Initial thoughts on Yii..

My initial thoughts on the Yii PHP framework can be summed up in one word:  Hell yeah!  Okay, it was more like two words, but it doesn't change the fact that I am very impressed so far with Yii.  Admittedly I have not done any extensive work with the framework as of yet.  The majority of my experience with Yii to date has been reading the (very good) documentation, playing around with its code generation utilities, and looking at how the demo applications were built.

So far the aspect of the framework I am most impressed with is how it is integrated with JQuery.  CakePHP injects javascript code throughout the page, a practice that most Jquery developers cringe at the thought of.  This is also why most Cake developers have abandoned the use of the JS helpers in favor of writing their own code.  This is why I like how Yii integrates JQuery so much: for the most part it separates the JQuery code into separate files and includes them at the top of the script.  This makes me happy.  This will also reduce the amount of time I spend creating my own custom JQuery scripts, since I will actually be using the helpful functions that are included with Yii.

Another aspect of Yii that I am impressed with is its documentation.  Cake has some good documentation, but often key elements are outdated or missing. What is also frustrating is the lack of documented best practices to use with the framework. I often found my answers from blog posts or forums, and wondered why such simple answers weren't included in the documentation to begin with.  This is not the case with Yii.  The documentation itself is very thorough, updated constantly, and very clearly defines best practices. What's more is the generated code as well as the demos it ships with show the majority of the functionality shipped with Yii in use.  This is great because if I want to see how to create a form in Yii I can either consult the documentation or pull up any of the demos that came with the framework. Handy!

Finally, the code generation utility shipped with yii is excellent.  In just a matter of minutes, Yii can generate a fully-functioning skeleton application complete with a login/logout system, contact form, CRUD, database access, etc.. all integrated with JQuery.  This has been a great skeleton to start with, and has managed to save me loads of setup time integrating basic components into the application.  (I can't say the same for Cake's skeleton application that is generated).

When I began playing around with Yii, I fully expected to find parts of the framework where I would sit back and reminisce of my days in the Cake world.  To my surprise, the more I learn about Yii the happier I am to embrace it.  Nothing against Cake, but I would recommend Yii to any developer looking for a powerful MVC PHP framework.

Switching PHP Framework from CakePHP to Yii

After about a year of developing with CakePHP, I have decided to make the switch to Yii.  There are several reasons I decided to make this switch, but the biggest one was performance related.  Don't get me wrong, I think CakePHP is a great development framework.  There were enough things that I personally did not like about Cakephp to justify my switch to learning a new MVC framework.  Here are a few of the reasons I decided to make the switch:

1) Yii is PHP 5 only.

      I really like PHP 5.  While CakePHP supports PHP 5, it also has to support PHP 4, and thus does some things under the hood which hinders its performance a little in order to support legacy PHP code.

2) Yii supports composite primary keys.

      One problem I had with CakePHP was how it did not support composite primary keys.  While this wasn't a huge deal breaker for me in Cake, it was definitely annoying.  Instead, every table had to have a unique ID as the sole primary key and your "composite" keys basically just had to be maintained through your own code.  Not terrible, but still rather annoying.  One thing I really did not like was how CakePHP thought that a "Has One" relationship should work in a database.  Take the example of Apple has one Banana.  Every textbook will tell you that to be in a proper normalized state, the Apple table will contain a field called 'banana_id', which will contain the ID of the corresponding Banana row.  This ensures that the Apple field can only contain one banana reference.  This is easily verified since Apple.banana_id holds one and only one value at a time.  Straight out of the CakePHP hasOne relationship documentation, it clearly states quite the opposite.  Does this produce a hasOne relationship?  Well, when you access models via Cake's API then sure it will hand you back one row, but your database is not in a normalized form.  There's technically nothing stopping you from firing up PhpMyAdmin and adding a few rows with the same Banana.apple_id.  This also means that if you are not careful with your queries or the way you access your data in Cake, you may end up with data redundancy.  This is why putting your databases in a normalized form is so important. There are ways around this in Cake but they require quite a bit of extra work, which of course defeats the purpose of its advertised "magic" in the first place.

3) CakePHP is too slow for my needs.

      If you search google for "CakePHP" and "Slow," you'll see many, many posts from developers wondering why they're application is responding so slowly.  You'll also notice that there are no real good answers as well.  Is CakePHP really that slow?

The quick answer:  No actually, it isn't slow.

Let me explain myself.  CakePHP can be fast.  By default however, it is very, very slow.  When you develop your application you will need to keep caching and performance in mind, something that most developers new to PHP frameworks don't do.  The problem is that in order to develop a fast CakePHP application, you cannot use the majority of the magic that Cake provides.  For example, Cake's documentation and tutorials will lead you to use mod_rewrite for pretty URLs (using .htaccess) and $this->link() to create formatted html links quick and easily.  This creates a lot of easily maintainable functionality quickly, but your performance will suffer greatly down the road.  Even an application relying heavily on XCache and Memcached still needs lots of customized work tailored specifically to your application in order to speed it up.  While this will be true with an application developed in Yii as well, its default performance is significantly greater than Cake's.  So while people complaining that Cake is slow are not necessarily right, you will have to work hard to get it speedy.

