DESCRIPTION

Not yet written yet, sorry...

$p

The source pixels (1..4 bytes per pixel, depending on format). Use like this:

 $p*3.5         # the return value is the result

$P

The source pixels without alpha. Use it like this:

 $P *= 0.5; $p  # modify $P inplace, return also modified $p as result

$x

A two-dimensional vector containing the x-coordinates of each point in the current tile:

 $x = (zeroes(long,$w)->xvals + $destination->x)->dummy(1,$h)->sever;

$y

A two-dimensional vector containing the y-coordinates of each point in the current tile:

 $y = (zeroes(long,$h)->xvals + $destination->y)->dummy(0,$w)->sever;

$bpp

The bytes per pixel value of the destination area.