//
//   Copyright 2014 DreamWorks Animation LLC.
//
//   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
//   distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
//   KIND, either express or implied. See the Apache License for the specific
//   language governing permissions and limitations under the Apache License.
//
#include "../sdc/type.h"
#include "../sdc/crease.h"
#include "../vtr/array.h"
#include "../vtr/refinement.h"
#include "../vtr/fvarLevel.h"

#include "../vtr/fvarRefinement.h"

#include <cassert>
#include <cstdio>
#include <cstring>
#include <algorithm>


//
//  FVarRefinement:
//      Analogous to Refinement -- retains data to facilitate refinement and
//  population of refined face-varying data channels.
//
namespace OpenSubdiv {
namespace OPENSUBDIV_VERSION {

namespace Vtr {

typedef FVarLevel::Sibling      Sibling;
typedef FVarLevel::SiblingArray SiblingArray;

//
//  Simple (for now) constructor and destructor:
//
FVarRefinement::FVarRefinement(Refinement const& refinement,
                                     FVarLevel&        parentFVarLevel,
                                     FVarLevel&        childFVarLevel) :
    _refinement(refinement),
    _parent(&parentFVarLevel),
    _child(&childFVarLevel),
    _childSiblingFromEdgeCount(0),
    _childSiblingFromVertCount(0) {
}

FVarRefinement::~FVarRefinement() {
}


//
// Methods supporting the refinement of face-varying data that has previously
// been applied to the Refinment member. So these methods already have access
// to fully refined child components.
//

void
FVarRefinement::applyRefinement() {

    //
    //  Transfer basic properties from the parent to child level:
    //
    _child->_options  = _parent->_options;
    _child->_isLinear = _parent->_isLinear;

    //
    //  It's difficult to know immediately how many child values arise from the
    //  refinement -- particularly when sparse, so we get a close upper bound,
    //  resize for that number and trim when finished:
    //
    estimateAndAllocateChildValues();
    populateChildValues();
    trimAndFinalizeChildValues();

    propagateEdgeTags();
    propagateValueTags();

    //
    //  The refined face-values are technically redundant as they can be constructed
    //  from the face-vertex siblings -- do so here as a post-process
    //
    if (_childSiblingFromEdgeCount || _childSiblingFromVertCount) {
        _child->initializeFaceValuesFromVertexFaceSiblings(_refinement._childVertFromFaceCount);
    } else {
        _child->initializeFaceValuesFromFaceVertices();
    }

    //printf("Refinement to level %d:\n", _child->getDepth());
    //_child->print();

    //printf("Validating refinement to level %d:\n", _child->getDepth());
    //_child->validate();
    //assert(_child->validate());
}

//
//  Quickly estimate the memory required for face-varying vertex-values in the child
//  and allocate them.  For uniform refinement this estimate should exactly match the
//  desired result.  For sparse refinement the excess should generally be low as the
//  sparse boundary components generally occur where face-varying data is continuous.
//
void
FVarRefinement::estimateAndAllocateChildValues() {

    int maxVertexValueCount = _refinement._childVertFromFaceCount;

    Index cVert = _refinement._childVertFromFaceCount;
    for (int i = 0; i < _refinement._childVertFromEdgeCount; ++i, ++cVert) {
        Index pEdge = _refinement.getChildVertexParentIndex(cVert);

        if ( _parent->_edgeTags[pEdge]._mismatch) {
            maxVertexValueCount += _refinement._parent->getEdgeFaces(pEdge).size();
        } else {
            maxVertexValueCount += 1;
        }
    }
    for (int i = 0; i < _refinement._childVertFromVertCount; ++i, ++cVert) {
        assert(!_refinement._childVertexTag[cVert]._incomplete);
        Index pVert = _refinement.getChildVertexParentIndex(cVert);

        if (_parent->_vertValueTags[pVert]._mismatch) {
            maxVertexValueCount += _parent->getNumVertexValues(pVert);
        } else {
            maxVertexValueCount += 1;
        }
    }

    //
    //  Now allocate/initialize for the maximum -- use resize() and trim the size later
    //  to avoid the constant growing with reserve() and incremental sizing.  We know
    //  the estimate should be close and memory wasted should be small, so initialize
    //  all to zero as well to avoid writing in all but affected areas:
    //
    //  Resize vectors that mirror the component counts:
    _child->resizeComponents();

    //  Resize the vertex-value tags in the child level:
    _child->_vertValueTags.resize(maxVertexValueCount);

    //  Resize the vertex-value "parent source" mapping in the refinement:
    _childValueParentSource.resize(maxVertexValueCount, 0);
}

void
FVarRefinement::trimAndFinalizeChildValues() {

    _child->_valueCount = _child->getNumVertices() + _childSiblingFromEdgeCount + _childSiblingFromVertCount;

