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SWU_emptyStringList
Some SAA calls (SAA_expressionGetStrings, for instance), require pointers to arrays of
strings, where the length of each string in the array is known in advance.
SW_emptyStringList builds the Tcl analogue of such an array. You pass it a list of
lengths, Li, and it returns a list of strings, where the ith string has Li
characters. You can then pass the name of this list of strings to any SAA function which
expects a pointer to an array of string of these lengths.
package require SWU
SWU_emptyStringList elementLengths [ extraChar ]
- elementLengths
- A tcl list or c array ID, where elements of the list or c array represent the various
lengths of the (Return Value's) list's elements.
- extraChar
- An optional parameter. If it is non-zero value then extra character will be added to the
each element of return list and if elementLengths is a cArray then each element
of the array will be incremented. If elementLengths is a list, it remains
unchanged. This is usefull for building null terminated strings.
- You can add room for the terminating null and correct the cArray of the strings length
when you create the strings.
Return Value
A tcl list consisting of strings (filled with "x"s), each of the specified
length.
Examples
- Allocate and retrieve the current scene:
- set curSceneID [SAA_AllocScene]
- SAA_sceneGetCurrent $curSceneID
- Retrieve the element sphere1 from the current scene:
- package require SW
- set elementID [SW_name2Element sphere1 $curSceneID]
- Retrieve the number of expressions that reference the track name nvisib:
- set trackname nvisib
- SAA_elementGetNbExpressions $curSceneID $elementID trackname FALSE nbExpr
- Retrieve the expressions that reference the track name nvisib:
- set exprID [SAA_AllocElem]
- SAA_elementGetExpressions $curSceneID $elementID trackname FALSE $nbExpr $exprID
- Retrieve the number of local variables in an expression:
- SAA_expressionGetNbVars $curSceneID $exprID nbVars
- Retrieve the string length of variable names, variable strings and expression strings:
- set varNameLens [SAA_AllocInteger $nbVars]
- set varStrLens [SAA_AllocInteger $nbVars]
- SAA_expressionGetStringLengths $curSceneID \
- $exprID $nbVars $varNameLens $varStrLens exprStrLen
- Since lengths do not include a terminal null, increase their values:
- incr exprStrLen
- Create lists to pass into SAA_expressionGetStrings. Set extraChar to 1 to
increase length's values and add an extra character:
- set varNames [ SWU_emptyStringList $varNameLens 1 ]
- set varStrs [ SWU_emptyStringList $varStrLens 1 ]
- Retrieve variable names, variable strings and expression string:
- SAA_expressionGetStrings $curSceneID $exprID $nbVars $varNameLens \
- $varStrLens $exprStrLen varNames varStrs exprStr
- puts "Names of the local variables are $varNames"
- puts "Strings of the local variables are $varStrs"
- puts "expression string is $exprStr"
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SWU_emptyStringList