STYLE Some feedback prompted me to add commentary.

Documented what the heck I meant by 'ptx', 'lsi', etc. etc.  Also where
the numbers came from, but the simplest answer is that you start a
simple dump of the registers to your console while holding the device
in your hand and you rotate it to the various positions, writing down
the numbers you see and then tuning as necessary.  Programming as an
empirical science, not a theoretical one.

Also: I have a really (REALLY) silly script that lets me see all the
projects currently underway in my ~/Projects directory, and it looks for
the DESCRIPTION.md file.  So that's what you're getting.

DESCRIPTION.md

@@ -0,0 +1 @@
+A series of tools for making the Surface Pro 3 usable under Linux.

autorotate/autorotate.py

@@ -32,6 +32,7 @@ def find_accelerometers():
     return (os.path.join(dpath[0], 'in_accel_x_raw'),
             os.path.join(dpath[0], 'in_accel_y_raw'))
 
+
 x_accel_path, y_accel_path = find_accelerometers()
 
 
@@ -46,20 +47,32 @@ def countdisplays():
 
 
 # Landscape
+
+# The 'X' means to read the 'x_accel_path' register, since that's what
+# we need to determine landscape (ls) or portrait (pt) mode.  'N' is
+# 'Normal' and 'I' is 'Inverted.'  The magic numbers for the 'X' are
+# around a 65536-based device register; I'm guessing Poel worked with
+# them by just dumping them to the screen while tilting the screen
+# this way and that.  They seem to work just fine.
+
 def lsx(thex, they): return thex >= 65000 or thex <= 650
 def lsn(thex, they): return they <= 65000 and they >= 64000
 def lsi(thex, they): return they >= 650 and they <= 1100
 
-# Portrait
+# Portrait: L for "Left" and R for "Right."
+
 def ptx(thex, they): return not lsx(thex, they)
 def ptl(thex, they): return thex >= 800 and thex <= 1000
-def ptr(thex, they): return thex >= 64500 and thex <=64700
+def ptr(thex, they): return thex >= 64500 and thex <= 64700
 
 # It's a little odd that X labels it 'left' when you've just turned
 # the tablet to the right, and vice versa, but that's the convention,
 # I guess.
+
+
 Transform = namedtuple('Tranform', ['name', 'mode', 'matrix', 'xrule', 'yrule'])
 
+
 transforms = [
     Transform('normal',   0, '1 0 0 0 1 0 0 0 1',   lsx, lsn),
     Transform('inverted', 1, '-1 0 1 0 -1 1 0 0 1', lsx, lsi),
@@ -113,5 +126,6 @@ def manage_orientation_and_palm_rejection(options):
                 currently_proximate = pen_status
                 os.system("xinput %s '%s'" % (xinput_statemap[pen_status], devicename))
 
+
 if __name__ == '__main__':
     manage_orientation_and_palm_rejection(sys.argv[1:])