Supported ISF features

Vuo recognizes most fragment shaders that conform to the ISF 2.0 specification.

Functions

Vuo supports these ISF-specific functions:

Function Description
vec4 IMG_PIXEL(image, vec2) The color of a pixel in an image, using pixel-based coordinates.
vec4 IMG_NORM_PIXEL(image, vec2) The color of a pixel in an image, using normalized coordinates.
vec4 IMG_THIS_PIXEL(image) The color of the pixel that the fragment shader is currently executing on.
vec4 IMG_THIS_NORM_PIXEL(image) The color of the pixel that the fragment shader is currently executing on.
vec2 IMG_SIZE(image) The size of an image, in pixels.

Vuo also supports these Vuo-specific functions in ISF code:

Function Description
int LIST_LENGTH(list) The number of items in a list that was declared in INPUTS.

Uniforms

Vuo supports these ISF-specific uniforms:

Uniform Description
vec2 RENDERSIZE The size of the output image, in pixels.
float TIME The time since the composition started, in seconds.
float TIMEDELTA The time since the previous frame was rendered, in seconds. For the first frame, this is 0.
vec2 isf_FragNormCoord The normalized coordinates of the pixel that the fragment shader is currently executing on.
vec4 DATE The current date and time: year, month, day, and seconds since midnight.
int FRAMEINDEX 0 for the 1st frame, 1 for the 2nd frame, 2 for the 3rd frame, and so on.

Unsupported

Vuo does not currently support:

  • multiple passes/buffers (PASSES key and PASSINDEX uniform)

  • image file loading (IMPORTED key)

  • audio input (audio and audioFFT data types)

  • IDENTITY key