View source for Handling Corona Effects.

You will have noticed the call ''SetFXCoronaTexture("corona",null);'' in the previous code examples. Corona effects specified in config.txt will be turned on when the object is loaded.  This call turns the corona off to begin with since it won't be needed until the doors start to open.  To deal with coronas we need to add some code, new sections are in blue.

 include "Buildable.gs"
 
 class Tutorial isclass Buildable {
 
    bool doorsOpen = false;
 
    public void Init(void) {
       inherited();
       SetFXCoronaTexture("corona",null);
       AddHandler(me,"Object","","ObjectHandler");
    }
 
 <font color=#808080>/* GetCorona is a utility method that will read the ''texture-kuid'' tag from the 
    ''config.txt'' of our shed.  When we turned the corona off in Init() the reference 
    to the KUID of the corona was lost and there is no easy way to reset it. This 
    method retrieves the value and returns it as a corona asset. Code which reads data 
    from a Soup, which is the Trainz word for database, is often very convoluted and 
    difficult to follow.  I have split the code into different calls here, and made 
    it a separate method in order to keep it readable, but it could have been written
    as one long statement.*/ </font>
  
    <font color=blue>Asset GetCorona(string mesh, string effect) {
       Soup meshtable = GetAsset().GetConfigSoup().GetNamedSoup("mesh-table");
       Soup effects = meshtable.GetNamedSoup(mesh).GetNamedSoup("effects");
       KUID kuid = effects.GetNamedSoup(effect).GetNamedTagAsKUID("texture-kuid");
       return World.FindAsset(kuid);
    }</font>
 
 <font color=#808080>/* We can use the same mechanism to control the coronas that we are using to open 
       and close the shed doors, we just need to add the appropriate statements. */</font> 
 
    void ObjectHandler(Message msg) {
       Vehicle vehicle = cast<Vehicle>msg.src;
       if (!vehicle) return;
       if (msg.minor == "InnerEnter") {
          doorsOpen = true;
          SetMeshAnimationState("default", true);
          <font color=blue>SetFXCoronaTexture("corona",GetCorona("default","corona"));</font>
       }
       else if (msg.minor == "InnerLeave") {
          doorsOpen = false;
          SetMeshAnimationState("default", false);
          <font color=blue>SetFXCoronaTexture("corona",null);</font>
       }
    }
 
 };

Accessing ''texture-kuid'' requires a lot of words but you should not be misled by this. Soups are very powerful and flexible and you will come across them quite frequently.  If you look at the ''config.txt'' structure you will see that the method GetCorona() needed to access a value in a database which is nested four levels deep!

Turning them on and off and, if you wish, changing the texture that they use is just about all that you can do with coronas. Size and frequency are preset in ''config.txt'' and can't be altered by script.<br><br>
Next Tutorial: [[Playing Sounds.]]<br>

[[Getting_Started_in_TrainzScript|Back to Getting Started]]