Sunday, December 26, 2010

Mayan calendar

UPDATE
I made the calendar much more readable by adding text labels around the rings like so:



I've just been cleaning up the code and found a couple of errors that have been corrected. You can find the code for the above here.

--Original post below-----------------------

I have been thinking about setting up a "year clock" using multiple rings showing progress in the year, month, day, hour, and minute. I had come up with some designs like so:


In this case the largest circle is the year and the dot on the circle is where we are in the year. The next largest circle is the month and the dot where we are in the month and so on. I had set it up so that everything moved in increments of 1 second. The right side shows what the set up would look like on midnight of December 31st. The nice thing about this clock is that it will never look the same twice in a year. However, it isn't exactly easy to read :)

Next I tried this:

Which uses similar mechanics as the clock above, but as you can see the rings are marked with information. Each circle rotated so that the current date/time was at the top of the ring. Unfortunately this clock proved to be extremely cpu intensive (it was actually pushing my cpu to 100%). I reoriented the circles to this:

But there was no was this script was going to be viable. But I liked the look of the above, with the rings within rings.

Then later I had the idea to try something else and this is what I came up with:

This is when things started looking very Mayan :)
In the above calendar clock, year is the innermost circle and instead of having the circles move I had indicators move around the circles. I also went on to add some system info indicators like so:


The code for the above is here.

Sector11 has also made some cool looking additions to the calendar part. You can see that here. I have a nice Mayan symbol dingbat font that may well be used in conjunction with my circlewriting script to add some glyphs to the calendar also.
I posted a perspective bar set up some time ago, and thought I would revisit a 3D approach. This is what I ended up with.



The bar rises and falls in relation to whatever conky output you feed it. The script can be found here.

It took a crash refresher course in basic trigonometry to get everything working and I can't guarantee that if you try the script it will work. The bar looks as I wanted it to, but I was hoping to be able to define simple coordinates and have multiple bars generated that all fitted together.

This didn't work out in this script as I the math I was using wasn't calculating the right perspectives for subsequent bars.
Updates, I have a couple of things that I've been working on recently.

First there is a amalgamated circle generating and circlewriting lua script.
It can do things like this:



And this is a little more complicated (obviously you can get whatever colors you want for rings and text I was just feeling monochrome when I made these.)


The intertwining effect is made by making different bits of the circle at different points in the lua script. In lua the later instances of cairo graphics are drawn above any earlier instances.

The script can be found here on the crunchbang Linux forum (where you can see a more colorful use of the script. It can also generate bars that can be placed and rotated freely.

Thursday, October 14, 2010

Splitting text into individual letters

One Lua trick that I use a lot is taking a string and splitting it up into individual characters which then get stored in a table.

I used this approach for my circle writing function and many other functions. This is how it's done.

You need the following function in the Lua script above the main function. I did not write this function and I cant remember exactly where I got it from but whoever did write it has my thanks!

function string:split(delimiter)
local result = { }
local from = 1
local delim_from, delim_to = string.find( self, delimiter, from )
while delim_from do
table.insert( result, string.sub( self, from , delim_from-1 ) )
from = delim_to + 1
delim_from, delim_to = string.find( self, delimiter, from )
end
table.insert( result, string.sub( self, from ) )
return result
end

These are the lines that split up the text...
text="text"
print (text) --> text

sub=string.gsub(text, ".", "%1|")
-- the above inserts "|" after every character
print (sub) --> t|e|x|t|

split=string.split(sub, "|")
-- the above splits the string whenever a "|" occurs and also deletes the "|"
the resulting split up characters are stored in a table called split in this case

slen=string.len(text)
-- slen is the length of the original text,
so will be the number of entries in that table "split"

so that:
split[1] = "t"
split[2] = "e"
split[3] = "x"
split[4] = "t"

now I can deal with each character individually.
I could give each character a different font, or a different color
or, in the case of my square font conky below, convert each character to the square font.

Square text conky

I had an idea for a conky. I wanted it to be extremely compact and involve text in different orientations. This is what I ended up with!



The problem was that I spent a long time looking for a square font. I found several fonts that I liked but when I came to rotate them and put rotated letters next to regularly orientated letters I found that none of the fonts were actually square. Non were the same width as height.

