/******************************************************************************
 * The MIT License (MIT)
 *
 * Copyright (c) 2018-2026 Baldur Karlsson
 *
 * 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 "d3d11_test.h"

RD_TEST(D3D11_Mip_Gen_RT, D3D11GraphicsTest)
{
  static constexpr const char *Description =
      "Tests rendering from one mip to another to do a downsample chain";

  std::string common = R"EOSHADER(

struct v2f
{
	float4 pos : SV_POSITION;
	float2 uv : UV;
};

)EOSHADER";

  std::string vertex = R"EOSHADER(

v2f main(uint vid : SV_VertexID)
{
	v2f OUT = (v2f)0;

	float2 positions[] = {
		float2(-1.0f,  1.0f),
		float2( 1.0f,  1.0f),
		float2(-1.0f, -1.0f),
		float2( 1.0f, -1.0f),
	};

	OUT.pos = float4(positions[vid], 0, 1);
	OUT.uv = positions[vid]*float2(1,-1)*0.5f + 0.5f;

	return OUT;
}

)EOSHADER";

  std::string pixel = R"EOSHADER(

Texture2D<float4> intex : register(t0);
SamplerState s : register(s0);

float4 main(v2f IN) : SV_Target0
{
	return intex.Sample(s, IN.uv);
}

)EOSHADER";

  int main()
  {
    // initialise, create window, create device, etc
    if(!Init())
      return 3;

    ID3DBlobPtr vsblob = Compile(common + vertex, "main", "vs_5_0");
    ID3DBlobPtr psblob = Compile(common + pixel, "main", "ps_5_0");

    ID3D11VertexShaderPtr vs = CreateVS(vsblob);
    ID3D11PixelShaderPtr ps = CreatePS(psblob);

    static const int NumMips = 8;

    ID3D11Texture2DPtr rt =
        MakeTexture(DXGI_FORMAT_R8G8B8A8_UNORM, 1024, 1024).RTV().SRV().Mips(NumMips);
    ID3D11RenderTargetViewPtr rtv[NumMips];
    ID3D11ShaderResourceViewPtr srv[NumMips];

    ID3D11SamplerStatePtr samp = MakeSampler();

    D3D11_VIEWPORT views[NumMips];

    for(int i = 0; i < NumMips; i++)
    {
      rtv[i] = MakeRTV(rt).FirstMip(i);
      srv[i] = MakeSRV(rt).FirstMip(i).NumMips(1);

      views[i] = {0.0f, 0.0f, (float)(512 >> i), (float)(512 >> i), 0.0f, 1.0f};
    }

    // fill upper mip with colour ramp
    uint32_t *ramp = new uint32_t[1024 * 1024];
    for(uint32_t i = 0; i < 1024 * 1024; i++)
    {
      float x = float(i % 1024);
      float y = float(i / 1024);
      ramp[i] = uint32_t(uint32_t(255.0f * (x / 1024.0f)) | (uint32_t(255.0f * (y / 1024.0f)) << 8) |
                         (uint32_t(255.0f * ((x + y) / 2048.0f)) << 16) | 0xff000000);
    }

    while(Running())
    {
      ClearRenderTargetView(bbRTV, {0.2f, 0.2f, 0.2f, 1.0f});
      for(int i = 0; i < NumMips; i++)
        ClearRenderTargetView(rtv[i], {0.2f, 0.2f, 0.2f, 1.0f});

      ctx->UpdateSubresource(rt, 0, NULL, ramp, 1024 * sizeof(uint32_t),
                             1024 * 1024 * sizeof(uint32_t));

      ctx->IASetPrimitiveTopology(D3D11_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP);

      ctx->VSSetShader(vs, NULL, 0);
      ctx->PSSetShader(ps, NULL, 0);

      ctx->PSSetSamplers(0, 1, &samp.GetInterfacePtr());

      // downsample chain
      for(int i = 0; i < NumMips - 1; i++)
      {
        ctx->RSSetViewports(1, &views[i]);
        ctx->OMSetRenderTargets(1, &rtv[i + 1].GetInterfacePtr(), NULL);
        ctx->PSSetShaderResources(0, 1, &srv[i].GetInterfacePtr());
        ctx->Draw(4, 0);
      }

      // now test that 'invalid' binds still get detected
      ctx->OMSetRenderTargets(1, &rtv[0].GetInterfacePtr(), NULL);
      ctx->PSSetShaderResources(0, 1, &srv[0].GetInterfacePtr());    // should bind NULL

      ctx->PSSetShaderResources(0, 1, &srv[1].GetInterfacePtr());
      ctx->OMSetRenderTargets(1, &rtv[1].GetInterfacePtr(),
                              NULL);    // should cause SRV to be unbound

      Present();
    }

    delete[] ramp;

    return 0;
  }
};

REGISTER_TEST();
