Is your goal to have the fog move at a constant speed regardless of the direction of travel, or if not even traveling at all?
For example:
Would you like the fog to scroll at a speed of 1 when the character is traveling up/down/left/right?
or would you like the fog to scroll at a speed of 1 when the character is traveling up/down but a speed of 5 when the character is traveling left/right?
I think what I am asking for is the exact opposite of your first sentence. The fog moves at different speeds relative to the speed and direction that the screen is scrolling.
Im not dead set on specific speeds, but kind of close to the way your mentioning. Essentially, I'm hoping to create more of an "Illusion" that the Fog layer is behaving more like clouds much higher than the character, if that makes a lick of sense, it is so hard to explain. And Im trying really hard to think of a way to explain it that isnt confusing. Let me try this way.
Say there is a "Light Breeze", so when the character is standing still, the Fog scrolls Down Right (direction doesnt really matter) at a speed of 1. But when the Screen is Scrolling, the Fog scrolls in addition to the way the screen is moving, so like if the character were moving straight up, and say their speed was set to 4 (I think that is default character move speed, usually), the Fog would move Right still at 1, but Down at 1 + 4 so 5. What I think will happen is that it will appear to the player as if the Fog Layer is much higher up than the character and the "Camera" is higher than the clouds, giving a birds eye perspective, of sorts.
I'll try again, same idea and math. Character is moving right
AND Screen is Scrolling, the Fog would scroll down at its default speed of 1, But since the character is moving Right at a speed of 4, the Fog would move at 1 - 4 so it would actually go the other direction at a speed of -3. If the character moved Left, the fog would scroll Right at 1 + 4 so its Right Speed would be 5, and Down Speed would still be 1. So character moving Down (Screen Scrolls Down), same speed, the Fog would scroll UP at a speed of 3, because 1 - 4 = -3, and the Negative just means the opposite direction.
But fog speed is completely dependant on the speed and direction the screen is scrolling, this usually assumes that the Player is moving, or could be a cutscene as well I guess, but basically only to take effect when the screen is scrolling, so if the player is close to the edge of a map and the screen is NOT scrolling, the fog speeds return to default. I tried to show that in the Demo / Example Download above (game jumps straight into it).
Does that make any sense? It barely makes sense to me.
Ok, I thought of something. Take a look at this YouTube video of how the Map (not the Combat) makes it look like there is a set of Pipes above the Player. (Clouds didnt show up too well in the Video, so I went for the Pipes version.) Just think of replacing the Pipes with Fog that is moving slowly. That is kind of the effect I'm hoping for...
http://www.youtube.com/watch?v=rFJUVdAzFb8(totally off topic, but is there a way to embed YouTube videos on this forum?)