Android Example LibGDX - New Project Template

wonder

Expert
Licensed User
Hi guys!

Here's a minimalistic libGDX template which can be useful when starting a new project.
It includes a background, a title and an array of objects. It does not include any animation.
The code should be pretty simple to understand, but if you're not familiar with the libGDX lifecycle, you should read Informatix's tutorial first.

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In this example, the camera coordinates are vertically flipped, so that the x,y origin is at the top left corner. If you follow this method, whenever you set a new texture region, you'll have to flip it as well, otherwise it will appear upside-down.

To keep things tidy, I've created a custom type of variable, the GDXObject2D type.
It contains the following properties:


Texture_File: A string containing the file name.
X: Location on screen.
Y: Location on screen.
Source_Pixel_Size_X: Image file size in pixels.
Source_Pixel_Size_Y: Image file size in pixels.
On_Screen_Size_X: Sprite output size on screen.
On_Screen_Size_Y: Sprite output size on screen.
Texture_Filter: Yes or No.
I've also added a dual-analog control scheme, which is composed by two transparent panels, each covering one half of the screen. The left analog controls Actor 0 and the right analog controls Actor 1.

Source code:
B4X:
#Region  Project Attributes
    #ApplicationLabel: LibGDX Template
    #VersionCode: 1
    #VersionName: 1
    'SupportedOrientations possible values: unspecified, landscape or portrait.
    #SupportedOrientations: Landscape
    #CanInstallToExternalStorage: True
    #AdditionalRes: C:\Android\android-sdk\extras\google\google_play_services\libproject\google-play-services_lib\res, com.google.android.gms
#End Region

#Region  Activity Attributes
    #FullScreen: True
    #IncludeTitle: False
#End Region

Sub Process_Globals
    'These global variables will be declared once when the application starts.
    'These variables can be accessed from all modules.

    Type GDXObject2D(Texture_File As String, X As Float, Y As Float, Source_Pixel_Size_X As Float, Source_Pixel_Size_Y As Float, On_Screen_Size_X As Float, On_Screen_Size_Y As Float, Texture_Filter As Boolean)
End Sub

Sub Globals
    'These global variables will be redeclared each time the activity is created.
    'These variables can only be accessed from this module.

    'LibGDX Setup
        Dim lGdx As LibGDX
        Dim Gl As lgGL
        Dim Camera As lgOrthographicCamera
        Dim Batch As lgSpriteBatch
        Dim GLView As View
        Dim lgStep As Float

    'LibGDX Objects
        Dim background_setup      As GDXObject2D
        Dim background_source     As lgTexture
        Dim background            As lgTextureRegion

        Dim title_setup           As GDXObject2D
        Dim title_source          As lgTexture
        Dim title                 As lgTextureRegion

        Dim actor_setup(6)        As GDXObject2D
        Dim actor_source(6)       As lgTexture
        Dim actor(6)              As lgTextureRegion

        background_setup.texture_file          = "background.png"
        background_setup.texture_filter        = True
        background_setup.source_pixel_size_x   = 1280
        background_setup.source_pixel_size_y   = 720
        background_setup.on_screen_size_x      = 100%x
        background_setup.on_screen_size_y      = 100%y
        background_setup.x                     = 0%x
        background_setup.y                     = 0%y

        title_setup.texture_file               = "title.png"
        title_setup.texture_filter             = True
        title_setup.source_pixel_size_x        = 400
        title_setup.source_pixel_size_y        = 200
        title_setup.on_screen_size_x           = 30%x
        title_setup.on_screen_size_y           = Same_Proportion_as_X(title_setup)
        title_setup.x                          = Screen_Center_X(title_setup)
        title_setup.y                          = 8%y

        For i = 0 To (actor.Length - 1)
            actor_setup(i).texture_file        = "actor_" & i & ".png"
            actor_setup(i).texture_filter      = True
            actor_setup(i).source_pixel_size_x = 200
            actor_setup(i).source_pixel_size_y = 200
            actor_setup(i).on_screen_size_x    = 10%x
            actor_setup(i).on_screen_size_y    = Same_Proportion_as_X(actor_setup(i))
            actor_setup(i).x                   = Anywhere_On_Screen_X(actor_setup(i))
            actor_setup(i).y                   = Anywhere_On_Screen_Y(actor_setup(i))
        Next

    'Setup Physics



    'Setup Touch Controls
        Private Analog_Left As Panel
        Dim Analog_Left_StartX As Float
        Dim Analog_Left_StartY As Float
        Dim Analog_Left_DeltaX As Float
        Dim Analog_Left_DeltaY As Float
        Dim Analog_Left_Active As Boolean
        Dim Analog_Left_TouchRatio = 1.8 As Float

