CHOP/CHOP_Spring.h

/*
 * 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.
 *
 *----------------------------------------------------------------------------
 * COMMENTS:
 *      Simulates spring-like action on an input channel.
 */

#ifndef __CHOP_Spring__
#define __CHOP_Spring__

#include <CHOP/CHOP_Realtime.h>

// First Page
#define ARG_SPR_SPRING_CONSTANT         (myParmBase + 0)
#define ARG_SPR_MASS                    (myParmBase + 1)
#define ARG_SPR_DAMPING_CONSTANT        (myParmBase + 2)
#define ARG_SPR_METHOD                  (myParmBase + 3)
#define ARG_SPR_GRAB_INITIAL            (myParmBase + 4)
#define ARG_SPR_INITIAL_DISPLACEMENT    (myParmBase + 5)
#define ARG_SPR_INITIAL_VELOCITY        (myParmBase + 6)

class UT_Interrupt;

namespace HDK_Sample {

class CHOP_Spring : public CHOP_Realtime
{
public:

    static OP_Node              *myConstructor(OP_Network  *, 
                                               const char  *,
                                               OP_Operator *);
    static OP_TemplatePair       myTemplatePair;
    static OP_VariablePair       myVariablePair;
    static PRM_Template          myTemplateList[];
    static CH_LocalVariable      myVariableList[];

    OP_ERROR                     cookMyChop(OP_Context &context) override;
    OP_ERROR                     cookMySlice(OP_Context &context,
                                             int start, int end) override;
    
    bool                         updateParmsFlags() override;

    bool                         evalVariableValue(
                                    fpreal &val, int i, int thread) override;
    // Add virtual overload that delegates to the super class to avoid
    // shadow warnings.
    bool                         evalVariableValue(
                                    UT_String &v, int i, int thread) override
                                 {
                                     return CHOP_Realtime::evalVariableValue(
                                                                v, i, thread);
                                 }

    int                          usesScope() const override
                                    { return 1; };
    int                          usesSampleMatch() const override
                                    { return 0; };
    int                          usesUnits() override
                                    { return getInput(0) ? 0 : 1; };

    int                          isSteady() const override;
    const char *                 getTimeSliceExtension() override
                                    { return "spring"; }

protected:

                                 CHOP_Spring(OP_Network  *net, 
                                             const char  *name,
                                             OP_Operator *op);
                                ~CHOP_Spring() override;
    
    ut_RealtimeData *            newRealtimeDataBlock(const char *name,
                                                      const CL_Track *track,
                                                      fpreal t) override;

private:
    
    // First Page
    int         METHOD()
                { return evalInt(ARG_SPR_METHOD, 0, 0); }

    fpreal      SPRING_CONSTANT(fpreal t)
                { return evalFloat(ARG_SPR_SPRING_CONSTANT, 0, t); }

    fpreal      MASS(fpreal t)
                { return evalFloat(ARG_SPR_MASS, 0, t); }

    void        SET_MASS(fpreal t, fpreal f)
                { setFloat(ARG_SPR_MASS, 0, t, f); }

    fpreal      DAMPING_CONSTANT(fpreal t)
                { return evalFloat(ARG_SPR_DAMPING_CONSTANT, 0, t); }

    bool        GRAB_INITIAL()
                { return (bool) evalInt(ARG_SPR_GRAB_INITIAL, 0, 0); }

    fpreal      INITIAL_DISPLACEMENT(fpreal t)
                { return evalFloat(ARG_SPR_INITIAL_DISPLACEMENT, 0, t); }

    fpreal      INITIAL_VELOCITY(fpreal t)
                { return evalFloat(ARG_SPR_INITIAL_VELOCITY, 0, t); }

    int         my_NC;
    int         my_C;
    int         myChannelDependent;
    int         mySteady;
};

} // End HDK_Sample namespace

#endif