Games [X2][solved] How to use transparent color?

fredo

Well-Known Member
Licensed User
(1) The Tileset .png file is given with "pink" as backgroundcolor to represent transparent pixels

(2) In the tool "Tiled" this is considered automatically.

(3) On the Form the surrogate-color "pink" should be transparent.


What should be done to make the tile backgrounds transparent?


2019-07-30_17-29-02.png

Code used:

B4X:
Private Sub GraphicCache_Put_Characters
    Log("#-Sub game.GraphicCache_Put_Characters")
    Dim bmp As B4XBitmap = xui.LoadBitmap(File.DirAssets, "RPGCharacterSprites32x32.png")
    
    Dim NumberOfSprites As Int = 12
    Dim RowWidth As Int = 32
    Dim RowHeight As Int = 32
    Dim CharHeightMeters As Int = 3
    '
    Dim RowOfChar1 As Int = 2
    Dim character1 As B4XBitmap = bmp.Crop(0, RowHeight * RowOfChar1, NumberOfSprites * RowWidth, RowHeight)
    Dim AllChar1 As List = X2.ReadSprites(character1, 1, NumberOfSprites, CharHeightMeters, CharHeightMeters)
    X2.GraphicCache.PutGraphic("character1 front walking", Array(AllChar1.Get(0), AllChar1.Get(1), AllChar1.Get(2), AllChar1.Get(3)))
    X2.GraphicCache.PutGraphic("character1 front standing", Array(AllChar1.Get(3)))
    X2.GraphicCache.PutGraphic("character1 back walking", Array(AllChar1.Get(4), AllChar1.Get(5), AllChar1.Get(6), AllChar1.Get(7)))
    X2.GraphicCache.PutGraphic("character1 back standing", Array(AllChar1.Get(7)))
    X2.GraphicCache.PutGraphic("character1 side walking", Array(AllChar1.Get(8), AllChar1.Get(9), AllChar1.Get(10)) )
    X2.GraphicCache.PutGraphic("character1 side standing", Array(AllChar1.Get(9)) )
    '
    Dim RowOfChar2 As Int = 3
    Dim character2 As B4XBitmap = bmp.Crop(0, RowHeight * RowOfChar2, NumberOfSprites * RowWidth,  RowHeight)
    Dim AllChar2 As List = X2.ReadSprites(character2, 1, NumberOfSprites, CharHeightMeters, CharHeightMeters)
    X2.GraphicCache.PutGraphic("character2 front walking", Array(AllChar2.Get(0), AllChar2.Get(1), AllChar2.Get(2), AllChar2.Get(3)))
    X2.GraphicCache.PutGraphic("character2 front standing", Array(AllChar2.Get(3)))
    X2.GraphicCache.PutGraphic("character2 back walking", Array(AllChar2.Get(4), AllChar2.Get(5), AllChar2.Get(6), AllChar2.Get(7)))
    X2.GraphicCache.PutGraphic("character2 back standing", Array(AllChar2.Get(7)))
    X2.GraphicCache.PutGraphic("character2 side walking", Array(AllChar2.Get(8), AllChar2.Get(9), AllChar2.Get(10)) )
    X2.GraphicCache.PutGraphic("character2 side standing", Array(AllChar2.Get(9)) )
    '
    
End Sub
 

fredo

Well-Known Member
Licensed User
...with support for tile sets with custom transparent colors.
Thank you for responding so quickly.

Since I'm not very advanced in X2 yet, I'm not sure in which ways a bitmap can be read.

Apparently we can read the bitmap directly, or via the setting in the tilemap.

  • Either the way loading the bitmap directly without regarding transparency:
B4X:
   Dim bmp As B4XBitmap = xui.LoadBitmap(File.DirAssets, "RPGCharacterSprites32x32.png")
    ...
    Dim character1 As B4XBitmap = bmp.Crop(0, RowHeight * RowOfChar1, NumberOfSprites * RowWidth, RowHeight)
    Dim AllChar1 As List = X2.ReadSprites(character1, 1, NumberOfSprites, CharHeightMeters, CharHeightMeters)
    X2.GraphicCache.PutGraphic("character1 front walking", Array(AllChar1.Get(0), AllChar1.Get(1), AllChar1.Get(2), AllChar1.Get(3)))
    ...
  • Or the way via the tile sets with support for custom transparent colors:
2019-07-31_12-22-04.png



In this case I need a tip on how to load a bitmap mentioned in the tileset including transparency info.


