#include <c4d_general.h>

Detailed Description

A class to evaluate mathematical expressions.

Note: Has to be created with Alloc() and destroyed with Free(). Use AutoAlloc to automate the allocation and destruction based on scope.

Public Member Functions
Bool	Eval (const maxon::String &str, Int32 error, Float res, Int32 unit=0, Int32 angletype=0, Int32 basis=10)

Bool	EvalLong (const maxon::String &str, Int32 error, Int32 res, Int32 unit, Int32 basis)

Bool	AddVar (const maxon::String &str, Float *value, Bool case_sensitive=false)

Bool	RemoveVar (const maxon::String &s, Bool case_sensitive=false)

Bool	RemoveAllVars (void)

void	GetParserData (ParserCache *p)

Bool	Init (const maxon::String &s, Int32 *error, Int32 unit=0, Int32 angle_unit=0, Int32 base=10)

Bool	ReEval (Float result, Int32 error)

Bool	Calculate (const ParserCache pdat, Float result, Int32 *error)

Bool	AddVarLong (const maxon::String &str, Int32 *value, Bool case_sensitive=false)

Bool	ReEvalLong (Int32 result, Int32 error)

Bool	CalculateLong (const ParserCache pdat, Int32 result, Int32 *error)

Bool	Reset (ParserCache *p=nullptr)

Static Public Member Functions
static Parser *	Alloc (void)

static void	Free (Parser *&pr)

Private Member Functions
	Parser ()

	~Parser ()

Shader Code Generation
Bool	GenerateShaderCode (const maxon::String &resultVariableName, maxon::String *result)

Bool	GenerateShaderCodeFromCache (const ParserCache pdat, const maxon::String &resultVariableName, maxon::String result)

Constructor & Destructor Documentation

◆ Parser()

Parser ( )

private

◆ ~Parser()

~Parser ( )

private

Member Function Documentation

◆ Alloc()

static Parser* Alloc ( void )

static

Allocates a parser. Destroy the allocated parser with Free(). Use AutoAlloc to automate the allocation and destruction based on scope.

Returns: The allocated parser, or nullptr if the allocation failed.

◆ Free()

static void Free ( Parser *& pr )

static

Destructs parsers allocated with Alloc(). Use AutoAlloc to automate the allocation and destruction based on scope.

Parameters

[in,out] pr The parser to destruct. If the pointer is nullptr nothing happens. The pointer is assigned nullptr afterwards.

◆ Eval()

Bool Eval	(	const maxon::String &	str,
		Int32 *	error,
		Float *	res,
		Int32	unit = `0`,
		Int32	angletype = `0`,
		Int32	basis = `10`
	)

Evaluates a string using the variables added with AddVar() and the built-in expressions supported by Cinema 4D. (See the Formula object in the manual.)

Note: Calls internally Init() and Calculate(), or if the string has not changed ReEval().

Parameters

[in]	str	The expression to evaluate.
[out]	error	Assigned an error value if failed: NEWPARSERERROR
[out]	res	Assigned the result of the expression.
[in]	unit	The unit used in the expression: UNIT
[in]	angletype	The angle unit used in the expression: ANGLE
[in]	basis	The base of the number system used in the expression.

Returns: true if successful, otherwise false.

◆ EvalLong()

Bool EvalLong	(	const maxon::String &	str,
		Int32 *	error,
		Int32 *	res,
		Int32	unit,
		Int32	basis
	)

Evaluates a string using the integer variables added with AddVarLong() and the built-in expressions supported by Cinema 4D. (See the Formula object in the manual.)

Note: Calls internally Init() and CalculateLong(), or if the string has not changed ReEvalLong().

Parameters

[in]	str	The expression to evaluate.
[out]	error	Assigned an error values if failed: NEWPARSERERROR
[out]	res	Assigned the result of the expression.
[in]	unit	The unit used in the expression: UNIT
[in]	basis	The base of the number system used in the expression.

Returns: true if successful, otherwise false.

◆ AddVar()

Bool AddVar	(	const maxon::String &	str,
		Float *	value,
		Bool	case_sensitive = `false`
	)

Adds a variable to the parser to be evaluated.
Example:

Float vu;
 
for (i=0; i<1000; i++)
{
  vu = i*0.2;
  parser->AddVar("u",&vu,true);
 
  parser->Eval("Sin(u)",...);
}

Parameters

[in]	str	The name of the variable to add, this is the name that will be used in the expression string.
[in]	value	Assigned the evaluated value for the variable.
[in]	case_sensitive	true if the variable string is case sensitive, otherwise false.

Returns: true if successful, otherwise false.

◆ RemoveVar()

Bool RemoveVar	(	const maxon::String &	s,
		Bool	case_sensitive = `false`
	)

Removes a variable from the parser evaluation.

Parameters

[in]	s	The name of the variable to be removed.
[in]	case_sensitive	true if the variable string is case sensitive, otherwise false.

Returns: true if successful, otherwise false.

◆ RemoveAllVars()

Bool RemoveAllVars ( void )

Remove all variables from the parser evaluation.

Returns: true if successful, otherwise false.

◆ GetParserData()

void GetParserData ( ParserCache * p )

Retrieves the cached parser data.

Parameters

[out] p Assigned the parser cache. The caller owns the pointed parser cache.
This is used for instance by the Calculate() method. It makes possible to use multiple caches with one parser.

◆ Init()

Bool Init	(	const maxon::String &	s,
		Int32 *	error,
		Int32	unit = `0`,
		Int32	angle_unit = `0`,
		Int32	base = `10`
	)

Initializes the parser with an expression string.

