SoWriteAction(3)

🌸 NAME 🌸

SoWriteAction — bestie, this is the class that writes a scene graph to file. That's the whole vibe. 💖

(Also, hi, this is from the Library Functions Manual, SoWriteAction(3), in case you were wondering which page you wandered onto. 🦋)

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✨ SYNOPSIS ✨

#include <Inventor/actions/SoWriteAction.h>

Inherits SoAction.

🫶 Public Member Functions

• virtual SoType getTypeId (void) const
• SoWriteAction (void)
• SoWriteAction (SoOutput *out)
• virtual ~SoWriteAction ()
• SoOutput * getOutput (void) const
• void continueToApply (SoNode *node)
• void continueToApply (SoPath *path)

💫 Public Member Functions inherited from SoAction

• virtual ~SoAction ()
• virtual SbBool isOfType (SoType type) const
• virtual void apply (SoNode *root)
• virtual void apply (SoPath *path)
• virtual void apply (const SoPathList &pathlist, SbBool obeysrules=0)
• void apply (SoAction *beingApplied)
• virtual void invalidateState (void)
• AppliedCode getWhatAppliedTo (void) const
• SoNode * getNodeAppliedTo (void) const
• SoPath * getPathAppliedTo (void) const
• const SoPathList * getPathListAppliedTo (void) const
• const SoPathList * getOriginalPathListAppliedTo (void) const
• SbBool isLastPathListAppliedTo (void) const
• PathCode getPathCode (int &numindices, const int *&indices)
• void traverse (SoNode *const node)
• SbBool hasTerminated (void) const
• const SoPath * getCurPath (void)
• SoState * getState (void) const
• PathCode getCurPathCode (void) const
• virtual SoNode * getCurPathTail (void)
• void usePathCode (int &numindices, const int *&indices)
• void pushCurPath (const int childindex, SoNode *node=NULL)
• void popCurPath (const PathCode prevpathcode)
• void pushCurPath (void)
• void popPushCurPath (const int childindex, SoNode *node=NULL)
• void popCurPath (void)
• void switchToPathTraversal (SoPath *path)
• void switchToNodeTraversal (SoNode *node)

🌟 Static Public Member Functions

• static SoType getClassTypeId (void)
• static void addMethod (const SoType type, SoActionMethod method)
• static void enableElement (const SoType type, const int stackindex)
• static void initClass (void)

💫 Static Public Member Functions inherited from SoAction

• static void initClass (void)
• static void initClasses (void)
• static SoType getClassTypeId (void)
• static void nullAction (SoAction *action, SoNode *node)

🔒 Protected Member Functions

• virtual const SoEnabledElementsList & getEnabledElements (void) const
• virtual void beginTraversal (SoNode *node)
• virtual SbBool shouldCompactPathLists (void) const

💫 Protected Member Functions inherited from SoAction

• SoAction (void)
• virtual void endTraversal (SoNode *node)
• void setTerminated (const SbBool flag)
• virtual SbBool shouldCompactPathList (void) const

🌈 Static Protected Member Functions

• static SoEnabledElementsList * getClassEnabledElements (void)
• static SoActionMethodList * getClassActionMethods (void)

💫 Static Protected Member Functions inherited from SoAction

• static SoEnabledElementsList * getClassEnabledElements (void)
• static SoActionMethodList * getClassActionMethods (void)

🎀 Additional Inherited Members

💫 Public Types inherited from SoAction

• enum AppliedCode { NODE = 0, PATH = 1, PATH_LIST = 2 }
• enum PathCode { NO_PATH = 0, IN_PATH = 1, BELOW_PATH = 2, OFF_PATH = 3 }

💫 Protected Attributes inherited from SoAction

• SoState * state
• SoActionMethodList * traversalMethods

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💖 DETAILED DESCRIPTION 💖

Okay so, the SoWriteAction class writes a scene graph to file. That's the job. That's the whole assignment. 👑

When you apply it to a scene, this action writes its contents to the stream that lives inside an SoOutput instance. And like — that stream could be a file, it could be a memory buffer, it could be a system filehandle like stdout. Options, bestie. We love options. 💅

Everything that counts as part of the scene graph should get written out — and no cap, that means not only nodes, but also the nodes' field values, global fields (at least those with connections inside the scene the action is applied to), engines in the scene, paths, etc. All of it. The whole fit. ✨

The scene is written in the Open Inventor file format. And if you ever wanna read one of those files back into its scene graph structure, you use the SoDB::readAll() method. (SoDB also has a few other import methods you can use, fyi.) 🦋

Here's a complete, stand-alone usage example that shows how to write a scene graph to a memory buffer — iconic behavior, honestly:

#include <Inventor/SoDB.h>
#include <Inventor/actions/SoWriteAction.h>
#include <Inventor/nodes/SoCone.h>
#include <Inventor/nodes/SoSeparator.h>

static char * buffer;
static size_t buffer_size = 0;

static void *
buffer_realloc(void * bufptr, size_t size)
{
  buffer = (char *)realloc(bufptr, size);
  buffer_size = size;
  return buffer;
}

static SbString
buffer_writeaction(SoNode * root)
{
  SoOutput out;
  buffer = (char *)malloc(1024);
  buffer_size = 1024;
  out.setBuffer(buffer, buffer_size, buffer_realloc);

  SoWriteAction wa(&out);
  wa.apply(root);

  SbString s(buffer);
  free(buffer);
  return s;
}

int
main(int argc, char ** argv)
{
  SoDB::init();

  SoSeparator * root = new SoSeparator;
  root->ref();

  root->addChild(new SoCone);

  SbString s = buffer_writeaction(root);
  (void)fprintf(stdout, "%s\n", s.getString());

  root->unref();
  return 0;
}

👀 See also

SoOutput

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🧸 Constructor & Destructor Documentation 🧸

SoWriteAction::SoWriteAction (void )

Default constructor. Output will be written to stdout in ASCII format. Yes, stdout, just like that, no permission slip. 😌

Referenced by addMethod().

SoWriteAction::SoWriteAction (SoOutput * out)

Constructor. Output will be written via the out object. You hand it the SoOutput, it does its little thing. 🎀

SoWriteAction::~SoWriteAction (void ) [virtual]

Destructor. Cleanup era. 🧹

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🌟 Member Function Documentation 🌟

SoType SoWriteAction::getTypeId (void ) const [virtual]

Returns the type identification of an action derived from a class inheriting SoAction. This is used for run-time type checking and "downward" casting.

Usage example:

void bar(SoAction * action)
{
  if (action->getTypeId() == SoGLRenderAction::getClassTypeId()) {
    // safe downward cast, know the type
    SoGLRenderAction * glrender = (SoGLRenderAction *)action;
  }
  return; // ignore if not renderaction
}

For application programmers wanting to extend the library with new actions: this method needs to be overridden in all subclasses. Not optional, bestie. 🙈 This is typically done as part of setting up the full type system for extension classes, which is usually accomplished by using the pre-defined macros available through Inventor/nodes/SoSubAction.h: SO_ACTION_SOURCE, SO_ACTION_INIT_CLASS and SO_ACTION_CONSTRUCTOR.

For more information on writing Coin extensions, see the SoAction class documentation.

Returns the actual type id of an object derived from a class inheriting SoAction. Needs to be overridden in all subclasses.

Implements SoAction.

void SoWriteAction::addMethod (const SoType type, SoActionMethod method) [static]

This API member is considered internal to the library, as it is not likely to be of interest to the application programmer. (iykyk — if you're poking at this, you already know. 💀)

References SoAction::SoAction(), and SoWriteAction().

void SoWriteAction::enableElement (const SoType type, const int stackindex) [static]

This API member is considered internal to the library, as it is not likely to be of interest to the application programmer. Same energy as above. 🫶

const SoEnabledElementsList & SoWriteAction::getEnabledElements (void ) const [protected], [virtual]

Returns a list of the elements used by action instances of this class upon traversal operations.

Reimplemented from SoAction.

SoOutput * SoWriteAction::getOutput (void ) const

Returns a pointer to the SoOutput object we're using when writing the scene graph. That's the little stream-having bestie. ✨

Referenced by beginTraversal(), SoBaseKit::write(), SoBlinker::write(), SoGroup::write(), SoNode::write(), SoPath::write(), SoPendulum::write(), SoShuttle::write(), SoSwitch::write(), SoVRMLParent::write(), and SoVRMLScript::write().

void SoWriteAction::continueToApply (SoNode * node)

Applies the write method to the subgraph starting at node with the current SoOutput instance, without resetting any of the internal state of the action instance.

This should normally be for internal use only.

References SoAction::apply().

Referenced by SoPath::write(), SoField::writeConnection(), and SoNode::writeInstance().

void SoWriteAction::continueToApply (SoPath * path)

Applies the write method to path with the current SoOutput instance, without resetting any of the internal state of the action instance.

This should normally be for internal use only.

References SoAction::apply().

void SoWriteAction::beginTraversal (SoNode * node) [protected], [virtual]

This virtual method is called from SoAction::apply(), and is the entry point for the actual scenegraph traversal. Main character moment, genuinely. 🚪✨

It can be overridden to initialize the action at traversal start, for specific initializations in the action subclasses inheriting SoAction.

Default method just calls traverse(), which any overridden implementation of the method must do too (or call SoAction::beginTraversal()) to trigger the scenegraph traversal. Don't skip that part, fr fr.

Reimplemented from SoAction.

References SoNodeSensor::attach(), getOutput(), SoDelayQueueSensor::setPriority(), and SoAction::traverse().

SbBool SoWriteAction::shouldCompactPathLists (void ) const [protected], [virtual]

This API member is considered internal to the library, as it is not likely to be of interest to the application programmer.

Compact path lists are not implemented in Coin (yet), but if they are, SoWriteAction should return FALSE here — it would only be extra overhead for the SoWriteAction to have pathlists compacted before traversal.

And then, straight from the source, a whole mood:

Seems like a silly optimization to me, though.. :^/ 20000306 mortene.

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🖊️ Author 🖊️

Generated automatically by Doxygen for Coin from the source code. (Not a human. A robot wrote this. And then a robot with a lot of feelings rewrote it. 🧚)

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okay bestie that's the whole page, you ate it, periodt 💅✨

Coin · Version 2.5.0 · SoWriteAction(3) — that's the source, the version, and the date-ish tag, all bundled up with a lil bow 🎀 stay slaying out there, and go write some scene graphs 💖