chickadee » sdl2 » colour-scale!

color-scale color factorprocedure
colour-scale color factorprocedure
color-scale! color factor #!optional destprocedure
colour-scale! color factor #!optional destprocedure

Efficiently multiply the RGBA values of color by factor (a float or integer). E.g. factor 0.5 halves the RGBA values, factor 2.0 doubles the values.

  • color-scale and colour-scale return a new managed sdl2:color.
  • color-scale! and colour-scale! modify and return dest. If dest is omitted, color is modified and returned.

Requires sdl2 egg 0.2.0 or higher.

The results are clamped to the range [0, 255]. sdl2:color can only hold integer values, so the results will be truncated to integers.