vbgs

vbgs is the core business logic behind vikebot. It runs the game-server itself and processes game actions to render-able data for graphical interfaces

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Implement additional operations

1. Create a new OpFile

Create a new file named opName.go where Name is single identifier (Camel-case) for the operation you want to implement. For example if you want to create the operation Radar you create opRadar.go in the repositories root folder.

2. Packet structures

In the file created in step one now add a namePacket and nameObj struct as shown below, where name is the identifier of the file in Pascal-case.

type radarObj struct {
}

type radarPacket struct {
    Type string   `json:"type"`
    Obj  radarObj `json:"obj"`
}

Parameters to your operation

If you need to pass parameters to your operation from the client side then add them to your nameObj struct as pointer fields. Only if we use pointers we can differentiate between the following two cases.

1. The client didn't sent the additional parameters
2. The client sent invalid fmt/values/etc for the parameters

Fields in the namePacket struct mustn't be pointers because they are checked in general by the packetHandler and dispatcher.

Below you can see an example from the move operation

type moveObj struct {
    Direction *string `json:"direction"`
}
type movePacket struct {
    Type string  `json:"type"`
    Obj  moveObj `json:"obj"`
}

3. Operation endpoint

Add the function that is responsible for handling a packet of your type. This function should be named after your filename (of course without the suffix .go) and accept a *ntcpclient and a packet of your type.

func opRadar(c *ntcpclient, packet radarPacket) {

}

4. Register your operation endpoint

In order to register your operation endpoint you need to add your identifier as a case in dispatcher.go's packet switch. In the case you need to unmarshal the data, check for err and call your own dispatch endpoint afterwards. For good examples look at the other operations already existing.

case "radar":
    var radar radarPacket
    err = json.Unmarshal(data, &radar)
    if err != nil {
        c.Respond(statusInvalidJSON)
        return
    }
    opRadar(c, radar)
    return

5. Implement your operation endpoint

You can now implement the operation itself. It should get prechecked and dispatched to your func. To get a feeling how good implementations look like look at the already existsing examples. In general you should keep a few things in mind:

• Add testing!!!
• Check for nil fields in your custom nameObj structs
• Don't forget to push updates to the updatePush network

Underlying construction of packages

+--------------+-------------------+-----------------------+
| IV (16bytes) | Encrypted payload | Suffix (1byte = '\n') |
+--------------+-------------------+-----------------------+

Payload

JsonPacket format -> Buffer -> Encrypt -> Base64