tea.ml

Graphics framework inspired by TEA. Uses kivy and VDOM-diffing internally. Supports GUIs, canvas graphics & shaders

Definitions

Types

type Color = Vec

Alias used for clarity. Vec of length 4.

data Uniform
	= UniformFloat String Number
	| UniformInt String Number
	| UniformVec2 String Vec
	| UniformVec3 String Vec
	| UniformVec4 String Vec
	| UniformTex0 String Img

Uniform types for shaders. Arguments: uniformName, value

data Widget
	= Rect Color Vec Vec
	| TRect Img Vec Vec
	| SRect String (List Uniform) Vec Vec
	| Btn String String Vec Vec
	| Slider String Number Number Number Number Vec Vec
	| Label String String Vec Vec
	| Line (List Vec) Number Color
	| Many (List Widget)
	| ColorPicker String Vec Vec

Attributes for Widgets
Rect	color, size, pos
TRect	texture, size, pos
Btn	name, text, size, pos
Slider	name, min, max, step, value, size, pos
Label	name, text, size, pos
Line	polygon-points, width, color
Many	children

data Event
	= Tick
	| BtnPressed String
	| BtnReleased String
	| BtnHeld String
	| SliderMoved String Number
	| ColorPicked String Color

Event type for the tick function in the app. Make sure pattern matching on
events is exhaustive, so tick does not throw an error.

Starting the App

app : state -> (Event -> state -> state) -> (state -> Widget) -> Unit

starts an app given an initial state, tick and view

forceUpdate : state -> state

The view gets updated based on the state. The app assumes that view is pure: It always returns the same Widgets for the same state. When side effects do need to be used for some reason, the tick function can request an update.

Example:

let view _ = Label "time" (str $ time ()) @(200, 200) @(0, 0);
let tick _ _ = forceUpdate (); # Note that the state is Unit and constant.
setTick () tick view

stop : Unit -> Unit

Effectful.
Stops the app. Takes effect on the next tick, the current tick is stil executed.

Example:

let tick event state = do
   if state > 1000 then stop ()
   inc state;

let view state = Label "mylabel" (str state) @(200, 200) @(0, 0);

setTick 0

Basic kinds of apps / patterns

staticView : (Unit -> Widget) -> Unit

Renders a view and then halts the app.
Use for graphing, etc.

Getters

width : Number

height: Number

getFPS : Unit -> Number

Positioning / layouts

setPos : Widget -> Vec -> Unit

randPos : Unit -> Vec

grid : Vec -> Vec -> Num -> Num -> List (Vec -> Widget) -> Widget

Colors & constants

red : Color

black : Color

white : Color

blue : Color

green : Color

yellow : Color