Color Operators

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;
}