Sprite Drawing Order

I don't know what they would have actually used in No Remorse, but I do know they didn't update every frame; just on motion events. But for some real fun, play it and hold down the "re-center" key while running around. The framerate (on release hardware) drops into the dirt; it's an easy way to get some better reaction time in tight firefights.

So... I'm gonna guess the map is probably quadtree-sorted by world coordinate, and when a new screen is built they build a doubly linked list sorting by camera coordinates from back to front; to update, they take the updating object's rectangle and push it backwards re-drawing the updating section until it has been completely re-drawn, and then walk forwards re-drawing anything which intersects with that rectangle.

Their update process is thus probably four-step; erase an item by doing the push-back and walk-forward steps on its old rectangle, move it (possibly changing its location in the list), draw it, then obscure it by doing the walk-forward step.

Overall, there may be better ways to do it. The on-screen list needs to be updated every time the camera moves, with more work involved for horizontal scrolling than for vertical scrolling.

Here's a Blitzbasic article and code which might help
Turtle's Iso z-order