Warp Dreams Game Blog

New Game: Doomsday Express

2011-12-28T14:19:00.000-08:00

Early Prototype:

Smart Brick HD for iPad is Available in App Store !

2010-06-18T19:58:00.001-07:00

Store link:

itms://itunes.apple.com/us/app/smart-brick-hd/id375581327?mt=8

Smart Brick Lite is Available in App Store

2010-05-31T16:58:00.000-07:00

Smart Brick Lite is LIVE in Apple Store! Have a free trial:

itms://itunes.apple.com/us/app/smart-brick-lite/id373771120?mt=8

Smart Brick HD for iPad in Development

2010-05-27T23:06:00.000-07:00

Coming soon...

Smar Brick is LIVE on App Store!

2010-05-13T16:34:00.000-07:00

Smart Brick is a puzzle game that challenges and trains your 3D space sense, packed with simplistic art style. your need to arrange bricks of different colors with a proper orientation within given time, in order to fill up layers and resolve them. Each level has its unique design not only to entertain, but also to move people emotionally. Intuitive multi-touch control enables manipulation of 3D objects in 3D spaces with ease.

Features:

- Full 3D graphics running smoothly at 40 FPS (on iPhone 3GS)
- Variant level designs with different pace, play styles and goals
- Smooth and intuitive multi touch control
- different sets of bricks, suiting from newbies to experts
- Multiple relaxed casual levels to spend time on, each has a distinct theme
- Full dynamic animation and background
- A highscore board where you can challenge yourself or your friends

How to play:

- Double tap the brick to drop it
- Press on the brick and hold to drag it around
- Tab the spinning rectangles around the brick to turn it in the shown direction
- Try fill up a full layer to make it disappear and score!

Game modes:

- Elimination: you must resolve specific bricks that scattered in the level to win. Some are hard to reach, and time is limited.
- Time Killer: have some time to spend on bus or subway? Relax and score as much as you can in the beatiful levels. No time limit.

Vist: warpdreams.blogspot.com for more screenshots and information about other games.

If you have any suggestions or need support, write to: dreams.warp@gmail.com

Store Link:

Find Warp Dreams on Facebook

2010-05-04T21:24:00.001-07:00

http://www.facebook.com/#!/pages/Warp-Dreams/119440868084050

Smart Brick Is Submitted for Review

2010-04-28T05:52:00.000-07:00

Now I have to wait patiently...

Smart Brick More Screenshot

2010-04-26T17:37:00.001-07:00

The Matrix Phone demo - iPhone 3GS/IPod Touch App HD

2010-04-23T06:00:00.000-07:00

Smart Brick More Screenshot

2010-04-20T07:09:00.000-07:00

3D Tetris - iPhone/iPod touch Game "Smart Brick" Empire State Building G...

2010-04-16T03:03:00.000-07:00

Smart Brick Icon

2010-04-11T17:25:00.000-07:00

Works for now I guess...

Warp Dreams Logo

2010-04-07T07:13:00.000-07:00

I consulted a logo design studio for a quote and they presented a whopping $1750 price tag... Well, not that I don't recognize the value of their work, but that price is simply way above my budget. So I DIYed one myself using a toy-like Paintbrush on Mac OS X. (GIMP for Mac just sucks because X window on Mac sucks. You have to click twice on a button to activate it if the window contains it is not the active window). Look at left of the page.

It does has some issues, like: top-right proportion of the logo seems too empty. However, I think it works for now. Maybe I'll pay $1750 when I am rich.

Using short value in vertex array instead of float

2010-04-07T06:45:00.000-07:00

I've been trying to squeeze more FPS from the rendering part of Smart Brick. I came across an article which suggests using GL_SHORT instead of GL_FLOAT in vertex array to boost performance:

http://stackoverflow.com/questions/1762866/using-gl-short-instead-of-gl-float-in-an-opengl-es-vertex-array

The solution quite makes sense. Basically you use short value to replace float values; to compensate the precision loss, a pair of additional glScalef and glTranslatef is required per-model.

A reply attached at the end of the post suggests that on iPhone it would be 30% faster. However, this is not the case for Smart Brick; not because the article is wrong, but I think the performance increment depends on actual scenarios. Here is my guess:

If your model contains large amounts of vertices the solution may help a lot. You get big computational savings for using short instead of float, with the price of only one additional glScale and glTranslate calls respectively.

However, it does not help Smart Brick, because Smart Brick renders large amounts of models, each of them contains only few vertices. This way, the savings on float vertices are probably offset by glScale and glTranslate calls, because they are called once per-model, and they are called a lot when there are a lot of models.

