PlayBasic Tutorial: Intro To Functions - (2018-07-06)
Hi welcome to our Intro to Functions tutorial. In this tutorial we start out with some revision of Gosub / Return statements, which are used to create a simple sub routine. Sub routines are changes in program flow, allowing the programmer to execute a chunk of code that's external to the section they may be writing, then upon completion the control returns to the caller. This is the same basic model that functions introduction to our programming, except functions are more formalized. Meaning they have some strict rules about syntax and intro a new concepts such as scope changes, which sub routines don't have.
The types of functions shown in video are very simple, initially we start by taking a sub routine that prints rows of text and convert that to function. Through this process we encounter our first problem which is variable scope and look at ways to solve it, such as making our variable global, or better yet passing a variable into the function as a parameter . Later in the video, we create our own custom distance function, as well building a function that does some simple string manipulation
NOTE: This video was recorded alive with only a few changes for length..
PlayBasic Tutorial: From Arrays To Types (Intro To Types) - (2018-06-12)
This tutorial picks up where the previous variables to arrays tutorial left off, in that it takes the array code, demos that code then we set about converting the parallel array approach shown in the previous tutorial and we build a structure (TYPE) to hold each characters properties. Once the type has been defined that includes all the required properties, we then define a typed array that will house the collection of characters. Later in the video take a look at using typed lists also. So if your struggling with types this could be a good place to start.
Example #1 - Converting the Parallel Arrays To Typed Array
PlayBasic Code:
Setfps20
Number_Of_Characters =50type tCharacter
Xpos#
Ypos#
Xspeed#
Yspeed#
Colour
Size
endtypedim Characters(Number_Of_Characters)as tCharacter
for lp =1to Number_Of_Characters
; Allocate a newe tCharacter and place it's handle; into the Character(lp) array / container at this position
Characters(lp)=new tCharacter
Characters(lp).Xpos =rnd(800)
Characters(lp).Ypos =rnd(600)
Characters(lp).Size =rndrange(16,50)
Characters(lp).Xspeed =rndrange(-5, 5)
Characters(lp).Yspeed =rndrange(-5,5)
Characters(lp).Colour =rndrgb()next//-------------------------------------------------------//---[ MAIN LOOP ]---------------------------------------//-------------------------------------------------------doClsrgb(0,400,20)for lp =1to Number_Of_Characters
Radius = Characters(lp).Size
x#=Characters(lp).Xpos
y#=Characters(lp).Ypos
circlec X#,Y#,Radius,true,Characters(lp).Colour
x# =wrapvalue(x# + Characters(lp).Xspeed , -Radius, 800+ Radius)
y# =wrapvalue(y# + Characters(lp).Yspeed , -Radius, 600+ Radius)
Characters(lp).xpos= x#
Characters(lp).ypos= y#
nextSyncloop
PlayBasic Tutorial: From Variables To Arrays (Intro To Arrays) 2017-09-17
Welcome programmers, in this tutorial we're going to introduce the concept of arrays starting out from variables. So first we build a simple game loop that controls two characters using only variables. The characters are represented on screen as filled circles. After we get up to speed with the variable version we then move onto how we can use parallel integer arrays to store the various properties of the characters. The array version can control as many or as few characters as you like, which is the benefit of Arrays over Variables
