THE ASSET PIPELINE EDITOR - PART 5

In this part of the series I'll answer some of the questions that some of you've been asking me lately, in particular:

• Does the APE watch source files?
• Is there a command-line version of it? And
• Why not publish it as open-source?

I attempted to give brief answers to a couple of them in this thread at GameDev, and also by email to the guys behind the WaveEngine, but I think they deserve a post here with further details.

So, let's begin ...

Does the APE watch source files?

To aswer this question, I need to explain what happens when a new solution is created and saved.

Basically, after saving a solution you will find the following structure on disk:

   + Root Path

      + [Solution's Name] folder

         - [SolutionFileName].fps

         + "Sources" folder

             - sourcefile1

             ...

             - sourcefileN

         + "Projects" folder

            + [Platform1's Name] folder

                - [ProjectFileName1].fpp

               + "Builds" folder

                  + [Profile1] folder

                     - output.fpb

                    + Content folder

             ...

            + [PlatformN's Name] folder

                - [ProjectFileNameN].fpp

               + "Builds" folder

                  + [Profile1] folder

                     - output.fpb

                    + Content folder

The APE creates a folder named "Sources" which will be used as a "local" repository for the whole solution. Within it, you will only find files (no folders). Thus, when you add a new file to any of your projects, the APE will copy that source file to the respository and create the corresponding raw file to the strcuture of your solution.

Following this rationale there is no need to dynamically watch file changes. Why? Simple, if you manually change one of the source files directly then the next time you build content that source file will be used to build assets provided it complies with the condition indicated for building: Always|New|None.

In other words, the APE watch changes over an existing source file only at the moment that new builds are requested. If a project is marked as "Build Always" then no matter what, all included raw files will generate a new asset file. If a project is marked as "Build If New" then only raw files with new source files assigned will end up having a new asset file. Finally, "None" will exclude the project from the build process.

Now, there was a second part in the question posted on GameDev's forum with had to do more with the processing-side of things than with what I've explained above.

The APE will NOT replace production tools like Photoshop, Sound Forge, and so on so forth. So you will need to create your source files there: jpegs, wavs, mov, etc.

What the APE provides is a way to indicate how to process source files to get the file format you need for your games. In case the built-in import/write units or the ones provided later on by me and or any other user are not useful to you, then you can implement your own with full control over them.

So, if you guys want to implement a processor that converts WAVs into OGGs, you can go ahead and do it with ease. What about resizing a texture? Sure. What else? Everything you can imagine of that can be achieved by setting parameters on a property grid.

For example, for the case of XNA'ers, in part 4 of the series I showed a processor with many features that pre-multiply alpha, resize textures, change formats and so on.

So to sum up this part of the question, to create source files you will need to use production tools. But to import them to your games with as asset files with given format, you can use the APE.

Is there a command-line version of it?

Yes, there is! And it's name is "APEBuild" (thanks Javier for suggesting the name!).

When I designed the APE I took into consideration server-side-like use cases. As a matter of fact, it resulted as a corolary when I develop the base test assembly for import/write units (please refer to part 1 to see an image of it).

In the current state of this command-like tool, only two actions can be executed: either you build an entire solution or only a set of projects. Let's have a look of the structure ...

The picture above shows what you get when execute the tool with no parameters (and also with wrong parameters).

So, if you want to build a solution, just execute the tool with one parameter: the path to the solution file. And if you want to build some of the projects in the solution, then add "p:" as an argument, followed by the names of the target platforms, separated by a comma. See the example in that picture.

Now, there are a few restrictions: first, the solution filename must always end with ".fps"; second, the tool will handle trimmed versions of the platforms' names; third, all passed platforms must exist in the solution or the tool won't execute; and fourth, when you pass a relative path to the solution, the path to the folder where APEBuild is located will be considered the root folder in order to build the absolute path.

So, when we execute the command for the entire solution we have been using as an example on the series, this is the result for a successful build:

And when you execute the command for a couple of pojects, the result would be the following:

You will also get messages in case of warnings and exceptions:

The above picture shows a warning indicating that an import unit that should have been plugged into the tool as an add-on is missing. However, since it's not used during the build process, the latter runs normally.

So, it is important to remember that:

1. Before executing the command you will need to check that all the import/write units are present in the corresponding folders associated to APEBuild (as you would also do with the APE's editor), and

2. When you commit source files, you will also need to commit the updated versions of the APE's solution/project files to the server or otherwise you won't get the results you were most-likely looking for.