Smark Brick Game Play

2010-04-05T02:55:00.000-07:00

This is a demo showing 2D mode in Smart Brick. Well, 2D is a special case of 3D after all.

The true 3D mode in Smart Brick.

Smart Brick Screenshot

2010-04-01T16:44:00.000-07:00

I love POC

2010-03-23T04:59:00.000-07:00

POC stands for Plain Old C structure. A POC contains no references nor pointers, but only primitive value types or other POCs. No C++ elements (no user defined constructor, operator, etc)

The good of POC is that it is guaranteed to be allocated within a continuous memory space, so classic memory functions such as memcpy, memset works nicely on POC or array of POCs. Additionally, you get a free assignment operator, which is quite important for data types.

POC works very good with NSData for local file storage. Just copy the memory content of a POC into NSData and call writeToFile, saving the whole byte string to the file, easily done. If it's not a POC... well good luck manual-serializing fields of an instance while saving and de-serializing them while loading, don't get the order wrong! Of course, using POC you probably need to mind the debug/release settings, for the compiler may pad within POC, causing a different size between debug and release mode. Files written by application compiled under different modes may not compatible.

Tips to Use Interface Builder As Much As Possible

2010-03-16T01:45:00.000-07:00

The Interface Builder of the XCode Suite is particularly powerful. It is very handy when developing for iPhone/iPod touch. However, it comes with some difficulty when you actually want to generate and place your widget programmingly. For example: you have a scroll view with several buttons inside that align vertically, however the number of buttons and the texts on them are decided at run-time so you can't simply drag some in using Interface Builder. But neither do you want to go after all these tedious API calls to create buttons then configure formats manually either; what then?

You can actually design a "sample button" using Interface Builder, have all the formats done (which is nice and easy using IB), then put it at the root of the widget hierarchy. Since it is not a sub-view of any other widgets, it is not shown at run-time. Then you can use the following code to copy this button as you want, place it anywhere you want, without worrying the format:

NSData *archived = [NSKeyedArchiver archivedDataWithRootObject: button_sample];

//Initiate buttons based on a sample

UIButton* b = [NSKeyedUnarchiver unarchiveObjectWithData: archived];

//set text, change position...

...

The Upcoming Game for iPhone

2010-03-11T15:14:00.000-08:00

Well... bad news first. The Matrix Phone are not going to be on App Store any sooner. Apparently it is too close to the movie The Matrix thus there is a copyright issue (although I have avoided reference to The Matrix in the application description) . Maybe I would negotiate with Walt Brothers about authorization; but that would be after my next game publishes.

Ok, the next game: Smart Brick. You can think it as a 3D version of Tetris. Instead of filling an 2D plane as in Tetris, the user should fill a 3D volume using bricks that stretches on all three dimensions. It is not a fresh idea actually, there are several versions of 3D Tetris over the web; however, the key is not about the idea, it's about the control. Manipulating bricks in a 3D space, like flipping and movement in three dimensions is far more complicated than in 2D. It will leads to frustration and fun-less-ness. However, thanks to the multi-touch technology of iPhone, "3D Tetris" is made possible. Screenshots and demos will go online soon. Stick closely.

It is also planned to port Smart Brick on iPad - natively, not "stretched" up. But not until I get the product. I need to wait longer because I actually want the 3G version.

For the end of the post, a little tip for the mix C++/Objective C development:

You can have C++ classes as parameters of Objective C functions. However, Objective C does not allow namespace syntax, the "::", in the function declaration. So you need to put a namespace using at the top of your Objective C header. It's kind of nasty, and I still prefer plain C struct as means of communication between C++ and Objective C.

Mix C++ code with Objective C for iPhone

2009-11-29T19:33:00.000-08:00

Objective C is not the only language you can use to program for iPhone; you can use C/C++ and mix the C/C++ code with your Objective C code. And I recommend to do so:

Reason 1: for cross-platform purposes. If you use only Objective C then you are locked on the Apple platform. Don't give up the chance of porting your program to other devices such as Zune HD.

Reason 2: for the better C++ standard STL library. IMHO the STL library is much better than Objective C Cocoa libraries; it is portable and easier to use. Especially the container part.

To those who are worried, iphone run-time have full support for C++, including virtual function, exception handling and RTTI. And Xcode does support template.

There is no explicit boundary between C++ and Objective C when you code for iphone. You can write Objective C code in C++ classes/functions, and vice versa. But notice that the source code file other than headers should be named as ".mm".

Althrough you can mix C++ and Objective C, a good idea is to separate them for better portability and maintainability. When comes to a problem that both C++ and Objective C have solutions, I prefer to write the C++ code when possible and only write Objective C code where Cocoa library provides an easier solution, or when only it has the solution. For example, the Cocoa container classes suck but they do provide very easy to use persistance functions; so I use STL container and only translate the content to the Cocoa counter part when I need to save the content to a file.

