This document is about: QUANTUM 2
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Blueless

Level 4

Overview

This sample is provided with full source code and demonstrates how Quantum can be used to create a fast and action-packed online 2D platform shooter.

Disclaimer: The sample game was developed by BitCake Studio for Photon Engine.

Download

Version Release Date Download
2.1.8 Apr 03, 2024 Quantum Blueless 2.1.8 Build 353

Before You Start

To run the sample in online multiplayer mode, first create a Quantum AppId in the PhotonEngine Dashboard and paste it into the AppId field in PhotonServerSettings asset.
Then load the Menu scene in the Scenes menu and press Play.

Technical Info

  • Unity: 2020.3.20f1.
  • Platforms: PC (Windows / Mac), WebGL and Mobile (Android)

Highlights

Technical

Gameplay

  • Fast paced, 2D platform shooter.
  • Double jump.
  • Area damage.
  • Grenade.
  • Weapon reload time.
  • Change weapon using weapon inventory.

Controls

Use A S to movement, Space to jump, Q E to change weapon, F to use the granade, Left Mouse Button to shoot and use the mouse cursor to aim.

Useful Patterns

Raycast projectiles based on delta-movement

This is a good approach to prevent fast bullets from crossing walls. A raycast based on direction and speed is used to predict the next bullet movement and detect a hit, if any.

C#

Physics2D.HitCollection hits = frame.Physics2D.LinecastAll(bulletTransform->Position, futurePosition);
for (int i = 0; i < hits.Count; i++)
{
  var entity = hits[i].Entity;
  ...
  if (entity == EntityRef.None)
  {
    bulletTransform->Position = hits[i].Point;
    // Applies polymorphic behavior on the bullet action
    data.BulletAction(frame, bullet, EntityRef.None);
    return true;
  }
}

Disconnect System

Using the DeterministicInputFlags we check if the player is present. So, the entities of players who are not present for a while are removed from the simulation.

C#

public override void Update(Frame frame)
{
  frame.Global->DisconnectTime += frame.DeltaTime;

  var robotsFilter = frame.Filter<PlayerID, Status>();
  while (robotsFilter.NextUnsafe(out var robot, out var playerID, out var robotStatus))
  {
    DeterministicInputFlags flags = frame.GetPlayerInputFlags(playerID->PlayerRef);

    if ((flags & DeterministicInputFlags.PlayerNotPresent) == DeterministicInputFlags.PlayerNotPresent)
    {
      robotStatus->DisconnectedTicks++;
    }
    else
    {
      robotStatus->DisconnectedTicks = 0;
    }
    if (robotStatus->DisconnectedTicks >= 15)
    {
      frame.Destroy(robot);
    }
  }
}
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