//
//   Copyright 2015 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
//   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 "../osd/d3d11PatchTable.h"

#include <D3D11.h>
#include "../far/patchTables.h"

namespace OpenSubdiv {
namespace OPENSUBDIV_VERSION {

namespace Osd {

D3D11PatchTable::D3D11PatchTable() :
    _indexBuffer(0), _patchParamBuffer(0), _patchParamBufferSRV(0) {
}

D3D11PatchTable::~D3D11PatchTable() {
    if (_indexBuffer) _indexBuffer->Release();
    if (_patchParamBuffer) _patchParamBuffer->Release();
    if (_patchParamBufferSRV) _patchParamBufferSRV->Release();
}

D3D11PatchTable *
D3D11PatchTable::Create(Far::PatchTables const *farPatchTables,
                        ID3D11DeviceContext *pd3d11DeviceContext) {
    D3D11PatchTable *instance = new D3D11PatchTable();
    if (instance->allocate(farPatchTables, pd3d11DeviceContext))
        return instance;
    delete instance;
    return 0;
}

bool
D3D11PatchTable::allocate(Far::PatchTables const *farPatchTables,
                          ID3D11DeviceContext *pd3d11DeviceContext) {
    ID3D11Device *pd3d11Device = NULL;
    pd3d11DeviceContext->GetDevice(&pd3d11Device);
    assert(pd3d11Device);

    std::vector<int> buffer;
    std::vector<unsigned int> ppBuffer;

    // needs reserve?
    int nPatchArrays = farPatchTables->GetNumPatchArrays();

    // for each patchArray
    for (int j = 0; j < nPatchArrays; ++j) {
        PatchArray patchArray(farPatchTables->GetPatchArrayDescriptor(j),
                              farPatchTables->GetNumPatches(j),
                              (int)buffer.size(),
                              (int)ppBuffer.size()/3);
        _patchArrays.push_back(patchArray);

        // indices
        Far::ConstIndexArray indices = farPatchTables->GetPatchArrayVertices(j);
        for (int k = 0; k < indices.size(); ++k) {
            buffer.push_back(indices[k]);
        }

        // patchParams
#if 0
        // XXX: we need sharpness interface for patcharray or put sharpness
        //      into patchParam.
        Far::ConstPatchParamArray patchParams =
            farPatchTables->GetPatchParams(j);
        for (int k = 0; k < patchParams.size(); ++k) {
            float sharpness = 0.0;
            ppBuffer.push_back(patchParams[k].faceIndex);
            ppBuffer.push_back(patchParams[k].bitField.field);
            ppBuffer.push_back(*((unsigned int *)&sharpness));
        }
#else
        // XXX: workaround. GetPatchParamTable() will be deprecated though.
        Far::PatchParamTable const & patchParamTables =
            farPatchTables->GetPatchParamTable();
        std::vector<Far::Index> const &sharpnessIndexTable =
            farPatchTables->GetSharpnessIndexTable();
        int numPatches = farPatchTables->GetNumPatches(j);
        for (int k = 0; k < numPatches; ++k) {
            float sharpness = 0.0;
            int patchIndex = (int)ppBuffer.size()/3;
            if (patchIndex < (int)sharpnessIndexTable.size()) {
                int sharpnessIndex = sharpnessIndexTable[patchIndex];
                if (sharpnessIndex >= 0)
                    sharpness = farPatchTables->GetSharpnessValues()[sharpnessIndex];
            }
            ppBuffer.push_back(patchParamTables[patchIndex].faceIndex);
            ppBuffer.push_back(patchParamTables[patchIndex].bitField.field);
            ppBuffer.push_back(*((unsigned int *)&sharpness));
        }
#endif
    }

    // index buffer
    D3D11_BUFFER_DESC bd;
    ZeroMemory(&bd, sizeof(bd));
    bd.ByteWidth = (int)buffer.size() * sizeof(int);
    bd.Usage = D3D11_USAGE_DYNAMIC;
    bd.BindFlags = D3D11_BIND_INDEX_BUFFER;
    bd.CPUAccessFlags = D3D11_CPU_ACCESS_WRITE;
    bd.MiscFlags = 0;
    bd.StructureByteStride = sizeof(int);
    HRESULT hr = pd3d11Device->CreateBuffer(&bd, NULL, &_indexBuffer);
    if (FAILED(hr)) {
        return false;
    }

    D3D11_MAPPED_SUBRESOURCE mappedResource;
    hr = pd3d11DeviceContext->Map(_indexBuffer, 0,
                                  D3D11_MAP_WRITE_DISCARD, 0, &mappedResource);
    if (FAILED(hr)) {
        return false;
    }
    unsigned int * indexBuffer = (unsigned int *) mappedResource.pData;
    memcpy(indexBuffer, &buffer[0], buffer.size() * sizeof(unsigned int));

    pd3d11DeviceContext->Unmap(_indexBuffer, 0);

    // patchparam buffer
    ZeroMemory(&bd, sizeof(bd));
    bd.ByteWidth = (int)ppBuffer.size() * sizeof(int);
    bd.Usage = D3D11_USAGE_DYNAMIC;
    bd.BindFlags = D3D11_BIND_SHADER_RESOURCE;
    bd.CPUAccessFlags = D3D11_CPU_ACCESS_WRITE;
    bd.MiscFlags = 0;
    bd.StructureByteStride = sizeof(unsigned int);
    hr = pd3d11Device->CreateBuffer(&bd, NULL, &_patchParamBuffer);
    if (FAILED(hr)) {
        return false;
    }

    D3D11_SHADER_RESOURCE_VIEW_DESC srvd;
    ZeroMemory(&srvd, sizeof(srvd));
    srvd.Format = DXGI_FORMAT_R32G32B32_UINT;
    srvd.ViewDimension = D3D11_SRV_DIMENSION_BUFFER;
    srvd.Buffer.FirstElement = 0;
    srvd.Buffer.NumElements = (int)ppBuffer.size()/3;
    hr = pd3d11Device->CreateShaderResourceView(
        _patchParamBuffer, &srvd, &_patchParamBufferSRV);
    if (FAILED(hr)) {
        return false;
    }
    hr = pd3d11DeviceContext->Map(_patchParamBuffer, 0,
                                  D3D11_MAP_WRITE_DISCARD, 0, &mappedResource);
    if (FAILED(hr)) {
        return false;
    }
    unsigned int *dst = (unsigned int *) mappedResource.pData;
    memcpy(dst, &ppBuffer[0], ppBuffer.size() * sizeof(int));
    pd3d11DeviceContext->Unmap(_patchParamBuffer, 0);

    return true;
}


}  // end namespace Osd

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