#include "DX11Texture.h"

#include "Image.h"
#ifdef WIN32
#    include <d3d11.h>
#endif

using namespace Framework;

DX11Texture::DX11Texture(ID3D11Device* device,
    ID3D11DeviceContext* context,
    Critical& deviceLock,
    TextureDirection dir)
    : Texture(dir),
      txt(0),
      view(0),
      device(device),
      context(context),
      useMips(dir == RAM_TO_GPU),
      deviceLock(deviceLock),
      readAccessTexture(0)
{}

DX11Texture::~DX11Texture()
{
#ifdef WIN32
    if (txt) txt->Release();
    if (view) view->Release();
    if (readAccessTexture) readAccessTexture->Release();
#endif
}

// Updates the texture. The pixels of the current image are copied into
// the graphics memory
bool DX11Texture::updateTextur()
{
    if (!bild) return 0;
#ifdef WIN32
    if (!txt || lastGr != bild->getSize())
    {
        if (txt) txt->Release();
        txt = 0;
        D3D11_TEXTURE2D_DESC bufferDesc;
        memset(&bufferDesc, 0, sizeof(D3D11_TEXTURE2D_DESC));
        bufferDesc.ArraySize = 1;
        bufferDesc.Width = bild->getWidth();
        bufferDesc.Height = bild->getHeight();
        bufferDesc.Format = DXGI_FORMAT_B8G8R8A8_UNORM;
        bufferDesc.BindFlags = (getDirection() == GPU_TO_RAM || useMips
                                       ? D3D11_BIND_RENDER_TARGET
                                       : 0)
                             | D3D11_BIND_SHADER_RESOURCE;
        bufferDesc.CPUAccessFlags = getDirection() == GPU_TO_RAM || useMips
                                      ? 0
                                      : D3D11_CPU_ACCESS_WRITE;
        bufferDesc.SampleDesc.Count = 1;
        bufferDesc.MipLevels = useMips ? 0 : 1;
        bufferDesc.Usage = getDirection() == GPU_TO_RAM || useMips
                             ? D3D11_USAGE_DEFAULT
                             : D3D11_USAGE_DYNAMIC;
        bufferDesc.MiscFlags = useMips ? D3D11_RESOURCE_MISC_GENERATE_MIPS : 0;
        deviceLock.lock();
        HRESULT r = device->CreateTexture2D(&bufferDesc, 0, &txt);
        deviceLock.unlock();
        if (r != S_OK) return 0;
    }
    if (getDirection() == RAM_TO_GPU && (bild->getNeedRender() || changed))
    {
        changed = 0;
        if (useMips)
        {
            deviceLock.lock();
            context->UpdateSubresource(txt,
                0,
                0,
                bild->getBuffer(),
                4 * bild->getWidth(),
                4 * bild->getWidth() * bild->getHeight());
            deviceLock.unlock();
        }
        else
        {
            D3D11_MAPPED_SUBRESOURCE buffer;
            deviceLock.lock();
            context->Map(
                txt, 0, D3D11_MAP::D3D11_MAP_WRITE_DISCARD, 0, &buffer);
            int* bgBuff = bild->getBuffer();
            int tmpBr = 4 * bild->getWidth();
            for (int y = 0, pitch = 0, bry = 0; y < bild->getHeight();
                ++y, pitch += buffer.RowPitch, bry += bild->getWidth())
            {
                memcpy(&((BYTE*)buffer.pData)[pitch],
                    (void*)&(bgBuff[bry]),
                    tmpBr);
            }
            context->Unmap(txt, 0);
            deviceLock.unlock();
        }
    }
    else if (getDirection() == GPU_TO_RAM)
    {
        if (!readAccessTexture || lastGr != bild->getSize())
        {
            if (readAccessTexture) readAccessTexture->Release();
            readAccessTexture = 0;
            D3D11_TEXTURE2D_DESC tempBufferDesc;
            memset(&tempBufferDesc, 0, sizeof(D3D11_TEXTURE2D_DESC));
            tempBufferDesc.ArraySize = 1;
            tempBufferDesc.Width = bild->getWidth();
            tempBufferDesc.Height = bild->getHeight();
            tempBufferDesc.Format = DXGI_FORMAT_B8G8R8A8_UNORM;
            tempBufferDesc.BindFlags = 0;
            tempBufferDesc.CPUAccessFlags = D3D11_CPU_ACCESS_READ;
            tempBufferDesc.SampleDesc.Count = 1;
            tempBufferDesc.MipLevels = 1;
            tempBufferDesc.Usage = D3D11_USAGE_STAGING;
            deviceLock.lock();
            HRESULT r = device->CreateTexture2D(
                &tempBufferDesc, 0, &readAccessTexture);
            deviceLock.unlock();
            if (r != S_OK) return 0;
        }
        else
        {
            deviceLock.lock();
            context->CopyResource(readAccessTexture, txt);
            deviceLock.unlock();
            D3D11_MAPPED_SUBRESOURCE buffer;
            deviceLock.lock();
            HRESULT r = context->Map(
                readAccessTexture, 0, D3D11_MAP::D3D11_MAP_READ, 0, &buffer);
            deviceLock.unlock();
            if (r != S_OK) return 0;
            int* bgBuff = bild->getBuffer();
            int tmpBr = 4 * bild->getWidth();
            for (int y = 0, pitch = 0, bry = 0; y < bild->getHeight();
                ++y, pitch += buffer.RowPitch, bry += bild->getWidth())
            {
                memcpy((void*)&(bgBuff[bry]),
                    &((BYTE*)buffer.pData)[pitch],
                    tmpBr);
            }
            for (int i = 0; i < bild->getWidth() * bild->getHeight(); i++)
            {
                if (bgBuff[i]) bgBuff[i] |= 0xFF000000;
            }
            deviceLock.lock();
            context->Unmap(readAccessTexture, 0);
            deviceLock.unlock();
        }
    }
    if (!view || lastGr != bild->getSize())
    {
        if (view) view->Release();
        view = 0;
        D3D11_SHADER_RESOURCE_VIEW_DESC resourceDesk;
        memset(&resourceDesk, 0, sizeof(D3D11_SHADER_RESOURCE_VIEW_DESC));
        resourceDesk.Format = DXGI_FORMAT_B8G8R8A8_UNORM;
        resourceDesk.ViewDimension = D3D11_SRV_DIMENSION_TEXTURE2D;
        resourceDesk.Texture2D.MipLevels = useMips ? -1 : 1;
        deviceLock.lock();
        HRESULT r = device->CreateShaderResourceView(txt, &resourceDesk, &view);
        deviceLock.unlock();
        if (r != S_OK) return 0;
        if (context && useMips)
        {
            deviceLock.lock();
            context->GenerateMips(view);
            deviceLock.unlock();
        }
    }
    lastGr = bild->getSize();
#endif
    return 1;
}

// Returns true if updateTextur needs to be called
bool DX11Texture::needsUpdate() const
{
    return !view;
}

// Returns the used shader resource view
DX11Texture::operator ID3D11ShaderResourceView*() const
{
    return view;
}

//! Returns the used texture
DX11Texture::operator ID3D11Texture2D*() const
{
    return txt;
}

//! specifies if a mip map should be generated
void DX11Texture::setUseMips(bool useMips)
{
    this->useMips = useMips;
}