    _child->_vertValueTags.resize(_child->_valueCount);

    _childValueParentSource.resize(_child->_valueCount);

    //  ? - Update vertex sibling offsets based on now-accurate sibling counts:

    //  Allocate/initialize the indices (potentially redundant after level 0):
    _child->_vertValueIndices.resize(_child->_valueCount);
    for (int i = 0; i < _child->_valueCount; ++i) {
        _child->_vertValueIndices[i] = i;
    }
}

inline int
FVarRefinement::populateChildValuesForEdgeVertex(Index cVert, Index pEdge, int siblingOffset) {

    //  If we have a boundary edge with a mismatched end vertex, we only have one
    //  value and such cases were already initialized on construction, so return:
    //
    IndexArray const pEdgeFaces = _refinement._parent->getEdgeFaces(pEdge);

    if (pEdgeFaces.size() == 1) return 0;
    assert(pEdgeFaces.size() == 2);

    //  Determine the number of sibling values for the child vertex:
    //
    IndexArray const cVertFaces = _refinement._child->getVertexFaces(cVert);

    int cSiblingCount = 0;
    if (cVertFaces.size() > 2) {
        cSiblingCount = 1;
    } else if (cVertFaces.size() == 2) {
        cSiblingCount = (cVertFaces[0] != cVertFaces[1]);
    }

    //
    //  We may have no sibling values here when the edge was discts, but only in the
    //  case where the refinement was sparse (and so the child vertex "incomplete").
    //  In such a case the source of the single value needs to be identified:
    //
    if (cSiblingCount == 0) {
        _childValueParentSource[cVert] = (cVertFaces[0] != pEdgeFaces[0]);
    } else {
        assert (cSiblingCount == 1);

        //  Update the count/offset:
        _child->_vertSiblingCounts[cVert]  = (LocalIndex) cSiblingCount;
        _child->_vertSiblingOffsets[cVert] = siblingOffset;

        //  Update the parent-source of any siblings (typically one):
        for (int j = 0; j < cSiblingCount; ++j) {
            _childValueParentSource[siblingOffset + j] = (LocalIndex) (j + 1);
        }

        //  Update the vertex-face siblings:
        SiblingArray cVertFaceSiblings = _child->getVertexFaceSiblings(cVert);
        for (int j = 0; j < cVertFaceSiblings.size(); ++j) {
            if (_refinement.getChildFaceParentFace(cVertFaces[j]) == pEdgeFaces[1]) {
                cVertFaceSiblings[j] = 1;
            }
        }
    }
    return cSiblingCount;
}

inline int
FVarRefinement::populateChildValuesForVertexVertex(Index cVert, Index pVert, int siblingOffset) {

    //
    //  We should not be getting incomplete vertex-vertices from feature-adaptive
    //  refinement (as neighboring vertices will be face-vertices or edge-vertices).
    //  This will get messy when we do (i.e. sparse refinement of Bilinear or more
    //  flexible and specific sparse refinement of Catmark) but for now assume 1-to-1.
    //
    assert(!_refinement._childVertexTag[cVert]._incomplete);

    int cSiblingCount = _parent->_vertSiblingCounts[pVert];
    if (cSiblingCount) {
        _child->_vertSiblingCounts[cVert]  = (LocalIndex) cSiblingCount;
        _child->_vertSiblingOffsets[cVert] = siblingOffset;

        // Update the parent source:
        for (int j = 0; j < cSiblingCount; ++j) {
            _childValueParentSource[siblingOffset + j] = (LocalIndex)(j + 1);
        }

        // Update the vertex-face siblings:
        SiblingArray const pVertFaceSiblings = _parent->getVertexFaceSiblings(pVert);
        SiblingArray       cVertFaceSiblings = _child->getVertexFaceSiblings(cVert);
        for (int j = 0; j < cVertFaceSiblings.size(); ++j) {
            cVertFaceSiblings[j] = pVertFaceSiblings[j];
        }
    }
    return cSiblingCount;
}

void
FVarRefinement::populateChildValues() {

    //  For values from face-vertices, they are guaranteed to be continuous, so there is
    //  nothing we need do here -- other than skipping them and starting with the first
    //  child vertex after all face vertices.
    //
    //  For values from edge-vertices and vertex-vertices, identify all associated values
    //  for those that do not have matching topology -- those that do will have been
    //  initialized appropriately on construction.
    //
    //  The "sibling offset" is an offset into the member vectors where sibling values are
    //  "located".  Every vertex has at least one value and so that value is located at the
    //  index of the vertex -- all additional values are located after the one-per-vertex.
    //
    int siblingValueOffset = _child->getNumVertices();