There are some features I'd like to add in future versions like, say, verbosity control (that is, the level of detail you get as output), but the tool gets the job done in its current state, what is really handy!

Why not publish it as open-source?

I'd have prefered to address this question more close to the campaign's launch date, but since a few of you've asked this question recently, I decided to answer it now.

But before moving forward, I'd like to state that I will neither argue nor open a discussion regarding whether open source is good or bad business-wise, since that depends on factors whose relevance may vary per person (yes, "YMMV") and therefore not only does it lay beyond the scope of this post but also I don't feel like pursuing a Phyrric Victory.

Instead, I'll be posting a few words explaining my decision to publish it as a commercial tool in the near future -that is, provided the campaign at IndieGoGo succeeds.

Honestly, I haven't decided yet the price for a license but I intend to license the APE per seat per platform per major version. Yes, if you buy one license at launch, you will be able to use it for the whole v1.x! No annual subscriptions, no different versions for indies/pros, no complications to anyone.

Now, although the price is not yet decided, believe me when I say that it will be low and even lower for those of you who decide to contribute to the campaign at IndieGoGo. I'm an indie, so I know what it feels not being able to afford licenses from time to time. So during the campaign it'd be like going out with some folks to a movie theatre, say, on Friday's night.

So, why this decision?

First, open souce is difficult to keep alive in time. You need to coordinate efforts, check contributor's code, handle branches, even maybe, at some point and to some extent, include contributors into the decision-making process.

But that is not it, most of the people in the team would likely have daytime jobs, so development of updates to the tool would be done during the night provided the is some spare time left. Going to college? Does your job demand most of your productive time? Have a wife/husband? How about some kids? Then, you know the drill ...

It's not a surprise that many open source APIs and tools eventually follow the commercial route, or that their owners publish a letter indicating why the cannot continue working on it or that updates will slow down. It's completely understandable! There's lot of time, effort and even money put into it, and even though donations could be received, the latter eventually end up being not enough to even cover costs of production. Not to mention, costs of living.

So, instead of trying the open source route first to then follow the commercial one, I prefer to skip that part and commercialize licenses of the APE from square one. Succeeding in this task will assure the continuation of the tool since I will dedicate, not my spare time, but my production one to make it happen. And if I fail I'll continue to use it as is for inhouse projects. No hard feelings.

I have one more thing to add in this respect as an example: the guys behind the Mono Framework started the project as a non-profitable endeavour. But then, they realized that in order to continue offering the products they loved to develop, a change in course was imminent. For many, this could have been a change in principles but for me it was a wise decision. Today, they're successfully runnning Xamarin, they're growing strong and their products are a must have for every serious dev that want to port .NET-based apps/games to many platforms. And even MSFT recognizes it!

Btw, regarding XNA's Content Pipeline: it was freely available as long as you didn't want to develop games for the XBox 360 (and then, the Windows Phone). Otherwise, you had to pay an annual subscription for the Creators' Club and a registration fee for the Windows Phone (both now unified).

So to wrap up this third question, before using the word "disappointing" -given the fact that it won't be open source, please give the APE an opportunity to show off its key features and wait for the campaign at IndieGoGo. You won't be dissapointed!

Ok, this is it for this part of the series. Hope you all come back for the upcoming part 6 next week.

See ya next time,

~Pete

PS: btw, I recommend you to have a look at Xamarin's subsciption plans if you haven't yet!

THE ASSET PIPELINE EDITOR - PART 4

On part 3 of the series, I talked about some of the features related to solutions and projects. So now it's time for me to refer to another key feature of the editor: building assets.

The picture below shows the last state of the solution we were using as an example for the series:

Let me remind you that the raw files named "bkgClouds" were bound to different source files: one sized 640x400 texels and another sized 320x200 texels.

Since the APE does not come bundled with any import/write units other than the pass-through ones, y clicking in one of the raw files we'll get the following view on the raw file tab:

Thus, as you can see, the pass-through importer is assigned by default to all the raw files in the solution. This default importer has no properties we can modify since all it does is to copy the source file associated to each raw file to the destination folder without any kind of processing/formatting.

However, there is one property that I'd like to highlight here that I didn't mention on my previous posts, and that is the checkbox named "Build Asset ?". If you have been following the series then you'll likely remember that for solutions and projects you could indicate the actions to execute for building and copying/moving, right? Well, this checkbox allows us to override those settings for a specific raw file, so if we unmark it, no build/copy actions will be applied to that raw file.

