still do not know why...
Did you call glClear(...) before and Display.update() after drawing each frame? Display.update() implies glFlush() as far as I know.
then flush it... :)
Quotefirst i fill my VBO with ts coordinats + xyz + color + normals and save it in the context with the texture (so i have to bind every texture only once).
you're unnecessarily calling glcleardepth(1)... there's something wrong with the depth testing. e.g. if you render everything at the same z-location.
see http://www.opengl.org/resources/faq/technical/depthbuffer.htm 1st issue, glenable(GL_DEPTH_TEST)