Parameters

[in]	s	The expression string for the initialization.
[out]	error	Assigned an error value if failed: NEWPARSERERROR
[in]	unit	The unit used in the expression: UNIT
[in]	angle_unit	The angle unit used in the expression: ANGLE
[in]	base	The base of the number system used in the expression.

Returns: true if successful, otherwise false.

◆ ReEval()

Bool ReEval	(	Float *	result,
		Int32 *	error
	)

Re-evaluates the expression.

Warning: The expression string must not change prior to using this method.

Parameters

[out]	result	Assigned the result of the expression.
[out]	error	Assigned an error values if failed: NEWPARSERERROR

Returns: true if successful, otherwise false.

◆ Calculate()

Bool Calculate	(	const ParserCache *	pdat,
		Float *	result,
		Int32 *	error
	)

Calculates the result for an expression in an existing parser cache.

See also: GetParserData()

Parameters

[in]	pdat	A parser cache.
[out]	result	Assigned the result of the expression.
[out]	error	Assigned an error values if failed: NEWPARSERERROR

Returns: true if successful, otherwise false.

◆ AddVarLong()

Bool AddVarLong	(	const maxon::String &	str,
		Int32 *	value,
		Bool	case_sensitive = `false`
	)

Adds an integer variable to the parser to be evaluated. Example:

for (i=0; i<1000; i++)
{
  parser->AddVar("i",&i,true);
 
  parser->EvalLong("2*i",...);
}

Parameters

[in]	str	The name of the variable to add, this is the name that will be used in the string.
[in]	value	Assigned the evaluated value for the variable.
[in]	case_sensitive	true if the variable string is case sensitive, otherwise false.

Returns: true if successful, otherwise false.

◆ ReEvalLong()

Bool ReEvalLong	(	Int32 *	result,
		Int32 *	error
	)

Re-evaluates the expression.

Warning: The expression string must not change prior to using this method.

Parameters

[out]	result	Assigned the result of the expression.
[out]	error	Assigned an error values if failed: NEWPARSERERROR

Returns: true if successful, otherwise false.

◆ CalculateLong()

Bool CalculateLong	(	const ParserCache *	pdat,
		Int32 *	result,
		Int32 *	error
	)

Calculates the result for an expression in an existing parser cache.

See also: GetParserData()

Parameters

[in]	pdat	A parser cache.
[out]	result	Assigned the result of the expression.
[out]	error	Assigned an error values if failed: NEWPARSERERROR

Returns: true if successful, otherwise false.

◆ Reset()

Bool Reset ( ParserCache * p = nullptr )

Resets certain functions used by the parser (Random etc.).
This is necessary in animated situations, otherwise results will not be consistent for the same frame.

Parameters

[in] p The parser cache to reset.

Returns: true if successful, otherwise false.

◆ GenerateShaderCode()

Bool GenerateShaderCode	(	const maxon::String &	resultVariableName,
		maxon::String *	result
	)

Returns an OpenGL Shading Language representation of the parsed expression.

Since: R17.032

Warning: Init() must be called before using this function, as it uses internally-cached data. Knowledge of the OpenGL Shading Language is required for correct use of this function.

Note: The generated OpenGL shader code assigns the result of the expression to a float variable with the given name (it must be a valid GLSL identifier).
Each expression variable name is converted to upper case before being inserted into the shader code.
Variable names with spaces are not supported and must be valid GLSL identifiers.
Declarations of these expression variables (such as those defined with AddVar()) must be added by the caller to the start of the code string and initialized with default values.
It is advisable to add braces around these declarations and the generated code so as to avoid naming conflicts.

Parameters

[in]	resultVariableName	The name of the variable in the shade code to which the result will be assigned.
[out]	result	The generated shader code.

Returns: true if successful, otherwise false.

◆ GenerateShaderCodeFromCache()

Bool GenerateShaderCodeFromCache	(	const ParserCache *	pdat,
		const maxon::String &	resultVariableName,
		maxon::String *	result
	)

Returns an OpenGL Shading Language representation of the parsed expression.

Since: R17.032

Warning: Knowledge of the OpenGL Shading Language is required for correct use of this function.

Note: The generated OpenGL shader code assigns the result of the expression to a float variable with the given name (it must be a valid GLSL identifier).
Each expression variable name is converted to upper case before being inserted into the shader code.
Variable names with spaces are not supported and must be valid GLSL identifiers.
Declarations of these expression variables (such as those defined with AddVar()) must be added by the caller to the start of the code string and initialized with default values.
It is advisable to add braces around these declarations and the generated code so as to avoid naming conflicts.

Parameters

[in]	pdat	A parser cache.
[in]	resultVariableName	The name of the variable in the shade code to which the result will be assigned.
[out]	result	The generated shader code.

Returns: true if successful, otherwise false.

Detailed Description

Public Member Functions

Static Public Member Functions

Private Member Functions

Shader Code Generation

Constructor & Destructor Documentation

◆ Parser()

◆ ~Parser()

Member Function Documentation

◆ Alloc()

◆ Free()

◆ Eval()

◆ EvalLong()

◆ AddVar()

◆ RemoveVar()

◆ RemoveAllVars()

◆ GetParserData()

◆ Init()

◆ ReEval()

◆ Calculate()

◆ AddVarLong()

◆ ReEvalLong()

◆ CalculateLong()

◆ Reset()

◆ GenerateShaderCode()

◆ GenerateShaderCodeFromCache()