# 核心常量（Core Constants）

## 修订版本号

`THREE.REVISION`
当前three.js的修订版本号（ [link:https://github.com/mrdoob/three.js/releases revision number]）。

## Color Spaces

`THREE.SRGBColorSpace THREE.LinearSRGBColorSpace`

[page:SRGBColorSpace] (“srgb”) refers to the color space defined by the Rec. 709 primaries, D65 white point, and nonlinear sRGB transfer functions. sRGB is the default color space in CSS, and is often found in color palettes and color pickers. Colors expressed in hexadecimal or CSS notation are typically in the sRGB color space.

[page:LinearSRGBColorSpace] (“srgb-linear”) refers to the sRGB color space (above) with linear transfer functions. Linear-sRGB is the working color space in three.js, used throughout most of the rendering process. RGB components found in three.js materials and shaders are in the Linear-sRGB color space. D

For further background and usage, see Color management.

## 鼠标按钮

`THREE.MOUSE.LEFT THREE.MOUSE.MIDDLE THREE.MOUSE.RIGHT`

## 源代码

[link:https://github.com/mrdoob/three.js/blob/master/src/constants.js src/constants.js]