Shmup Development (using XNA and C#)

Ladybird Galaxy

2008-08-22T13:13:00.003+02:00

I have just started a blog about the development of my new game "Ladybird Galaxy", you find it at http://ladybirdgalaxy.blogspot.com

My next game

2008-06-08T10:44:00.006+02:00

I have been thinking a lot about the design of my next game. My design goals was that it should be easy to play and largely focused on multiplayer.

First, I tried a whole lot of shmup ideas. I really didn't like any of them, it was very hard to come up with a good idea what would play nice and didn't take forever to create.

I think I have come up with a idea I really like. Shocking news! It won't be a shmup! Instead it will be about boosting through space trying to crash into other players and picking up items.
It began one day when I was surfing the web and came across some cool graphics at Lost Garden. From those images I have now created something that is playable, singleplayer and multiplayer (on the same Xbox 360, systemlink or Xbox Live).

The game has really easy to understand game mechanics (just like a shmup): watch out for the bad guys and pick up the good stuff, simple enough? The final version of the game will still be released in the end of this year (when Microsoft releases community games for the Xbox 360).

The design of a new shmup game begins

2008-02-25T21:34:00.006+01:00

The last couple of weeks I have been trying to figure out the design for my next game. Coming up with a solid design for a game is not an easy task. Some of the design goals I had was:

Should be easy to figure out, just pick up and play.
Feature both a fun and fast singleplayer experience and an addictive multiplayer mode.
Be able to play multiplayer four players locally (on the same console) or over the internet.
Lots of bullets and action of course :-)

This time didn't want to design the game where I had to create all the levels manually, instead I want to design a gameplay system that create random stages/levels. Oh, and there will not be a stage like in "Bullet Hell Tactics", there will be more like an arena style of gameplay.

I won't tell you much more about the game right now (this time I will be a little more secret about it). Of course I will post screenshots and gameplay movies when the time comes. I'll keep you posted in the development of my new game if you are interested.

The target release date for the game will be the end of this year, and you will be able to download it from Xbox Live and play on your Xbox 360.

Components of a shmup game: Manage and recycle objects

2008-01-16T18:04:00.000+01:00

I thought about writing some series about developing a shmup game. It will be from my perspective (with the shmup engine I'm creating) and focus on some of the components in a shmup game. If I provide examples and code there will be with C# and XNA. I will probably not explain in detail what the sourcecode looks like, I will more explain the concept and design. Ok, lets go!

This is the first part of the series "Components of a shmup game" where I will write about how my shmup engine manages and recycles objects.

Introduction to objects in a shmup game

In a shmup game lots of objects are created and destroyed very often. Bullets that the player is firing, enemies that are spawned and then milliseconds later are destroyed, explosion particles and so on... The average lifetime of an object in a shmup game is very short.

Every time the player fires a bullet I don't want to create a new bullet (new Bullet()) because this will be pretty inefficient for the garbage collector, instead I want to recycle an already destroyed bullet. This makes all of the objects in the game need to know when they should be destroyed and recycled.

With this in mind I decided to create a few classes that helps me achieve this.

What the classes looks like when managing objects

What we know: Every game object in the shmup engine can be updated and drawn. It also need to know when it should be destroyed, recycled and how to be created from the "recycle bin".

Product - Base for every game object. Provides functionality to be updated/drawn. Can also be added to a manager through the method Activate(IManager manager) and removed from an manager with the Deactivate() method.

IManager - Interface for every object manager. Provides functionality to add an object with Add(IProduct product).

Manager - An implementation for a manager. Provides functionality to update and draw all the objects in the manager. When an object is destroyed and wants to be recycled it uses the associated Factory to add it to the "recycle bin".

IManufacturer - Interface for a manufacturer. Provides functionality to create an object with the method Create().

Factory - Handles creation of objects. Provides functionality to add and create objects to/from the "recycle bin". Manufacturers can be registered (with a name) to the factory for creation of objects that has not been recycled.

What is a factory and manufacturer, and how does it work?

It's pretty simple, a manufacturer is used to create objects. It has a single method, Create() that returns a created object. Every manufacturer knows how to create exactly one object.

