1dynload_overview(3)                  Coin                  dynload_overview(3)
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NAME

6       dynload_overview - Dynamic Loading of Extension Nodes
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8       When Coin tries to get hold of a node type object (SoType) for a class
9       based on the name string of the node type, it will - if no such node
10       type has been initialized yet - scan the file system for a dynamically
11       loadable extension node with that given name. This can be completely
12       disabled by setting the environment variable COIN_NO_SOTYPE_DYNLOAD to
13       a positive integer value, new from Coin v2.5.0.
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15       On UNIX, extensions nodes are regular .so files. On Win32, extension
16       nodes are built as DLLs. On Mac OS X systems, extension nodes are built
17       as .dylib files. (Note: The extension nodes have to be built using the
18       flag '-dynamiclib', not '-bundle'.)
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20       Whether the dynamically loadable objects should be named with or
21       without the 'lib' prefix is optional. Both schemes will work.
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23       People don't usually program in a way so that they instantiate new
24       nodes through the node class' SoType object, but that is the way nodes
25       are created when model files are loaded. This means that for all Coin
26       applications that load model files, the custom extension nodes will
27       automatically be supported for the model files without you having to
28       modify their source code and rebuild the applications.
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30       See ftp://ftp.coin3d.org/pub/coin/src/dynloadsample.tar.gz for an
31       example using two dynamically loadable extension nodes. You only use an
32       examiner viewer to view the two extension nodes in action.
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34       Only a limited set of C++ compilers are supported as of yet. This is
35       because, to initialize the extension node, it is necessary to know
36       something about how the C++ compiler mangles the initClass symbol. If
37       we don't know that, there is no way to locate the initClass method in
38       the library, which means the extension node can not make itself known
39       to the type system.
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41       If your C++ compiler is not supported, the source file to add support
42       for a new compiler in is src/misc/cppmangle.icc. It is fairly trivial
43       to add support for new compilers, but if you don't understand how, just
44       ask us about it. Patches with support for new compilers are of course
45       very welcome.
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47       See also
48           SoType
49
50       Since
51           Coin 2.0
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53Version 2.5.0                   Wed Jan 18 2023            dynload_overview(3)
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