SOP_PolyKnitParser.h

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/*
 * PROPRIETARY INFORMATION.  This software is proprietary to
 * Side Effects Software Inc., and is not to be reproduced,
 * transmitted, or disclosed in any way without written permission.
 *
 * NAME:        SOP Library (C++)
 *
 * COMMENTS:
 *      Parser for the PolyKnit SOP.
 *
 *      Grammar for the format:
 *      Legend:
 *              /\  - empty
 *              <?> - non-terminal
 *              #   - number
 *
 *      <S>     ->      <T0> | <Q0> | /\
 *      <T0>    ->      t###<T1> | ###<T1> | t###<Q1> | ###<Q1>
 *      <T1>    ->      #<T1> | t#<T1> | #<Q1> | t#<Q1> | /\
 *      <Q0>    ->      q####<T1> | ####<T1> | q####<Q1> | ####<Q1> | ##q##<Q1>
 *                      | #q###<T1> | #q###<Q1>
 *      <Q1>    ->      ##<Q1> | q##<Q1> | ##<T1> | q##<T1> | /\
 *
 */

#ifndef __SOP_PolyKnitParser_h__
#define __SOP_PolyKnitParser_h__

#include "SOP_API.h"
#include <UT/UT_IntArray.h>

#include <GOP/GOP_Parser.h>
#include <GU/GU_Detail.h>

// Parser tokens
#define         CHAR_TRIANGLE           't'
#define         CHAR_QUAD               'q'
#define         CHAR_META_TRIANGLE      'T'
#define         CHAR_META_QUAD          'Q'

class SOP_Node;

class SOP_API SOP_PolyKnitParser : public GOP_Parser
{
public:
     SOP_PolyKnitParser(UT_String &str, GU_Detail &gdp,
                        UT_IntArray &ptArray, UT_IntArray &typeArray);
    ~SOP_PolyKnitParser() override {}

    bool                        haveMetas() const { return myHaveMetas; }

    // Returns the token which caused the error
    const char                 *errorToken() const 
                                { return (const char *)myErrorToken; }

protected:
    void                        handleError() override;

private:
    void                        init() override;
    void                        finish() override;
    bool                        dispatch(char c) override;

    // State handlers
    void                        handleStart() override;

    void                        handleTrianglePoint();
    void                        handleQuadPoint();
    void                        handleMetaTrianglePoint();
    void                        handleMetaQuadPoint();
    void                        handlePoint(int polytype, int numpoints);

    // Updates the myCanSwitch flag based on new point count
    void                        updateCanSwitch();

    // Small method to make code a little cleaner
    void                        switchOutput(int out);

    GU_Detail                  &myGdp;
    UT_IntArray                &myPtArray;
    UT_IntArray                &myTypeArray;

    // Points seen so far in the current primitive being constructed.
    int                         myCurrentPrimPoints;    

    // Contains the current polygon type 
    int                         myCurrentPolyType;

    // Are we at a point where we can switch the poly
    bool                        myCanSwitch;

    // Flag for whether or not we have meta polys
    bool                        myHaveMetas;

    UT_String                   myErrorToken;
    int                         myErrorPoint;
};

#endif