A factory contains a dictionary of manufacturers. Manufacturers are registered (added) to the factory with the method Register(string name, IManufacturer manufacturer). The factory is also used with the Manager to handle destroyed objects. The factory got a Create(string name) method (the name is specified for the method so it knows which manufacturer to use to create the object). The factory also got a dictionary of destroyed objects (with the name of the object as the key).

When the Create(string name) method on the factory is called it first looks in the recycled objects dictionary to see if there are any objects available. If there are objects available it will be removed from the list and immediately returned. If there are no objects available the Manufacturer (with the specified name) is used to create the object and return it.

Example when the player fires bullets

Let me explain the object management of a bullet that is fired by the player and then hits a enemy (some stuff are excluded to we can focus on object management).

First we need to do some setup (this is before the game has been started):

We created a BulletManufacturer class that creates a bullet.
Register the BulletManufacturer in the Factory (with the name "MyBullet").

This is what happens when the game is running and player wants to fire a bullet:

Player presses space to fire a bullet. The Create("MyBullet") method on the Factory is called.
Factory checks if there are any recycled objects available. There are not (because the bullet has never been fired before).
Factory gets the BulletManufacturer (with "MyBullet" name) and calls the Create() method which returns a bullet. We now got our bullet that we add to our Manager (that handles bullets).
Manager updates and draws the bullet as it moves across the screen for a few frames.
The bullet collides with an enemy. Now we want our bullet to be removed from the Manager so we call Deactivate() on it.
When the bullet is deactivated the Manager will add it to the Factory recycled objects.
A few frames passes by and the player wants to fire another bullet. The Create("MyBullet") method on the Factory is called.
Factory checks if there are any recycled objects available. There are, so we just return the recycled bullet. We now got our bullet that we add to our Manager again.

That's how it works. I have provided more concept than code, but I hope this can help some of you to understand how you could implement this kind of object management.

I have the intention to write more about developing shmup components (for example):

Rendering system
How the stage and timeline works
Behaviors for entities
Developing a datadriven shmup

Would anyone be interested in that? Please write some comments...

Domain registered: shmup.net is mine

2008-01-07T11:03:00.000+01:00

I have just registered the domain shmup.net for this blog. I was certain that the domain was already taken, but it wasn't... and now it's mine!! Mohahahaha...

Shmup engine running on the Xbox 360

2008-01-04T21:18:00.001+01:00

I'm now a member of the XNA creators club, which means I can run my games on Xbox 360. It's so much more fun to develop and see it in action on a console.

Here are some of the features that has been in focus:

Rendering system: graphics can be drawn in the renderer in any order. Then when the draw function of the renderer is called all the queued graphics (models, sprites, particles) is sorted (by graphicstype and draworder) and then drawn. This works very well, just don't care in which order to draw the graphics.
Base classes: entity, enemy, player, stage, bullet, behavior...
Content pipeline: stage and enemy can now be loaded with the content pipeline.
Behaviors: can be added to any entity. Have created a few like chasebehavior (for enemies to chase the player or homing missiles), weaponbehavior (to fire bullets, both for player and enemy), scopebehavior (so objects can be removed when outside the screen), splinebehavior (make objects follow a spline).

Features I will continue to work with:

Bullet patterns: patterns will be loaded with the content pipeline.
State management: Screens and menus.
Editor: A simple editor to create enemies and bullet patterns.

Some screenshots (and video maybe) is coming later. I'm creating games for the Xbox 360, cool or what? :-)

The shmup framework/engine for XNA in development

2007-12-11T10:47:00.000+01:00

It has been some time now since the last post and I havn't been doing any real XNA programming since I finished the Bullet Hell Tactics demo.

I have been thinking a lot about what the next project should be. I have thought about 3D engines, game engines or just game frameworks (to speed things up a bit when starting other projects)... Then I got the perfect idea about what to do! I should continue to work on my shmup framework/engine, I have already started and also created a shmup game with it so I now know how it should be done.

The engine I used for Bullet Hell Tactics was a good start, but while I was creating the game I found some mistakes and missing features I would like to include:

- It was not very easy to create levels. The only level in the game was created with XML, that itself is not a bad idea but the implementation was not the greatest. My idea was that all enemies could be specified directly in the XML file. That required a lot of thinking about how the enemies could be created (and also a lot of XML code). In the end I just created many different classes for the enemies, that was much easier than trying to specifiy them in XML.

