oat
/
uranium-template
Template
1
0
Fork 0
Code Issues Pull Requests Releases 5 Activity
uranium-template/MANUAL.md

32 KiB
Raw Blame History

If you're viewing this in VSCode, it's recommended that you open it in a preview with `Ctrl+Shift+V`!

Uranium Template α

Official manual!!!!

Uranium Template is a Love2D-inspired NotITG game development template, focusing on keeping things as Lua-pure as possible with enough abstractions to make you feel like you're not dealing with Stepmania jank at all.

Uranium Template originally formed during the creation of a currently unreleased project, and since then I've went ahead and refined and polished it up to be usable on its own. Most of the design decisions came from experience using prototype versions of it!

Testimonies

  • "this template really adds some spice to your modfiles. think industrial glitter in your next chilli!" - Mayflower
  • "a good template that i have definitely used! jill can i go now. jill please i just want to see my family" - Aura

Installation

Installation is the exact same as any other NotITG template:

  1. Unzip your installation zip, as you would a modfile
  2. Edit Song.sm in your editor of choice (ArrowVortex, NotITG) to include necessary metadata; replace silence.ogg with an actual track, if necessary
  3. Edit main.lua to do whatever you wish to do with it! The entirety of the src/ folder is yours!
  4. (Recommended) Install sumneko's Lua LSP and grab the latest NotITG typings here (put them in a folder like .typings!)

Distribution

After you're done with writing your file, be sure to take these steps to reduce the filesize and get your game ready for zipping up!

  • Remove MANUAL.md, jillo_png.png, docs/, .vscode/, .gitconfig, .gitignore and template/typings.lua. These are files that aren't necessary outside of a development environment!
  • Optionally, remove Song.sm.auto and Song.sm.old. These files may not exist depending on certain factors.
  • If you've followed step 4 during Installation, be sure to remove your typings folder (likely .typings)
  • If you're using Git, PLEASE REMOVE YOUR .git/ FOLDER!!!

Afterwards, it should be safe to zip everything up and send it over!

How do I start writing code?

main.lua is the entry-point for your code! From there, you can do the following:

If you're still a bit clueless, why not check out the Examples section?

Defining actors

Actors are defined in Uranium Template before any other callback runs, and are defined by a single function of their type:

local quad = Quad()
local sprite = Sprite('file/location.png')
local text = BitmapText('common', 'hello, world!')

All actors that take in filenames have their filenames starting from the root of the project; meaning if you had a file in myModFile/src/test.png, you'd have to pass in a filename of src/test.png. If an image is blank, or a single pink pixel, it hasn't loaded properly.

Initializing actors

Once you have an actor defined, you can run whatever methods you want.

Note Even though you get a fully functional actor, what you actually get is a proxied actor! What this means for you is that you really shouldn't call any getters on the actor, as it'll just return nil.

local text = BitmapText('common', 'hello, world!')
text:xy(scx, scy)
text:zoom(2.3)
text:rotationz(30)
text:diffuse(1, 0.8, 0.8, 1)

All methods that you run upon definition will be ran again at the start of every frame:

local quad = Quad()
quad:xy(scx, scy)
quad:zoomto(60, 60)
quad:diffusealpha(1)

function uranium.update()
  -- doesn't need a reset! it'll automatically zoomto 60, 60 and set its alpha to 1
  quad:Draw()
  quad:zoomto(120, 120)
  quad:diffusealpha(0.5)
  quad:Draw()
end

If you want to avoid this, or otherwise call getter methods, use the uranium.init callback:

local sprite = Sprite()

function uranium.init()
  someTexture = sprite:GetTexture()
end

Alternatively, you can also use the actors' individual InitCommands:

local sprite = Sprite()
sprite:addcommand('Init', function(self)
  someTexture = self:GetTexture()
end)

Actor-specific notes

ActorFrameTexture

AFTs work in the same way as usual AFTs do in terms of ordering: they capture everything that was drawn to the screen before them:

quad:Draw() -- will be drawn to the AFT

aft:Draw()

sprite:Draw() -- will not be drawn to the AFT

See the AFT example for a quick setup to play around with, or the example in the aft library for a barebones setup. The ability to dynamically adjust at which point in the stack they render makes them a lot more powerful than you'd expect.

