[SOLVED] Questions related to modifying the stock FPS camera

[Spinland]

Hi again!

I'm working to modify the FPS camera to include vertical movement, and am having mixed results. I figured I'd start a question thread and run through the issues I'm having in the hopes not only of getting things ironed out but of learning something in the process.

First, I needed a couple of extra enumerations for the vertical up and down motion (I suppose I could have just used jump and crouch, but I wanted to learn how to do it right). Here is the original code (from SKeyMap.h):

Code: Select all

	enum EKEY_ACTION
	{
		EKA_MOVE_FORWARD = 0,
		EKA_MOVE_BACKWARD,
		EKA_STRAFE_LEFT,
		EKA_STRAFE_RIGHT,
		EKA_JUMP_UP,
		EKA_CROUCH,
		EKA_COUNT,
		//! This value is not used. It only forces this enumeration to compile in 32 bit.
		EKA_FORCE_32BIT = 0x7fffffff				
	};

Now I'm not sure how the 32 bit force part works in this context. I first tried just adding my new enumerations at the end of the list, like so:

Code: Select all

	enum EKEY_ACTION
	{
		EKA_MOVE_FORWARD = 0,
		EKA_MOVE_BACKWARD,
		EKA_STRAFE_LEFT,
		EKA_STRAFE_RIGHT,
		EKA_JUMP_UP,
		EKA_CROUCH,
		EKA_COUNT,
		//! This value is not used. It only forces this enumeration to compile in 32 bit.
		EKA_FORCE_32BIT = 0x7fffffff,
                EKA_MOVE_UP,
                EKA_MOVE_DOWN
	};

This netted me many overflow errors when compiling. I then tried moving the new items to just above the last one:

Code: Select all

	enum EKEY_ACTION
	{
		EKA_MOVE_FORWARD = 0,
		EKA_MOVE_BACKWARD,
		EKA_STRAFE_LEFT,
		EKA_STRAFE_RIGHT,
		EKA_JUMP_UP,
		EKA_CROUCH,
		EKA_COUNT,
                EKA_MOVE_UP,
                EKA_MOVE_DOWN,
		//! This value is not used. It only forces this enumeration to compile in 32 bit.
		EKA_FORCE_32BIT = 0x7fffffff
	};

This compiles, but some behavior that comes later makes wonder whether this is correct? Do I need to do something the the 0x7fffffff value to reflect that the number of items in the enumeration has changed?

Thanks in advance!

[greenya]

= If enumeration has "count" value -- you must add only before it, OR it will not play its role.
= If enumeration has "force 32 bit" value -- this value must be the last any way and you may not add values after it.

In case of EKEY_ACTION, if you want safely add values, you have to do it just before 'EKA_COUNT'.

[Spinland]

Thanks, that's a big help. I've implemented that change, and most (if not all) of my issues cleared right up. So much for needing a whole thread!


There's one more small thing but I might know how to handle it already. If I turn out to run into a brick wall I'll follow up here with any questions.

Thanks again, you guys are great!