In fact, if you carefully look at the first screenshot above corresponding to the solution tree, you will notice a checkbox beside some of the nodes. By checking/unchecking that control not only we can include/exclude a raw file for build/copy actions but also the nodes of an entire folder or container. And yes, when you save solutions and projects, this selections are also persisted. Nice!

Now, how can we build an entire solution or a specific project? Glad you asked. Please take a look at the picture below and follow the numbers:

First, for each project at a time, check the Project tab and select the corresponding values for each field. In particular for this example, we need to set the build/copy actions and indicate the correct path to copy/move the asset files. For now, we disregard the Group Id field and the writers grid since we have only one writer we can use at this moment and thus we have no use for the former.

Second, we indicate which nodes among the containers, folders and raw files must be included in or excluded from the build process by checking/unchecking the respective checkbox.

Third, we select the correct writer for the project ("Default Writer") for the compilation profile to use ("Debug", as shown in the picture above).

Fourth, we select whether to build the entire solution (that is to say, all projects) or one project (the one shown in the Project tab). Also, we indicate the target compilation profile (the one that corresponds to your game's executing assemby, as compiled in Visual Studio, Xamarin Studio, Eclipse, Netbeans or other).

Having done that, we also need to indicate for the solution whether we want our asset files copied or moved to their final location ...

Then, we are ready to go. So all we need to do is compile the solution or project by clicking the "Build" button (the arrow in green).

You can also build the solution or project using menu options, "F5" for the entire solution or "Control + F5" for the selected project.

Now, what result shall we obtain for our example? To see that, we pick one of the projects in the solution explorer and open its folder with the "Open In Explorer" menu option, say, the iPhone.

You will get as an asset file a copy of the image sized 320x200 texels. And believe me when I say that if we built the entire solution (or only the Windows project) we also get the image sized 640x400 texels as an asset file located in the path corresponding to the Windows project.

But this isn't all we get as the picture below shows:

The Ape mantains a repository on the corresponding path for our solution, but is also moves/copy the obtained files with the correct path structure to the location you specify as an output folder, adjusted for the corresponding compilation profile. Since we said we wanted all our asset copied, the "local" repository keeps a copy of all asset files. Otherwise, no local copies would exist.

Again, when we compile the solution we also obtain the asset for non selected projects -provided they are alos marked for build + copy/move actions.

Now, when your game expects a file with a specific format (other than public ones like png, jpg, wav, wmv, and so on so forth) and or a specific file extension, then the above example is not useful for you. Therefore, for the following example I'll use a Texture2D importer and a XNA-like writer for a Monogame project. But please remember that you can use the APE for any game engine not related to XNA/Monogame, provided that the corresponding import/write units are plugged into the editor.

So, allow me to introduce you to a nice feature that the APE has: clean solution/project.

Both operations are similar, being the only difference that cleaning the solution will clear the content of all projects. This operations must be used with caution since they will delete the entire content of the folders indicated in the corresponding lines and not only raw files and nested folders. So before pressing start we should check that the paths are right. You can always cancel the operation by clicking the cancel button or by closing the window -in case you need to. And you can indicate whether to clean one folder (the local folder or the output folder), both folders or none. This is indeed a handy and powerful feature, don't you think?

Ok, after cleaning the solution and adding the corresponding import/write units to the editor we are now able to reload our solution and once we get it, we need to get something like this:

In order to get it, first we need to select the only raw file we have on the Windows Project. Then, we need to select the category "Textures" (1) and finally select the importer named "Xna Texture Importer" (2), which in this case is selected by default. As you can see we get some information about the importer and, in this case, a couple of read-only properties ("Group Id" and "Is Source File Also Copied ?").

As a result of the above we can now realize in practice how the Group Id field on the Project tab can be used (3): a value of zero indicates that we want to target XNA/Monogame's HiDef profile and a value above it the Reach profile.

If we expand the panel with the properties for the 2D Texture Processor we'll get:

I won't explain each of the fields you see there. Some of them are similar to what we had on XNA's CP GUI but there are some additional ones -which I believe speak for them-selves. All I can say is that this is not a mock-up; in fact, it's a real processor in alpha stage currently consuming WPF's bindings for WIC. During the campaign at IndieGoGo I'll give more details about this.

After tweaking some of the parameters, let's have a look at the formatter:

Nothing to do here. The "Xna Binary Formatter" will give the proper format to the asset data but with one difference for those of us accustomed to XNA's CP (given the way I've implemented these import/write units): the XNA's header for the asset file is not included as part of the format. That will be added by the writer later on. Needless to say that you can design your import/write units so that the formatter includes the header instead of the writer, which is fantastic given that it shows how flexible the APE really is!!!

