[orca-list] Full lScreen on Large TFTs: Tips and Math Q

[Veli-Pekka Tätilä <vtatila gmail com>]

Hi, I just bought a new TFT screen for my LInux laptop and have a tip
for magnification users:
Formerly due to a very small FoV, I've always chosen to use 4:3 screens
that are 15 to 17 inches in size. Now, though, the smallest option was
19 inches, and most were 22 or more. THat's less than ideal as a
magnification user, I'd take a great quality 15 inch TFT, not made, over
that any day.

At any rate, while this may be obvious for many, I find it rather hard
to use full screen magnification with a comparatively large display. It
is difficult to see the cursor at the cetner, and the left side of the
screen, too. Not to mention the fact that most of the area going totally
unused. Granted I'm mostly a speech user but even with a bit of sight,
heavy magnfiication helps in coding Lua and editing text.

So waht I would recommend in such a situation in stead, would be to use
windowed magnification as thoguh you had a full screen magnifier. You
can simply ignore all the rest of the screen that's not magnified, as
though it was not there. ON my 19 inch TFT, I adjusted the screen
magnifier as follows for 5 x magnification.

Native res: 1400 x 900 pixels
width (left, right): 150 to 950 pixels 
height (top, bottom). 150 to 750 pixels 

I've set the border to white, 15 pixels, and all this works great now. I
wish I had hotkeys for moving and resizing the magnified rect from the
keyboard,. Having to give  the coords in  absolute pixels is more than a
bit programmer convenient, and not very intuitive.

I just start out with a window that's full screen, and then subtract
from right or add to left to narrow the screen. SImilarly I add to top
and subtract from bottom to squeeze  it vertically. FOr moving  add or
subtract from both left and right, or top and bottom, respectively.

Here's a math fquestion, that's sort of related. I've got a 15 inch 1024
x 768 TFT display on my primary Win desktop. If I'd experimentally like
a physically similarly sized chunk of the 1400 x 900 19 inch screen, how
should I set the coords of windowed magnification to approximate  this?
Howabout  the general case: for screen s1 with resolution x to y pixels
of i inches, and emulating it on screen s2 that's  x2 by y2 pixels with
a diameter of  i2 inches.