I'm guessing the problem is the offset, but we would need some more info or pics or vids or whatever

hard to guess whats wrong, if you only say "it gets screwed up" =D

yeah its exactly what I said, you need to add/subtract the camera position from the calculation

the sprites location should absolute, the camera moves and the mouse location is local... so whenever you have mouseX and mouseY you have to add the camera/offset x and y

How do I get absolute positioning compared to screen positioning?

What do I use for camera.x? I tried getting the x in g.translate(x, y), but that just messed it up completely.

Okay, I will.
So, there is another way of doing it? g.translate() is the only way I know how.

Well thats not really how I would do it.

all my objects have absolute locations on the map

then you have a camera, which is just a rectangle with the size of the screen
you move the player and adjust the camera to look at the player

now at rendering you render everything with that camera.

first, to not render stuff that wouldn't be on the screen, you say, well is the object inside the camera
basically camera.intersects(object)
and for every object that is, you render it with its absolute location minus the camera's location

It's just a concept that came to me naturally and I have been using it every since, it's not a way I read somewhere - but it might be the same or very similar to "what you're supposed to do"

anyway, using this you can also have parallax scrolling with layers and different cameras easily, as well as scenes in which the camera would look/shift to something other than the player

in Slick? setClip on the given Graphics object inside a render method

Me too, at least not for camera issues

(More like split screen stuff or for my map editor)

I think I get it now, I was in a completely different mindset. I was focused on the canvas moving around, instead of the objects moving around dynamically to the "camera". Thanks for the tips, I'll see how it works.

The rectangle in the minimap still perpetuates the "camera" idea.  Imagine the minimap rectangle is stuck in the center of the minimap, and the entire map scrolls to fit the visible part within that rectangle.  That's how the camera works: your camera never moves, you simply move the whole world into view.

 Then you will see that it is not the spoon that bends, but yourself

Another way of thinking about it is you move the minimap rectangle internally, but to actually render things into view you translate (move) it and the world back in the reverse direction so it's back at the center where your fixed unmoving camera lives. 

In that case, the camera, such as it is, is like any other object in the world, except you always render it first and you use the inverse of the normal translation and rotation to get your camera transform on the world.