Thank you for the Collision Detection-links. It was helpful.
Did I forget to tell that I was using OpenGL as a 3D API for my game?
Well… I just found out that OpenGL supports the SELECTION that tells when ever a polygon intersect (or collide) with a giving viewing volume, the viewing volume does not have visible by the user!
The select-buffer and frame-buffer are seperate things.
I am able to define the viewing volume as a brick (glOrtho-function) that surrounds the player.
Now, when the viewing-volume (player) intersecs with any polygon, then I know that the player touches the ground/floor, and then I can stop the gravitational pull or compensate.
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