inconsistent rendering

I am trying to draw my own text(just numbers), very simply through lines and points. While testing this I noticed that the numbers while drawn the same every time didn’t always appear the same on different parts of the screen specifically the bottom quarter of the display area. I noticed this holds true for other lines and polygons as well. This is a mfc project, i have tried both double buffering and rendering to a DIB. Any insignt on this would be extremely appreciated.

What do you mean by it not appearing “the same”? What’s different?

My first guess is that you’re drawing in a perspective view and noticing that the characters warp slightly towards the edges of the screen - that’s normal, and a function of the way perspective views work. Try switching to an orthogonal view instead: look at glOrtho or gluOrtho2D.

Thanks for your reply. I am however currently using gluOrtho2D and have tried glOrtho as well. The reason they do not look the same is that 1 has perfect looking numbers and the other the numbers are distorted looking for example the number 2 is not a consistent looking number, there is a break in the diagonal part of it right below the rounded top section. and then that top rounded part is 1 pixel too high. The goal of my display setup is simply to create a view that mimicks pixel coordinates on the screen.

Since you are using MFC, you need to properly synchronize the GL and the GDI, as this can cause snow among other problems.


This is correct rendering and I would recommend turning on line antialiasing, or setting the line width to a larger number.