VEX/VEX_Example.C

/*
 * Copyright (c) 2013
 *      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 is a sample VEX operator DSO
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <math.h>
#include <UT/UT_Thread.h>
#include <VEX/VEX_VexOp.h>

namespace HDK_Sample {

#if !defined(WIN32)
static void
drand_Evaluate(int, void *argv[], void *)
{
    float       *result = (float *)argv[0];
    const int   *seed = (const int *)argv[1];

    srand48(*seed);
    *result = drand48();
}
#endif

static void
time_Evaluate(int, void *argv[], void *)
{
    int         *result = (int *)argv[0];

    *result = time(0);
}

// Simple class to show shared storage.  A single gamma table is shared between
// all instances of the gamma() function.
class gamma_Table {
public:
     gamma_Table() : myRefCount(1) { }
    ~gamma_Table() { }

    float       evaluate(float v)       { return 0; }

    int         myRefCount;
};

static gamma_Table      *theGammaTable = NULL;

static void *
gamma_Init()
{

    if (!theGammaTable)
        theGammaTable = new gamma_Table();
    else
        theGammaTable->myRefCount++;
    return theGammaTable;
}

static void
gamma_Cleanup(void *data)
{
    gamma_Table *table = (gamma_Table *)data;

    UT_ASSERT(table == theGammaTable);
    table->myRefCount--;
    if (!table->myRefCount)
    {
        delete table;
        theGammaTable = NULL;
    }
}

static void
gamma_Evaluate(int, void *argv[], void *data)
{
    float       *result = (float *)argv[0];
    const float *value = (const float *)argv[1];

    gamma_Table *table = (gamma_Table *)data;
    *result = table->evaluate(*value);
}
}

//
// Installation function
//
using namespace HDK_Sample;
void
newVEXOp(void *)
{
#if !defined(WIN32)
    //  Returns a random number based on the seed argument
    new VEX_VexOp("drand@&FI",          // Signature
                drand_Evaluate,         // Evaluator
                VEX_ALL_CONTEXT,        // Context mask
                NULL,                   // init function
                NULL);                  // cleanup function
#endif

    // Return the time() function.  This is non-deterministic, so the
    // optimization level has to be lowered.
    new VEX_VexOp("time@&I",            // Signature
                time_Evaluate,          // Evaluator
                VEX_ALL_CONTEXT,        // Context mask
                NULL,                   // init function
                NULL,                   // cleanup function
                VEX_OPTIMIZE_1);        // Optimization level

    // Use the default optimization (better performance)
    new VEX_VexOp("gamma@&FF",          // Signature
                gamma_Evaluate,         // Evaluator
                VEX_ALL_CONTEXT,        // Context mask
                gamma_Init,             // init function
                gamma_Cleanup);         // Cleanup function
}