Surely there is a collision event you can react to. Such as when you collide with enemies. Does a similar event fire for the ground? That can tell you.

It does seem a safe assumption for any library geared towards making platformers/games. if groundHit then currentlyJumping=false, or what have you.

I'm interested in why you decided to have the player move from right to left, when most other platformers have the player more left to right?

it really doesn't affect the game much, it's just an interesting decision.

I have to get to my day job for the next 10 hours but I'll at least answer the 'jumping' bit. Players always have gravity applied to them via the physics engine, so they are indeed 'held down' to ~something~ by default. There is no "floor" technically. Whenever you jump, it does pulse a linear velocity upwards to cause a jump; the arc of the jump is fine (holding doesn't produce infinite jump), the issue is pressing jump AGAIN (causing the just to re-apply). I do get hit events, but there are some catches. I cannot simply say 'am i colliding with something" because if I did, wall jumps would work, as would "ceiling jumping". I can't go by vertical momentum because vertical platforms adjust this by pushing the player up or letting them fall - plus there is a point in the player's jump that "appears" to be stopped (at the peak), which allowed for a double jump.

My solution will be to place a collision sensor at the very bottom center of the character, I just haven't done it yet.

And for the column, I'll let my artist know about that; thanks Krohm!

I think you should reconsider this "PLZ" and write it out as "Please".

That said, gratz on going this far with this. Looks interesting!

[quote name='hpdvs2' timestamp='1358909611' post='5024572']
If that Y-force is at 0
[/quote]

To address this point made my hpdvs2, you cannot simply check to see if the force is at 0 since the force would also be at 0 at the peak of the jump, this would make it possible to jump again while at the top of your jump an infinite number of times.

If that Y-force is at 0

To address this point made my hpdvs2, you cannot simply check to see if the force is at 0 since the force would also be at 0 at the peak of the jump, this would make it possible to jump again while at the top of your jump an infinite number of times.

PyroDragn is right, of course. Another case is obviously when you collide with something above you, your y-vel will be 0, so you could stick to the ceiling if you're quick enough on the jump key.

Not sure if this applies exactly to your game, but I am too working on a 2d platformer, and the way I handled jumping was to grab my collision shapes, move them slightly downwards, check if they collided, and if they did, perform the jump.

Of course after I check if the shapes collided, I restore all the original parameters of my player - both in position, and collision info (in my case the collision flag and a normal vector)

On a side-note, this also works with wall jumping, by attempting to move the player slightly left/right and checking if he's collided. And as I said, as an added bonus, you also obtain a normal vector with this method, so you can jump based on that.

Milcho: That's basically my solution, only instead of moving the physical body i'll just have a sensor that checks for collision 1 pixel underneath. Thanks again for all the responses! I'll post an update in the next week or two - until then I'll just spam the twitters with updates as usual :)

If I recall correctly, Box2D allows you to listen for contacts between object, and then find the position and normal of each contact point. If touching a floor, your player object will have a contact point on the bottom, with a normal pointing downwards (approximately - sloped floors will mean some variation here). Check out http://box2d.org/forum/viewtopic.php?f=9&t=8005

I think the level's high-level layout flows nicely enough. Shouldn't be too confusing for a player - there's one major branch (the underground area), and it's fairly obvious to the player when they have explored the entire underground area and need to return to the surface (so they won't get frustrated trying to find a way through)

I am working on some areas for my game and wanted to get feedback on the general layout of things. It is a mix between an RPG and platformer. You can see an example of how the game plays here:

And what I have so far of one of my areas is here:

http://img833.imageshack.us/img833/8852/startingarea.png (warning: large image!)

Please note that the background is white because in-game it renders the background (as per the video). Also note all in-game assets are NOT present in the image export because that layer also contains collision data and is very hard to see the actual layout if I show it as well -- this includes vertical platforms (as hinted by the rails), doors, enemies, flame pipes, item boxes, etc. And of course, the left part of the lower drop is not done yet.

I just want to know if the general flow of the areas makes sense or if I will cause too much confusion for the players. I want to lead them somewhat, but give them freedom without them feeling totally lost.

Any feedback would be greatly appreciated!

It looks good. I wanted to suggest maybe getting a copy of super meat boy if you haven't already played it. While it's arguable its sort of in a genre on its own, the platformer is still a vast majority of it. The mechanics in the game led to some very intricate level design mainly through the placement of things that will kill you. I mention SMB because I for one absolutely loved the levels, and the way in which they ramp up the difficulty as you progress and perfect old moves.

With that said, your game will most undoubtedly have its own nuances in which you can design your levels around your mechanics. In addition you can always put, say extra lives, in tricky and/or dangerous spots. Tempation is a good motivator.