HStreamFileToolkit

Fields

AUTOMATIC
RETAIN_AS_IS
FLOAT_IF_SAFE
FORCE_FLOAT
FORCE_DOUBLE
ATTRIBUTES
GEOMETRY
char const ** m_search_strings

Detailed Description

class HStreamFileToolkit : public BStreamFileToolkit

The HStreamFileToolkit class provides support for exporting/importing HOOPS Stream File information from/to a HOOPS/3dGS scene-graph.

The HSF file reading process involves reading the opcode at the start of each piece of binary information, and calling the Read method of the associated opcode handler. After the opcode handler reports that reading is complete, the Execute method should be called. The ParseBuffer method of the BStreamFileToolkit object encapsulates this process.

The HSF file writing process involves determining the proper opcode for each piece of binary information, and calling the Interpret method of the associated opcode handler. After interpretation is complete, the Write method of the opcode handler should be called until writing is complete. The GenerateBuffer method of the HStreamFileToolkit encapsualetes this process.

This class provides a HOOPS/3dGS-specific implementation of the BStreamFileToolkit object. It has HOOPS/3dGS-specific opcode handlers registered with it (of the naming convention HTK_XXX). These opcode handlers overload the following two methods of the base opcode handler:

  • Interpret : this method will query the HOOPS/3dGS scene-graph (meaning, extract the graphics data); the data will then be written out to an HSF via the Write method
  • Execute : this method will map the HSF data to custom data structures after it has been read in from the HSF file via the Read method

Public Types

enum DoubleMode

Values:

enumerator AUTOMATIC

handling choice is left to the importer

enumerator RETAIN_AS_IS

data is kept in the format from the file

enumerator FLOAT_IF_SAFE

data is converted to float if it appears safe, otherwise it is retained as double

enumerator FORCE_FLOAT

data is forced to single-precision

enumerator FORCE_DOUBLE

data is forced to double-precision

enum DoubleAdded

Values:

enumerator ATTRIBUTES
enumerator GEOMETRY

Public Functions

HStreamFileToolkit()

Default constructor for an HStreamFileToolkit object

~HStreamFileToolkit()
virtual void Restart()

Initializes the file toolkit. This is useful if a single toolkit object is to be used for dealing with different files, rather than deleting the current toolkit object and creating a new instance. Call this function after processing of the current file is complete.

TK_Status GenerateBuffer(char *b, int s, int &f, char const *start_segment = 0)

Traverses the HOOPS database beginning at the currently open segment and calls the Interpret method of the opcode handler associated with each object encountered. The Interpret methods of the default object handlers query the HOOPS database to obtain segment, geometry and attribute information. After interpretation is complete, GenerateBuffer continually calls the Write method of the opcode handler until writing is complete. The Write methods of the default handlers convert the HOOPS database information into a specific binary format.

A HOOPS segment must currently be open before calling GenerateBuffer, or a segment name must be given.

If the buffer being generated ends in the middle of an object, it will be saved along with any HOOPS database state information and the next buffer will be appended to it.

Parameters:
  • b – A character pointer. Returned to user.
  • s – An integer denoting the length of the buffer in bytes.
  • f – An integer denoting the length of the buffer that was written back, in bytes.
  • start_segment – Explicit name of a hoops segment to process (currently open segment if null)
Returns:

The result of the function call.

TK_Status GenerateOneItemBuffer(char *b, int s, int &f, HC_KEY item)

This method is similar to GenerateBuffer. However, instead of traversing the HOOPS database beginning at the currently open segment, only the item specified will be processed.

If the buffer being generated ends in the middle of an object, it will be saved along with any HOOPS database state information and the next buffer will be appended to it.

Parameters:
  • b – A character pointer. Returned to user.
  • s – An integer denoting the length of the buffer in bytes.
  • f – An integer denoting the length of the buffer that was written back, in bytes.
  • item – Key of the single segment or piece of geometry to process.
Returns:

The result of the function call.

unsigned POINTER_SIZED_INT CountObjects (char const *start_segment=0)

Traverses the HOOPS database beginning at the currently open segment and estimates the number of objects that will be written by a matching call (or series of calls) to GenerateBuffer()

A HOOPS/3dGS segment must currently be open before calling CountObjects, or a segment must be specified.

Parameters:start_segment – Explicit name of a Hoops segment to process (current segment if null).
Returns:The result of the function call.
virtual void ActivateContext(ID_Key key)

While parsing a buffer it may be necessary to keep a context. This method will be called by ParseBuffer to activate a context, and should be overloaded to provide custom context-activation.