So I decided to make my own font using the Lua script. I had done something similar in my ascii text lua; a function that read each letter of the text I wanted displayed and converted the letter into ascii.

In this case I created my own square font out of the webdings font. With webdings a "g" gave me a solid color square, while "c" gave me a black square with a color outline. I simply constructed my letters using those blocks like so:

if letter=="T" then
font="webdings"
acrosst=across
downt=down
rotate=rotate*math.pi/180
cairo_translate (cr, acrosst, downt)
cairo_rotate (cr, rotate)
cairo_select_font_face (cr, font, CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL);
cairo_set_font_size (cr, fontsize);
cairo_set_source_rgba (cr, red, green, blue, alpha);
cairo_move_to (cr, 0, 0);
cairo_show_text (cr, "ggggg")
ldown=fontsize
cairo_move_to (cr, 0, ldown);
cairo_show_text (cr, "ccgcc")
ldown=fontsize+ldown
cairo_move_to (cr, 0, ldown);
cairo_show_text (cr, "ccgcc")
ldown=fontsize+ldown
cairo_move_to (cr, 0, ldown);
cairo_show_text (cr, "ccgcc")
ldown=fontsize+ldown
cairo_move_to (cr, 0, ldown);
cairo_show_text (cr, "ccgcc")
cairo_rotate (cr, -1*rotate)
cairo_translate (cr, -1*acrosst, -1*downt)
end
I actually really like the look of the resulting square "font". And everything fitted nicely together with no gaps :)

Go here to take a look at the code via the link. This is another really long script, mainly because of the letter conversion function. Originally I set up the function converting lowercase letters into upper case letters of the square font. But I didn't like the way they looked, so I re-wrote the letter conversion function to include converting uppercase letters to a different version of the square font.

I just used the lua command string.upper to make everything uppercase and fed it to the conversion function. I never bothered to delete the lowercase conversion lines :)

Final Fantsy VII

I am a big final fantasy 7 fan, so when rabidofx posted a FF7 themed conky, I immediately thought of the potential to turn the FF7 bottom combat panel into a conky display.

And this is what I eventually came up with!



I have tried to be as faithful as I can to the FF7 panel while still allowing the conky to function as a source of information.

It still needs some work and the script needs a good cleanup and improvements to make it more user friendly. You can get the code here at conky-pitstop! Or here on the crunchbanglinux forum. While your on the forum check out rabidfox's post directly above. He has modified ADcomps Adeskbar to look like materia slots (very nice!).

So why does it take 2200 lines of lua code to produce my FF7 panel conky?
Well 3 reasons... first because it's just a little messy. A lot of copying and pasting went on and I'm sure that I could comb through it an eliminate a large number of supurflouous lines :)

Second drawing in lua with the cairo library takes a lot of lines. To draw the blue shaded rectangles required this:
sa=5
sd=5
rh=120
rw=280
red=1
green=1
blue=1
alpha=1
pat = cairo_pattern_create_linear (sa, sd, rh, rw)
cairo_pattern_add_color_stop_rgba (pat, 0, red-1, green-1, blue, alpha)
cairo_pattern_add_color_stop_rgba (pat, 1, red-1, green-1, blue-1, alpha)
cairo_set_source (cr, pat)
cairo_rectangle (cr, sa, sd, rw, rh)
cairo_fill (cr)
I could have used less lines and specified the positions and colors etc in the actual pattern and drawing lines, but this way is just so much easier for fine tuning. I set the colors up like this becasue I kept forgetting which number represented what in the cairo_set_pattern lines! :)

The grey border around the blue was also line intensive.

