samples/SOP/SOP_Star.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.
 *
 *----------------------------------------------------------------------------
 * The Star SOP
 */

#include <limits.h>
#include <UT/UT_DSOVersion.h>
#include <UT/UT_Math.h>
#include <UT/UT_Interrupt.h>
#include <GU/GU_Detail.h>
#include <GU/GU_PrimPoly.h>
#include <CH/CH_LocalVariable.h>
#include <PRM/PRM_Include.h>
#include <OP/OP_Operator.h>
#include <OP/OP_OperatorTable.h>
#include "SOP_Star.h"

using namespace HDK_Sample;

//
// Help is stored in a "wiki" style text file.  This text file should be copied
// to $HOUDINI_PATH/help/nodes/sop/star.txt
//
// See the sample_install.sh file for an example.
//


///
/// newSopOperator is the hook that Houdini grabs from this dll
/// and invokes to register the SOP.  In this case we add ourselves
/// to the specified operator table.
///
void
newSopOperator(OP_OperatorTable *table)
{
    table->addOperator(
            new OP_Operator("hdk_star",                 // Internal name
                            "Star",                     // UI name
                             SOP_Star::myConstructor,   // How to build the SOP
                             SOP_Star::myTemplateList,  // My parameters
                             0,                         // Min # of sources
                             0,                         // Max # of sources
                             SOP_Star::myVariables,     // Local variables
                             OP_FLAG_GENERATOR)         // Flag it as generator
            );
}

static PRM_Name         negativeName("nradius", "Negative Radius");
//                                   ^^^^^^^^    ^^^^^^^^^^^^^^^
//                                   internal    descriptive version

static PRM_Default      fiveDefault(5);         // Default to 5 divisions
static PRM_Default      radiiDefaults[] = {
                           PRM_Default(1),              // Outside radius
                           PRM_Default(0.3)             // Inside radius
                        };

PRM_Template
SOP_Star::myTemplateList[] = {
    PRM_Template(PRM_INT_J,     1, &PRMdivName, &fiveDefault, 0,
                                        &PRMdivision2Range),
    PRM_Template(PRM_XYZ_J,     2, &PRMradiusName, radiiDefaults),
    PRM_Template(PRM_TOGGLE,    1, &negativeName),
    PRM_Template(PRM_XYZ_J,     3, &PRMcenterName),
    PRM_Template(PRM_ORD,       1, &PRMorientName, 0, &PRMplaneMenu),
    PRM_Template()
};


// Here's how we define local variables for the SOP.
enum {
        VAR_PT,         // Point number of the star
        VAR_NPT         // Number of points in the star
};

CH_LocalVariable
SOP_Star::myVariables[] = {
    { "PT",     VAR_PT, 0 },            // The table provides a mapping
    { "NPT",    VAR_NPT, 0 },           // from text string to integer token
    { 0, 0, 0 },
};

float
SOP_Star::getVariableValue(int index, int thread)
{
    // Note that "gdp" may be null here, so we do the safe thing
    // and cache values we are interested in.
    if (myCurrPoint < 0) return 0;
    switch (index)
    {
        case VAR_PT:    return myCurrPoint;
        case VAR_NPT:   return myTotalPoints;
    }
    // Not one of our variables, must delegate to the base class.
    return SOP_Node::getVariableValue(index, thread);
}

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

SOP_Star::SOP_Star(OP_Network *net, const char *name, OP_Operator *op)
        : SOP_Node(net, name, op)
{
    myCurrPoint = -1;   // To prevent garbage values from being returned
}

SOP_Star::~SOP_Star() {}

unsigned
SOP_Star::disableParms()
{
    return 0;
}

OP_ERROR
SOP_Star::cookMySop(OP_Context &context)
{
    float                now;
    float                rad, tx, ty, tz;
    int                  divisions, plane, negradius;
    int                  xcoord, ycoord, zcoord;
    float                tmp, tinc;
    GEO_Point           *ppt;
    GU_PrimPoly         *poly;
    int                  i;
    UT_Interrupt        *boss;

    now = context.myTime;

    // Since we don't have inputs, we don't need to lock them.

    divisions  = DIVISIONS(now)*2;      // We need twice our divisions of points
    myTotalPoints = divisions;          // Set the NPT local variable value
    myCurrPoint   = 0;                  // Initialize the PT local variable

    plane      = ORIENT();
    negradius  = NEGRADIUS();
    tx         = CENTERX(now);
    ty         = CENTERY(now);
    tz         = CENTERZ(now);

    switch (plane)
    {
        case 0:         // XY Plane
                xcoord = 0;
                ycoord = 1;
                zcoord = 2;
                break;
        case 1:         // YZ Plane
                xcoord = 1;
                ycoord = 2;
                zcoord = 0;
                break;
        case 2:         // XZ Plane
                xcoord = 0;
                ycoord = 2;
                zcoord = 1;
                break;
    }

    // Check to see that there hasn't been a critical error in cooking the SOP.
    if (error() < UT_ERROR_ABORT)
    {
        boss = UTgetInterrupt();
        if (divisions < 4)
        {
            // With the range restriction we have on the divisions, this
            //  is actually impossible, but it shows how to add an error
            //  message or warning to the SOP.
            addWarning(SOP_MESSAGE, "Invalid divisions");
            divisions = 4;
        }
        gdp->clearAndDestroy();

        // Start the interrupt server
        boss->opStart("Building Star");

        // Build a polygon
        poly = GU_PrimPoly::build(gdp, divisions, GU_POLY_CLOSED);
        tinc = M_PI*2 / (float)divisions;

        // Now, set all the points of the polygon
        for (i = 0; i < divisions; i++)
        {
            // Check to see if the user has interrupted us...
            if (boss->opInterrupt())
                break;

            myCurrPoint = i;

            // Since we expect the local variables to be used in specifying
            // the radii, we have to evaluate the channels INSIDE the loop
            // through the points...

            tmp = (float)i * tinc;
            rad = (i & 1) ? XRADIUS(now) : YRADIUS(now);
            if (!negradius && rad < 0)
                rad = 0;

            ppt = poly->getVertex(i).getPt();
            ppt->getPos()(xcoord) = cos(tmp) * rad + tx;
            ppt->getPos()(ycoord) = sin(tmp) * rad + ty;
            ppt->getPos()(zcoord) = 0 + tz;
        }

        // Highlight the star which we have just generated.  This routine call
        // clears any currently highlighted geometry, and then it highlights 
        // every primitive for this SOP. 
        select(GU_SPrimitive);

        // Tell the interrupt server that we've completed
        boss->opEnd();
    }

    myCurrPoint = -1;
    return error();
}

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