    Index cVert = _refinement._childVertFromFaceCount;

    for (int i = 0; i < _refinement._childVertFromEdgeCount; ++i, ++cVert) {
        Index pEdge = _refinement.getChildVertexParentIndex(cVert);
        if (_parent->_edgeTags[pEdge]._mismatch) {
            int cSiblingCount = populateChildValuesForEdgeVertex(cVert, pEdge, siblingValueOffset);

            siblingValueOffset += cSiblingCount;
            _childSiblingFromEdgeCount += cSiblingCount;
        }
    }
    for (int i = 0; i < _refinement._childVertFromVertCount; ++i, ++cVert) {
        Index pVert = _refinement.getChildVertexParentIndex(cVert);
        if (_parent->_vertValueTags[pVert]._mismatch) {
            int cSiblingCount = populateChildValuesForVertexVertex(cVert, pVert, siblingValueOffset);

            siblingValueOffset += cSiblingCount;
            _childSiblingFromVertCount += cSiblingCount;
        }
    }
}

void
FVarRefinement::propagateEdgeTags() {

    //
    //  Edge tags correspond to child edges and originate from faces or edges:
    //      Face-edges:
    //          - tag can be initialized as cts (*)
    //              * what was this comment:  "discts based on parent face-edges at ends"
    //      Edge-edges:
    //          - tag propagated from parent edge
    //          - need to modify if parent edge was discts at one end
    //              - child edge for the matching end inherits tag
    //              - child edge at the other end is doubly discts
    //
    FVarLevel::ETag eTagMatch(false);

    for (int eIndex = 0; eIndex < _refinement._childEdgeFromFaceCount; ++eIndex) {
        _child->_edgeTags[eIndex] = eTagMatch;
    }
    for (int eIndex = _refinement._childEdgeFromFaceCount; eIndex < _child->getNumEdges(); ++eIndex) {
        Index pEdge = _refinement.getChildEdgeParentIndex(eIndex);

        _child->_edgeTags[eIndex] = _parent->_edgeTags[pEdge];
    }
}

void
FVarRefinement::propagateValueTags() {

    //
    //  Value tags correspond to vertex-values and originate from all three sources:
    //      Face-values:
    //          - trivially initialized as matching
    //      Edge-values:
    //          - conditionally initialized based on parent edge continuity
    //          - should be trivial though (unlike edge-tags for the child edges)
    //      Vertex-values:
    //          - if complete, trivially propagated/inherited
    //          - if incomplete, need to map to child subset
    //
    FVarLevel::ValueTag valTagMatch(false);
    FVarLevel::ValueTag valTagMismatch(true);
    valTagMismatch._corner = true;

    Index cVert = 0;
    for (cVert = 0; cVert < _refinement._childVertFromFaceCount; ++cVert) {
        _child->_vertValueTags[cVert] = valTagMatch;
    }
    for (int i = 0; i < _refinement._childVertFromEdgeCount; ++i, ++cVert) {
        Index pEdge = _refinement.getChildVertexParentIndex(cVert);
        bool pEdgeIsSplit = _parent->_edgeTags[pEdge]._mismatch;

        FVarLevel::ValueTag const& cValueTag = pEdgeIsSplit ? valTagMismatch : valTagMatch;

        _child->_vertValueTags[cVert] = cValueTag;

        int vSiblingCount = _child->_vertSiblingCounts[cVert];
        if (vSiblingCount) {
            int cOffset = _child->_vertSiblingOffsets[cVert];
            for (int j = 0; j < vSiblingCount; ++j) {
                _child->_vertValueTags[cOffset + j] = cValueTag;
            }
        }
    }
    for (int i = 0; i < _refinement._childVertFromVertCount; ++i, ++cVert) {
        assert(!_refinement._childVertexTag[cVert]._incomplete);

        Index pVert = _refinement.getChildVertexParentIndex(cVert);

        _child->_vertValueTags[cVert] = _parent->_vertValueTags[pVert];

        int vSiblingCount = _child->_vertSiblingCounts[cVert];
        if (vSiblingCount) {
            int cOffset = _child->_vertSiblingOffsets[cVert];
            int pOffset = _parent->_vertSiblingOffsets[pVert];
            for (int j = 0; j < vSiblingCount; ++j) {
                _child->_vertValueTags[cOffset + j] = _parent->_vertValueTags[pOffset + j];
            }
        }
    }
}

} // end namespace Vtr

} // end namespace OPENSUBDIV_VERSION
} // end namespace OpenSubdiv