Big QPixmaps crashes with OpenGL

Question

Hello!

I'm programming a QGraphicsView that has a lot of images. But when I display a JPEG with resolution 8528 x 1128 px (a panorama image), the QGraphicsPixmapItem does not render. It just displays a black square. Images of "normal" size renders good. I have not tried to find the "magick limit" for what sizes the problem occures on.

On my laptop with Ubuntu 10.10 x64 it also chrashes the graphics card driver and restarts the Gnome session!

Everything works fine if I disable OpenGL.

Why? Are there anything I can do?

I've found another having a very similar problem: http://www.qtforum.org/article/34238/really-strange-problem-with-qgraphicsview-and-opengl.html

Answer 1

Make sure this returns something greater than 8528 on your OpenGL implementation:

GLint texSize;
glGetIntegerv(GL_MAX_TEXTURE_SIZE, &texSize);

If it doesn't you're going to have to resort to some sort of tiled rendering system so you can fit all your image data in textures smaller than the maximum size.