This post isn't meant to bash Cake.  I really do like the framework.  As I have gotten more used to developing in the MVC architecture I realize that Cake provided a great learning experience for me and worked as a great stepping stone in creating an MVC application.  I think that Yii will be the next step forward for my project, and future posts in this blog will hilight my experiences using Yii.

Are you currently using CakePHP?  Did you end up switching to Yii, or another framework?  I'd love to hear your thoughts!

Creating MARPAT digital camouflage textures with Photoshop

Fireteams.net was in need of a camouflage texture. After a couple hours of scouring the web searching for a decent MARPAT (MARine PATtern) image, I gave up and decided to make my own.  I put together this little photoshop tutorial showing the techniques I used to create a Digital Desert Camouflage texture.

Just a warning: I'm a programmer, not an artist.  Also, my photoshop abilities are the result of following tutorials on the internet. If you know of better or easier ways to accomplish the same thing, I would love to hear about it in the comments!

Here is the final MARPAT camouflage image we'll be creating:

MARPAT Digital Desert Camouflage

We'll start our tutorial by taking a quick look at real desert MARPAT camouflage.  This will give us a better idea of the look we want to achieve in our final image.

Sample of real desert MARPAT camouflage.
Courtesy of http://www.helloelastic2.co.uk/justlooking/

It's easy to see that there are some unique characteristics that define MARPAT:

Color

• For Desert MARPAT, there are four colors which are used in the image.
• Colors are layered with lighter colors underneath darker ones.
• Blobs become smaller and less connected as they get darker.
• In digital desert camouflage, each color is a different shade of brown.

Shape

• Every blob-like shape in this image is composed of small square shapes. 
• Blobs tend to look stretched, flowing in more of a horizontal direction.
• Blobs are randomly shaped and have many holes in them.

Now that we have some background on what we want to achieve, let's get started with our tutorial!


1) Begin by selecting four colors to use with your image. You can place each color into a swatch or paint them into a layer for easy access.  Here are the four colors I chose to use:

Base Color:	#d7cebd
Light Color:	#c1b59c
Medium Color:	#a99265
Dark Color:	#88602b

2) Make a new layer and paint it black. Apply a "Difference Clouds" filter on this layer:

Filter > Render > Difference Clouds

This will create a nice spread of light and dark shades which will help us to create our blob shapes later on.

Difference Clouds!

3) Increase the contrast of the clouds.  This can be done through the following menu option:

Image > Adjustments > Brightness / Contrast

Increase the contrast to a value between 75 and 100.  I used a value of 90 for each of my cloud layers.

4) Apply a mosaic filter to the clouds:

Filter > Pixelate > Mosaic

Select a small cell size, I chose a size of 5.  Sizes of 7-8 will produce images that look more zoomed in.  The cell size will represent the smallest "square" that will be in the image.  I encourage playing around with this value until you find the size you desire.

5) Repeat steps 2 through 4 two more times. This will give us a total of three layers of pixelated difference clouds.  The variability found in each cloud layer will help prevent our blobs from having too similar of patterns.


6) Now that we have our clouds, it is time to start creating our camouflage!  We'll start with the lightest color first: the Base color.  Make a new layer and use the paint bucket tool to color the layer with our Base color. That's it! (at least for this layer).  I wish the other layers were this easy though...

7) Before we continue, I would like to quickly explain what we are going to try and accomplish here.  Using the Magic Wand Tool, we're going to select multiple areas of a cloud layer (by holding the Shift key while selecting with the wand), then fill-in our selection with one of our three remaining colors. If while clicking around you accidently let go of shift (and lose all of your selections), just hit ctrl-z to get all your work back. We will use a different cloud image for each of our colors.

Select the Magic Wand Tool (W is the keyboard shortcut) and choose a very small Tolerance. I chose a value of 2. You can play around with larger values, but I recommend no larger than 4. For this layer we're going to create the Light color portion of the camo. This color should cover about 75% of the base color, and should contain large, connected blobs.  Here are a couple images of my selections in progress. This will give you a good idea on how to progress.

Result after a few shift-clicks

Final selection. Takes a while, but I swear it is worth it!

8) Now that we have our selection, copy (Ctrl-C) and paste (Ctrl-V) your selection into a new layer.  Set a color overlay on this layer to the color you chose for your Light color.  This can be done through:

Layer > Layer Style > Color Overlay

Make sure that Blend Mode is set to Normal, and Opacity to 100%.  Click on the colored icon, and set it to your color.  This is only one of many ways to set the color for our selection. I like this method as it makes it very easy to change the color of the entire layer at once (especially handy if you want to change the color later).

Result after a copy and paste.  I moved the Base layer

above the clouds so that we can actually see the selection.

Result after setting the blending options. Finally starting

to look like camouflage.

9) Repeat steps 7-9 for our next two colors, using a different cloud layer for each color. Remember that these blobs get smaller and less connected as they get darker. Below are the results for my next two colors:

Selection mask for Medium color.

Result after applying medium color layer.

Dark color selection mask.

Final camouflage image

That is all there is to it! This technique can be done on a larger scale to produce nice backgrounds or textures in games. If this tutorial was useful to you, or you found better techniques or easier ways to accomplish things, please let me know in the comments!

Hope you found this useful!