BlitzCoder - Blitz Basic Game Development Resources

Blitz2D Newbies: Getting Started with BlitzBasic by Krylar

Introduction:

BlitzBasic is a tool that was originally created for the Amiga a long long time ago in a galaxy...well, it was this galaxy, but anyway. The idea was to create a really powerful game engine that had a simple programming interface. This concept is now being moved from the Amiga to the PC, and it's sweet!

Currently, the engine works with DirectX 7.0 or higher and sports the following features:

Full featured BASIC programming language
Built in IDE and compiler, with a pretty nice debugger to boot
REALLY high-speed 2D Graphics with Buffering
Tons of image functions (including PIXEL-Perfect collision detection!)
Font functions for putting up your text as you want
Input device functions (keyboard, mouse, and joystick)
Sound and Music functions
File I/O functions
String manipulation functions
Time functions (no more worrying about "how do I work the timers in Windows?")
All the necessary math functions for 2D (to be expanded with 3D, no doubt)
And, get this, Multiplayer functions!

I've been messing with this language for roughly 2 days now and I gotta say that this is one of the coolest toys I've played with. It's simple to use, but it still requires that YOU program your game. Basically, you still have to handle the AI, physics, game-play mechanics, balancing issues, level controls, hit points, modifiers, etc...the only thing you no longer have to worry about is working with DirectX.

In order to follow along, you'll need to download the latest version of BlitzBasic and you'll need to have DirectX 7.0 or higher. You can get BlitzBasic by going to the BlitzBasic Website.

Quick note, I'll likely use "BB" in place of writing "BlitzBasic" everywhere...so now you'll know what that means ;)

Simple, eh? Enough talk, show me!

Okay, I'm going to show you how simple this really is. This little piece of source will setup the graphics mode, display a .bmp image (I use a little ship that comes with the BlitzBasic download) and allow you to move that image all over the screen with your mouse.

; Setup our constants
  Const g_ScreenWidth=800, g_ScreenHeight=600

; Call the BB "Graphics" routine to initialize DirectX
  Graphics g_ScreenWidth, g_ScreenHeight
 
  ; Set up BB to support page-flipping
  SetBuffer BackBuffer()
 
  ; Create a global var for the Player's Image
  Global g_PlayerImage
 
  ; Create globals to keep track of the mouse positions
  Global g_OldMouseX=1, g_OldMouseY=1
  
  ; Create a Type (which is just like a C/C++ Struct)
  Type MainShip
    Field x#,y#
  End Type

; Create an object of MainShip, called Ship
  Ship.MainShip=New MainShip

; Set the x,y for the Ship
  Ship\x#=1
  Ship\y#=1

; Call BB's LoadImage function to load the .BMP
  ; Make sure you put the proper path to the .BMP!
  g_PlayerImage=LoadImage( "graphics\player.bmp" )

; Our main game loop is here. 
  ; While the ESC key is not pressed
  While Not KeyHit(1)
        ; If mouse position isn't the same as last loop 
        ; update the x,y coords for the ship
        If g_OldMouseX<>MouseX() Or g_OldMouseY<>MouseY()
        
           ; update the x coord for the ship placement
           Ship\x#=MouseX()
           ; update the y coord for the ship placement
           Ship\y#=MouseY()
           
        EndIf

; Save the current mouse x,y
        g_OldMouseY=MouseX()
        g_OldMouseY=MouseY()

; Call BB's DrawImage function to put the ship
        ; up in the proper spot
        DrawImage g_PlayerImage, Ship\x#, Ship\y#

; Call BB's Flip function to flip the pages
        Flip

; Clear the back buffer
        Cls

; end of our main loop
   Wend

; free the Ship Oject
   Delete Ship

; End of the program
   End

Now I'm sure there are a few things that may look a bit odd, so let me explain.

First off, you use a ";" as a comment indicator. It will consider anything after that character a comment for the rest of that line.

Secondly, you'll notice that in the Type section there is a Field command. This command basically instructs the Type that this is a piece of it's element. You can put different vars and such in here.

Third, what's with that # next to x and y? Well, that little jobbie basically tells BB to use floating point. Thus, we can put x#=1.99834, which we couldn't do without the #. You won't get an error if you try, but everything after the decimal is dropped.

Finally, where C uses -> for struct references, BB uses a \. So when you see Ship\x=1, think Ship->x=1. For those of you who don't know C, think of the \ as pointing at the x. So, Ship\x=1 is basically saying, "make the value x, that sits inside the Type Ship, equal 1". I guess another way to look at is as Type Ship is a directory and x is a sub-directory within it. In order access that directory in DOS, you would have to type in the old CD ship\x...that might help you DOS-types (and Unix types, just flip the / in your world to \ ;)).

Conclusion:

In a nutshell, I think that this is one of the coolest toys for the hobbyist developer I've seen. But, if you're a good programmer, you should really be able to code darn near anything using this...especially when the 3D stuff is done.

I'll keep you posted of little accomplishments I make with this system and how I made them. In the meantime, you may consider playing around with BB a bit.

Until next time...cya!

-Krylar

For a printable copy of this article, please click HERE.