Ok then, and please again follow the numbers, before proceeding to compile the texture asset for the Windows project we'll need to get something like ...

First, we select the Window project.

Second, we need to set the proper writer for the compilation profile we are going to use (in this case, for "Debug").

Third, we need to select the "Normal" compression mode on the Writers panel instead of the "Automatic" one that is shown in the picture above. Why? Because I haven't implemented yet the so called LZX compression -which is a real pain, believe me- or any other compression for the writer.

I'd like to add a side note here: do you notice the data displayed on the writer panel for the Xna Writer? (default, version, etc.) In particular check the following three: "Writes checksum", "Requires password", "Encodes Data". These fields if marked as "Yes" indicate that the writer May or May Not do the associated task (depending on whether is activated manually/automatically as implemented by us), like calculating an writing an MD5/SHA checksum somewhere into the asset file, adding password protection and or encoding/encrypting the asset file. And if marked as "No" then the writer does not support that action.

Fourth, and this is really important: we need to save the solution!!! (this is required to apply changes)

Fifth, we need to indicate that we're going to build only a project (the selected one) for the "Debug" compilation profile.

Finally, build the assets by pressing the corresponding menu option, button or keyboard shortcut ("Control + F5"), being the result in the local repository the following:

This is a well-formatted xnb file with pre-multiplied alpha, a mip-mapped chain and its top-most texture resized to the nearest power-of-two value for 640x400 texels (I leave the answer to the latter as homework for you). Since this asset file is not LZX-compressed, its size on disk is rather high. Again, a copy of this file is located on the output folder that the XNA/Monogame solution uses.

Finally, if we run the game's solution with a line like the following within the method of the LoadContent operation ...

   this.texture = this.Content.Load<Texture2D>("textures/backgrounds/bkgClouds");
      

... and the corresponding one on the Draw method, as shown in the trailer for the APE, we'll get something like this on a WindowsGL-targeted game using Monogame (and please don't ask me "why do you need mipmaps for this example?"):

Enough said!

In the following parts we'll be getting into more technical stuff.

Cheers!
~Pete

THE ASSET PIPELINE EDITOR - PART 3

On part 2 of the series, I talked about some basic features of the APE, so it's time to show how to change the structure of a project and populate it with some raw files, that is, before starting to build assets.

I could begin this post by telling you how to create a new solution from scratch, but instead, I'll show you a nice small feature the editor has that allows you to open recent solutions, which spares you from having to use the Open Solution menu option ("Control + O") and browse folders until you locate the solution file.

Do you notice the small red (almost transparent) cross beside the only entry in the list of recent solutions? If you press it, you will be prompted to confirm entry's removal from the list. The cool thing is that APE does not need to restart in order to refresh the list. Ditto for "Clear All ..." option.

Once the solution is loaded we can start modifying the tree structure to meet the needs for our game. This is how the solution looks like so far:

Let's add a couple of nested folders to the Windows_Own container by selecting the "Add Folder" menu option (or clicking "Control + Shift + F") twice. Now our solution looks like this:

By default, folders will be created with the name "folder_<#>", so let's renamed them with a meaningful word (by double-clicking the node):

Better, right? But wait a minute! What if we want to have a similar structure on the default container? All you have to do is open a context menu for the node you want to copy (right-click over "textures") and you will be presented with this:

\

You have two options there: either you move or copy the node and all of its content to another non-nested location; in this case, to the Windows_Default container. Note: if you try to move or copy the "images" folder into the "backgrounds" folder the operation will fail.

Since we want to replicate the structure, we then select the copy option. Then, by opening the context menu fro the default container we will get the following:

By pressing paste, the new structure for our solution will look like this:

It's important to mention here than we could have obtained the same result by using drag'n'drop. Yes! Dragging the textures folder and dropping it onto the default container would have been allowed. In fact, when you drag'n'drop nodes in the solution explorer, the APE asks us what we want to do with them: move, copy or cancel.

Also, it's worth mentioning that, in this case, we could have copied the whole content of the self container ("Windows_Own") by using the context menu for the container. That is also allowed. The difference is that in this case the container it-self won't be moved or copied, just its child nodes.

Now, let's add some raw files. Shall we?

