B4J Question Disabling anti aliasing on text

[wimpie3]

I'm using canvas.DrawText to draw text. However, there seems to be anti-aliasing on the text, and I want to disable that.

According to https://docs.oracle.com/cd/E17802_0...javafx.scene.text/javafx.scene.text.Text.html there seems to be an option called "smooth", but that parameter isn't available in B4XCanvas. How can I disable the anti-aliasing on the text in B4J?

 

[Daestrum]

Are you confusing Text (the Object) with text inside the canvas?

javafx.scene.text.Text is an object that can be added anywhere in the scene graph it doesn't need a container.

what you probably want is (uses JavaObject Library)

(Canvas1).As(JavaObject).RunMethodjo("getGraphicsContext2D",Null).RunMethod("setImageSmoothing",Array(False))

 

[wimpie3]

Thanks, but this gives me

java.lang.RuntimeException: Method: getGraphicsContext2D not found in: anywheresoftware.b4a.objects.B4XCanvas

 

[Daestrum]

thats odd - working fine here with

Sub Process_Globals
    Private fx As JFX
    Private MainForm As Form
    Private xui As XUI 
    Private Button1 As B4XView
    Private Canvas1 As B4XView
End Sub

Sub AppStart (Form1 As Form, Args() As String)
    MainForm = Form1
    MainForm.RootPane.LoadLayout("Layout1")
    MainForm.Show
    Dim txt As JavaObject
    txt.InitializeNewInstance("javafx.scene.text.Text",Array("hello"))  
    MainForm.RootPane.AddNode(txt,20,20,100,20)
    (Canvas1).As(JavaObject).RunMethodjo("getGraphicsContext2D",Null).RunMethod("setImageSmoothing",Array(False))
End Sub

Sub Button1_Click
    Canvas1.As(Canvas).DrawText("Hello",20,20,xui.CreateFont(fx.DefaultFont(20),20),fx.Colors.Blue,"LEFT")
End Sub

 

[wimpie3]

I suspect this is because I'm using

Dim Canvas As B4XCanvas

and you're using

Dim Canvas1 As B4XView

 

[wimpie3]

Still stuck with this... it would be so much easier if you could DISABLE the anti aliasing on B4XCanvas.

 

[William Lancee]

You can get the native canvas from B4XCanvas with this (from @Erel)
And then apply the solution of @Daestrum MAYBE, I haven't tested it.

'B4J and B4A
Sub GetNativeCanvas (b4x As B4XCanvas) As Canvas
   Dim jo As JavaObject = b4x
   jo = jo.GetFieldJO("cvs")
   If XUI.IsB4J Then Return jo.RunMethod("getObject", Null)
   Return jo
End Sub

 

[kimstudio]

Just curious, why do you need disabling anti aliasing on text? I may just use a bitmap font and make a font rendering function myself.

​

 

[Daestrum]

You can put it in one line but the code looks horrendous where cv is a B4XCanvas

(((cv).As(JavaObject).GetFieldJO("cvs")).As(B4XView)).As(JavaObject).RunMethodJO("getGraphicsContext2D",Null).RunMethod("setImageSmoothing",Array(False))

 

[wimpie3]

It's not working unfortunately, the text is still anti aliased. I've added a Wish on the forum to add this function on B4XCanvas. What I thought would be simple is sometimes SO complex in B4X...
I could switch to a bitmap font and create the font rendering myself, but that's a lot of work (and probably overkill).

 

[kimstudio]

Can you try this? found from internet.

g2d.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_OFF);