ActorFrame, ActorScroller

Due to Uranium Template's recursive actor loader, these are impossible to implement in a meaningful way. Actors are loaded in a manner like so:

local actor1 = Quad()
local actor2 = Sprite()
local actor3 = BitmapText()

<Layer Type="ActorFrame"/>
<children>
  <Layer Type="Quad"/>
  <Layer Type="ActorFrame"/>
  <children>
    <Layer Type="Sprite"/>
    <Layer Type="ActorFrame"/>
    <children>
      <Layer Type="BitmapText"/>
    </children>
  </children>
</children>

This is a technical limitation; NotITG does not allow loading a dynamic amount of arbitrary actors defined via Lua in any way other than this (as far as I know). Meaning, if you defined an ActorFrame or ActorScroller, you would not be able to add anything to its' children.

However, if you're looking to do what ActorFrame does, the standard library transform module can handle that for you! (NYI)

Callback usage

Uranium uses a unique callback system - to define a callback, you define a function under uranium. with your desired callback name:

function uranium.update(dt)
  -- runs every frame
end

You can do this as many times as you like - it'll call every single function that's defined as uranium.update, not just the last!

If you return a non-falsy value in a callback, however, it'll cancel every other callback after it. This can be useful for, eg. capturing inputs and ensuring they don't get passed through to other callbacks on accident.

Default callbacks

These are the callbacks that are built into Uranium:

uranium.update(dt: number)

Called every frame. dt is the time passed since the last frame, the "deltatime".

uranium.init()

Called once on OnCommand. Every actor has been created, and the game should be starting shortly.

Custom callbacks

Custom callbacks require no extra setup. Define your callback like usual:

function uranium.somethingHappened(value)
  -- ...
end

Then all you need to do to call it is:

uranium:call('somethingHappened', extra, values, go, here)

Callbacks support as many extra values as Lua supports arguments in a function - so let's just say you won't be running out of them any time soon.

Requiring files

require in Uranium works a lot like Lua's vanilla require, and is a direct copy of Mirin's require.

Say you have a file structure like this:

src/main.lua

local value = require('test')
print(value)

src/test.lua

return 'hello!'

Your setup would print 'hello!'.

All standard library modules are required with require, see further notes in Importing modules.

Standard library

The Uranium Template standard library is split up into a few convinient modules. This section aims to comprehensively document them all.

Importing modules

You can import a module like so:

require('stdlib.vector2D')

-- can use vector() here

Some modules won't export any globals, and therefore need to be loaded like so:

uwuify = require('stdlib.uwuify')
print(uwuify('hello!'))

These modules have a label near their header in this manual reading "Exports globals".

vector2D

Exports globals

vector2D is a simple 2D vector class system. For example, to define a vector:

local vec = vector2D(0, 0)
-- or
local vec = vector(0, 0)
-- or
local vec = vector(0)
-- or
local vec = vector()

Then add another vector to it:

vec = vec + vector(1)
print(vec) --> (1, 1)

Then measure its length:

local len = vec:length()
print(len) --> 1.4142135623730951
           --  (sqrt of 2)

Then rotate it and index it:

vec:rotate(180)

local x = vec.x
-- or
local x = vec[1]

print(x) --> -1

vector2D(x: number | nil, y: number | nil): vector2D

Creates a new vector. If only x is passed in, y = x. If no arguments are passed, x = y = 0.

vectorFromAngle(ang: number | nil, amp: number | nil): vector2D

Creates a new vector pointing in a specific angle. Specify ang in degrees. ang defaults to 0, amp defaults to 1.

vector2D:length(): number

Returns the vector's length. Equal to vector:distance(vector()).

vector2D:lengthSquared(): number

Returns the vector's length, squared. Here mainly for optimization purposes; this is a cheaper version of length() that's less accurate.