- The engine was not designed to recycle destroyed enemies/bullets. If I someday what my shmup engine running on Xbox 360 I must recycle objects (cause of the garbage collection). In a shmup game a lot of objects (enemies, bullets, particles, explosions) is created and destroyed so recycling objects is a very good idea.

- Weaponsystem and upgrades for players was not supported. Also rendering of sprites and particles could be faster.

- It was not very easy to create enemy movements/patterns and in the end I instead used different velocity/acceleration parameters. I would like it to be easy to create patterns without those. Maybe creating the movements in another application and then import them into the game.

- Bullet Hell Tactics didn't have much of a intersting background (just a spinning skybox). It did the job well but in the end I would like a more dynamic world to blow things up in.

- Model animation was not supported by the engine, this time I want the enemies to be a little more interesting.

- Enemies in group (waves) was not supported.

This time I also would like it be of use for others that wants to create a shmup game. Maybe I'll put it up on sourceforge or something similar (though this is not certain).

Maybe you who read this have some ideas of what a shmup framework/engine should include, just write me, it would be interesting to discuss.

Download Bullet Hell Tactics Demo 1.0 (Windows)

2007-08-04T14:01:00.000+02:00

Bullet Hell Tactics Demo 1.0 (Windows) is now available for download. Please read the requirements before downloading. Also read how to play the game (if you can't figure it out for yourself).

Download Bullet Hell Tactics Demo 1.0 (Windows) - 32,5 MB

I have worked really hard with this game and had a blast creating it, hope you like it, have fun!

If you find any bugs or having difficulties running the game, please make a comment to this post and I'll try to help you.

Disappointed

2007-08-04T13:25:00.000+02:00

I'm quite disappointed that Bullet Hell Tactics didn't make it to the final in the Dream-Build-Play contest, I actually thought it would make it. Oh well, the demo will soon be available for download...

Nominated in Microsoft .NET Awards 2007

2007-06-29T12:27:00.000+02:00

Bullet Hell Tactics has been nominated in Microsoft .NET Awards 2007 (Xbox/XNA category) and I will attend at Partner Summit the 6th of September. Read more about .NET Awards here (Swedish).

Entering Dream-Build-Play

2007-06-27T22:18:00.000+02:00

I have now submitted Bullet Hell Tactics to the global contest Dream-Build-Play.

The final deadline is July 2, 2007. First-, second- and third-prize winners will be announced at the Microsoft Gamefest 2007 conference in Seattle, WA on August 12, 2007.

After the contest the final demo version will be downloadable at this website.

Weekend SGA 2007

2007-06-05T21:09:00.000+02:00

This weekend I attended with Bullet Hell Tactics at Swedish Game Awards 2007. It's was really fun to show people the game and see them play. Good feedback to watch people play that doesn't know anything about the game, I think most of them liked it and thought that it looked cool (as you can see in the picture below).

Little kids could play the game (even with the gamepad upside down!) at the Bullet Hell Tactics booth ;-)

Too bad Bullet Hell Tactics didn't win the "Best XNA Game" award. In the bright side of things I got some games and stuff from DICE (a minor award for Bullet Hell Tactics being a fun game). And it wasn't all for nothing when being nominated. The game has gained some publicity, for example, it is being mentioned in the XNA Team blog:

"On behalf of the XNA Community Game Platform team, I’d like to congratulate both teams on the great work they did on their games. It’s very inspiring to see such great games built on top of the technology we’ve built."

Nominated in Swedish Game Awards 2007

2007-05-28T10:02:00.000+02:00

Bullet Hell Tactics has been nominated as "Best XNA Game" in Swedish Game Awards 2007. The final will take place June 2 at Kulturhuset in Stockholm, Sweden. Read more about this here.

About 400 people will see the Bullet Hell Tactics trailer and they will also be able to play the game demo. Lots of fun!

Download Bullet Hell Tactics Test 0.9.6 for Windows

2007-05-10T21:55:00.000+02:00

This will be the one and only public testversion before the final demo is released. Before downloading, please read the requirements. If you are having problems running the game read the troubleshooting instructions. Please also read about how to play the game.