 

Erel

Administrator
Staff member
Licensed User
This is the code that removes the color:
B4X:
Private Sub RemovePseudoTransparentColor(TilesBC As BitmapCreator, clrstring As String)
   Dim clr As Int = 0xff000000 + Bit.ParseInt(clrstring.SubString(1), 16)
   Dim ptranspm As PremultipliedColor
   Dim trans As PremultipliedColor
   Dim pm As PremultipliedColor
   
   Dim argb As ARGBColor
   TilesBC.ColorToARGB(clr, argb)
   TilesBC.ARGBToPremultipliedColor(argb, ptranspm)
   For y = 0 To TilesBC.mHeight - 1
       For x = 0 To TilesBC.mWidth - 1
           TilesBC.GetPremultipliedColor(x, y, pm)
           If Bit.And(0xff, pm.r) = ptranspm.r And Bit.And(0xff, pm.g) = ptranspm.g And Bit.And(0xff, pm.b) = ptranspm.b And Bit.And(0xff, pm.a) = ptranspm.a Then
               TilesBC.SetPremultipliedColor(x, y, trans)
           End If
       Next
   Next
End Sub
Add it to your code.
Convert the bitmap to BitmapCreator with X2.BitmapToBC. Set the scale to 1.
Call removePseudoTransparentColor.
Get the bitmap with BC.Bitmap.
 

fredo

Well-Known Member
Licensed User
Worked. Thanks!
2019-08-01_14-21-32.png



B4X:
Private Sub GraphicCache_Put_Characters
    Log("#-Sub game.GraphicCache_Put_Characters")
   
    ' Use bitmap as is: Dim bmp As B4XBitmap = xui.LoadBitmap(File.DirAssets, "RPGCharacterSprites32x32.png")
   
   
    ' Use bitmap without the transparent placeholdercolor:
    Dim bc As BitmapCreator = X2.BitmapToBC( xui.LoadBitmap(File.DirAssets, "RPGCharacterSprites32x32.png"), 1)
    RemovePseudoTransparentColor(bc, "#ff00ff") ' pink, magenta
    Dim bmp As B4XBitmap = bc.Bitmap
   
   
    Dim NumberOfSprites As Int = 12
    Dim RowWidth As Int = 32
    Dim RowHeight As Int = 32
    Dim CharHeightMeters As Int = 3
    '
    Dim RowOfChar1 As Int = 2
    Dim character1 As B4XBitmap = bmp.Crop(0, RowHeight * RowOfChar1, NumberOfSprites * RowWidth, RowHeight)
    Dim AllChar1 As List = X2.ReadSprites(character1, 1, NumberOfSprites, CharHeightMeters, CharHeightMeters)
   
   
    X2.GraphicCache.PutGraphic("character1 front walking", Array(AllChar1.Get(0), AllChar1.Get(1), AllChar1.Get(2), AllChar1.Get(3)))
    X2.GraphicCache.PutGraphic("character1 front standing", Array(AllChar1.Get(3)))
    X2.GraphicCache.PutGraphic("character1 back walking", Array(AllChar1.Get(4), AllChar1.Get(5), AllChar1.Get(6), AllChar1.Get(7)))
    X2.GraphicCache.PutGraphic("character1 back standing", Array(AllChar1.Get(7)))
    X2.GraphicCache.PutGraphic("character1 side walking", Array(AllChar1.Get(8), AllChar1.Get(9), AllChar1.Get(10)) )
    X2.GraphicCache.PutGraphic("character1 side standing", Array(AllChar1.Get(9)) )
    '
    Dim RowOfChar2 As Int = 3
    Dim character2 As B4XBitmap = bmp.Crop(0, RowHeight * RowOfChar2, NumberOfSprites * RowWidth,  RowHeight)
    Dim AllChar2 As List = X2.ReadSprites(character2, 1, NumberOfSprites, CharHeightMeters, CharHeightMeters)
    X2.GraphicCache.PutGraphic("character2 front walking", Array(AllChar2.Get(0), AllChar2.Get(1), AllChar2.Get(2), AllChar2.Get(3)))
    X2.GraphicCache.PutGraphic("character2 front standing", Array(AllChar2.Get(3)))
    X2.GraphicCache.PutGraphic("character2 back walking", Array(AllChar2.Get(4), AllChar2.Get(5), AllChar2.Get(6), AllChar2.Get(7)))
    X2.GraphicCache.PutGraphic("character2 back standing", Array(AllChar2.Get(7)))
    X2.GraphicCache.PutGraphic("character2 side walking", Array(AllChar2.Get(8), AllChar2.Get(9), AllChar2.Get(10)) )
    X2.GraphicCache.PutGraphic("character2 side standing", Array(AllChar2.Get(9)) )
    '
   
End Sub

Private Sub RemovePseudoTransparentColor(TilesBC As BitmapCreator, clrstring As String)
    ' Erel --> https://www.b4x.com/android/forum/threads/x2-how-to-use-transparent-color.108173/#post-676534
    Dim clr As Int = 0xff000000 + Bit.ParseInt(clrstring.SubString(1), 16)
    Dim ptranspm As PremultipliedColor
    Dim trans As PremultipliedColor
    Dim pm As PremultipliedColor
    Dim argb As ARGBColor
    TilesBC.ColorToARGB(clr, argb)
    TilesBC.ARGBToPremultipliedColor(argb, ptranspm)
    For y = 0 To TilesBC.mHeight - 1
        For x = 0 To TilesBC.mWidth - 1
            TilesBC.GetPremultipliedColor(x, y, pm)
            If Bit.And(0xff, pm.r) = ptranspm.r And Bit.And(0xff, pm.g) = ptranspm.g And Bit.And(0xff, pm.b) = ptranspm.b And Bit.And(0xff, pm.a) = ptranspm.a Then
                TilesBC.SetPremultipliedColor(x, y, trans)
            End If
        Next
    Next
End Sub
 
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