Map an image to a polygon

21

Yes. At the time I took the screen shot I was just testing the basic principles of the matrix math & picture transform functions I wrote.

22

Shame Appleā€™s killing OpenGL and Metal still isnā€™t a complete replacement for it. Woulda been nice if Apple kept up to date, mind you, that might have made OpenGL apps much faster than Metalā€¦ lolā€¦

23

Okā€¦ I donā€™t want/need to do anything fancy like OpenGL etcā€¦ This is supposed to be a one-off program to create a series of static images (ie. isometric dice)

for the image I posted above I can map the ORANGE and CYAN faces with acceptable resultsā€¦ but am still having issues with the TOP (magenta)

I have a series of images (128x128) and the approach I am taking is to scan each image (RGBSurface) then take the X,Y coordinate and the pixel color and attemp to map it to the face.

Here is the code (there are 9 images, as the 2,3 and 6 are rotated in some renderings)

Public Sub make_dice(index as string, value as integer, face1 as integer, face2 as integer)
  Dim f As FolderItem
  Dim x As Integer
  Dim y As Integer
  Dim i As Integer
  Dim c As Color
  Dim face As Picture
  Dim face_r As RGBSurface
  p=New picture(dice_size*1.74,dice_size*2.5)
  face_dice=p.RGBSurface
  For i = 1 To 3
    Select Case i
    Case 1
      face=zGetImage(value)
    Case 2
      face=zGetImage(face1)
    Case 3
      face=zGetImage(face2)
    End Select
    //
    face_r=face.RGBSurface
    For x=0 To face.Width-1
      For y=0 To face.height-1
        c=face_r.Pixel(x,y)
        Select Case i
        Case 1
          zMapTop(x,y,c)
        Case 2
          zMapLeft(x,y,c) // this works
        Case 3
          zMapRight(x,y,c) // this works
        End Select
      Next y
    Next x
  Next i
  //
  Select Case value
  Case 7
    value=2
  Case 8
    value=3
  Case 9
    value=6
  End Select
  f=GetFolderItem("").child("dice"+Str(value)+index+".png")
  p.Save(f,picture.SaveAsPNG)
End Sub


Public Sub zMapLeft(old_x as double, old_y as double, c as color)
  // calculate new x,y
  Dim newX As Double
  Dim newY As Double
  newX = (p.width/2)-(old_x * Cos(angle))
  newY = (p.height)-(old_x*Sin(angle))-old_y
  face_dice.Pixel(newX,newY)=c
End Sub



Public Sub zMapRight(old_x as double, old_y as double, c as color)
  // calculate new x,y
  Dim newX As Double
  Dim newY As Double
  newX = (p.width/2)+(old_x * Cos(angle))
  newY = (p.height)-(old_x*Sin(angle))-old_y
  face_dice.Pixel(newX,newY)=c
End Sub


// THIS ONE IS WHERE THE PROBLEM IS
Public Sub zMapTop(old_x as double, old_y as double, c as color)
  // calculate new x,y
  Dim newX As Double
  Dim newY As Double
  Dim pcx As Double =(p.width/2)
  Dim cx As Double =  pcx-old_X
  Dim cy As Double =  pcx-old_y
  newX = (cx * Cos(angle) - cy * Sin(angle))+ pcx
  newY = (cy * Cos(angle) + cx * Sin(angle)) 
  //
  //newX=old_x
  //newY=old_y
  face_dice.Pixel(newX,newY)=c  
End Sub

Calling the above as

make_dice("A",1,2,3)

renders this image
dice1A

24

Solved

dice2B

25

That feels like a lot of work to get a set of dice images when you can get polished ones as a set for (usually) about $15

Are you putting other images on, or was it just the dice faces?

26

This is how I wanted to do itā€¦ I donā€™t spend money on things I can do myself :slight_smile:

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