//ClearScreenWithTexture.hlsl
Texture2D<float4> image : register(t0);
RWTexture2D<float4> screen : register(u0);
[numthreads(1, 1, 1)]
void main(uint2 DTid : SV_DispatchThreadID) {
  uint2 image_size;
  image.GetDimensions(image_size.x, image_size.y);
  [branch]
  if (DTid.x < image_size.x && DTid.y < image_size.y) {
    screen[DTid] = image[DTid];
  } else {
    //imageの範囲外をクリアするときは黒で埋める
    screen[DTid] = float4(0, 0, 0, 1);
  }
}

//ClearScreenWithSampler.hlsl
Texture2D<float4> image : register(t0);
SamplerState point_sampler : register(s0);
RWTexture2D<float4> screen : register(u0);
[numthreads(1, 1, 1)]
void main(uint2 DTid : SV_DispatchThreadID) {
  uint2 screen_size;
  screen.GetDimensions(screen_size.x, screen_size.y);
  float2 uv = (float2)DTid / (float2)screen_size;
  screen[DTid] = image.SampleLevel(point_sampler, uv, 0);
}

//ClearScreenWithSampler.hlslの一部
float2 uv = (float2)DTid / (float2)screen_size;
screen[DTid] = image.SampleLevel(point_sampler, uv, 0);

//UV座標の計算の一例
//この例ではuvの値は{0.5f, 0.5f}になる
float2 textureSize = {200.f, 100.f};
float2 texel = {100.f, 50.f};
float2 uv = texel / textureSize;

//Scene::onRender関数の一部
//テクスチャの設定
std::array<ID3D11ShaderResourceView*, 1> ppSRVs = { { this->mpImageSRV.Get(), } };
this->mpImmediateContext->CSSetShaderResources(0, static_cast<UINT>(ppSRVs.size()), ppSRVs.data());
//サンプラの設定
std::array<ID3D11SamplerState*, 1> ppSamplers = { { this->mpSampler.Get(), } };
this->mpImmediateContext->CSSetSamplers(0, static_cast<UINT>(ppSamplers.size()), ppSamplers.data());

//生成するID3D11Texture2Dの情報
D3D11_TEXTURE2D_DESC desc = {};
desc.Width = 256;
desc.Height = 128;
desc.BindFlags = D3D11_BIND_SHADER_RESOURCE;
desc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
desc.MipLevels = 1;
desc.ArraySize = 1;
desc.SampleDesc.Count = 1;
//画像データを適当に生成
//設定する値はdesc.Formatに合ったものにすること
std::vector<uint32_t> rawData;
rawData.resize(desc.Width * desc.Height);
for (auto y = 0; y < desc.Height; ++y) {
  for (auto x = 0; x < desc.Width; ++x) {
    auto index = y * desc.Width + x;
    if (index % 52 < 10) {
      rawData[index] = 0xff55ffff;
    } else {
      rawData[index] = 0xffff5555;
    }
  }
}
D3D11_SUBRESOURCE_DATA initData;
initData.pSysMem = rawData.data();
initData.SysMemPitch = sizeof(rawData[0]) * desc.Width;//1行当たりのデータ長
initData.SysMemSlicePitch = sizeof(rawData[0]) * desc.Width * desc.Height;//ここでは全体のサイズ
//テクスチャを表すID3D11Texture2Dの作成
auto hr = this->mpDevice->CreateTexture2D(&desc, &initData, this->mpTex2D.GetAddressOf());
if (FAILED(hr)) {
  throw std::runtime_error("ID3D11Textureの作成に失敗");
}
//シェーダで使うためのビュー作成
D3D11_SHADER_RESOURCE_VIEW_DESC viewDesc = {};
viewDesc.ViewDimension = D3D11_SRV_DIMENSION_TEXTURE2D;
viewDesc.Format = desc.Format;
viewDesc.Texture2D.MipLevels = desc.MipLevels;
viewDesc.Texture2D.MostDetailedMip = 0;
hr = this->mpDevice->CreateShaderResourceView(this->mpTex2D.Get(), &viewDesc, this->mpTex2DSRV.GetAddressOf());
if (FAILED(hr)) {
  throw std::runtime_error("ID3D11ShaderResourceViewの作成に失敗");
}

auto hr = this->mpDevice->CreateTexture2D(&desc, &initData, this->mpTex2D.GetAddressOf());

hr = this->mpDevice->CreateShaderResourceView(this->mpTex2D.Get(), &viewDesc, this->mpTex2DSRV.GetAddressOf());

//サンプラステートの作成
D3D11_SAMPLER_DESC desc = {};
desc.AddressU = D3D11_TEXTURE_ADDRESS_WRAP;
desc.AddressV = D3D11_TEXTURE_ADDRESS_WRAP;
desc.AddressW = D3D11_TEXTURE_ADDRESS_WRAP;
desc.Filter = D3D11_FILTER_MIN_MAG_MIP_POINT;
auto hr = this->mpDevice->CreateSamplerState(&desc, this->mpSampler.GetAddressOf());
if (FAILED(hr)) {
  throw std::runtime_error("ポイントサンプラーの作成に失敗");
}