Originally Posted by
passel
Yes, that should work.
The first parameter after page, should scale the X (normally defaulted to 1) (i.e. a percentage of X is applied to X) and the fourth parameter should scale the Y (a percentage of Y is applied to Y).
The second parameter would apply a percentage of X to the Y value, and the third parameter would apply a percentage of Y to the X value.
That is why to rotate 90 and 270, you are using 1 and -1 combinations, to have 100% of X applied to the Y axis and 100% of Y assigned to the X axis.
The -1 would just flip the direction of the corresponding axis, so the coordinates go the reverse direction to match the direction it needs to go for the rotation.
In the case of 180 degree rotation, you just need to flip the X coordinates and the Y coordinates (i.e. scale both by -1, i.e. the first and fourth parameters).
Perhaps with this additional information, and some more thought, it might make a little more sense.