ExpressionType class final

The type of a value in the expression language: its name, how many numbers it has (components) and the dimension they measure.

An open class with constants: float, vec2, vec3, vec4, boolean and texture are the engine's, and a host may make its own with the constructor (a handle it samples, as the material language's texture is).

Equal by all four fields, so a float in meters is not a float in seconds, and a dimensionless vec3 is vec3.

Constructors

ExpressionType(String name, int components, {Dimension dimension = Dimension.none, bool isBoolean = false})

A type written name, of components numbers measuring dimension; isBoolean for a truth value.

const

Properties

components → int

How many numbers a value of it has; zero for texture.

final

dimension → Dimension

What its numbers measure; Dimension.none for a pure number.

final

hashCode → int

The hash code for this object.

no setter, override

isBoolean → bool

Whether it is a truth value rather than a number.

final

isNumeric → bool

Whether arithmetic takes it: a number or a vector, of any dimension.

no setter

name → String

How it is written: float, vec3, bool.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

The name, with the dimension in brackets when it has one: vec3, float [m·s⁻¹].

override

withDimension(Dimension other) → ExpressionType

This type measuring other instead.

Operators

operator ==(Object other) → bool

The equality operator.

override

Static Methods

measuring(Unit unit, {int components = 1}) → ExpressionType

The type of components numbers that measure what unit measures.

Constants

boolean → const ExpressionType

A truth value: what a comparison answers and a condition asks. Held as one number, one for true and nought for false, and not a number to arithmetic: (a < b) + 1.0 is refused.

float → const ExpressionType

One number.

numeric → const Map<int, ExpressionType>

The dimensionless numeric types, by how many components they have — numeric[3] is vec3. Index zero is absent on purpose: there is no zero-component number, and texture taking that slot would make an arithmetic mistake resolve to a texture instead of failing.

texture → const ExpressionType

A texture slot. Not a value: it can be sampled and nothing else, which is why its components is zero rather than some number of channels.

vec2 → const ExpressionType

Two numbers.

vec3 → const ExpressionType

Three numbers.

vec4 → const ExpressionType

Four numbers.