Borderless printing. How to set zero?

Question

Android

I'm writing a print service.
You can set minimum margins in the printer description.
The problem is that a pdf is generated with fields that are unknown to me.
The selection method is not comme il faut.
X useful points.
L,r fields. W media width.
Add information to decide.
Since there are only 384 points on the line, each one is valuable.

Answer 1

1pt = 1dot
yes this is not true, but only if we write that the density is 72dpi, we can address each point.
with a real resolution of 203dpi, the line will be 127px for the browser,
since when working with canvas, the minimum resolution is 1/72 inch.
Since there is no way to find out the size of the margins, then in the answer about the paper format we indicate that the minimum margins
are 500 mils = 1/2 inch, and the entire width is int(1000 + 1000 * number_points/72)
Alas, even with this rounding we lose a few points
In the driver itself, after rendering, just bite off 36 pixels at the edges.
I couldn't come up with a better solution in 4 months.