## Operators

Functions for performing operations on sources.

- [add](#add)
- [blend](#blend)
- [diff](#diff)
- [layer](#layer)
- [mult](#mult)

### add

`.add( texture, amount )`

* `texture`
  * `color` :: see [color `vec4`](#color-vec4)
  * `src` :: see [`src`](#src)
  * `shape` :: see [`shape`](#shape)
* `amount` :: float (default `0.5`)

Add textures.

### blend

`.blend( texture, amount )`

* `texture`
  * `color` :: see [color `vec4`](#color-vec4)
  * `src` :: see [`src`](#src)
  * `shape` :: see [`shape`](#shape)
* `amount` :: float (default `0.5`)

Blend textures.

### diff

`.diff( texture )`

* `texture`
  * `color` :: see [color `vec4`](#color-vec4)
  * `src` :: see [`src`](#src)
  * `shape` :: see [`shape`](#shape)

Return difference of textures.

### layer

`.layer( texture )`

* `texture`
  * `color` :: see [color `vec4`](#color-vec4)
  * `src` :: see [`src`](#src)
  * `shape` :: see [`shape`](#shape)

Overlay texture based on alpha value.

### mult

`.mult( texture, amount )`

* `texture`
  * `color` :: see [color `vec4`](#color-vec4)
  * `src` :: see [`src`](#src)
  * `shape` :: see [`shape`](#shape)
* `amount` :: float (default `1.0`)

Multiply images and blend with the texture by `amount`.