SOP/SOP_PointWave.C

/*
 * Copyright (c) 2025
 *      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.
 *
 *----------------------------------------------------------------------------
 * The PointWave SOP.  This SOP PointWaves the geometry onto a plane.
 */

#include "SOP_PointWave.h"

#include <GU/GU_Detail.h>
#include <OP/OP_Operator.h>
#include <OP/OP_AutoLockInputs.h>
#include <OP/OP_OperatorTable.h>
#include <PRM/PRM_Include.h>
#include <UT/UT_DSOVersion.h>
#include <UT/UT_Matrix3.h>
#include <UT/UT_Matrix4.h>
#include <SYS/SYS_Math.h>
#include <stddef.h>

using namespace HDK_Sample;

void
newSopOperator(OP_OperatorTable *table)
{
    table->addOperator(new OP_Operator(
        "hdk_pointwave",
        "Point Wave",
        SOP_PointWave::myConstructor,
        SOP_PointWave::myTemplateList,
        1,
        1,
        0));
}

static PRM_Name names[] = {
    PRM_Name("amp",     "Amplitude"),
    PRM_Name("phase",   "Phase"),
    PRM_Name("period",  "Period"),
};

PRM_Template
SOP_PointWave::myTemplateList[] = {
    PRM_Template(PRM_STRING,    1, &PRMgroupName, 0, &SOP_Node::pointGroupMenu,
                                0, 0, SOP_Node::getGroupSelectButton(
                                                GA_GROUP_POINT)),
    PRM_Template(PRM_FLT_J,     1, &names[0], PRMoneDefaults, 0,
                                   &PRMscaleRange),
    PRM_Template(PRM_FLT_J,     1, &names[1], PRMzeroDefaults),
    PRM_Template(PRM_FLT_J,     1, &names[2], PRMoneDefaults),
    PRM_Template(),
};


OP_Node *
SOP_PointWave::myConstructor(OP_Network *net, const char *name, OP_Operator *op)
{
    return new SOP_PointWave(net, name, op);
}

SOP_PointWave::SOP_PointWave(OP_Network *net, const char *name, OP_Operator *op)
    : SOP_Node(net, name, op), myGroup(NULL)
{
    // This indicates that this SOP manually manages its data IDs,
    // so that Houdini can identify what attributes may have changed,
    // e.g. to reduce work for the viewport, or other SOPs that
    // check whether data IDs have changed.
    // By default, (i.e. if this line weren't here), all data IDs
    // would be bumped after the SOP cook, to indicate that
    // everything might have changed.
    // If some data IDs don't get bumped properly, the viewport
    // may not update, or SOPs that check data IDs
    // may not cook correctly, so be *very* careful!
    mySopFlags.setManagesDataIDs(true);
}

SOP_PointWave::~SOP_PointWave() {}

OP_ERROR
SOP_PointWave::cookInputGroups(OP_Context &context, int alone)
{
    // The SOP_Node::cookInputPointGroups() provides a good default
    // implementation for just handling a point selection.
    return cookInputPointGroups(
        context, // This is needed for cooking the group parameter, and cooking the input if alone.
        myGroup, // The group (or NULL) is written to myGroup if not alone.
        alone,   // This is true iff called outside of cookMySop to update handles.
                 // true means the group will be for the input geometry.
                 // false means the group will be for gdp (the working/output geometry).
        true,    // (default) true means to set the selection to the group if not alone and the highlight flag is on.
        0,       // (default) Parameter index of the group field
        -1,      // (default) Parameter index of the group type field (-1 since there isn't one)
        true,    // (default) true means that a pointer to an existing group is okay; false means group is always new.
        false,   // (default) false means new groups should be unordered; true means new groups should be ordered.
        true,    // (default) true means that all new groups should be detached, so not owned by the detail;
                 //           false means that new point and primitive groups on gdp will be owned by gdp.
        0        // (default) Index of the input whose geometry the group will be made for if alone.
    );
}

OP_ERROR
SOP_PointWave::cookMySop(OP_Context &context)
{
    // We must lock our inputs before we try to access their geometry.
    // OP_AutoLockInputs will automatically unlock our inputs when we return.
    // NOTE: Don't call unlockInputs yourself when using this!
    OP_AutoLockInputs inputs(this);
    if (inputs.lock(context) >= UT_ERROR_ABORT)
        return error();

    // Duplicate our incoming geometry with the hint that we only
    // altered points.  Thus, if our input was unchanged, we can
    // easily roll back our changes by copying point values.
    duplicatePointSource(0, context);

    fpreal t = context.getTime();

    // We evaluate our parameters outside the loop for speed.  If we
    // wanted local variable support, we'd have to do more setup
    // (see SOP_Flatten) and also move these inside the loop.
    float phase = PHASE(t);
    float amp = AMP(t);
    float period = PERIOD(t);

    if (error() >= UT_ERROR_ABORT)
        return error();

    // Here we determine which groups we have to work on.  We only
    // handle point groups.
    if (cookInputGroups(context) >= UT_ERROR_ABORT)
        return error();

    GA_Offset ptoff;
    GA_FOR_ALL_GROUP_PTOFF(gdp, myGroup, ptoff)
    {
        UT_Vector3 p = gdp->getPos3(ptoff);

        p.y() += SYSsin( (p.x() / period + phase) * M_PI * 2 ) * amp;

        gdp->setPos3(ptoff, p);
    }

    // If we've modified P, and we're managing our own data IDs,
    // we must bump the data ID for P.
    if (!myGroup || !myGroup->isEmpty())
        gdp->getP()->bumpDataId();

    return error();
}