Client API Triggers

Triggers are fundemental concept in Fusion, they allow for the level to perform code actions when events occur.

Trigger types

The two trigger types are:

• ObjectEnter: Fire the trigger when an object(even the player) enters it
• PlayerJump: Fire the trigger when the player is in contact with the trigger, and jumps

Trigger output

The trigger output is the name you use when LINK_TRIGGER_HANDLER, its the name of the trigger to dispatch

Trigger parameters

Trigger parameters allow a trigger level object to pass variables data to the client on trigger activate/deactivate. There are three types of parameters:

• LvlObject: Pass a level object by ID to the trigger
• Integer: Pass a static number to the trigger
• String: Pass a static string to the trigger

Trigger parameters are stored as a key/value pair, and the client can get the values by using the parameters objects multiple get methods, by passing in the parameter name(aka key), and getting the parameter value.

Trigger flags

Trigger flags are flags on how the trigger should work in the level, they can be added in Fission's trigger flags editor.

Detailed descriptions of the trigger flags are below:

• NoFlag: Nothing
• AllowPhysicsObjects: Only works with ObjectEnter, trigger will also fire when a physics object interacts with it
• DisallowRepeat: Trigger is removed once it is deactivated
• AllowEveryTick: Trigger is fired every tick while it is activated

API Reference

Below is the complete API reference for Fusion client triggers

Best practice! Use a triggers.hpp header file

Have a header file, usually named triggers.hpp which imports all triggers, and registeres them.

#pragma once
#include "Fusion/etc/trigger.hpp"
#include "helloWorldTrigger.hpp"
#include "Fusion/game/game.hpp"

BEGIN_LINK_TRIGGER_HANDLERS

LINK_TRIGGER_HANDLER("helloWorld", HelloWorldTriggerHandler);

END_LINK_TRIGGER_HANDLERS

MACRO: BEGIN_LINK_TRIGGER_HANDLERS

Begins linking trigger handlers, anything between this call and END_LINK_TRIGGER_HANDLERS is called on LINK_TRIGGER_HANDLERS.

Developer note:

This macro creates the function cInitTriggerHandlers, and END_LINK_TRIGGER_HANDLERS simply closes it

MACRO: END_LINK_TRIGGER_HANDLERS

Ends linking trigger handlers, now to batch link all triggers handlers use LINK_TRIGGER_HANDLERS on game startup

MACRO: LINK_TRIGGER_HANDLER(STRING NAME, CLASS HANDLER)

Links the trigger name to the trigger handler class

MACRO: LINK_TRIGGER_HANDLERS

Batch links all trigger handlers, this should be called once on game boot

CLASS: TriggerHandler

Base class for all trigger handlers, child classes should override onActivate(...), and onDeactivate(...)

FUNCTION: TriggerHandler::onActivate(Parameters params)

Called whenever the trigger is activated, the parameters are used to pass parameters from the level to the client

FUNCTION: TriggerHandler:onDeactivate(Parameters params)

Called whenever the trigger is deactivated, parameters are used the same way as onActivate uses them.

EXAMPLES

SWITCH LEVEL TRIGGER HANDLER

Header:

/**
    * Default trigger handler, switches the game level to ```LevelName```
*/
class SwitchLevelTriggerHandler : public TriggerHandler {
public:
    SwitchLevelTriggerHandler();

    void onActivate(Parameters params) override;

    void onDeactivate(Parameters params) override;
};

Implementation:

SwitchLevelTriggerHandler::SwitchLevelTriggerHandler() = default;

void SwitchLevelTriggerHandler::onActivate(Fusion::Parameters params) {
    Fusion::Game::switchLevel(params.getStringValue("LevelName"));
}

void SwitchLevelTriggerHandler::onDeactivate(Fusion::Parameters params) {

}

Best practice, triggers.hpp:

#include <Fusion/etc/trigger.hpp>
#include <Fusion/game/game.hpp>
#include <MyGame/triggers/switchLevelTrigger.hpp>

BEGIN_LINK_TRIGGER_HANDLERS

LINK_TRIGGER_HANDLER("switchLevelTrigger", SwitchLevelTriggerHandler)

END_LINK_TRIGGER_HANDLERS

Editor: