GLSL Preview package

Live preview fragment shaders in the Atom editor, with ctrl-shift-G.

Make sure you install language-glsl for syntax highlighting.

Uniforms

The following default uniforms are included, no need to add these into your fragment shaders. Uncheck Include default uniforms in the package settings to declare these yourself.

uniform vec2 iResolution; // size of the preview
uniform vec2 iMouse; // cursor in normalized coordinates [0, 1)
uniform float iGlobalTime; // clock in seconds

The variants u_resolution, u_mouse and u_time can also be used to match the style found in The Book of Shaders.

Textures

Textures can be loaded by defining a uniform with a comment containing the path to the file. The syntax is:

uniform sampler2D <texture_name>; // <path_to_file>

For example:

uniform sampler2D inThisDirectory; // foo.jpg
uniform sampler2D inOtherDirectory; // ../other_textures/bar.png
uniform sampler2D withAbsolutePath; // /Users/ford/textures/blah.bmp

Shader errors

If the shader fails to compile, the tab and line number will subtly highlight in red.

If enabled in the package settings, a notification will show the error message:

Capture images

Right click on the preview to copy or save a still image of the shader. This can also be done by running the command "Glsl Preview: Copy Image" or "Glsl Preview: Save Image" from the command palette (cmd-shift-P).

Examples

Example shaders can be found in the examples/ directory.

glslify

Supports glslify for importing glsl modules.

// Import from local file:
#pragma glslify: map = require('./map')

// Import from npm installed module:
#pragma glslify: rainbow = require('glsl-colormap/rainbow')

Frag snippet

Create a new .glsl file, type frag, and hit enter. This will output the base fragment shader code to get started from.

Credits

Markdown Preview for the boilerplate code.

three.js for simplifying WebGL.