pogp 0.1.0

The POG Protocol defines language-neutral binary and json representations of Inputs and State.
Documentation
pogp-0.1.0 has been yanked.

Portable Open Game Protocol 0.0.3

Making games is hard. It shouldn't have to be.

Making games should feel like playing games.

Introducing the POG protocol

The POG Protocol defines language-neutral binary and json representations of Inputs and State.

Portable

  • prototype and playtest game logic in rust, c++, c# or typescript in the browser

  • compile your logic for unreal, unity, bevy, godot etc (WIP)

  • support online multiplayer by running your logic on a server or exchanging binary input payloads peer to peer

Open

  • input representations are based on web standards

  • state representations use open standards (WIP)

  • games that adopt the protocol can benefit from shared solutions for common functionality

Game

  • immersion during the development process is sacrosanct. making games feels like playing games.

  • memory management is baked in to the protocol

  • all the tools you use to build for mobile and console targets can be used with your pogp-compliant binary (WIP)

Goals

The goal of the POG protocol is to help create better games for players, to allow indie devs to effectively compete with AAA, and to reduce crunch globally.

If this sounds ambitious, just look at the development ecosystem for web and app developers.

Industry-wide adoption of the HTTP protocol and open source technologies like Linux leveled the playing field for web and app developers.

Shared solutions and common development environments saved everyone countless years of time-to-market and ushered in an era of innovation and enlightenment in developer experience.

I believe that in many ways, game development is still in the dark ages.

Why does it take most teams 3-4 years to get a game to market?

Yes, crafting compelling experiences takes time and is hard. But the average hollywood movie takes 2 years to create.

Yes, writing software takes time and is hard. But the average tech startup releases a first product in the first 6-12 months of development.

I believe that technical debt is the silent killer across our industry.

I believe that a lack of shared solutions is creating a barrier to entry for making games that excludes many voices.

I believe it's inhumane for us to subject ourselves to 30 second immersion-breaking compilation times every day for years of development.

I love games, and I hope that there can be a better world for developers and players of games.

Project Status

The Pog Protocol is in a pre-alpha state. The protocol itself is still being written, and client libraries do not yet exist beyond the demos in this repo.

For this to work for devs, we'll need domain experts contributing to client libraries for each major game engine and runtime environment.

If you are interested in contributing or adding an environment to the list, please open a github issue or drop me a line on discord nu11#1111 or neil at nullent.com

Game Logic Client Libraries

language dev environment inputs state wasm support
c# unity OPEN OPEN OPEN
c++ unreal OPEN OPEN OPEN
rust bevy OPEN OPEN OPEN
c# browser OPEN OPEN OPEN
c++ browser OPEN OPEN OPEN
rust browser @ns @ns @ns
typescript browser @ns @ns @ns

Rendering Client Libraries

language framework environment status
c# unity pc/mac/mobile/console OPEN
c++ unreal pc/mac/mobile/console OPEN
rust bevy pc/mac OPEN
swift xcode/autolayout ios OPEN
typescript pixi.js browser @ns

Contributors:

@ns - @neilsarkar

Why

Why would it be useful to write these pieces in different languages or run them in different engines?

Surely most devs / teams would prefer to write everything in one language and one framework (e.g. c++ with unreal, c# with unity, javascript with phaser, rust with bevy).

In practice, any given team will likely stick to the language(s) and framework(s) they're currently using. But the shared input and state representations will allow for greater portability and sharing of solutions.

Also the separation of logic and rendering will enable teams to scale their development better as the project size grows without having to embark on a costly rewrite when already behind schedule and over budget.

Interactive Examples (WIP)

https://pogp.gg/examples/pong (WIP)

Reference

Inputs

Inputs contain the state of the input at the current frame.

Whenever possible, representations are based on open standards.

Gamepad (a.k.a. Controller) Input

Touch Input

Mouse Input

Keyboard Input

Gamepad Input

Gamepad input represents what's commonly called a "Controller".

We extend the open standard https://developer.mozilla.org/en-US/docs/Web/API/Gamepad with a standard for generic positional identifiers.