A trick is that, you can provide Objective C implementation for C++ classes. I would use multiple implementation files for a C++ class interface: keep C++ only impl in one and Objective C impl in another.

How to select 3D object from cursor/touch in OpenGL ES

2009-10-28T22:30:00.000-07:00

When writing 3D games there is a requirement quite common (forget about OpenGL ES at the moment):

How to select an 3D object in the scene, by mouse/touch?

This problem is not so trivial as it seems. Actually the more you think about it, the more you will find it is not so easy to solve.

Basically, we are trying to map the windows coordinate back to the 3D coordinate. If you understand how an object in OpenGL coordinate is projected onto your 2D display:

screen_vector = ((3D_vector_4x1) * model_view_matrix_4x4) * projection_matrix_4x4;

All we need to do is do the reverse, multiply the screen_vector with the reverse of model view/projection matrices:

3D_vector_4x1 = (screen_vector * (projection_matrix_4x4_inv)) * model_view_matrix_4x4_inv;

Actually, in desktop version of OpenGL, you don't have to do the calculation yourself. There is the mighty gluUnproject that handles it for you.

But there is still a problem. Since your LCD screen is 2D, you only get the x,y component of screen_vector. Where is z? z is actually the depth component and you can find it in the depth buffer. In desktop version of OpenGL, you can call glReadPixels with GL_DEPTH_COMPONENT flag. Of course it is not the full story: the depth buffer only stores pixel depth values that are minimal (unless you change the OpenGL depth function), when transformed back to 3D_vector_4x1 you only get the nearest object. Usually it is desired, but if your wanted object is painted behind other transparent polygons, there is a little bit of problem - but hey it's not a big deal.

But when comes to OpenGL ES, there is a big problem implementing all these:
1. You don't get GLU package. So there is no gluUnproject.
2. You don't have access to the depth buffer. (No GL_DEPTH_COMPONENT for you!)

So the previous solution won't work!
Face it, in OpenGL ES it is a one-way road: you can get windows coordinate from a 3D coordinate, but there is no other way around. Then how to solve the problem?

Well... brutal force always works. First, you define what object is selectable in the game world. Second, you calculate the window coordinate of that object during OpenGL paint, keeping it updated. Last, when a mouse click/touch happens, compare the event windows coordinate to all existing window coordinates that updated during OpenGL paint, and pick one that is nearest. Of course, it is not universal and not all objects in the world can be selected; but hey, do you really need that?

Or you can use ray-tracing.

The Matrix Phone Improved - been Objective C, now go back to C++

2009-10-22T22:10:00.001-07:00

The first version of The Matrix Phone is submitted to AppStore and is pending for review; however, this is far from the end. I'm now planning to develop a better game scheme for The Matrix Phone.

(Now the geek part)
As my first application that is written in Objective C, it is far from optimal: I were not familar with Objective C at that time - now I realize that the code is a mess, and is almost impossible to refactory to support new gaming schemes. After a period of struggling, I decide to re-write it in C++ (plus some Objective C code for iphone); I just have to do this anyway, maybe The Matrix Phone can be on Microsoft Zune.

Been Objective C, now go back to C++:
I know the STL containers are not the only way, but without them and use NS containers of Objective C just don't feel right! Basically, the NS containers is generic typeless "store-by-pointer" containers like those in Java - but without garbage collection. And you can't store regular C structure by value; and there is no auto boxing/unboxing so even if it is int you have to pack it/cast it back manually with NSNumber. So I avoid using it and end up with stinky malloc.
And string operation using NSMutableString is so painful. Even putting two strings together is a hard job. No simple "+" like Java; no container-like operations like std::string. So I just use C string but that's no better...

The Matrix Phone demo, and technical thoughts

2009-10-15T04:59:00.000-07:00

The Matrix Phone is a simple application that simulates the digital rain effect seem in my favorite movie trilogy The Matrix.

The first demo version of The Matrix Phone is complete. Please check out the video attached (I hope this one has a higher resolution than YouTube!).

I will submit this app to the App Store soon... Please wait patiently.

Now... the technical discussion. (Ignore the following if you are not a true geek)
The Matrix Phone supports only iPhone 3GS and third generation iPod Touch since it uses OpenGL 2.0, and OpenGL 2.0 is not backwards compatible. Since the resolution of the video is low, it is hard to see the glow and the interlaced scan line effect that intentionally simulates the old CRT (please see the screenshot); the effect is done through a pixel shader... (maybe it is an over kill, maybe it can also be implemented using blending of the old-school Open GL 1)