--------------------------------------------------------------
BULLET HELL TACTICS TEST IS NO LONGER AVAILABLE FOR DOWNLOAD. THE FINAL DEMO WILL BE AVAILABLE SOON.
--------------------------------------------------------------

Download Bullet Hell Tactics Test 0.9.6 for Windows (32,5 MB)
Just unpack the zip file and run "BulletHellTactics.exe".

The testversion is there for download so you can tell me what you think about the game. Please give feedback if you download it, it will be appreciated a lot!

Please mail feedback to [address removed] rather than leave comments here.

Requirements and troubleshooting

2007-05-10T21:40:00.000+02:00

These are the requirements to play Bullet Hell Tactics:

Windows XP/Vista
Microsoft .NET Framework 2.0
Microsoft XNA Framework 1.0 Refresh
Microsoft DirectX 9.0c
A graphics card that supports DirectX 9.0c and Shader Model 1.1

If you can't get the game to run, please check these things first:

Make sure you have the latest version of DirectX 9.0c. Sometimes just having the DirectX 9.0c is not enough, you must have the latest version. Download the latest version of DirectX 9.0c with the webinstaller.
Make sure you have a graphics card that supports Shader Model 1.1 and have the latest drivers installed.

If you get an error while running the game, a file called "Error.txt" will be created in the same directory as the game. The error file contains information about why and where the error occurred.

New gameplay video and screenshots

2007-04-25T23:01:00.000+02:00

Bullet Hell Tactics Demo is about 95% complete and this is what it looks like!

Better than the inspiration?

2007-04-25T12:24:00.000+02:00

The inspiration sources for this game has been "Zero Gunner 2" and "Ikaruga" (and some others). These are the two best shoot'em'up games I know. Last night I played some "Zero Gunner 2" for Dreamcast to remember how they implemented the aim/rotate thing. I quickly felt that compared to "Bullet Hell Tactics" it felt slow and not as good looking graphics as I once thought. "Bullet Hell Tactics" actually felt like more action and better looking effects.

It just felt very cool that after playing "Zero Gunner 2" one can think that hmm... "Bullet Hell Tactics" is not that bad...

The last week I have been working with the graphics, effects and polishing the game a lot. There has been a huge difference just in a few days with the overall feeling of the game.

Today or tomorrow I'll post new screenshots and gameplay video. On Friday I'll go to Italy and when I get back home (next week) I'll build the final test version, and everyone who wants can try it.

Updated graphics and titlescreen

2007-04-19T23:19:00.000+02:00

Tonight I worked with some new graphics for player shield and the "energypacks" the enemies drop. Sometimes it's fun to just sit and play around with colors and some filters in photoshop, what a difference - so much better!

Also created a new titlescreen:

Last 90% of a game

2007-04-18T15:11:00.000+02:00

Somewhere I read "When you think you are 90% complete with a game, you just have the other 90% left". It's true.

It was a pretty long time ago this project started (about 8 months) and it's now very near completion. It's a insane amount of hours put in this little game, and remember this is only a demo with 5 minutes(!!) of gameplay. Of course it wouldn't be as much work finishing more levels but I feel that I have soon finished what I started, and I'm satisfied with that!

Right now I'm trying to make what I have as good and polished as I can. This game will not be anything groundbreaking or graphically revolutionary, BUT IT WILL BE A REAL SHOOT'EM'UP GAME with lots of bullets, action, explosions, music/sounds, bosses, 3d graphics and highscores. I'll be really proud of it, finishing a game :-) I have not yet seen many finished games created with XNA, but I guess it will be a lot more one year from now...

In about 3-4 weeks time this project will be done and I will let it go, until I want to make it a full game :-)

How to play the game

2007-04-08T23:14:00.000+02:00

Bullet Hell Tactics demo includes one level. The goal is to kill the final boss and get as high score as you can.

How to play the game
You control a small spaceship and must destroy hordes of evil enemies. Shoot them down with your lasers while trying to evade the bullets they shoot back. When a enemy is destroyed they drop energy, pick these up fill up your own energy. You can also aim your ship and shoot in 360 degrees and not let a single enemy survive.