Reason 3, and perhaps the main reason for the length of the script is the way you have to use cairo to display text. And if you look closely you will see that every piece of text has a black "shadow" ...which is simply the same piece of text, colored black and printed behind and offset a little.

font="Acknowledge TT (BRK)"
text=topl1
fsize=20
red=0
green=0
blue=0
alpha=1
across=32
down=22
cairo_select_font_face (cr, font, CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL);
cairo_set_font_size (cr, fsize);
cairo_set_source_rgba (cr, red, green, blue, alpha);
cairo_move_to (cr, across, down);
cairo_show_text (cr, text)
red=0.8
green=0.8
blue=0.8
alpha=1
across=across-2
down=down-2
cairo_set_source_rgba (cr, red, green, blue, alpha);
cairo_move_to (cr, across, down);
cairo_show_text (cr, text)
So I had to set the font, set the font size, set the red, green, blue and alpha, set the position, write the font, fontsize and color setup lines, move cairo to the coordinates and then tell it to diaplay the text. That gave me the shadow, then I had to change the color and position, set up the text drawing variables and draw the main text.

I kept this format throughout the script, so i could easily change colors and positions without wading through a sea of setup lines.

Saturday, September 11, 2010

Here is my latest conky configuration

conkybar!

and this is what it looks like currently:



Nothing out of the ordinary in terms of content over many other conkyrc generated displays.

But with a few differences.

The first thing is that every is generated in a lua script. The second is that those black triangles at the top are clickable buttons. Here is how this setup functions.



A while ago on the crunchbanglinux website a poster by the name of jpope had a wallpaper that had a large power button right in the middle of the screen. Here is the post:
http://crunchbanglinux.org/forums/post/45907/#p45907

ADcomp had written a python script to place a button on the desktop that would launch a command or script. The button could be placed anywhere and you could make your own icons for it to use and it could execute any command when you click it. It was all set up in the script.

I thought that was pretty cool and I stored it in the back of my mind.

Then recently I started looking into the file io function of lua, the ability to open files in the lua script, read their contents and store that as strings which could be manipulated in the script. I had been working on some bash scripts using curl to download information from webpages, then editing the html to pull out specific pieces of information.

I had been using the conky_parse command in lua to execute the bash scripts via conky, but I was trying to bring some of the operations into the native lua language to make the scripts run a little lighter cpu wise.

However, once I started playing around with the file io commands I realised that I could affect the whole lua script by having the script "watching" a text file and then editing the file, initially via a terminal command.

something like this:
$ touch /tmp/setw.txt; echo "1" > /tmp/setw.txt

the touch command creates the file then the > writes a "1" into the file.
a similar command could then easily ovewrite the "1" with a "2"

so if i had the Lua script watching that file I could put the output into a string and use the string as a basis for an if statement.

These are the lines that watch the text files in the lua script

wread = io.open("/home/mcdowall/conkyset/wset.txt", "r")
wset = wread:read("*lines")

I've changed the names and moved the files out of /tmp so they are persistant.

So now a simple:

if wset=="1" then
--display one thing--
end

if wset=="2" then
--display something else--
end

gives me interactive control over the script.

I then remembered the button script I had seen, and after some searching (and asking) I had the link to the script.

take a look at this entry on the ubuntu conky thread for more infomation on how the interaction works.
http://ubuntuforums.org/showpost.php?p=9826304&postcount=13840

The actual lua script can be found here. It is still very much a work in progress.
http://ubuntuforums.org/showpost.php?p=9830734&postcount=13855

The fact that everything has to be constructed in lua was itself a challenge. Lua doesn't have all the goodies pre-programmed into it like the objects you can get in a conkyrc by putting in the right command

The calendars were tricky. I saw londonali1010's post on lua calendars here
http://mylittledesktop.blogspot.com/2009/10/argh-my-first-snag-with-my-lovely.html

I looked over her code and borrowed a couple of lines (for calculating start day), but went about contructing the calendar in a very different way. The result was a calendar that looked very similar to the one available through a conkyrc. I'm still trying to perfect the day indicator however.

The biggest limitation to using Lua to construct a complete conky output is how it handles displaying text. It takes a lot of lines to get the tables you see in my output, far more than if I were to do the same thing in a straight conkyrc.

Anyway, I'm still working on the content of the conky but I am happy how the mechanics have worked out!

As it stands right now this setup is no more cpu draining than my regular all conkyrc setup. And when I have all the sections rolled up (except system monitor so that I can see the cpu usage) it runs much lighter. When a section is "rolled up" or inactive the lua script does not have to do any of the calculations or rendering for that section.