        Private Analog_Right As Panel
        Dim Analog_Right_StartX As Float
        Dim Analog_Right_StartY As Float
        Dim Analog_Right_DeltaX As Float
        Dim Analog_Right_DeltaY As Float
        Dim Analog_Right_Active As Boolean
        Dim Analog_Right_TouchRatio = 1.8 As Float

    'Debug
        Private Debug As Label

End Sub


Sub Activity_Create(FirstTime As Boolean)
    'Initialize Layout
        Activity.LoadLayout("Main")

    'Initialize libGDX
        GLView = lGdx.InitializeView("LG")
        Activity.AddView(GLView, 0%x, 0%y, 100%x, 100%y)

    'Analog_Left
        Analog_Left.Left          =   0%x
        Analog_Left.Top           =   0%y
        Analog_Left.Width         =  50%x
        Analog_Left.Height        = 100%y

    'Analog_Right
        Analog_Right.Left         =  50%x
        Analog_Right.Top          =   0%y
        Analog_Right.Width        =  50%x
        Analog_Right.Height       = 100%y

    'Debug
        Debug.Left    =   0%x
        Debug.Top     =   0%x
        Debug.Width   = 100%x
        Debug.Height  = 100%y

    'BTFs
        Analog_Left.BringToFront
        Analog_Right.BringToFront
        Debug.BringToFront

End Sub

Sub Activity_Resume
    If lGdx.IsInitialized Then lGdx.Resume
End Sub


Sub Activity_Pause (UserClosed As Boolean)
    If lGdx.IsInitialized Then lGdx.Pause
End Sub

Sub LG_Create
    Batch.Initialize

    'Initialize Object Textures
        background_source.Initialize(background_setup.Texture_File)
        If background_setup.Texture_Filter = True Then background_source.SetFilter(background_source.FILTER_Linear, background_source.FILTER_Linear)

        title_source.Initialize(title_setup.Texture_File)
        If title_setup.Texture_Filter = True Then title_source.SetFilter(title_source.FILTER_Linear, title_source.FILTER_Linear)

        For i = 0 To actor.Length - 1
            actor_source(i).Initialize(actor_setup(i).Texture_File)
            If actor_setup(i).Texture_Filter = True Then actor_source(i).SetFilter(actor_source(i).FILTER_Linear, actor_source(i).FILTER_Linear)
        Next

    'Initialize Objects
        background.InitializeWithTexture(background_source)
        background.Flip(False, True)
        title.InitializeWithTexture(title_source)
        title.Flip(False, True)

        For i = 0 To (actor.Length - 1)
            actor(i).InitializeWithTexture(actor_source(i))
            actor(i).Flip(False, True)
        Next

End Sub


Sub LG_Resize(Width As Int, Height As Int)
    'Sets the camera viewport
        Camera.Initialize
        Camera.SetToOrtho2(True, lGdx.graphics.Width, lGdx.Graphics.Height)
End Sub


Sub LG_Render

    'Clears the screen
        Gl.glClear(Gl.GL10_COLOR_BUFFER_BIT)
            
    'Updates the matrices of the camera
        Camera.Update

    'Uses the coordinate system specified by the camera
        Batch.ProjectionMatrix = Camera.Combined

    'Step Setup
        If lGdx.Graphics.DeltaTime > (1/60) AND lGdx.Graphics.DeltaTime <= (1/30) Then
            lgStep = lGdx.Graphics.DeltaTime
        Else If lGdx.Graphics.DeltaTime <= (1/60) Then
            lgStep = (1/60)
        Else If lGdx.Graphics.DeltaTime > (1/30) Then
            lgStep = (1/30)
        End If

    'Display Objects on Screen
        Batch.Begin

            Batch.DrawRegion2(background, background_setup.X, background_setup.Y, background_setup.On_Screen_Size_X, background_setup.On_Screen_Size_Y)
            For i = 0 To (actor.Length - 1)
                Batch.DrawRegion2(actor(i), actor_setup(i).X, actor_setup(i).Y, actor_setup(i).On_Screen_Size_X, actor_setup(i).On_Screen_Size_Y)
            Next
            Batch.DrawRegion2(title, title_setup.X, title_setup.Y, title_setup.On_Screen_Size_X, title_setup.On_Screen_Size_Y)

        Batch.End

    'Call the Auxiliary Engine
        lGdx.CallSubUI("Aux_Engine", Null)

