Extensions in Maxwell are dynamic link libraries, that are loaded on demand. They have extension Their filename end with the suffix ".<platform>.mxx", where platform can be one of win32, win64, osx or linux64, and are typically stored stored in the "extensions" folder inside Maxwell applications installation folder. They must be compiled and linked with the maxwell SDK.
All the extensions actually currently distributed in with Maxwell have been created with this same API, without tricks or shortcuts, so it shows is a good showcase of what can be achieved with it.
There are several extensions extension types that group extensions with the same functionality, and that need to implement some specific methods depending on type. All extensions types inherit from class CbaseExtension that handle the general interface with Maxwell, and the methods all that every extension must implement in order to work correctly. There are currently 3 geometry extension types that can be created, and there are plans in the future for more extension types for other different needs and not only geometry, but they are in the works and not fully supported yet.
A An extension must inherit from one of the types, implement some generic basic 3 methods for the interface, and implement the specific methods of the extension type its writingtype (it depends in every type). Also, it has to implement a couple of methods to properly register and start the extension in maxwell.
Example of a basic extension implementing generic methods.
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class CubeExampleExtension : public CgeometryLoaderExtension
{
// Macro for burocracy,bureaucracy. parametersParameters: extension name, main class in the extension, and the version number
DECLARE_EXTENSION_METHODS( "CubeExample", CubeExampleExtension, 1 )
public:
//declare internal variables for calculation, they can be public or private, itand mustshould include at least
//variables for storing extensionData values
double cubeSize;
CubeExampleExtension()
{
// create here the editable values of the extensions, they can be modified when used,
// getExtensionData returns the internal MxParamList to create new fields
// check MxParamList for all possibilities of types creation
//create parameter with Default name, default value, minimum value and maximum value
getExtensionData()->createDouble( "Cube size", 1.0, 0, 1000 );
}
~CubeExampleExtension()
{
//not needed to implement since we don't reserve memory.
}
bool initialize(initializeForRendering( Cmaxwell* pMaxwell )
{
//We must at least copy the extensionData values to internal variables, this will be called usually just one time,
//before maxwell needs it, and never during render time. All the heavy work must be done here.
getExtensionData()->getDouble( "Cube size", cubeSize );//Get the parameter value and store it before using it
return true;
}
bool loadMesh( Cmaxwell::Cobject &cube )
{
...
// CgeometryLoaderExtension method, will be explained in the corresponding chapter
...
}
bool getBoundingBox( Cvector &bmin, Cvector& bmax)
{
...
// CgeometryLoaderExtension method, will be explained in the corresponding chapter
...
}
}
extern "C" ALWAYSEXPORT int getSdkVersion()
{
return MAXWELL_SDK_VERSION;
}
extern "C" ALWAYSEXPORT int StartExtension( CextensionManager& extensionManager )
{
int i = 0;
if( extensionManager.registerGeometryLoaderExtension( new CubeExampleExtension ) ) i++;
return i;
} |