GLCanvas Animation with glOrtho

[2kewl4u]

Hey guys. sry for bothering you, but i'm trying to animate a simple box with LWJGL in a SWT GLCanvas.

i took the example with the torus: http://www.java2s.com/Code/Java/SWT-JFace-Eclipse/drawarotatingtorususingtheLWJGLOpenGLbinding.htm

i change the glu perspective to

glOrtho(0.0, bounds.width, bounds.height, 0.0, -1.0, 1.0);

and instead of drawing the torus i draw a simple quad:

GL11.glBegin(GL11.GL_LINE_LOOP);
GL11.glVertex2f(rot, 100);
GL11.glVertex2f(rot + 200, 100);
GL11.glVertex2f(rot + 200, 100 + 200);
GL11.glVertex2f(rot, 100 + 200);
GL11.glEnd();

might be that i have a problem with my eyes, but i notive that the picture is shacking. the animation is not smooth. if i do the same animation with only Display of LWJGL, i don't notice the shacking. so i guess it has something to do with the GLCanvas. the torus example uses a GLU perspective and i couldn't notice anything bad with the animation of the example, but when i use ortho-mode, the problem appears.

can anyone confirm what i see or give me a tip where to search for a solution?

thanks for any help..

greetz Ben