How player energy works
Player energy is displayed in the upper left corner of the screen. To fill up energy you must collect the green stuff the enemies drop when they are destroyed. You can use your energy in two ways:

Spinning shield, makes you invurnable to bullets (this is very important to use, but be careful not to run out of energy)
Homing laser missiles, very strong weapon that destroys most of whats in it's way (all of your energy will be used, so be careful!)

How bonus works
You get a multiplier for every bullet that bounces from your shield, and that multiplier is then used to calculate bonus when destroying enemies. If you die, the bonus and multiplier is lost. You collect the bonus when firing your homing lasers.

How to control player spaceship

Keyboard & Mouse:

Move - Mouse
Shoot - Left mouse button
Shield - Right mouse button
Aim (set pivot point) - Left Ctrl
Homing missiles - Left Shift

Xbox 360 controller:

Move - Left thumbstick
Shoot - A button (or right trigger)
Shield - B button (or left trigger)
Aim (set pivot point) - Hold X button
Homing missiles - Left/right shoulder button

Beta testers wanted

2007-04-02T18:05:00.000+02:00

Would you like to help me beta test Bullet Hell Tactics? These are the requirements:

Windows XP (SP2)/Vista
Microsoft .NET Framework 2.0
Microsoft XNA Framework 1.0
Microsoft DirectX 9.0c
A graphics card that supports DirectX 9.0c and Shader Model 1.1

Please respond to this post with your name and email, "yourname at website dot com" (so spammers ignore). You can also send me mail to [address removed].

If you decide you want to help me, you will get more information this week. Thanks in advance!

Tips from SGA jury

2007-03-17T18:30:00.000+01:00

I just got back from a two week vacation in Koh Chang (Thailand). The trip home took about 30 hours (without any sleep), that's madness...

Not only that, as soon as I got home I took my new Sony Vaio notebook under my arm and went to the SGA workshop to show the game to the jury (for some tips how to make a better game). They thought it looked cool and they all wanted to try it out (I only got 10 minutes to show off), so I guess that's positive feedback.

The SGA jury tips:

The controls need more polish
More sound effects are needed
Other people should play the game (for balancing and not being too easy/hard)
Polish some effects and graphics

These tips weren't all that new to me and I would have fixed them anyway, but it's still very good to hear this from real professionals, so I know I'm on the right track :-)

Game enters large competition

2007-02-27T17:29:00.000+01:00

Bullet Hell Tactics has officially entered the biggest game development competition in Sweden. This will be really fun and interesting, the deadline for the final demo of the game is 19th of May 2007.

Swedish Game Awards (SGA) is Sweden's largest game development competition. Their vision is to connect the Swedish student world and professional game development world.

The jury consists of representatives from e.g. Avalanche Studios, Grin, Peligroso, Starbreeze, Massive Entertainment, Digital Illusions and Microsoft.

Updated GUI/HUD

2007-02-20T23:23:00.000+01:00

I updated the player GUI/HUD, this is now what it looks like:

Level 1

2007-02-20T23:05:00.000+01:00

I have created different kinds of formations and enemies and I'm now putting it together to create level 1 (the demo level for the game). I have also begun the work of the first boss (I think I have decided to have one middle-level boss and one final for level 1).

I'll first complete the "gameflow" (start, cutscenes, end) of level 1 and then begin to work with various fun effects like better explosions/backgrounds/particles. I'm hoping to have beta 1 out in middle/end of march.

Screenshots and gameplay video

2007-01-29T21:53:00.000+01:00

I have created a first test version of my game with a stage that´s almost a whole minute long (whooho)... All the graphics are not done yet (some are just temporary) but the models and backgrounds are the final ones. I have come a long way in the development, but I have a lot left... I'm also beginning to feel a little bit tired working with the project, must finish...

Here comes a gameplay video and a few screenshots:

Bullet Hell Tactics

2007-01-18T15:11:00.000+01:00

Bullet Hell Tactics will be the name of the game and a testdemo will be complete in January (along with screenshots and gameplay videos).

