Lines Visibility Problem

We are developing a CAD like software for PCB design related problems. We have imported the text file exported from the PCB softwares in our first step. In our project, we are displaying the imported text file in a image using the OpenGL API functions. The design gets rendered successfully. But the problem we are facing is…, while it is in smaller size, some areas of the design is not visible to the viewer, (particularly lines). If we are zooming in, then it is visible. We dont know how to solve it. We are using orthographic projection. Please help us to solve this problem. If we use to draw in LINES using glpolygonmode, then the problem gets solved… But while zooming in, the PCB traces are visible as the polygons which filled in as lines instead of solid fill appearance… so to solve it we use solid filled polygons…

Please do not repost the same problem after it has been answered. Provide new information in the earlier thread, I’m closing this one.