Getting Started


This is a good introduction to FB for QBasic programmers, based on SJ Zero's tutorial.

Getting started with the software

You can download FreeBASIC here: http://www.freebasic.net
And FBIDE here: http://fbide.sourceforge.net/

When installing FBIDE, select "FBIDE only," to not install the old version of FB included in that package.
When running FBIDE the first time, you will have to browse to find the FB compiler on your computer.

Hello World!

Open up FBIDE and type the following:

PRINT "Hello World!"
SLEEP


Now press F5. Congratulations, you've just seen how much like QB FreeBASIC really is. Now you can use most console commands for QB just like you remember. For example:

LOCATE 10,10
PRINT "I'm the center of the universe!"
SLEEP


The Amazing Screen 13

Now, put "SCREEN 13" before your code, to see how easy it is to use graphics modes:
SCREEN 13
PRINT "Hello World!"
SLEEP


From there, all of the standard QB graphics commands work as you remember, as you can see in this example:

SCREEN 13
LINE (1,1)-(100,100),1,bf
PRINT "Hello World!"
CIRCLE (10,10),10,11
PSET (30,15),15

SLEEP


FreeBASIC also has new graphics features. For example, QB has never had a screen 14 or greater. Try running this program:
SCREEN 15
LINE (1,1)-(100,100),1,bf
PRINT "Hello World!"
CIRCLE (10,10),10,11
PSET (30,15),15

SLEEP


After opening a graphics window via the SCREEN command, you can also hit ALT-ENTER to change between windowed and fullscreen modes.

Another nice feature of the graphics library in FreeBASIC is that you can do page flipping in any video mode. The following code demonstrates this.

DIM as integer page
DIM as integer notpage
DIM as integer a, b


screen 12, , 2 'This sets the screen for 2 pages
notpage = 1    'This sets the backpage

DO
   IF page = 0 THEN page = 1 ELSE page = 0          'These two lines flip the page and the
   IF notpage = 1 THEN notpage = 0 ELSE notpage = 1 'backpage

   SCREENSET page, notpage 'This flips the page

   CLS  'First we clear the screen
   b = b + 1 
   IF b > 100 THEN b = 0
   FOR a = 1 TO 128
	  PSET (b,a),a 'Then we draw a line. It moves without flickering.
   NEXT a
   SLEEP 10

LOOP UNTIL INKEY = CHR(27) 'Press Escape key to quit the program.


This works for any mode, so you can use the high resolution modes for your programs with page flipping, using standard QB graphics commands!


Why ASM is No Longer Required

I wouldn't be saying this if it wasn't true. Using ASM in BASIC to increase the functionality of your program is no longer necessary. Ignoring SDL, Allegro, DirectX, OpenGL, et. al. for a minute, you've got the above page flipping and advanced graphics modes at your disposal, as well as Inkey, which we've all grown to love or hate, but there are also two new input commands which do things QBers have had to resort to assembly code to do since the dawn of time:

DIM as integer x, y, buttons
CONST as integer escapeKey = 1
SCREEN 12

WHILE NOT MULTIKEY(escapeKey) 'this checks the escape key every frame
   GETMOUSE x, y, , buttons    'This gets the mouse state 
   PRINT x,y,buttons   
WEND


With this knowledge, you should be able to begin programming in FreeBASIC, with all the perks that it entails; Speed, power, and portability!
Valid XHTML :: Valid CSS: :: Powered by WikkaWiki



sf.net phatcode