Legacy:Color Operators - Unreal Wiki

# Legacy:Color Operators

### From Unreal Wiki, The Unreal Engine Documentation Site

Useful operators for the color Variable Type. This is an example of Scripting Operators.

See also RGB to HLS conversion and HLS to RGB conversion.

Due to the lack of any color operators, let's make a few:

    // Lighten color by 1
    static final preoperator color ++ ( out color A )
    {
      A.R++;
      A.G++;
      A.B++;
      return A;
    }
    // Darken color by 1
    static final preoperator color -- ( out color A )
    {
      A.R--;
      A.G--;
      A.B--;
      return A;
    }

    // Postoperator version
    static final postoperator color ++ ( out color A )
    {
      local color Copy;
      Copy = A;
      A.R++;
      A.G++;
      A.B++;
      return Copy;
    }

    // Postoperator version
    static final postoperator color -- ( out color A )
    {
      local color Copy;
      Copy = A;
      A.R--;
      A.G--;
      A.B--;
      return Copy;
    }

    // Remember that averaging operator we just used? Now it's suddenly useful, so I've copied it into here
    final operator(18) int : ( int A, int B )
    {
      return (A + B) / 2;
    }

    // Interpolate 2 colors
    static final operator(22) color Mix ( color A, color B )
    {
      local Color Result;
      Result.R = A.R : B.R;
      Result.G = A.G : B.G;
      Result.B = A.B : B.B;
      return Result;
    }

    // UT Provides a * operator for colors, but no /. Ramp a color by a float
    static final operator(16) color / ( color A, float B )
    {
      local Color Result;
      Result.R = A.R / B;
      Result.G = A.G / B;
      Result.B = A.B / B;
      return Result;
    }

    // Same thing, but this one affects the color
    static final operator(34) color /= ( out color A, float B )
    {
      A = A / B;
      return A;
    }

    // UT Provides *, not *=, so let's implement it
    static final operator(34) color *= ( out color A, float B )
    {
      A = A * B;
      return A;
    }

    // Add a byte value to each component
    static final operator(20) color + ( color A, byte B )
    {
      local Color Result;
      Result.R = A.R + B;
      Result.G = A.G + B;
      Result.B = A.B + B;
      return Result;
    }

    // Subtract a byte value to each component
    static final operator(20) color - ( color A, byte B )
    {
      local Color Result;
      Result.R = A.R - B;
      Result.G = A.G - B;
      Result.B = A.B - B;
      return Result;
    }

    // Out versions of the operators
    static final operator(34) color += ( out color A, byte B )
    {
      A = A + B;
      return A;
    }

    static final operator(34) color -= ( out color A, byte B )
    {
      A = A - B;
      return A;
    }

    // Out version of the operator UT provides
    static final operator(34) color += ( out color A, color B )
    {
      A = A + B;
      return A;
    }

    static final operator(34) color -= ( out color A, color B )
    {
      A = A - B;
      return A;
    }

## Related Topics

- Operators

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