Concept art, CGI footage from Ron Howard's aborted Dark Tower film | Blastr
You will notice the following horrible changes:
1. It isn't just Roland in Tull. The whole gang is there with him which fundamentally changes things in ways I can't even begin to rant about.
2. All of them have legs in the concept art.
3. Someone has a 70s (not 60s) style hairdo.
4. Tull (going backwards here) isn't an old West town anymore but a a modern city after the end of the world.
*I'm going to let you do the rest of the analysis yourself. It suffices to say that if this stuff is back in play, the changes to the story make the casting choice of Roland totally academic because we aren't even in the same galaxy of story anymore.