Vignette effect

[sx2008]

Delphi-Quellcode:

function CalcVignetteBrightness(X, Y: Single): Single;
var
  distance : Single;
  inner_radius, outer_radius, : Single;
begin
  inner_radius := 50;
  outer_radius := 150;
  x := x * 0.75;  // <= try this

  // calculate the distance from the origin (center of the image)
  distance := SQRT(SQR(x) + SQR(Y));