Process SMIL directives in XML data

Process SMIL directives in XML data is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

In order to represent evolutions of contents over time, the SMIL standard provides a solution to record the animation of data. Smil animations can be added to any kind of contents formated in XML.

• SMIL on Wikipedia and at W3

The task is to create an utility that given the first Smiled XML file, would return the following ones:

<lang xml><?xml version="1.0" ?> <smil> <X3D>

 <Scene>
   <Viewpoint position="0 0 8" orientation="0 0 1 0"/>
   <PointLight color='1 1 1' location='0 2 0'/>
   <Shape>
     <Box size='2 1 2'>
       <animate attributeName="size" from="2 1 2"
                                       to="1 2 1" begin="0s" dur="10s"/>
     </Box>
     <Appearance>
       <Material diffuseColor='0.0 0.6 1.0'>
         <animate attributeName="diffuseColor" from="0.0 0.6 1.0"
                                                 to="1.0 0.4 0.0" begin="0s" dur="10s"/>
       </Material>
     </Appearance>
   </Shape>
 </Scene>

</X3D> </smil></lang>

At t = 0 second here is the expected output:

<lang xml><?xml version="1.0" ?> <X3D>

 <Scene>
   <Viewpoint position="0 0 8" orientation="0 0 1 0"/>
   <PointLight color='1 1 1' location='0 2 0'/>
   <Shape>
     <Box size='2 1 2'/>
     <Appearance>
       <Material diffuseColor='0.0 0.6 1.0'/>
     </Appearance>
   </Shape>
 </Scene>

</X3D></lang>

At t = 2 second here is the expected output:

<lang xml><?xml version="1.0" ?> <X3D>

 <Scene>
   <Viewpoint position="0 0 8" orientation="0 0 1 0"/>
   <PointLight color='1 1 1' location='0 2 0'/>
   <Shape>
     <Box size='1.8 1.2 1.8'/>
     <Appearance>
       <Material diffuseColor='0.2 0.56 0.8'/>
     </Appearance>
   </Shape>
 </Scene>

</X3D></lang>

Tcl

Works with: Tcl version 8.6

Library: tDOM

<lang tcl>package require Tcl 8.6 package require tdom

1. Applies a time-based interpolation to generate a space-separated list

proc interpolate {time info} {

   dict with info {

scan $begin "%fs" begin scan $dur "%fs" dur

   }
   if {$time < $begin} {

return $from

   } elseif {$time > $begin+$dur} {

return $to

   }
   set delta [expr {($time - $begin) / $dur}]
   return [lmap f $from t $to {expr {$f + ($t-$f)*$delta}}]

}

1. Applies SMIL <transform> elements to their container

proc applySMILtransform {sourceDocument time} {

   set doc [dom parse [$sourceDocument asXML]]
   foreach smil [$doc selectNodes //smil] {

foreach context [$smil selectNodes {//*[animate]}] { set animator [$context selectNodes animate] set animated [$context selectNodes @[$animator @attributeName]] $context removeChild $animator $context setAttribute [$animator @attributeName] \ [interpolate $time [lindex [$animator asList] 1]] } if {[$smil parentNode] eq ""} { set reparent 1 } else { [$smil parentNode] replaceChild $smil [$smil firstChild] }

   }
   if {[info exist reparent]} {

set doc [dom parse [[$smil firstChild] asXML]]

   }
   return $doc

}

set t [expr {[lindex $argv 0] + 0.0}] set result [applySMILtransform [dom parse [read stdin]] $t] puts {<?xml version="1.0" ?>} puts -nonewline [$result asXML -indent 2]</lang>

Demonstration:

Note that input.smil contains the source document from the task description.

$ tclsh8.6 applySmil.tcl 0 < input.smil
<?xml version="1.0" ?>
<X3D>
  <Scene>
    <Viewpoint position="0 0 8" orientation="0 0 1 0"/>
    <PointLight color="1 1 1" location="0 2 0"/>
    <Shape>
      <Box size="2.0 1.0 2.0"/>
      <Appearance>
        <Material diffuseColor="0.0 0.6 1.0"/>
      </Appearance>
    </Shape>
  </Scene>
</X3D>
$ tclsh8.6 applySmil.tcl 2 < input.smil
<?xml version="1.0" ?>
<X3D>
  <Scene>
    <Viewpoint position="0 0 8" orientation="0 0 1 0"/>
    <PointLight color="1 1 1" location="0 2 0"/>
    <Shape>
      <Box size="1.8 1.2 1.8"/>
      <Appearance>
        <Material diffuseColor="0.2 0.5599999999999999 0.8"/>
      </Appearance>
    </Shape>
  </Scene>
</X3D>