DX12ClearScreenScene.cpp

#include "scene.hpp"

#include <assert.h>
#include <stdio.h>
#include <stdexcept>

#include <d3d12.h>
#include "d3dx12.h"
#include <dxgi1_4.h>
#include <wrl/client.h>

#include "util.hpp"

using Microsoft::WRL::ComPtr;

extern HWND g_hwnd;
extern int WIN_W, WIN_H;

extern ID3D12Device* g_device12;
extern IDXGIFactory4* g_factory;
extern ID3D12CommandQueue* g_command_queue;
extern ID3D12Fence* g_fence;
extern int g_fence_value;
extern HANDLE g_fence_event;
extern IDXGISwapChain3* g_swapchain;
extern ID3D12DescriptorHeap* g_rtv_heap;
extern ID3D12Resource* g_rendertargets[];
extern unsigned g_rtv_descriptor_size;
extern int g_frame_index;

void InitDeviceAndCommandQ();
void InitSwapChain();
void WaitForPreviousFrame();

void DX12ClearScreenScene::Update(float secs) {
}

void DX12ClearScreenScene::InitPipelineAndCommandList() {
  CE(g_device12->CreateCommandAllocator(D3D12_COMMAND_LIST_TYPE_DIRECT,
    IID_PPV_ARGS(&command_allocator)));

  CE(g_device12->CreateCommandList(0, D3D12_COMMAND_LIST_TYPE_DIRECT,
    command_allocator, nullptr, IID_PPV_ARGS(&command_list)));
  CE(command_list->Close());

  {
    ID3DBlob* error = nullptr;
    unsigned compile_flags = D3DCOMPILE_DEBUG | D3DCOMPILE_SKIP_OPTIMIZATION;
    D3DCompileFromFile(L"shaders/clear_screen.hlsl", nullptr, nullptr,
      "VSMain", "vs_5_0", compile_flags, 0, &VS, &error);
    if (error) printf("Error compiling VS: %s\n", (char*)(error->GetBufferPointer()));

    D3DCompileFromFile(L"shaders/clear_screen.hlsl", nullptr, nullptr,
      "PSMain", "ps_5_0", compile_flags, 0, &PS, &error);
    if (error) printf("Error compiling PS: %s\n", (char*)(error->GetBufferPointer()));
  }

  {
    CD3DX12_VERSIONED_ROOT_SIGNATURE_DESC root_sig_desc;
    root_sig_desc.Init_1_1(0, NULL, 0, NULL,
      D3D12_ROOT_SIGNATURE_FLAG_ALLOW_INPUT_ASSEMBLER_INPUT_LAYOUT);

    ComPtr<ID3DBlob> signature, error;
    HRESULT hr = D3DX12SerializeVersionedRootSignature(&root_sig_desc,
      D3D_ROOT_SIGNATURE_VERSION_1_1,
      &signature, &error);
    if (signature == nullptr) {
      printf("Could not serialize root signature: %s\n",
        (char*)(error->GetBufferPointer()));
    }

    CE(g_device12->CreateRootSignature(0, signature->GetBufferPointer(),
      signature->GetBufferSize(), IID_PPV_ARGS(&root_signature)));
    root_signature->SetName(L"Root signature");
  }

  D3D12_INPUT_ELEMENT_DESC input_element_desc[] = {
    { "POSITION", 0, DXGI_FORMAT_R32G32B32_FLOAT,  0, 0,
      D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
    { "COLOR", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, 12,
      D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
  };

  D3D12_GRAPHICS_PIPELINE_STATE_DESC pso_desc = {
    .pRootSignature = root_signature,
    .VS = CD3DX12_SHADER_BYTECODE(VS),
    .PS = CD3DX12_SHADER_BYTECODE(PS),
    .BlendState = {
      .RenderTarget = {
        {
          .BlendEnable = TRUE,
          .SrcBlend = D3D12_BLEND_SRC_ALPHA,
          .DestBlend = D3D12_BLEND_INV_SRC_ALPHA,
          .BlendOp = D3D12_BLEND_OP_ADD,
          .SrcBlendAlpha = D3D12_BLEND_SRC_ALPHA,
          .DestBlendAlpha = D3D12_BLEND_INV_SRC_ALPHA,
          .BlendOpAlpha = D3D12_BLEND_OP_ADD,
          .RenderTargetWriteMask = D3D12_COLOR_WRITE_ENABLE_ALL,
        },
      },
    },
    .RasterizerState = CD3DX12_RASTERIZER_DESC(D3D12_DEFAULT),
    .DepthStencilState = CD3DX12_DEPTH_STENCIL_DESC(D3D12_DEFAULT),
    .InputLayout = {
      input_element_desc,
      2
    },
    .PrimitiveTopologyType = D3D12_PRIMITIVE_TOPOLOGY_TYPE_TRIANGLE,
    .NumRenderTargets = 1,
    .RTVFormats = {
      DXGI_FORMAT_R8G8B8A8_UNORM,
    },
    .DSVFormat = DXGI_FORMAT_D32_FLOAT,
    .SampleDesc = {
      .Count = 1,
    },
  };

  CE(g_device12->CreateGraphicsPipelineState(&pso_desc, IID_PPV_ARGS(&pipeline_state)));
}

DX12ClearScreenScene::DX12ClearScreenScene() {
  InitPipelineAndCommandList();
}

void DX12ClearScreenScene::Render() {
  CE(command_allocator->Reset());
  CE(command_list->Reset(command_allocator, pipeline_state));
  command_list->SetGraphicsRootSignature(root_signature);

  CD3DX12_CPU_DESCRIPTOR_HANDLE handle_rtv(
    g_rtv_heap->GetCPUDescriptorHandleForHeapStart(),
    g_frame_index, g_rtv_descriptor_size);
  float bg_color[] = { 1.0f, 1.0f, 0.8f, 1.0f };
  command_list->ResourceBarrier(1, &keep(CD3DX12_RESOURCE_BARRIER::Transition(
    g_rendertargets[g_frame_index],
    D3D12_RESOURCE_STATE_PRESENT,
    D3D12_RESOURCE_STATE_RENDER_TARGET)));
  command_list->ClearRenderTargetView(handle_rtv, bg_color, 0, nullptr);
  command_list->ResourceBarrier(1, &keep(CD3DX12_RESOURCE_BARRIER::Transition(
    g_rendertargets[g_frame_index],
    D3D12_RESOURCE_STATE_RENDER_TARGET,
    D3D12_RESOURCE_STATE_PRESENT)));
  CE(command_list->Close());
  g_command_queue->ExecuteCommandLists(1,
    (ID3D12CommandList* const*)&command_list);
  CE(g_swapchain->Present(1, 0));
  WaitForPreviousFrame();
}