Parameters:key – A context identifier
virtual void DeactivateContext(ID_Key key)

While parsing a buffer it may be necessary to keep a context. This method will be called by ParseBuffer to deactivate a context, and should be overloaded to provide custom context-deactivation.

Parameters:key – A context identifier
virtual void NewFileContext(ID_Key key)

While processing External_References a previously visited context will be revisited. This method will be called by the default Read_Stream_File to indicate that context should be prepared to receive content, and should be overloaded to provide custom preparation. This might include operations such as clearing out any placeholder geometry.

Parameters:key – A context identifier
inline int GetHoopsVersion()

Determines the version of HOOPS/3dGS the toolkit is using. Some features may not be present on older versions or may be handled differently or can be emulated; querying the version allows opcode handlers to adjust their behaviour accordingly.

Returns:The version times 100, for instance, version 7.15 would be returned as 715.
TK_Status StringToHandler(char const *type, BBaseOpcodeHandler **handler)

Generates clones of OpcodeHandlers to interpret geometry lists, such as those found in LODs intended primarily (but not exclusively) for internal use.

Parameters:
  • type – the string returned from HOOPS’ Find_Contents.
  • handler – the opcode handler (returned to user)
Returns:

TK_Error on failure.

TK_Status StringToOpcode(char const *type, unsigned char *opcode_out)

maps HOOPS strings to the opcodes that handle them. intended primarily (but not exclusively) for internal use.

Parameters:
  • type – the string returned from HOOPS’ Find_Contents.
  • opcode_out – the opcode (returned to user), assigned to one of the TKE_Object_Types as defined in BOpcodeEnums.h
Returns:

TK_Error on failure.

void SetThumbnail(BBaseOpcodeHandler *handler)

Registers an opcode handler which will be called by the toolkit after the header and before it gets into
other processing (and possibly compressing data). This allows the user to include a simple thumbnail image which an application might load as a preview for things like file selection.

Parameters:handler – A pointer to an BBaseOpcodeHandler object.
void SetThumbnail(int format, int width, int height, unsigned char const *data)

Generates an opcode handler preset with the provided image data which will be called by the toolkit after the header and
before it gets into other processing (and possibly compressing data). This allows the user to include a simple thumbnail image which an application might load as a preview for things like file selection.

Parameters:
  • format – format of the thumbnail. Formats are specified in TKO_Thumbnail_Formats
  • width – width of the thumbnail image
  • height – height of the thumbnail image
  • data – array of thumbnail image data
TK_Status Write_Stream_File()

Writes the file associated with the toolkit (internal utility).

Returns:The result of the function call.
void AddExcludedSegments(int count, HC_KEY const keys[])

Adds to the list of keys indicating segments to skip during write

Parameters:
  • count – the number of keys in the array
  • keys – the array of keys of segments
inline void AddExcludedSegment(HC_KEY key)

Adds one key to the list of segments to skip during write

Parameters:key – the key of one segment
bool SegmentIsExcluded(HC_KEY key) const

Determines if a particular segment key is on the exclusion list

Parameters:key – key of the segment to be checked
Returns:true if the segment is to be excluded
void ClearExcludedSegments()

Clears the list of excluded segments;

inline int GetExcludedSegmentCount() const

Gets the current number of keys of excluded segments

Returns:number of keys
inline HC_KEY const *GetExcludedSegments() const

Gets the array of keys of excluded segments

Returns:the array of keys of excluded segments
void SetPrependRootSegment(char const *segment)

Sets a segment to prepend to rooted segments well reading

Parameters:segment – name of segment
inline char const *GetPrependRootSegment()

Gets the segment to prepend to rooted segments well reading

Parameters:segment – name of segment
virtual bool MatchPreviousExRef() const

See if we can match a previous ExRef and just include the segment it generated

Returns:true if the function matched and handled the reference, false if we need to try to read the reference
inline void SetAttributePrecisionMode(int mode)

Sets the manner in which double-precision attributes (primarily modelling matrices) are handled

Parameters:mode – handling mode
inline int GetAttributePrecisionMode()

Returns the chosen the manner in which double-precision attributes (primarily modelling matrices) are handled

Returns:double-precision handling mode
inline int GetAddedDoubleTypes() const

Indicates whether double-precision data was added to the database

Returns:bitmask of types which were added as double-precision
inline void AddDoubleType(int type)

internal use

inline void record_texture_chain(char const *name)
inline bool check_one_texture(char const *geometry, char const *channel)
inline void check_diffuse_textures(char const *geometry)

Public Members

char const **m_search_strings