GL_LINES on different positions

OpenGL OpenGL: Basic Coding
1

In my OpenGL program I draw lines using glBegin(GL_LINES)

I have tested this program on two different computers. All lines are drawn one pixel below on the first computer compared to the second computer. Why are the lines not drawn in the same position on both computers? Is it possible to make sure that the lines are drawn at the same position on both computers?

2

Read the section of the specification about line rasterization.

Then draw your lines on pixel centers, instead of pixel corners.

3

Thanks a lot for your reply! I really appreciate it.

Do you by this mean that I should use coordinate values like 100.5, 102.5, 110.5 instead of 100, 102, 110?

4

Yes.