Features:

Fast gameplay with lots of bullets and lots of action
3D graphics but with 2D style gameplay
Unique controls enable you to aim in 360 degrees
Player autofire and "heatseeking" laser missiles
1 player can play alone or 2 players can play co-op
Beautiful rendered space backgrounds
16 different enemies and lots of different formations and bullet patterns
Combo system that lets you get higher score
Highscoretable that lists the best players
Runs on Windows and Xbox 360
Works with Xbox 360 controller, mouse or keyboard

The real game has begun

2006-12-14T16:19:00.000+01:00

I have finally come to a point where I can begin develop the real game, not just my shmup engine/framework.

I can now:

Jump between gamestates (ex. startmenu, playing game, settings etc.).
Create different enemies and bullet patterns with my configuration XML format, load them into a stage and play it through.
Easily add new behaviors to enemies, bullets and players.
Control player with both keyboard and mouse (soon also Xbox 360 controller).
I'm almost finished figuring out all of the gameplay.

I'm looking forward to see what can be done with my shmup engine/framework. I have been working so hard with the functionality, now it's time to get creative!

An ugly tech demo

2006-11-15T12:51:00.000+01:00

This is what I have done since last time:

Decided to use AABB's. This game will be a fast one I you won't have time to see that the collision detection isn't perfect. Maybe I'll upgrade this one to OBB later.
Created a class to render bounding boxes (makes it much more simple to debug collisions).
Fixed my particle system to work in 3D space.
Created my own Sprite class to render 2D graphics like explosions and bullets. Will also be used by particle system. It's quite slow right now be I'll speed it up later on.
Created a shockwave effect with particle system (for test with bullet/enemy collision).
Can now render 3D models, jahoodi!! :-)

So here goes nothing, it's still borrowed graphics and they are pretty lousy:

It's a screenshot of my current progress, a simple tech demo.

Particles and collision detection

2006-11-07T13:07:00.000+01:00

I have created a particle system which I will use to create various special effects. I will use it in the creation of explosions, rockets, smoke, trails and other stuff. I have looked at another particle system created with XNA called Mercury and created a similar one. You can add different kind of modifiers to an emitter to simulate things like gravity. Modifiers can also change values of a particle, for example: opacity, color and scale.

I'm also looking into creating better collision detection between players/enemies/bullets. Up to now it has been a small fixed AABB (Axis Aligned Bounding Box) that has been the same size for all models. Now I want to change that and automatically calculate the AABB for a model. When the model rotates or scales the AABB will be recalculated. Later I will change this to use a OBB (Oriented Bounding Box) to rotate with the model (this will result in better collision detection), but I have not yet found a solution for this.

Waiting for the content pipeline

2006-10-29T21:13:00.000+01:00

There is a very important component missing in the current beta of XNA, the content pipeline. This is the one that loads 3D models and I really need this to further develop my game. Lucky for me the beta 2 of XNA should be released "in a couple of weeks" (they say). It includes the content pipeline and I hope they have fixed the most important bugs.

It will be lots of fun to try it out, I need to know how many enemies/bullets can be onscreen at once. After the beta 2 has been released I will create a small playable demo which will show various bullet patterns and enemy pathways. Then I will be able to see what my little shmup engine is capable of. I don't think there will be any serious graphics at that point, I guess I'll have to borrow some 3D models that others have created.

Just waiting right now...

Configuration editor

2006-10-25T22:47:00.000+02:00

I have been working on the configuration editor for a few days. It's a simple little tool for creating levels/formations/enemies/bullet patterns/etc... With it I can quickly test various configurations for my game. For example I can write a bullet pattern and then see it running live with just a button push. I can also write a whole level, and then drag the timeline back and forth (while the game is running) to jump directly to a certain frame.

For now I don't want to create a too advanced editor. This is a simple one, but very usable. No more in and out from Visual Studio when I want to test some patterns or enemy paths. I'll give this one more work, but right now it serves it's purpose: to speed up level creation for the game.

Rewritten and redesigned

2006-10-17T14:35:00.000+02:00

The last weeks I have rewritten the whole thing, well not the WHOLE thing, but a lot. Of course I have copied much of the old design and code. I'm much more happy with the code now, It's a lot cleaner and the whole idea is based around "Behaviors".

