   pegtop.net  >  delphi section  >  articles  >  blend modes  >  quadratic modes delphi section  articles  blend modes  introduction  normal mode  average mode  multiply mode  screen mode  darken mode  lighten mode  difference modes  overlay mode  hard light mode  soft light mode  dodge modes  burn modes  quadratic modes  additive modes  interpolation mode  logical modes  RGB modes  HSL modes  opacity  dark modes  bright modes  final words  components  about me  reflect mode  Description: This mode is useful when adding shining objects or light zones to images. Michael Hansen introduced it to me, and gave it this name. The formula is similar to color dodge, but the result is not that bright in most cases. The result looks a bit like soft light. Formula: f(a,b) = a2 / (1 - b) Disadvantage: The formula can result in values greater than 1, so some truncation can occur (but not as extreme as for color dodge). Code: if b = 255 then result := 255 else begin c := a*a DIV (255-b); if c > 255 then result := 255 else result := c; end; glow mode  Description: This mode is a variation of reflect mode (base and blend color swapped). I gave it this name because it is the "opposite" of reflect mode. The result looks a bit like hard light. Formula: f(a,b) = b2 / (1 - a) Disadvantage: The formula can result in values greater than 1, so some truncation can occur (but not as extreme as for inverse color dodge). Code: if a = 255 then result := 255 else begin c := b*b DIV (255-a); if c > 255 then result := 255 else result := c; end; freeze mode  Description: Another variation of reflect mode (base and blend color inverted, the result inverted again). I'm seriously running out of names, but due to some examples I tried, I decided to take this name. Formula: f(a,b) = 1 - (1 - a)2 / b Disadvantage: The formula can result in values smaller than 0, so some truncation can occur (but not as extreme as for color burn). Code: if b = 0 then result := 0 else begin c := 255 - sqr(255-a) DIV b; if c < 0 then result := 0 else result := c; end; heat mode  Description: Another variation of reflect mode (like freeze mode, but base and blend color swapped). I gave it this name because it is the "opposite" of freeze mode. Formula: f(a,b) = 1 - (1 - b)2 / a Disadvantage: The formula can result in values smaller than 0, so some truncation can occur (but not as extreme as for inverse color burn). Code: if a = 0 then result := 0 else begin c := 255 - sqr(255-b) DIV a; if c < 0 then result := 0 else result := c; end;
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