- C-a == Ctrl-a
- M-a == Alt-a
:q close
:w write/saves
:wa[!] write/save all windows [force]
:wq write/save and close
data:text/html, <style type="text/css">#e{position:absolute;top:0;right:0;bottom:0;left:0;}</style><div id="e"></div><script src="http://d1n0x3qji82z53.cloudfront.net/src-min-noconflict/ace.js" type="text/javascript" charset="utf-8"></script><script>var e=ace.edit("e");e.setTheme("ace/theme/monokai");e.getSession().setMode("ace/mode/ruby");</script> |
local random = math.random | |
local function uuid() | |
local template ='xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx' | |
return string.gsub(template, '[xy]', function (c) | |
local v = (c == 'x') and random(0, 0xf) or random(8, 0xb) | |
return string.format('%x', v) | |
end) | |
end |
The Liang-Barsky algorithm is a cheap way to find the intersection points between a line segment and an axis-aligned rectangle. It's a simple algorithm, but the resources I was pointed to didn't have particularly good explanations, so I tried to write a better one.
Consider a rectangle defined by x_min ≤ x ≤ x_max and y_min ≤ y ≤ y_max, and a line segment from (x_0, y_0) to (x_0 + Δ_x, y_0 + Δ_y). We'll be assuming at least one of Δ_x and Δ_y is nonzero.
(I'm working with Flash, so I'll be using the convention that y increases as you go down.)
We want to distinguish between the following cases:
--[[ | |
ProFi v1.3, by Luke Perkin 2012. MIT Licence http://www.opensource.org/licenses/mit-license.php. | |
Example: | |
ProFi = require 'ProFi' | |
ProFi:start() | |
some_function() | |
another_function() | |
coroutine.resume( some_coroutine ) | |
ProFi:stop() |