Question

I want to know if it possible for me to create a line or a triangle or any shape with only c++ code.

Answer 1

Based on the OP comments elsewhere in this thread, it sounds like he wants to do this by direct manipulation of the low-level instructions on the various pieces of hardware used for rendering images. To do this:

1. Understand the hardware you have for performing this. This means doing exensive research into how the hardware is designed and used.
2. Understand how to directly invoke the manufacturer’s device drivers. Again, this requires extensive research and is usually made more complicated by the fact that hardware manufacturers generally obfuscate their device driver source code, if they publish it at all, and they usually don’t release documentation for the device driver code.
3. Understand how you can directly manipulate hardware using C++ to write your own API to manage the hardware functions.

Once that’s done, you can use your API to draw a triangle or any other polygon you like. Personally, this seems a bit too much for me, and so I’ll use an existing API. But this might be a worthwhile learning experience for somebody without a spouse and children.