Minimap View

The C++ side of the Minimap consists of the following files (located in Apps\Kits\HUD):

• FxMinimap.h: Declares interfaces that game environments and applications can implement to plug into the minimap demo core.
• FxMinimapView.h/.cpp: Provides types used by the minimap view.

The minimap view interface declares the following types:

• FxMinimapIconType: An icon type definition, which includes a type ID and an extra sub-type value for additional specialization.
• FxMinimapIcon: Icon resource that is linked to an element in the view.
• FxMinimapIconCache: Icon cache that stores sets of icons of a specific type. The icon view states are managed by the cache as needed, and the cache also supports fading in/out of icons that enter/exit the detectable range. The cache uses a factory to generate new icons. The base implementation of the factory is a templatized class called MinimapIconFactoryBase. Each factory handles attaching the icons’ MovieClips to its appropriate canvas MovieClip as necessary and removing these MovieClips when the Minimap is destroyed. Multiple factory types are defined to support the different icon types listed below. Each icon type contains an Update() method that implements icon type specific update logic, such as translation, rotation and textField changes:
  • PlayerIcon: Represents both friendly and enemy icon resources because both icon types share the same logic. They only differ by the icon creation methods.
  • FlagIcon
  • ObjectiveIcon
  • WaypointIcon
• FxMinimapView: The main controller for the minimap view. Its UpdateView() method is called by the application to refresh the view.

The following code is the PlayerIcon::Update() method (FxMinimapView.cpp; line 116). It shows the logic used to update the player icons in the view using the Direct Access API. The MovieClip member contains a reference to the icon MovieClip on stage. The SetDisplayInfo method directly modifies the MovieClip’s display properties (the display matrix, visibility flag or alpha value) instead of going through the slower SetMember() method. Note that GFx::Value::SetMember is still faster than GFx::Movie::SetVariable:

virtual voidUpdate(FxMinimapView* pview, FxMinimapEntity* pentity,
float distSquared)
{
    SF_UNUSED(distSquared);
    bool hasIcon = (pentity->GetIconRef() != NULL);
    PointF pt = pentity->GetPhysicalPosition();
    bool showDir = pview->IsShowingPlayerDir();

    // If entity did not have an icon attached before, then wait for the
    // next update to set the state data. picon is most probably not initialized
    // (the movie needs to advance after creation)
    if (hasIcon && (State != (int)showDir))
    {
        // state 0: no arrow, state 1: show arrow
        Value frame(Double(showDir ? 2.0 : 1.0));
        MovieClip.Invoke("gotoAndStop", NULL, &frame, 1);
        State = (SInt)showDir;
    }

    pt = pview->GetIconTransform().Transform(pt);
    Value::DisplayInfo info;
    if (State)
    {
        info.SetRotation(pview->IsCompassLocked() ? (pentity->GetDirection() +  90)  :
                (pentity->GetDirection() –  pview->GetPlayerDirection()));
    }
    info.SetPosition(pt.x, pt.y);
    MovieClip.SetDisplayInfo(info);

}