A "Behavior" is a baseclass that all other behaviors inherit from. A behavior can describe how your ship is controlled, how the enemies fly and attack, how an powerup works and so on. I really like this system because it introduce so much freedom with the design. For example I could write a behavior that describes how a enemy should explode (sprites, particles, shockwaves...). If I'm happy with this explosion I could then apply it to my player ship as well very easy. All entities inherit from "Entity" which has a "Behaviors" property, this is a list so I can add how many behaviors I want. It's like baking a cake and have the flexibility to add any ingredients you want...

I have also created a configuration system which is very flexible. It simply is an xml file which can include a whole level (with enemy paths, graphics, behaviors...). If I decide to create a new behavior (let's say a new enemy bullet pattern) I can add this in the xml file and then tell the system how this behavior should be created from the xml node.

I think I have come up with a system that is flexible, and I kind of like that. I think the most used word in this post is "flexible"!

Stolen graphics and bullet patterns

2006-09-28T20:51:00.000+02:00

I found some better graphics on the web which I temporary use in my game now, it's quite a difference when it actually looks like a game. I also added a gunshot sound when firing, it made it feel a lot cooler when shooting down those enemies.

Right now I'm working on a bullet pattern system which I think would be of good use in the development. I have looked at BulletML (Bullet Markup Language) which a guy called Kenta Cho have created. Only implementations in Java, C++ and D languages has been created, I'm using C# so I'm trying to create my own implementation of BulletML. It won't be exactly as BulletML, but pretty close (or better). It looks like it could work, it's very easy to create advanced bullet patterns with it.

BulletML: http://www.asahi-net.or.jp/~cs8k-cyu/bulletml/index_e.html

Absolutely core

2006-09-23T15:14:00.000+02:00

I have created what I think is the absolutely core functionality for a shmup game.

I got objects that can be recycled, and in this type of game this is very important. Lots of different enemies spawn and then dissapear again (they exit view or die) after a few seconds. Also lots and lots of bullets will spawn and then dissapear again (when they hit something or can't be seen). Everytime a new enemy or bullet spawn I don't want to create a new instance, so I have created this "Factory" class to deal with this problem. I must say that it works pretty good.

Waypoint functionality have also been created. Every enemy can have a set of waypoints added, and then fly through all the points in order, smoothly and with curves. I used something called "CatmullRom" which operates on vectors. I just give this function four vectors and a "time" value between 0 and 1 and it calculates the new position for the enemy. Effective, and it is very easy to create new paths for enemies.

I have also created a very basic "Player" class that can be controlled with the keyboard. The player can also aim with the mouse and shoot in all directions. Very basic collision detection has also been implemented, so you can actually shoot the enemies that come flying and they will explode and die if they are hit!

I work with my project everytime I can and it's slowly progressing. The graphics are so lousy that you want to cry but I have created something that could very well look like a game. Of course not any game rules have been applied yet and there is no meny system or anything, but still... I got something to work with!

Shmup engine

2006-09-13T15:45:00.000+02:00

Right now I'm building my Shmup engine, and it's a lot to think about. In the first couple of weeks of development I will definitely focus on the core functions. It's pretty important that it has good design from the beginning. I don't want myself in a position where I forgot a feature I wanted in the final game, and then realize it's impossible with the current design. Here are some core functionality I'm currently working on:

Enemy movement with smooth paths, waypoints and formations
Player movement, this game will feature 360 degree movement (only in 2D)
Adding/removing entities in the game world and collision detection
Flight path and movement for a stage
Triggers/actions/behaviors, when will enemies attack in formations?
How will the Shmup designer work, what will you be able to modify?
Configuration in XML (stages, paths, waypoints, formations, triggers, behaviors, enemies, weapons)
How will upgrades/powerups of weapons and player work?

This surely isn't all, but I must have something to work with.

Development has begun

2006-09-13T08:33:00.000+02:00

A few weeks ago I started a project I have wanted to do for a long time. It's a shoot-em-up game (where you blow up everything that moves on the screen, lots of enemies, bullets everywhere and lots and lots of explosions and other cool effects). The game will feature 3D graphics but with 2D gameplay. I will use Microsoft newly (beta) released XNA Game Studio Express (with the C# programming language and XNA Framework).

I have tried some other projects before but failed most due to lost of interest and I can't promise I'll complete this one (it's a lot of work to really finish a game). But this time I have chosen a game type I really enjoy. Who knows, maybe this blog will help me in the progress. Good luck to me!