shinygradient

Shiny app to generate gradient RGB palettes

This is a first exercise in Shiny app creation.

I saw Inigo Quilez's beautiful video and decided to write an R implementation. It then made sense to make it interactive, giving me an excuse to learn some Shiny development.

This is a barebones implementation that seems to get the job done.

Requirements

You need to have shiny installed. It can be found on CRAN:

install.packages("shiny")

Or you can go to the online deployment for the three slider version and the XY pad version.

Usage

Clone this repository and choose one of the two versions from each of the two folders:

• three_sliders is the first version with separate sliders for each value.
• xypad uses the XYpad input method from the XYpad R package by Stéphane Laurent

Within each folder you can open the app.R file in RStudio, then run the app.

There you can use the slides for the 4 parameters that control the RGB curves. Each color channel can be controlled independently.

• A: controls the brightness/luminance of the R, G, B curves (how tall does the whole cosine wave sit?)
• B: controls the contrast of the R, G, B (how quickly does the wave change? also known as amplitude)
• C: controls how much R, G, B change across the color vector (also known as period)
• D: controls where the maxima for each channel are (also known as delay)

The xypad app has a button to randomize values.

You can also choose the number of colors. The color vector is printed at the end of the page.