JSON Schema | JSON Example

Binary Schema | Binary Example

Gamepad JSON Schema

type

id

vendorId

productId

vendorName

  • A human readable name for the vendor, e.g. Nintendo, Microsoft, Sony etc

productName

  • A human readable name for the product, e.g. Left joy-con, Xbox Series S, Dualshock 5

buttons

  • An array of Button states
    • label
      • the text printed on the button, e.g. Triangle, A, ZR
    • value
      • int representing the percentage depressed with four digits of precision
    • touched
      • boolean representing whether button is touched
    • position
      • string enum representing button position , e.g. left-face-top, right-shoulder-front

axes

  • An array of Axes states
    • hand
      • string enum representing hand intended to be used with joystick: left | right | unknown
    • value
      • an array of two signed longs representing the x and y position of the thumbstick

Gamepad JSON Example

{
	type: 'Gamepad',
	id: 'Stadia Controller rev. A (STANDARD GAMEPAD Vendor: 18d1 Product: 9400)'
	vendorName: "Google",
	productName: "Stadia",

	buttons: [
		{
			label: 'A',
			position: 'right-face-bottom',
			value: 100000 // 100%
		},
		{
			label: 'B',
			position: 'right-face-right',
			value: 500600 // 50.06%
		},
		{
			label: 'X',
			position: 'right-face-left',
			touched: true,
			value: 0
		},
		{
			label: 'Y',
			position: 'right-face-top',
			value: 0
		},
		{
			label: 'L1',
			position: 'left-shoulder-front',
			value: 0
		},
		{
			label: 'L2',
			position: 'left-shoulder-back',
			value: 0
		},
		// ...
	],
	axes: [
		{
			hand: 'left',
			value: [
				0n, // x-axis idle
				2147483647n // y-axis max up
			]
		},
		{
			hand: 'right',
			value: [
				-2147483647, // x-axis full left
				-2147483647  // y-axis full down
			]
		}
	],
}

Gamepad Binary Schema

data example type index length (bytes)
type 1 byte (Input Type) 0 1
buttons.length 12 uint16 1 2
axes.length 12 uint16 3 2
buttons [Button, Button] Button 5 69 * buttons.length
axes [Axes, Axes] Axes 5 + (69 * buttons.length) 129 * axes.length

Gamepad Button Binary Schema

data example type index length (bytes)
position 2 byte (ButtonPosition) 0 1
value 100000 uint32 1 4
label "A" string 5 64

Gamepad Axes Binary Schema

data example type index length (bytes)
hand 1 byte (Hand) 0 1
x 100000 int64 1 64
y 100000 int64 65 64

Keyboard Input

Keyboard keys are represented using the w3 standard, supporting standard 101, Korean, Brazilian and Japanese keyboards.

https://www.toptal.com/developers/keycode

https://www.w3.org/TR/uievents-code/#keyboard-mac

{
       type: "keyboard",
       keys: [
               27,
               65
       ]
}
data type byte index bit index
Null bool 0 0
ArrowDown bool 0 1
ArrowLeft bool 0 2
ArrowRight bool 0 3
ArrowUp bool 0 4
Backspace bool 0 5
Tab bool 0 6
CapsLock bool 0 7
Enter bool 1 0
ShiftLeft bool 1 1
ShiftRight bool 1 2
ControlLeft bool 1 3
MetaLeft bool 1 4
AltLeft bool 1 5
Space bool 1 6
AltRight bool 1 7
MetaRight bool 2 0
... bool ... ...
IntlRo bool 9 4

Touch Input (WIP)

{
	type: "touch",
	resolution: [0,0],
	fingers: [
		// there will always be at least one element
		{
			position: [0,0],
			pressure: 0
		}
	]
}

Mouse Input (WIP)

{
	type: "mouse",
	resolution: [1920, 1080],
	position: [100, 100],
	buttons: [
		{
			id: 'left',
			down: true
		},
		{
			id :'right',
			down: false
		},
	],
	wheels: [
		{
			id: 'scroll',
			delta: [0,20,0]
		}
	]
}

Custom (WIP)

{
	type: "custom",
	id: 'my-flightstick',
	fields: [
		{
			id: 'whammybar',
			values: [420,69]
		},
		{
			id: 'something',
			values: [0]
		}
	]
}

State (WIP)

Game state represents the state of the game. This is going to be custom for each game.

