OpenSubdiv/opensubdiv/far/patchTableFactory.h

//
//   Copyright 2013 Pixar
//
//   Licensed under the Apache License, Version 2.0 (the "Apache License")
//   with the following modification; you may not use this file except in
//   compliance with the Apache License and the following modification to it:
//   Section 6. Trademarks. is deleted and replaced with:
//
//   6. Trademarks. This License does not grant permission to use the trade
//      names, trademarks, service marks, or product names of the Licensor
//      and its affiliates, except as required to comply with Section 4(c) of
//      the License and to reproduce the content of the NOTICE file.
//
//   You may obtain a copy of the Apache License at
//
//       http://www.apache.org/licenses/LICENSE-2.0
//
//   Unless required by applicable law or agreed to in writing, software
//   distributed under the Apache License with the above modification is
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#ifndef OPENSUBDIV3_FAR_PATCH_TABLE_FACTORY_H
#define OPENSUBDIV3_FAR_PATCH_TABLE_FACTORY_H

#include "../version.h"

#include "../far/patchTable.h"

namespace OpenSubdiv {
namespace OPENSUBDIV_VERSION {

namespace Far {

//  Forward declarations (for internal implementation purposes):
class PtexIndices;
class TopologyRefiner;

class PatchTableFactory {
public:
    //  PatchFaceTag
    //  A simple struct containing all information gathered about a face that is relevant
    //  to constructing a patch for it (some of these enums should probably be defined more
    //  as part of PatchTable)
    //
    //  Like the HbrFace<T>::AdaptiveFlags, this struct aggregates all of the face tags
    //  supporting feature adaptive refinement.  For now it is not used elsewhere and can
    //  remain local to this implementation, but we may want to move it into a header of
    //  its own if it has greater use later.
    //
    //  Note that several properties being assigned here attempt to do so given a 4-bit
    //  mask of properties at the edges or vertices of the quad.  Still not sure exactly
    //  what will be done this way, but the goal is to create lookup tables (of size 16
    //  for the 4 bits) to quickly determine was is needed, rather than iteration and
    //  branching on the edges or vertices.
    //
    struct PatchFaceTag {
    public:
        unsigned int   _isRegular       : 1;
        unsigned int   _transitionMask  : 4;
        unsigned int   _boundaryMask    : 4;
        unsigned int   _boundaryIndex   : 2;
        unsigned int   _boundaryCount   : 3;
        unsigned int   _hasBoundaryEdge : 3;
        unsigned int   _isSingleCrease  : 1;

        void clear();
        void assignBoundaryPropertiesFromEdgeMask(int boundaryEdgeMask);
        void assignBoundaryPropertiesFromVertexMask(int boundaryVertexMask);
    };
    typedef std::vector<PatchFaceTag> PatchTagVector;

    struct Options {

        enum EndCapType {
            ENDCAP_NONE = 0,             ///< no endcap
            ENDCAP_BILINEAR_BASIS,       ///< use bilinear quads (4 cp) as end-caps
            ENDCAP_BSPLINE_BASIS,        ///< use BSpline basis patches (16 cp) as end-caps
            ENDCAP_GREGORY_BASIS,        ///< use Gregory basis patches (20 cp) as end-caps
            ENDCAP_LEGACY_GREGORY        ///< use legacy (2.x) Gregory patches (4 cp + valence table) as end-caps
        };

        Options(unsigned int maxIsolation=10) :
             generateAllLevels(false),
             triangulateQuads(false),
             useSingleCreasePatch(false),
             maxIsolationLevel(maxIsolation),
             endCapType(ENDCAP_GREGORY_BASIS),
             shareEndCapPatchPoints(true),
             generateFVarTables(false),
             numFVarChannels(-1),
             fvarChannelIndices(0)
        { }

        /// \brief Get endcap patch type
        EndCapType GetEndCapType() const { return (EndCapType)endCapType; }

        /// \brief Set endcap patch type
        void SetEndCapType(EndCapType e) { endCapType = e; }

        unsigned int generateAllLevels    : 1, ///< Include levels from 'firstLevel' to 'maxLevel' (Uniform mode only)
                     triangulateQuads     : 1, ///< Triangulate 'QUADS' primitives (Uniform mode only)
                     useSingleCreasePatch : 1, ///< Use single crease patch
                     maxIsolationLevel    : 4, ///< Cap adaptive feature isolation to the given level (max. 10)

                     // end-capping
                     endCapType              : 3, ///< EndCapType
                     shareEndCapPatchPoints  : 1, ///< Share endcap patch points among adjacent endcap patches.
                                                  ///< currently only work with GregoryBasis.

                     // face-varying
                     generateFVarTables   : 1;///< Generate face-varying patch tables
        int          numFVarChannels;          ///< Number of channel indices and interpolation modes passed
        int const *  fvarChannelIndices;       ///< List containing the indices of the channels selected for the factory
    };

    /// \brief Factory constructor for PatchTable
    ///
    /// @param refiner              TopologyRefiner from which to generate patches
    ///
    /// @param options              Options controlling the creation of the table
    ///
    /// @return                     A new instance of PatchTable
    ///
    static PatchTable * Create(TopologyRefiner const & refiner,
                               Options options=Options());

private:
    //
    // Private helper structures
    //
    struct BuilderContext;

    //
    //  Methods for allocating and managing the patch table data arrays:
    //
    static PatchTable * createUniform(TopologyRefiner const & refiner,
                                      Options options);

    static PatchTable * createAdaptive(TopologyRefiner const & refiner,
                                       Options options);

    //
    //  High-level methods for identifying and populating patches associated with faces:
    //

    static bool computePatchTag(BuilderContext & context,
                                Index const levelIndex,
                                Index const faceIndex,
                                PatchTableFactory::PatchFaceTag &patchTag);

    static void identifyAdaptivePatches(BuilderContext & context);

    static void populateAdaptivePatches(BuilderContext & context,
                                        PatchTable * table);

    static void allocateVertexTables(PatchTable * table, bool hasSharpness);

    static void allocateFVarChannels(BuilderContext const & context,
                                     PatchTable * table);

    static PatchParam computePatchParam(BuilderContext const & context,
                                        int level, int face,
                                        int boundaryMask, int transitionMask);
};

} // end namespace Far

} // end namespace OPENSUBDIV_VERSION
using namespace OPENSUBDIV_VERSION;

} // end namespace OpenSubdiv


#endif /* OPENSUBDIV3_FAR_PATCH_TABLE_FACTORY_H */