Here I have a sheet of example sprites, a four frame 4x4 and a four frame 3x3. When I set them to an animated combo and place it on an FFC...
It doesn't animate right at all. This is because the FFC uses the tiles extending down and to the right from the combo's current animation frame. With a normal animation, that top left corner is only advancing one tile at a time and so we get this weird effect you see here. To fix this, we want it to advance four tiles at a time (since the graphic is four tiles wide) and this is where A.SkipX comes in.
Here we set A.SkipX to 3, telling it to skip over three tiles when animating. Paired with the one tile it advances as it animates this gives us the four tile spacing we need.
And it works like a charm. So basically, any large graphic you want to animate, you set the combo to the top left tile and A.SkipX to its tile width minus one.
Now we're doing something a little more complicated. That four frame animation I did before is a little jumpy at the end because it's actually meant to duplicate the middle two frames for a total of 6. But now the animation fills up more than one row of tiles along the top and the results are once again...
It might not be entirely clear what's going on here. The above image shows the frames as we want them to display going blue, red, green, blue, red, green from left to right, top to bottom...
ZC does not naturally understand this and only shifts that last frame one tile down, causing the buggy effect. So this is where we use A.SkipY.
Like with A.SkipX, we set the A.SkipY to the sprite's tile height minus one. Unlike A.SkipX, this skip is only applied when the top left tile wraps across the right edge of the table. So the sprites will still progress left to right unless you set a large A.SkipX to tell them otherwise.
And once again everything is working fine. But in this case, the tile width of the table was evenly divisible by the width of the tile block. It worked for 4x4, but what about 3x3?
The 3x3 animations are messier looking, but you can wrap a frame around the right side of the table just fine. It just works.
Of course nothing's stopping you from just treating the 3x3 animation as a 4x4 if you prefer not to have frames getting cut off.
So that's basically A.SkipX and A.SkipY. Hope this helped.
Edited by Moosh, 07 August 2019 - 10:05 AM.