vector2D:angle(): number

Returns the vector's angle in radians.

vector2D:normalize(): vector2D

Normalizes the vector, setting its length to 1 but keeping its angle. Equal to vector:resize(1)

vector2D:resize(length: number): vector2D

Resizes the vector, setting its length but keeping its angle.

vector2D:unpack(): number, number

Unpacks the vector into its X and Y coordinates. Useful for quickly unpacking it into a function call:

local quad = Quad()
quad:xy(center:unpack())

vector2D:distance(vect: vector2D): number

Gets the distance between one vector and another.

vector2D:distanceSquared(vect: vector2D): number

Gets the distance between one vector and another, squared. Here mainly for optimization purposes; this is a cheaper version of distance() that's less accurate.

Operations

Here are all valid operations for vectors:

  • vector2D + number: equal to vector2D + vector2D(number)
  • vector2D + vector2D: adds the vectors' X and Y coordinates together, respectively, forming a new vector
  • vector2D - number: equal to vector2D - vector2D(number)
  • vector2D - vector2D: subtracts the vectors' X and Y coordinates, respectively, forming a new vector
  • vector2D * number: equal to vector2D * vector2D(number)
  • vector2D * vector2D: multiplies the vectors' X and Y coordinates together, respectively, forming a new vector
  • vector2D / number: equal to vector2D / vector2D(number)
  • vector2D / vector2D: divides the vectors' X and Y coordinates, respectively, forming a new vector
  • vector2D == vector2D: checks if the two vectors' X and Y coordinates are equivalent; returns false with any other type
  • -vector2D: negates the X and Y coordinates of the vector

color

Exports globals

color is a simple wrapper around all things color-related.

rgb(r: number, g: number, b: number, a: number | nil): color

Constructs a new color using the r, g, b and a values. Assumes all values are contained in the set [0, 1]. a defaults to 1.

hsl(h: number, s: number, l: number, a: number | nil): color

Constructs a new color using the h, s, l and a values using the HSL color model. Assumes all values are contained in the set [0, 1]. a defaults to 1; h wraps around.

hsv(h: number, s: number, v: number, a: number | nil): color

Constructs a new color using the h, s, v and a values using the HSV color model. Assumes all values are contained in the set [0, 1]. a defaults to 1; h wraps around.

shsv(h: number, s: number, v: number, a: number | nil): color

Equal to hsv(), except the hue value is smoothed using cubic smoothing. Not accurate, but produces neater-looking color blends for rainbow-shifting colors.

local rainbow = shsv(t, 1, 0.5)

hex(hex: string): color

Reads in a hex string and parses it into a color. Accepted hex string formats are #ffffff, ffffff, #fff and fff.

color:unpack(): number, number, number, number

Unpacks the color into its R, G, B and A values. Useful for diffuse:

local quad = Quad()
quad:diffuse(col:unpack())

color:rgb(): number, number, number

Returns the color's R, G and B values.

color:hsl(): number, number, number

Returns the color's H, S and L values in the HSL color model.

color:hsv(): number, number, number

Returns the color's H, S and V values in the HSV color model.

color:hex(): string

Returns the color's hex string representation in the format ffffff.

color:hue(h: number): color

Sets the color's hue value in the HSL/HSV color model.

color:huesmooth(h: number): color

Equivalent to color:hue(), except the hue value is smoothed using cubic smoothing. Not accurate, but produces neater-looking color blends for rainbow-shifting colors.

color:alpha(a: number): color

Sets the color's alpha channel.

color:malpha(a: number): color

Sets the color's alpha channel, multiplying the previous value with a.

color:invert(): color

Inverts the color.

color:grayscale(): color

Makes the color grayscale using a more accurate formula than just multiplying every value by 0.5.

color:hueshift(a: number): color

Shifts the color's hue by a.

