//
// Copyright (c) 2008-2017 the Urho3D project.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//

#include "../../Precompiled.h"

#include "../../Graphics/Graphics.h"
#include "../../Graphics/GraphicsImpl.h"
#include "../../Graphics/ShaderVariation.h"
#include "../../Graphics/VertexBuffer.h"
#include "../../Graphics/VertexDeclaration.h"
#include "../../IO/Log.h"

#include "../../DebugNew.h"

namespace Atomic
{

static const DXGI_FORMAT d3dElementFormats[] =
{
    DXGI_FORMAT_R32_SINT,
    DXGI_FORMAT_R32_FLOAT,
    DXGI_FORMAT_R32G32_FLOAT,
    DXGI_FORMAT_R32G32B32_FLOAT,
    DXGI_FORMAT_R32G32B32A32_FLOAT,
    DXGI_FORMAT_R8G8B8A8_UINT,
    DXGI_FORMAT_R8G8B8A8_UNORM
};

VertexDeclaration::VertexDeclaration(Graphics* graphics, ShaderVariation* vertexShader, VertexBuffer** vertexBuffers) :
    inputLayout_(0)
{
    PODVector<D3D11_INPUT_ELEMENT_DESC> elementDescs;
    unsigned prevBufferDescs = 0;

    for (unsigned i = 0; i < MAX_VERTEX_STREAMS; ++i)
    {
        if (!vertexBuffers[i])
            continue;

        const PODVector<VertexElement>& srcElements = vertexBuffers[i]->GetElements();
        bool isExisting = false;

        for (unsigned j = 0; j < srcElements.Size(); ++j)
        {
            const VertexElement& srcElement = srcElements[j];
            const char* semanticName = ShaderVariation::elementSemanticNames[srcElement.semantic_];

            // Override existing element if necessary
            for (unsigned k = 0; k < prevBufferDescs; ++k)
            {
                if (elementDescs[k].SemanticName == semanticName && elementDescs[k].SemanticIndex == srcElement.index_)
                {
                    isExisting = true;
                    elementDescs[k].InputSlot = i;
                    elementDescs[k].AlignedByteOffset = srcElement.offset_;
                    elementDescs[k].InputSlotClass = srcElement.perInstance_ ? D3D11_INPUT_PER_INSTANCE_DATA : D3D11_INPUT_PER_VERTEX_DATA;
                    elementDescs[k].InstanceDataStepRate = srcElement.perInstance_ ? 1 : 0;
                    break;
                }
            }

            if (isExisting)
                continue;

            D3D11_INPUT_ELEMENT_DESC newDesc;
            newDesc.SemanticName = semanticName;
            newDesc.SemanticIndex = srcElement.index_;
            newDesc.Format = d3dElementFormats[srcElement.type_];
            newDesc.InputSlot = (UINT)i;
            newDesc.AlignedByteOffset = srcElement.offset_;
            newDesc.InputSlotClass = srcElement.perInstance_ ? D3D11_INPUT_PER_INSTANCE_DATA : D3D11_INPUT_PER_VERTEX_DATA;
            newDesc.InstanceDataStepRate = srcElement.perInstance_ ? 1 : 0;
            elementDescs.Push(newDesc);
        }

        prevBufferDescs = elementDescs.Size();
    }

    if (elementDescs.Empty())
        return;

    const PODVector<unsigned char>& byteCode = vertexShader->GetByteCode();

    HRESULT hr = graphics->GetImpl()->GetDevice()->CreateInputLayout(&elementDescs[0], (UINT)elementDescs.Size(), &byteCode[0],
        byteCode.Size(), (ID3D11InputLayout**)&inputLayout_);
    if (FAILED(hr))
    {
        ATOMIC_SAFE_RELEASE(inputLayout_);
        ATOMIC_LOGERRORF("Failed to create input layout for shader %s due to missing vertex element(s) (HRESULT %x)",
            vertexShader->GetFullName().CString(), (unsigned)hr);
    }
}

VertexDeclaration::~VertexDeclaration()
{
    ATOMIC_SAFE_RELEASE(inputLayout_);
}

}