APEX/apex_external_lib.C

/*
 * Copyright (c) 2026
 *      Side Effects Software Inc.  All rights reserved.
 *
 * Redistribution and use of Houdini Development Kit samples in source and
 * binary forms, with or without modification, are permitted provided that the
 * following conditions are met:
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. The name of Side Effects Software may not be used to endorse or
 *    promote products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY SIDE EFFECTS SOFTWARE `AS IS' AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
 * NO EVENT SHALL SIDE EFFECTS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

// This source file builds the plugin DSO. It combines the various node type callbacks.
// Two geometry examples are implemented in the adjacent headers.
#include "apex_opencl.h"
#include "apex_pointtransforms.h"

// UT_DSOVersion.h is needed to mark the shared library as compiled with the
// HDK. Houdini will refuse to load shared libraries built without it.
#include <UT/UT_DSOVersion.h>

#include <APEX/APEX_Include.h> 
#include <APEX/APEX_Callback.h> 
#include <APEX/APEX_CallbackPlugin.h> 
#include <APEX/APEX_Generic.h> 
#include <APEX/APEX_Registry.h> 
#include <GU/GU_AttribValueLookupTable.h>
#include <GU/GU_Detail.h>
#include <GA/GA_Names.h>
#include <GA/GA_SplittableRange.h>
#include <UT/UT_ParallelUtil.h>
#include <UT/UT_StringHolder.h>

using namespace apex;

// A small stateless callback shows the basic APEX node pattern: declare its
// typed ports, then implement the operation in operator().
class Determinant
    : public APEX_GenericFunction<Determinant, Float, const Matrix4>
{
public:
    // funcname identifies the node in APEX; argnames supplies its port labels.
    static constexpr UT_StringLit funcname = "hdk::Determinant";
    static constexpr const char *argnames[] = {"det", "matrix"};

    void operator()(Float &det, const Matrix4 &m) const
    {
        det = m.determinant();
    }
};

// ============================================================================
// Plugin DSO Entry Point
// ============================================================================
// Houdini scans apexdso/ for this symbol to register the node during startup.
// Keep callback objects alive for the lifetime of the DSO because the registry
// stores their addresses. Registering them makes their funcname values usable
// when an APEX graph is compiled.
extern "C" APEX_VISIBILITY_EXPORT
void addApexFunction(APEX_Registry &reg)
{
    using namespace apex_hdk;

    static Determinant determinant;
    static SetPointTransforms set_point_transforms;
    static GetPointTransforms get_point_transforms;
    static TranslateOpenCLGeometry translate_opencl_geometry;

    reg.addCallback(&determinant);
    reg.addCallback(&set_point_transforms);
    reg.addCallback(&get_point_transforms);
    reg.addCallback(&translate_opencl_geometry);
}