There are three ways to add raw files to containers or folders: (a) you select the container/folder and then use the "Add Raw File" menu option/button (or press "Control + Shift + R"), (b) you select the container/folder, open the context menu for it and click on the  "Add Raw File" option, or (c) you use drag'n'drop (you can import raw files into your solution by dragging them from the explorer and dropping them onto the container/folder).

In the picture below, you can see how to use the context menu for the target folder.

One important feature to mention here is that you can import more than one file at a time (batching) with any of the three ways the editor offers, including drag'n'drop.

For the example, we just added a nice cloud background to the backgrounds folder:

The picture above shows a lot of new information about the editor:

1. The name given to the added raw file is its filename (without the extension, if any). This is true provided that the name does not exist in the same "relative" location of the solution's structure, or else it will be renamed to "file_<#>".

2. On the container tab, the editor will show you the proper previewer for the file (remember that if none is found it will just show the system icon for it).

3. A new tab gets enabled: "Raw File". Here is were you tweak import settings for the raw file. The APE will try to assign an importer to it based on the file extension, giving priority to the importers marked as default (more on this on later posts).

4. The source file is copied into the "Sources" folder for the solution. This folder works as a repository for the entire solution, so you cannot have two source files co-existing with the same name on the folder since one of them will be replaced. This has nothing to do with the names you give to the nodes on the solution explorer (you can have two nodes with the same name in different "relative" locations on the solution tree).

In order to change the name of the raw file we could do it in the same way as before by double clicking on the node, but in this case we will use the "Name" field on the raw file tab and rename the node to "bkgClouds".

Now, before showing you how the structure of the solution currently looks like, let's add a new project for, say, the iPhone platform. And here it is ...

As you can see the default containers on both projects have the same exact structure; however, the self containers are different. In effect, that is the purpose of self containers.

Although the "bkgClouds" raw file is present in both default containers, it is treated as a deep copy; so mirror operations are bound only to add/remove/copy/move. For properties, like importer, processor and formatter-like settings, each node is independent, so you can have one set of settings for the raw file for the iPhone and a different set its sibbling on Windows. Really great!

Now, what if you want to import two different source files but keeping them under the same raw file on different projects? Let me translate it with an example ... say that you want to replace the source image for bkgClouds but only on the iPhone project with a lower_res version, well ... yes, you can! How? Simple. Look at the picture below:

On the Raw File tab there is field named "File" with a button labeled "..." (marked all in red), which shows the location to the source file in the solution. When you click on the button you can browse your folders until you get the file you desire.

In this case, we'll select the 320x200 texels version of the cloud image for the iPhone platform to get this window:

The APE will prompt us to confirm the operation and also it'll let us delete the existing source file if needed. Since this is not the case, given that we need both of them (one for Windows and the new one for iPhone) we let this checkbox unmarked.

Once the operation completes, the image previewer for the "bkgClouds" raw file on the iPhone project will show the new information. Now we have two different source files for the same logical name. And therefore, after building assets, when you load the "bkgClouds" texture on your game, you will get the 640x400 version on Windows and the 320x200 on the iPhone. No need to add "_640x400" or "_320x200" to the load operation.

Let's have a look at our solution's Source folder:

As you can see, the respository has both source files for the same raw file. And I guess that you now fully understand the difference between "source" and "raw"" file (if not, the former is the actual file and the latter its representation on the solution's tree).

Ok, before finishing this post, let me show you one more relevant feature the APE offers. For this task, say that you accidentally messed with the Source folder and deleted one of the images; for instance, the one ending in _640x400. What would happen? Well, when you re-open the editor, you will see the following:

The APE is indicating you that the solution is corrupted and also marks the path to the offending raw file. To fix it, you can either manually copy+paste the source file to the Sources folder or you can use the Raw File tab -as we did before- by clicking the "..." button beside the "File" field and browsing to the location of the source file.

In order to valdiate the solution you have to options, either you save, close and re-open the solution (in which case the APE will warn you that you are attempting to save a corrupt solution) or use the validate menu option ("Control + Shift + V") ...

Having finished the validation processed, the editor will look like this:

So, we can now safely continue to work normally with our solution and save it whenever we want.

Btw, you can browse to the folder where you solution is located by using the "Open In Explorer" menu item (ditto for projects) ...

And you'll get to ...

Do you notice the icon on "MySolution"? When the editor is closed you can open it and also load the solution by clicking its file. Indeed. The APE will open and load the solution for you.

Ok guys, this is all for this post. On my next post we'll talk about building assets.

See ya!
~Pete