int is short for int32

{
	// this is the pog protocol major version
	pog: 0,
	// this is the pog protocol minor version
	pogMinorVersion: 1

	// these are the members of the state.
	fields: {
		// primitives
		timeLeft: 'int',

		// objects defined below
		player: 'player',
		level: 'level',

		// arrays of primitives or objects
		enemy: ['enemy'],

		// dictionaries of primitives or objects
		levelClearTimes: {
			int: 'int'
		},
		levelsById: {
			int: 'level'
		}
	},

	// these are objects defined by the game
	objects: [
		player: {
			position: 'vector2',
			score: 'int',
			jump: 'bool',
			myIntList: ['int'],
		}
		enemy: {
			position: 'vector2',
			health: 'int',
		},
		level: {
			id: 'int',
			tiles: ['tile']
		},
		tile: {
			position: 'vector2',
			type: 'int'
		}
	],
}

The json state will exist in both the logic and the renderer, so object structures are not shared, only the values

data example type index length (bytes)
pog major version 0 int 0 4
pog minor version 1 int 4 4 
* fields are done alphabetically

* vectors and fixed length structs are inline

* arrays, lists and dictionaries are represented as an integer of their total length

* array, list and dictionary reading happens after reading the primitives in the state

* strings are utf32 encoded

tic tac toe example:

{
	// 0 is not taken, 1 is X 2 is O
	board: [
		0, 0, 0,
		0, 2, 0
		1, 0, 0
	]
}

// fields
uint 9  // length of array

// arrays, lists and dictionaries
ubyte 0 // top left
ubyte 0 // top middle
ubyte 0 // top right
ubyte 0 // middle left
ubyte 2 // middle middle
ubyte 1 // bottom left
ubyte 0 // bottom middle
ubyte 0 // bottom right

pong example:

{
	isGameOver: false,
	player1: {
		position: [0, 100],
		score: 1
	}
	player2: {
		position: [100,-100],
		score: 0
	},
	ball: {
		position: [50, 50]
	}
}

Client libraries:

(json schema) => file of native object

(binary data, json schema) => native object

(native object, json schema) => binary data

e.g. csharp

public static string StateFile(string json, string path) {
	// outputs a .cs file to path that has the structure of the json file
}

Button Position Enum

value name example (xbox one)
0 null
1 left-face-top dpad up
2 left-face-right dpad right
3 left-face-bottom dpad down
4 left-face-left dpad left
5 left-shoulder-front LB
6 left-shoulder-back LT
7 left-thumbstick L3
8 right-face-top Y
9 right-face-right B
10 right-face-bottom A
11 right-face-left X
12 right-shoulder-front RB
13 right-shoulder-back RT
14 right-thumbstick R3
15 middle Xbox Button
16 middle-left View Button
17 middle-right Menu Button

Input Type Enum

value name
0 null
1 gamepad
2 touch
3 mouse
4 keyboard
5 custom

Hand Enum

value name
0 null
1 left
2 right

Key Enum

value name
0 Null
1 ArrowDown
2 ArrowLeft
3 ArrowRight
4 ArrowUp
5 Backspace
6 Tab
7 CapsLock
8 Enter
9 ShiftLeft
10 ShiftRight
11 ControlLeft
12 MetaLeft
13 AltLeft
14 Space
15 AltRight
16 MetaRight
17 ContextMenu
18 ControlRight
19 Backquote
20 Digit1
21 Digit2
22 Digit3
23 Digit4
24 Digit5
25 Digit6
26 Digit7
27 Digit8
28 Digit9
29 Digit0
30 Minus
31 Equal
32 IntlYen
33 KeyQ
34 KeyW
35 KeyE
36 KeyR
37 KeyT
38 KeyY
39 KeyU
40 KeyI
41 KeyO
42 KeyP
43 BracketLeft
44 BracketRight
45 Backslash
46 KeyA
47 KeyS
48 KeyD
49 KeyF
50 KeyG
51 KeyH
52 KeyJ
53 KeyK
54 KeyL
55 Semicolon
56 Quote
57 IntlBackslash
58 KeyZ
59 KeyX
60 KeyC
61 KeyV
62 KeyB
63 KeyN
64 KeyM
65 Comma
66 Period
67 Slash
68 IntlRo