Easier Smooth Key Input

[Conquistador]

This code's based on the bool keys example in the wiki. It can be extended for use with GUI's and mouse input events as well.

CEventReceiver.h:

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#ifndef __CEVENTRECEIVER
#define __CEVENTRECEIVER

// Include headers
#include <irrlicht.h>

// Use namespaces
using namespace irr;
using namespace core;

// Event Receiver Class
class CEventReceiver : public IEventReceiver
{
   public:
      CEventReceiver();
      virtual bool OnEvent(SEvent Event);
      bool getKeyState(EKEY_CODE key);
   private:
      bool keys[KEY_KEY_CODES_COUNT];
};

#endif

CEventReceiver.cpp

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// Include headers
#include <CEventReceiver.h>

// Constructor
CEventReceiver::CEventReceiver()
{
	// Set the keypress array to false
	for (s32 i = 0; i < KEY_KEY_CODES_COUNT; i++)
	{
	  keys[i] = false;
	}
}

// Event handler function
bool CEventReceiver::OnEvent(SEvent Event)
{
   // If the event type is a key input event
   if (Event.EventType == EET_KEY_INPUT_EVENT)
   {
      // Set the corresponding value in the array to the state of the key
      keys[Event.KeyInput.Key] = Event.KeyInput.PressedDown;
   }

   // Return false - ensures FPS cameras will still work
   return false;
}

// Get key state
bool CEventReceiver::getKeyState(EKEY_CODE key)
{
   return keys[key];
}

That's pretty much it. In your main loop, you can check the status of keys like so:

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CEventReceiver Receiver;

while (Device->run())
{
   if (Receiver.getKeyState(KEY_UP))
   {
       // Do something
   }
}

Hope this helps somebody.

[Halan]

very good thanks
but i got a little prob (think its not related to your code)
what did i do wrong if it says theres a double definition of the constructor and the 2 functions

/me aint so good at classes

[Guest]

You're supposed to replace the existing code not just paste this in.

[lostpencil]

Thanks Conquistador, that works nicely! For those of you who tend to forget things, like me, don't forget to register the event receiver in your createDevice call.

[Halan]

You're supposed to replace the existing code not just paste this in.

i didnt paste it in

i think the problem was writing "#include "CEventReceiver.cpp"" instead of "#inlcude "CEventReceiver.h""

edit:
btw heres my guibutton extension

first you need 1 more varaible GUIButton

then you add in the constructor this:

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GUIButton = false;

in the on event this:

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   if (Event.GUIEvent.EventType == EGET_BUTTON_CLICKED)
   {
       GUIButton = Event.GUIEvent.Caller->getID();
       return true;                           
   }

and the function to look for it

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bool CEventReceiver::getButtonState()
{
   return GUIButton;     
}

[Halan]

EDIT: fixed

[TheRLG]

can we see an example, maybe just using one of the tutorials, just to see the difference.

[genesisrage]

is there a way to register more than on reciever with the createdevice call?
or in other words, somehow to make it modular so you only have to add the events that are needed (instead of recreating one everytime or adding everything)

[Conquistador]

make it modular so you only have to add the events that are needed

You can make it modular with only one receiver. Example:

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class CEventReceiver : public IEventReceiver
{
   public:
      virtual bool OnEvent(SEvent Event)
      {
         if (Event.EventType == EET_KEY_INPUT_EVENT)
         {
            // Do something
         }
         else if (Event.EventType == EET_MOUSE_INPUT_EVENT)
         {
            // Do something else
         }
      }
};

There, the receiver is set up to only handle key and mouse events, and it will only execute the commands corresponding to the type of event it is. As far as recreating one for every program, you could make a basecode for an event receiver, handling only simple events using a method you'll use for every project, then just modify it and add the things that suit your needs. That's how I do it.

[jam]

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if (Event.EventType == EET_KEY_INPUT_EVENT)
         {
            // Do something
         }
         else if (Event.EventType == EET_KEY_INPUT_EVENT)
         {
            // Do something else
         }

Ok, I have a question, if EET_KEY_INPUT_EVENT in the first if evaluates out to false, then wouldn't the second if(EET_KEY_INPUT_EVENT) also be false thus you would never end up in the second if? and thus a bit redundant? Or am I just reading the code wrong?

[Conquistador]

Sorry, that was a mistake on my part, it was supposed to be EET_MOUSE_INPUT_EVENT. It has been corrected.

[Quall]

FYI:

I had to edit the getKeyState() method in the class like so, or else the events will re-occure over and over even after I released the key.

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bool CEventReceiver::getKeyState(EKEY_CODE key)
{
	bool x = keys[key];
	keys[key] = false;
	return x;
} 

Editting like this also crapped on the good movement as well

[Halan]

FYI:

I had to edit the getKeyState() method in the class like so, or else the events will re-occure over and over even after I released the key.

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bool CEventReceiver::getKeyState(EKEY_CODE key)
{
	bool x = keys[key];
	keys[key] = false;
	return x;
} 

Editting like this also crapped on the good movement as well

i think you miss this:

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// Constructor
CEventReceiver::CEventReceiver()
{
   // Set the keypress array to false
   for (s32 i = 0; i < KEY_KEY_CODES_COUNT; i++)
   {
     keys[i] = false;
   }
} 

but ive a problem also the array stays false if i press a button

[TheRLG]

well the OnEvent is called automatically right? just falsify all the keys again at the start of OnEvent in that case.

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virtual bool OnEvent(SEvent Event)
{ 
for (s32 i = 0; i < KEY_KEY_CODES_COUNT; i++){keys[i] = false;}

....Do the regular stuff here!!!

......

[Quall]

ah, nevermind. There was a problem with my game code and using the same receiver between states. All is good now :p.