Operations

Here are all valid operations for colors:

  • color + number: equal to color + rgb(number, number, number)
  • color + color: adds the colors' R, G and B values together, respectively, forming a new color
  • color - number: equal to color - rgb(number, number, number)
  • color - color: subtracts the colors' R, G and B values, respectively, forming a new color
  • color * number: equal to color * rgb(number, number, number)
  • color * color: multiplies the colors' R, G and B values together, respectively, forming a new color
  • color / number: equal to color / rgb(number, number, number)
  • color / color: divides the colors' R, G and B values, respectively, forming a new color
  • color == color: checks if the two colors' R, G and B values are equivalent; returns false with any other type

easable

A simple way of making a number easable. See this post for implementation details.

local easable = require('stdlib.easable')

local n = easable(0)

-- each time you want to set it, call this instead
n:set(value)
-- or
n:add(value)

-- to avoid the ease, do this instead
n:reset(value)

-- then, in your update function
function uranium.update(dt)
  n(dt) -- multiply this image by some value to speed it up
  print(n.a) -- retrieve the eased value
  print(n.toa) -- retrieve the target value it's easing towards
end

easable(default: number): easable

Creates a new easable, setting the default to default. Can technically be anything that has T * number, number - T and T + T defined, including a vector2D.

easable:set(new: number): void

Sets the target value (toa) to new, easing the current value to the new value.

easable:add(new: number): void

Equivalent to easable:add(easable.toa + new).

easable:reset(new: number): void

Sets the current (a) and target (toa) values to new, not easing the current value to the new value.

Operations

Every operation supported on the eased value is supported with an easable.

input

Defines callbacks

input is the library that handles everything input-related. Its main feature is providing the press and release callbacks, but you can also access the raw inputs with the inputs table (each value is -1 if the key is not pressed and the time at which it was pressed, estimated with t if it is pressed) and the raw inputs (ignoring callback returns) with rawInputs. Additionally, for your convinience, it provides a directions enum:

directions = {
  Left = {-1, 0},
  Down = {0, 1},
  Up = {0, -1},
  Right = {1, 0}
}

uranium.press(direction: string)

Called when the player presses on a certain key. Currently only supports arrow keys!! direction can be Left, Down, Up or Right (TODO: change this to an enum).

uranium.release(direction: string)

Same as uranium.press, except for releasing a key.

A note about keyboard inputs

Working with left/down/up/right inputs can be tiring at times and it's hard to always fit designs to work with them. However, if you're willing to take a little compromise, you can also access all keyboard inputs. However, it's worth noting that this depends on NotITG's Simply Love (any forks will work fine too) both for your development environment and for all players. That being said, if you want to access the keyboard API, this is how you do it:

-- check if the user is using simply love at all
if not stitch then error('This modfile requires the Simply Love theme! https://github.com/TaroNuke/Simply-love-NotITG-ver.-') end

keyboard = stitch('lua.keyboard')

-- table that contains every keyboard key as the key and a boolean as the value
local buffer = keyboard.buffer
-- for example:
local isDebugKeyHeld = buffer['F3']

-- contains booleans for shift, ctrl, alt, win and altgr
local special = keyboard.special
local isDebugKeyAndShiftHeld = isDebugKeyHeld and special.shift

bitop

A Lua 5.0 port of bitop-lua. See their repository for documentation.

local bitop = require('stdlib.bitop')

scheduler

Defines callbacks

A simple scheduler.

local scheduler = require('stdlib.scheduler')

scheduler.schedule(when: number, func: function): number

Schedules a function to run in a specific amount of time. when is in seconds.

scheduler.scheduleInTicks(when: number, func: function): number

Schedules a function to run in a specific amount of uranium.update calls/ticks.

scheduler.unschedule(i: index): void

Unschedules a function. Use the index returned to you when originally scheduling the function.

scheduler.unscheduleInTicks(i: index): void

Unschedules a function in ticks. Use the index returned to you when originally scheduling the function.

rng

A xoshiro128** reimplementation in Lua.

rng.init(seed: number[] | nil): rng

Initializes a new RNG class. seed must be a table of size 4; if it is not provided, os.time() is used in its place. (Not os.clock()!!! Two RNG values created at the same time with no provided seed will be the same.)