End Sub


Sub Aux_Engine(param As Object)
    'Debug
        Dim centerX0 = Round(actor_setup(0).X + (actor_setup(0).On_Screen_Size_X / 2)) As Float
        Dim centerY0 = Round(actor_setup(0).Y + (actor_setup(0).On_Screen_Size_Y / 2)) As Float
        Dim centerX1 = Round(actor_setup(1).X + (actor_setup(1).On_Screen_Size_X / 2)) As Float
        Dim centerY1 = Round(actor_setup(1).Y + (actor_setup(1).On_Screen_Size_Y / 2)) As Float

        Debug.text = "LibGDX Speed: " & lGdx.Graphics.FramesPerSecond & " FPS / " & Round2(1 / lGdx.Graphics.DeltaTime, 2) & " Hz" & CRLF & _
                     "Actor 0: " & centerX0 & ", " & centerY0 & CRLF & _
                     "Actor 1: " & centerX1 & ", " & centerY1
End Sub


Sub LG_Dispose
    background_source.dispose
    title_source.dispose
    For i = 0 To (actor.Length - 1)
        actor_source(i).dispose
    Next
End Sub


Sub LG_Pause
End Sub


Sub LG_Resume
End Sub


Sub Analog_Left_Touch (Action As Int, X As Float, Y As Float)

    Select Action
        Case Activity.ACTION_DOWN
            Analog_Left_StartX = X
            Analog_Left_StartY = Y
            Analog_Left_Active = True

        Case Activity.ACTION_MOVE
            Analog_Left_DeltaX = X - Analog_Left_StartX
            Analog_Left_DeltaY = Y - Analog_Left_StartY
            Analog_Left_StartX = X
            Analog_Left_StartY = Y

            actor_setup(0).X = actor_setup(0).X + (Analog_Left_DeltaX * Analog_Left_TouchRatio)
            actor_setup(0).Y = actor_setup(0).Y + (Analog_Left_DeltaY * Analog_Left_TouchRatio)

        Case Activity.ACTION_UP
            Analog_Left_DeltaX = 0
            Analog_Left_DeltaY = 0
            Analog_Left_Active = False

    End Select
End Sub


Sub Analog_Right_Touch (Action As Int, X As Float, Y As Float)
    Select Action

        Case Activity.ACTION_DOWN
            Analog_Right_StartX = X
            Analog_Right_StartY = Y
            Analog_Right_Active = True

        Case Activity.ACTION_MOVE
            Analog_Right_DeltaX = X - Analog_Right_StartX
            Analog_Right_DeltaY = Y - Analog_Right_StartY
            Analog_Right_StartX = X
            Analog_Right_StartY = Y

            actor_setup(1).X = actor_setup(1).X + (Analog_Right_DeltaX * Analog_Right_TouchRatio)
            actor_setup(1).Y = actor_setup(1).Y + (Analog_Right_DeltaY * Analog_Right_TouchRatio)

        Case Activity.ACTION_UP
            Analog_Right_DeltaX = 0
            Analog_Right_DeltaY = 0
            Analog_Right_Active = False

    End Select
End Sub

Sub Same_Proportion_as_X(object_name As GDXObject2D) As Float
    Return (object_name.source_pixel_size_y * object_name.on_screen_size_x) / object_name.source_pixel_size_x
End Sub

Sub Same_Proportion_as_Y(object_name As GDXObject2D) As Float
    Return (object_name.source_pixel_size_x * object_name.on_screen_size_y) / object_name.source_pixel_size_y
End Sub

Sub Screen_Center_X(object_name As GDXObject2D) As Float
    Return 50%x - (object_name.on_screen_size_x / 2)
End Sub

Sub Screen_Center_Y(object_name As GDXObject2D) As Float
    Return 50%y - (object_name.on_screen_size_y / 2)
End Sub

Sub Anywhere_On_Screen_X(object_name As GDXObject2D) As Float
    Dim minimum = Round(object_name.on_screen_size_x) As Int
    Dim maximum = Round(100%x - object_name.on_screen_size_x) + 1 As Int
    Return Rnd(minimum, maximum)
End Sub

Sub Anywhere_On_Screen_Y(object_name As GDXObject2D) As Float
    Dim minimum = Round(object_name.on_screen_size_y) As Int
    Dim maximum = Round(100%y - object_name.on_screen_size_y) + 1 As Int
    Return Rnd(minimum, maximum)
End Sub
 
Last edited:

wonder

Expert
Licensed User
Where can I get the resource?
Hello hello!

Thank you for your interest, but this is an old project.
I'm sure you'll find Informatix's LibGDX examples and templates way more useful and well build.

Nevertheless, I can't really remember why did I include that #AdditionalRes line in the source code, it might have been nothing more than copy-paste mistake.
LibGDX doesn't need it. Just delete that line and you should be good to go.

If on the other hand you're really interested in that resource, I believe it is an AdMob dependency.
A quick forum search will lead you on the right track. :)
 
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