R/rgb_weighted_mean.R

In dpcarballo/coloR: Various Tools for Working with Color

#' Finds a color between those received as input in RGB palette
#' @param col1 First color. Hexcode, c(r,g,b), color
#' name as character and "color" class object are all supported.
#' @param col2 Second color. Hexcode, c(r,g,b), color
#' name as character and "color" class object are all supported.
#' @param w1 Number between 0 and 1. Represents how similar the output will be to col1. Defaults to .5
#' @param w2 Number between 0 and 1. Represents how similar the output will be to col2. Defaults to 1-w1
#' @param smooth_factor Correction to prevent mixtures from appearing too dark, making the palette more related to human perception of color. Defaults to 2
#' @param output Format in which output will be returned. Use "hex" to get a hexcode. Use "color"
#' for a "color" class object to be returned. Defaults to "hex"
#' @return The corresponding hexcode or "color" class object.
#' @examples
#'  rgb_weighted_mean("red", "green", smooth_factor=1)
#'  rgb_weighted_mean("red", "green", smooth_factor=7000)
rgb_weighted_mean <- function(col1, col2, w1=.5, smooth_factor=2, output="hex") {
  w2=1-w1
  if(!is_color(col1))
    col1 <- color(col1)
  if(!is_color(col2))
    col2 <- color(col2)
  w1 = w1^(1/smooth_factor)
  w2 = w2^(1/smooth_factor)
  r <- w1*col1$r + w2*col2$r
  g <- w1*col1$g + w2*col2$g
  b <- w1*col1$b + w2*col2$b
  col <- color(r,g,b, maxVal = 255)
  if(output=="hex")
    col=hex(col)
  return(col)
}