First Cerberus X steps

Skid spills some source...

Main

We begin with the smallest Cerberus X program.

Function Main()
Print "Hello"
End

In which, with the HTML5 target selected, we verify we are able to create and view our Cerberus X developments.

To learn more about the Main entry point of a program make sure you read the Programs and Declarations section of the Language reference.

Game App

We now build a mojo App which we call Game (in Cerberus X class names are typically capitalized).

Import mojo

Class Game Extends App

Method OnCreate()
Print "hello"
End

End

Function Main()
New Game()
End

A mojo App is used to provide us methods of input, graphics and sound. The framework above creates a single App using the Game class definition.

Spiral animation

With our game object defined we extend the basic Update and Render parts of the app.

The minimum requirements for an animating Cerberus X application are an App implementing the methods:

OnCreate must call SetUpdateRate

OnUpdate can use mojo input commands

OnRender can use mojo drawing commands

The following draws an animated spiral shape using the DrawPoint command.

Import mojo

Class Game Extends App

' radial sprial with axis aligned phase

Function DrawSpiral(clock)
Local w=DeviceWidth/2
For Local i#=0 Until w*1.5 Step .2
Local x#,y#
x=w+i*Sin(i*3+clock)
y=w+i*Cos(i*2+clock)
DrawPoint x,y
Next
End

Field updateCount

Method OnCreate()
Print "spiral"

SetUpdateRate 60
End

Method OnUpdate()
updateCount+=1
End

Method OnRender()
Cls
DrawSpiral updateCount
DrawSpiral updateCount*1.1
End

End

Function Main()
New Game()
End

Each spiral drawn by the program begins at the middle of the screen and spirals out using the Maths functions Sin and Cos.

Here is the final application: