BamFile

from panda3d.core import BamFile

class BamFile

Bases:

Bases: BamEnums

The principle public interface to reading and writing Bam disk files. See also BamReader and BamWriter, the more general implementation of this class.

Bam files are most often used to store scene graphs or subgraphs, and by convention they are given filenames ending in the extension “.bam” when they are used for this purpose. However, a Bam file may store any arbitrary list of TypedWritable objects; in this more general usage, they are given filenames ending in “.boo” to differentiate them from the more common scene graph files.

Inheritance diagram

__init__()

close(): Closes the input or output stream.

property file_endian → BamEndian: Returns the endian preference indicated by the Bam file currently being read or written.

property file_stdfloat_double → bool: Returns true if the file stores all “standard” floats as 64-bit doubles, or false if they are 32-bit floats.

get_current_major_ver() → int: Returns the system current major version number. This is the version number that will be assigned to any generated Bam files.

get_current_minor_ver() → int: Returns the system current minor version number. This is the version number that will be assigned to any generated Bam files.

get_file_endian() → BamEndian: Returns the endian preference indicated by the Bam file currently being read or written.

get_file_major_ver() → int: Returns the major version number of the file currently being read, or the system current major version number if no file is currently open for reading.

get_file_minor_ver() → int: Returns the minor version number of the file currently being read, or the system current minor version number if no file is currently open for reading.

get_file_stdfloat_double() → bool: Returns true if the file stores all “standard” floats as 64-bit doubles, or false if they are 32-bit floats.

get_reader() → BamReader: Returns the BamReader in charge of performing the read operations. This will return NULL unless open_read() was called.

get_writer() → BamWriter: Returns the BamWriter in charge of performing the write operations. This will return NULL unless open_write() was called.

is_eof() → bool: Returns true if the reader has reached end-of-file, false otherwise. This call is only valid after a call to read_object().

is_valid_read() → bool: Returns true if the Bam file is open and ready for reading with no errors so far detected, or false otherwise.

is_valid_write() → bool: Returns true if the Bam file is open and ready for writing with no errors so far detected, or false otherwise.

open_read(bam_filename: Filename, report_errors: bool) → bool: Attempts to open the indicated filename for reading. Returns true if successful, false on error.

open_read(in: istream, bam_filename: str, report_errors: bool) → bool: Attempts to open the indicated stream for reading. The filename is just for information purposes only. Returns true if successful, false on error.

open_write(bam_filename: Filename, report_errors: bool) → bool: Attempts to open the indicated file for writing. If another file by the same name already exists, it will be silently removed. Returns true if successful, false otherwise.

open_write(out: ostream, bam_filename: str, report_errors: bool) → bool: Attempts to open the indicated stream for writing. The filename is just for information purposes only. Returns true if successful, false on error.

read_node(report_errors: bool) → PandaNode

Although the bam file format is general enough to store a list of objects of arbitrary type, bam files on disk usually contain just one object, a PandaNode that is the root of a scene graph. (Bam files that store other kinds of things are usually given the extension “boo”, for “binary other objects”, to differentiate them from the normal scene graph type file.)

This is a convenience method for when you believe you are reading a scene graph bam file. It reads the one PandaNode and returns it. It also calls resolve() to fully resolve the object, since we expect this will be the only object in the file.

If the bam file contains something other than a PandaNode, an error is printed and NULL is returned.

read_object() → TypedWritable

Reads and returns the next object from the Bam file, or NULL if the end of the file has been reached, or if there is an error condition. Use is_eof() to differentiate these two cases.

The pointers returned by this method will not be valid for use until resolve() is subsequently called.

property reader → BamReader: Returns the BamReader in charge of performing the read operations. This will return NULL unless open_read() was called.

resolve() → bool: This must be called after one or more objects have been read via calls to read_object() in order to resolve all internal pointer references in the objects read and make all the pointers valid. It returns true if all objects are successfully resolved, or false if some have not been (in which case you must call resolve() again later).

write_object(object: TypedWritable) → bool: Writes the indicated object to the Bam file. Returns true if successful, false on error.

property writer → BamWriter: Returns the BamWriter in charge of performing the write operations. This will return NULL unless open_write() was called.