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#include "../osd/cpuEvalLimitController.h"
#include "../osd/cpuEvalLimitKernel.h"
#include "../far/patchTables.h"

namespace OpenSubdiv {
namespace OPENSUBDIV_VERSION {

OsdCpuEvalLimitController::OsdCpuEvalLimitController() {
}

OsdCpuEvalLimitController::~OsdCpuEvalLimitController() {
}


int 
OsdCpuEvalLimitController::_EvalLimitSample( OpenSubdiv::OsdEvalCoords const & coords, 
                                             OsdCpuEvalLimitContext const *context,
                                             unsigned int index ) {
    
    int npatches=0; 
    FarPatchTables::PatchHandle const * patchHandles;
    
    // Get the list of all children patches of the face described in coords
    if (not context->GetPatchesMap()->GetChildPatchesHandles(coords.face, &npatches, &patchHandles))
        return 0;
    
    // Position lookup pointers at the indexed vertex
    float const * inQ = context->GetInputVertexData();
    float * outQ = context->GetOutputVertexData() + index * context->GetOutputDesc().stride;
    float * outdQu = context->GetOutputVertexDataUDerivative() + index * context->GetOutputDesc().stride;
    float * outdQv = context->GetOutputVertexDataVDerivative() + index * context->GetOutputDesc().stride;

    for (int i=0; i<npatches; ++i) {
    
        FarPatchTables::PatchHandle const & handle = patchHandles[i];

        FarPatchParam::BitField bits = context->GetPatchBitFields()[ handle.serialIndex ];

        float frac;
        if (bits.NonQuadRoot()) {
            frac = 1.0f / float( 1 << (bits.GetDepth()-1) );
        } else {
            frac = 1.0f / float( 1 << bits.GetDepth() );
        }
        
        // Are the coordinates within the parametric space covered by the patch ?
        float pu = (float)bits.GetU()*frac;
        if ( (coords.u < pu) or (coords.u > pu+frac) )
            continue;
        
        float pv = (float)bits.GetV()*frac;
        if ( (coords.v < pv) or (coords.v > pv+frac) )
            continue;

        assert( handle.array < context->GetPatchArrayVector().size() );

        FarPatchTables::PatchArray const & parray = context->GetPatchArrayVector()[ handle.array ];

        unsigned int const * cvs = &context->GetControlVertices()[ parray.GetVertIndex() + handle.vertexOffset ];

        // normalize u,v coordinates
        float u = (coords.u - pu) / frac,
              v = (coords.v - pv) / frac;

        assert( (u>=0.0f) and (u<=1.0f) and (v>=0.0f) and (v<=1.0f) );

        typedef FarPatchTables::Descriptor PD;

        // Rotate u,v to compensate for transition pattern and boundary orientations
        switch( bits.GetRotation() ) {
             case 0 : break;
             case 1 : { float tmp=v; v=1.0f-u; u=tmp; } break;
             case 2 : { u=1.0f-u; v=1.0f-v; } break;
             case 3 : { float tmp=u; u=1.0f-v; v=tmp; } break;
             default:
                 assert(0);
        }

        // Based on patch type - go execute interpolation
        switch( parray.GetDescriptor().GetType() ) {

            case FarPatchTables::REGULAR  : { evalBSpline( v, u, cvs,
                                                           context->GetInputDesc(),
                                                           inQ,
                                                           context->GetOutputDesc(),
                                                           outQ, outdQu, outdQv);
                                              return 1; }
            
            case FarPatchTables::BOUNDARY : { evalBoundary( v, u, cvs,
                                                            context->GetInputDesc(),
                                                            inQ,
                                                            context->GetOutputDesc(),
                                                            outQ, outdQu, outdQv);
                                               return 1; }
            
            case FarPatchTables::CORNER   : { evalCorner( v, u, cvs,
                                                          context->GetInputDesc(),
                                                          inQ,
                                                          context->GetOutputDesc(),
                                                          outQ, outdQu, outdQv);
                                              return 1; }
 
            
            case FarPatchTables::GREGORY  : { evalGregory(v, u, cvs,
                                                          context->GetVertexValenceBuffer(),                             
                                                          context->GetQuadOffsetBuffer() + parray.GetQuadOffsetIndex() + handle.vertexOffset,  
                                                          context->GetMaxValence(),
                                                          context->GetInputDesc(),                                       
                                                          inQ,                                                           
                                                          context->GetOutputDesc(),                                      
                                                          outQ, outdQu, outdQv);                                         
                                              return 1; }

            case FarPatchTables::GREGORY_BOUNDARY : { 
                                              evalGregoryBoundary(v, u, cvs,
                                                                  context->GetVertexValenceBuffer(),
                                                                  context->GetQuadOffsetBuffer() + parray.GetQuadOffsetIndex() + handle.vertexOffset,
                                                                  context->GetMaxValence(),
                                                                  context->GetInputDesc(),
                                                                  inQ,
                                                                  context->GetOutputDesc(),
                                                                  outQ, outdQu, outdQv);
            
                                              return 1; }

            default:
                assert(0);
        }        
    }
    return 0;
}

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