rng(a: number | nil, b: number | nil): number

Acts identical to math.random(). Pass in no arguments to get a random float from 0 to 1, pass in one argument to get a random inclusive integer from 1 to a, pass in two arguments to get a random integer from a to b.

rng:int(min: number, max: number | nil): number

Generates an inclusive random integer. Pass in one argument to get a random integer from 1 to a, pass in two arguments to get a random integer from a to b.

rng:float(max: number | nil): number

Generates a random fractional number from 0 to max. max defaults to 1.

rng:bool(): boolean

Generates either a true or a false randomly.

rng:seed(seed: number): void

Sets the seed and advances the state.

rng:next(): number

Gets the next pseudo-random value. Recommended to use int, float, etc. over this.

rng:jump(): void

The jump function:

This is the jump function for the generator. It is equivalent to 2^64 calls to next(); it can be used to generate 2^64 non-overlapping subsequences for parallel computations.

rng:longJump(): void

The long-jump function:

This is the long-jump function for the generator. It is equivalent to 2^96 calls to next(); it can be used to generate 2^32 starting points, from each of which jump() will generate 2^32 non-overlapping subsequences for parallel distributed computations.

ease

Exports globals

A direct copy of Mirin Template's ease.lua, for convinience. See the docs for those here.

util

Exports globals

A big ol' module that holds a bunch of useful functions. These were too specific or too niche to go in any singular module; so they're all here now.

There's a bit too many functions to document, so I'd recommend just looking through the source code. I promise it doesn't bite.

aft

An AFT setup library. Sets up sprites and AFTs with sprite and aft, respectively, making them ready for texturing use.

local aftSetup = require('stdlib.aft')

local aft = ActorFrameTexture()

local aftSprite = Sprite()
aftSetup.sprite(aftSprite)

aft:addcommand('Init', function(self)
  aftSetup.aft(aft) -- put this here; else it'll recreate it every frame!
  aftSprite:SetTexture(self:GetTexture())
end)

noautplay

A single function which can be called before uranium.ready() to disable autoplay for the duration of the file if the player has it on.

require('stdlib.noautoplay')()

uwuify

uwuify = require('stdlib.uwuify')
print(uwuify('hello, world!')) --> hewwo, wowwd!

A very important library I don't see enough game engines include in their standard libraries.

Examples

Here are a couple of examples. All of these are standalone main.lua files that you can plug in and view the results of!

Default Uranium Template code

require('stdlib.color')

-- define a basic quad
local quad = Quad()
quad:xy(scx, scy)
quad:zoom(120)
quad:diffuse(0.8, 1, 0.7, 1)
quad:skewx(0.2)

-- define a sprite
local sprite = Sprite('docs/uranium.png')
sprite:xy(scx, scy)
sprite:zoom(0.4)
sprite:glow(1, 1, 1, 0)

-- let's add some text aswell
local text = BitmapText('common', 'hello, uranium template!')
text:xy(scx, scy + 100)

-- update gets called every frame
-- dt here refers to deltatime - the time that has passed since the last frame!
function uranium.update(dt)
  -- let's rotate our quad
  quad:rotationz(t * 80)
  -- then shove it to the screen - similar to a drawfunction!
  quad:Draw()
  -- and you can do this multiple times of course!
  quad:zoomto(180, 180)
  quad:rotationz(t * 100)
  quad:diffusealpha(0.4)
  quad:skewx(0.1)
  quad:Draw()
  -- no need to reset properties - uranium resets all properties that you set upon definition!

