Event Dispatching, void pointer and alternatives
- by PeeS
i have my event dispatching / handling functionality working fine, but there is one issue that i need to resolve. Long story short, here are the details.
// The event structure
struct tEventMessage
{
// Type of the event
int Type;
// (void*) Allows those to be casted into per-Type objects
void *pArgument1;
void *pArgument2;
};
I am sending events from different modules in my engine by using the above structure, which requires a pointer to an argument.
All messages are queued, and then dispatched on the next ::Tick().
It works fine, untill i try to send something that doesn't exist in next ::Tick, for example:
When a mouse click is being handled, it calculates the click coordinates in world space.
This is being sent with a pointer to a vector representing that position, but after my program quits that method, this pointer gets invalid obviously, cause local CVector3 is destructed:
CVector2 vScreenSpacePosition = vAt;
CVector3 v3DPositionA = CVector3(0,0,0);
CVector3 v3DPositionB = CVector3(0,0,0);
// Screen space to World space calculation for depth zNear
v3DPositionA = CMath::UnProject(vScreenSpacePosition,
m_vScreenSize,
m_Level.GetCurrentCamera()->getViewMatrix(),
m_Level.GetCurrentCamera()->getProjectionMatrix(),
-1.0 );
// Screen space to World space calculation for depth zFar
v3DPositionB = CMath::UnProject(vScreenSpacePosition,
m_vScreenSize,
m_Level.GetCurrentCamera()->getViewMatrix(),
m_Level.GetCurrentCamera()->getProjectionMatrix(),
1.0);
// Send zFar position and ScreenSpace position to the handlers
// Obviously both vectors won't be valid after this method quits..
CEventDispatcher::Get()->SendEvent(CIEventHandler::EVENT_SYSTEM_FINGER_DOWN,
static_cast<void*>(&v3DPositionB),
static_cast<void*>(&vScreenSpacePosition));
What i want to ask is, if there is any chance i could make my tEventMessage more 'template', so i can handle sending objects like in the above situation + use what is already implemented?
Can't figure it out at the moment..
What else can be done here to allow me to pass some locally available data ?
Please can somebody shed a bit of light on this please?
