samples/expr/channel.C

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/*
 * Copyright (c) 2012
 *      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.
 *
 *----------------------------------------------------------------------------
 */

#include <string.h>
#include <malloc.h>
#include <math.h>
#include <UT/UT_DSOVersion.h>
#include <EXPR/EXPR.h>
#include <OP/OP_Director.h>
#include <CH/CH_Support.h>
#include <CH/CH_Collection.h>
#include <CMD/CMD_Manager.h>


static void
getTimeValues(int thread,
              float &t, float &t0, float &t1, float &v0, float &v1,
              float *m0=0, float *m1=0, float *a0=0, float *a1=0)
{
    CH_Collection       *channels;
    channels = OPgetDirector()->getChannelManager()->getEvalCollection(thread);

    // Get the current time and the values for the function
    channels->getGlueTime(t, t0, t1, v0, v1, thread);

    // Now, get the slope & accell
    if (m0 || m1 || a0 || a1)
        channels->getGlueSlope(m0, m1, a0, a1, thread);
}

#ifndef EV_START_FNNA
#define EV_START_FNNA(name) \
            static void name(EV_FUNCTION *, EV_SYMBOL *result, \
                             EV_SYMBOL **, int thread)
#endif // EV_START_FNNA

EV_START_FNNA(fn_myLinear)
{
    float       t, t0, t1, v0, v1;
    float       dt;

    getTimeValues(thread, t, t0, t1, v0, v1);
    dt = t1 - t0;
    result->value.fval = (dt == 0) ? (v0+v1)*0.5F
                                   : v0 + (v1-v0)*(t - t0)/dt;
}

#define EVF     EV_TYPEFLOAT
#define EVS     EV_TYPESTRING
#define EVV     EV_TYPEVECTOR

//
//  These flags are important so that JIVE will display the correct handles for
//  the curve.
#define VAL_FLAGS       (CH_EXPRVALUE)
#define VALSLOPE_FLAGS  (CH_EXPRVALUE | CH_EXPRSLOPE)

static EV_FUNCTION funcTable[] = {
    EV_FUNCTION(VAL_FLAGS, "myLinear",  0, EVF, 0,      fn_myLinear),
    EV_FUNCTION(),
};

void
CMDextendLibrary(CMD_Manager *)
{
    int         i;

    for (i = 0; funcTable[i].getName(); i++)
        ev_AddFunction(&funcTable[i]);
}

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