'
' This example creates two shaders in a simple render tree, and applies
' texture layers to them.  Then it moves some of the layers up and down,
' illustrating the MoveTextureLayers command.
' In particular, it builds the following stacks of layers.
'
' Phong      Fractal
'   A           A
'   B           E
'   C           B
'   D           D
'
option explicit
dim oSph, oPhong, oFractal, oLyr(4)
' Build our shaders (a Phong and a Fractal), which will be the "texture
' layer containers" that will each be able to hold a stack of layers.
NewScene , False
set oSph = CreatePrim( "Sphere", "MeshSurface" )
set oPhong = SIApplyShader( "Phong", oSph )
set oFractal = BlendInPresetsInsp( "Fractal", , , True, siReplaceNoBlend, False, False, True )
' Now create and add all the layers, as indicated above.
' Add 'A', 'B' and 'D' to both containers at the end.
set oLyr(0) = AddTextureLayer( , oPhong & "," & oFractal, "A", True )
set oLyr(1) = AddTextureLayer( , oPhong & "," & oFractal, "B", True )
set oLyr(3) = AddTextureLayer( , oPhong & "," & oFractal, "D", True )
' Add 'C' before 'D' in the first container.
set oLyr(2) = AddTextureLayer( , oPhong, "C", False, oLyr(3) )
' Add 'E' after 'A' in the second container.
set oLyr(4) = AddTextureLayer( , oFractal, "E", True, oLyr(0) )
'
' Now start moving layers around.  Note that they dependencies
' as expressed when we were adding layers will be maintained at all
' times.
' Start by moving 'D' up two spots. -2 means move up two steps.
MoveTextureLayers oLyr(3), -2
' It is likely now above 'B' and 'C'.  The two steps could equally well have
' moved it above 'C' and 'E' -- either is valid, based on the relationships
' expressed above.  Which one actually happens depends on how the moving
' algorithm is implemented and the order in which the containers and layers
' were created.
' Now let's move 'A' and 'E' down a bunch of slots, ensuring they are
' at the end.  We'll just provide a big number for the number of steps down
' to make, if we can't guess the exact number...
MoveTextureLayers oLyr(0) & "," & oLyr(4), 10
PrintTextureLayersInContainer oPhong
PrintTextureLayersInContainer oFractal
sub PrintTextureLayersInContainer( in_cont )
        dim oStack, oItem, oStr
        oStr = "Texture Layers in Container: " & in_cont & vbCrLf
        set oStack = EnumElements( in_cont & ".TextureLayers" )
        for each oItem in oStack
                oStr = oStr & "    " & oItem.name & vbCrLf
        next
        logmessage oStr
end sub
'
' The output from the example should look something like this:
'
'INFO : "Texture Layers in Container: sphere.Material.Phong
'    D
'    B
'    C
'    A
'"
'INFO : "Texture Layers in Container: sphere.Material.Phong.Fractal
'    D
'    B
'    A
'    E
'"