  -- throw in the logo aswell, because why not
  -- zoom and glow is done for a quick-and-dirty outline
  sprite:zoom(sprite:GetZoom() * 1.1)
  sprite:glow(1, 1, 1, 1)
  sprite:Draw()
  -- if you can't wait until the start of a frame to reset properties, you can manually do it
  reset(sprite)
  sprite:Draw()

  -- for the text, get a rainbow color
  local col = shsv(t * 0.6, 0.5, 1)
  text:diffuse(col:unpack()) -- the :unpack() is necessary when passing into :diffuse()
  -- wag the text
  text:rotationz(math.sin(t * 2) * 10)
  text:Draw()
end

Simple platformer base

require('stdlib.vector2D')
local input = require('stdlib.input')

-- constants are just those that felt nice to me. this is completely valid to do in gamedev
local DAMPING = 1/9500
local SPEED = 2
local JUMP_FORCE = 32
local GRAVITY = 2.3
local PLAYER_SIZE = 50

local groundY = sh * 0.8

local protagActor = Quad()
protagActor:zoomto(PLAYER_SIZE, PLAYER_SIZE)
local ground = Quad()
ground:zoomto(sw, 4)
ground:xy(scx, groundY + PLAYER_SIZE/2 + 4/2)

local coverQuad = Quad()
coverQuad:diffuse(0, 0, 0, 0.6)
coverQuad:xywh(scx, scy, sw, sh)

local pos = vector(scx, groundY)
local vel = vector(0, 0)
local hasHitGround = true -- let's define this so that you can't jump mid-air

-- called whenever the player recieves an input
function uranium.press(direction)
  if direction == 'Up' and hasHitGround then
    vel.y = vel.y - JUMP_FORCE
    hasHitGround = false
    return true -- input eaten! further callbacks won't recieve this
  end
end

function uranium.update(dt)
  -- respond to l/r inputs
  if input.inputs.Left ~= -1 then
    vel.x = vel.x - SPEED
  end
  if input.inputs.Right ~= -1 then
    vel.x = vel.x + SPEED
  end

  -- apply gravity
  vel.y = vel.y + GRAVITY

  -- update position, apply damping to velocity
  pos = pos + vel
  vel = vel * math.pow(DAMPING, dt)

  -- make sure the player can't clip through the ground
  if pos.y >= groundY then
    pos.y = groundY
    if vel.y >= 0 then vel.y = 0 end
    hasHitGround = true
  end

  -- make sure the player can't leave the screen on accident
  pos.x = math.min(pos.x, sw - PLAYER_SIZE/2)
  pos.x = math.max(pos.x, 0  + PLAYER_SIZE/2)

  -- slightly cover up the regular nitg gameplay
  coverQuad:Draw()

  -- draw them!
  protagActor:xy(pos.x, pos.y)
  protagActor:Draw()

  -- draw the ground
  ground:Draw()
end

AFTs

VSync recommended

local aftSetup = require('stdlib.aft')
require('stdlib.color')
require('stdlib.vector2D')

local coverQuad = Quad()
coverQuad:diffuse(0, 0, 0, 1)
coverQuad:xywh(scx, scy, sw, sh)

local testQuad = Quad()
testQuad:zoom(50)

local aft = ActorFrameTexture()

local aftSprite = Sprite()
aftSetup.sprite(aftSprite)
aftSprite:diffusealpha(0.99)
aftSprite:zoom(1.01)
aftSprite:rotationz(0.2)

aft:addcommand('Init', function(self)
  aftSetup.aft(aft) -- put this here; else it'll recreate it every frame!
  aftSprite:SetTexture(self:GetTexture())
end)

local text = BitmapText('common', 'uranium template!')
text:xy(scx, scy)

function uranium.update(dt)
  coverQuad:Draw()

  aftSprite:Draw()

  local rainbow = shsv(t * 1.2, 0.5, 1)

  testQuad:xy((vectorFromAngle(t * 160, 100) + vector(scx, scy)):unpack())
  testQuad:diffuse(rainbow:unpack())
  testQuad:zoom(50 * math.random())
  testQuad:Draw()

  aft:Draw()

  text:Draw()
end

Credits

XeroOl - Mirin Template was a massive design inspiration; early stages of this template borrowed lots of code from it and the current require implementation has been grabbed directly from it
Mayflower, Aura - Testing, design help
mangoafterdawn - The Uranium Template logo!




You didn't delete the included image of Jillo, did you?