add depth buffer. fix issue of viewport.

viewport.MinDepth and viewport.MaxDepth were not initialized, so they were both 0, which prevents the depth buffer from being calculated correctly.
fix this issue by explicitly specify viewport.MinDepth as 0 and viewport.MaxDepth as 1.

PracticeDx/WinMain.cpp

@@ -140,6 +140,16 @@ const ColorConstantBuffer ccb =
     }
 };
 
+// Define depth stencil buffer
+Microsoft::WRL::ComPtr<ID3D11DepthStencilState> pDepthStencilState;
+
+// Define depth stencil texture
+Microsoft::WRL::ComPtr<ID3D11Texture2D> depthStencilTexture;
+
+// Define depth stencil view
+Microsoft::WRL::ComPtr<ID3D11DepthStencilView> pDSView;
+
+
 // Define input layout
 ID3D11InputLayout* pInputLayout;
 
@@ -196,7 +206,7 @@ void DefineIndexBuffer()
     devcon->IASetIndexBuffer(pIndexBuffer.Get(), DXGI_FORMAT_R16_UINT, 0u);
 }
 
-void DefineConstantBuffer(float angle)
+void DefineConstantBuffer(float angle, float z)
 {
     cb =
     {
@@ -209,7 +219,7 @@ void DefineConstantBuffer(float angle)
             // scaling
             //* dx::XMMatrixScaling(heightWidthRatio, 1.0f, 1.0f)
             // translation
-            * dx::XMMatrixTranslation(0.0f, 0.0f, 4.0f)
+            * dx::XMMatrixTranslation(0.0f, 0.0f, z)
             // projection
             * dx::XMMatrixPerspectiveLH(1.0f, heightWidthRatio, 0.5f, 10.0f)
         )
@@ -250,6 +260,47 @@ void DefineColorConstantBuffer()
     devcon->PSSetConstantBuffers(0u, 1u, pColorConstantBuffer.GetAddressOf());
 }
 
+void DefineDepthStencilBuffer()
+{
+    // Create depth stencil state
+    D3D11_DEPTH_STENCIL_DESC depthStencilDesc = {};
+    depthStencilDesc.DepthEnable = TRUE;
+    depthStencilDesc.DepthWriteMask = D3D11_DEPTH_WRITE_MASK_ALL;
+    depthStencilDesc.DepthFunc = D3D11_COMPARISON_LESS;
+
+    // Create depth stencil state
+    dev->CreateDepthStencilState(&depthStencilDesc, &pDepthStencilState);
+
+    // bind depth state
+    devcon->OMSetDepthStencilState(pDepthStencilState.Get(), 1u);
+
+    // Create the depth stencil texture
+    D3D11_TEXTURE2D_DESC depthStencilTextureDesc = {};
+    depthStencilTextureDesc.Width = 800;
+    depthStencilTextureDesc.Height = 600;
+    depthStencilTextureDesc.MipLevels = 1u;
+    depthStencilTextureDesc.ArraySize = 1u;
+    depthStencilTextureDesc.Format = DXGI_FORMAT_D32_FLOAT;
+    depthStencilTextureDesc.SampleDesc.Count = 1u;
+    depthStencilTextureDesc.SampleDesc.Quality = 0u;
+    depthStencilTextureDesc.Usage = D3D11_USAGE_DEFAULT;
+    depthStencilTextureDesc.BindFlags = D3D11_BIND_DEPTH_STENCIL;
+
+    // Create texture
+    dev->CreateTexture2D(&depthStencilTextureDesc, nullptr, &depthStencilTexture);
+
+    // Create the depth stencil view
+    D3D11_DEPTH_STENCIL_VIEW_DESC depthStencilViewDesc = {};
+    depthStencilViewDesc.Format = DXGI_FORMAT_D32_FLOAT;
+    depthStencilViewDesc.ViewDimension = D3D11_DSV_DIMENSION_TEXTURE2D;
+    depthStencilViewDesc.Texture2D.MipSlice = 0u;
+    dev->CreateDepthStencilView(depthStencilTexture.Get(), &depthStencilViewDesc, &pDSView);
+
+    // Bind depth stencil view to out put merger
+    //devcon->OMSetRenderTargets(1u, targetView.GetAddressOf(), pDSView.Get());
+
+}
+
 void DefineInputLayout()
 {
     // Create input elements description, choosing whatever need to send to GPU
@@ -275,7 +326,7 @@ void DefineInputLayout()
     devcon->IASetInputLayout(pInputLayout);
 
     // bind render target
-    devcon->OMSetRenderTargets(1u, targetView.GetAddressOf(), nullptr);
+    //devcon->OMSetRenderTargets(1u, targetView.GetAddressOf(), nullptr);
 }
 
 void DrawPrimitive()
@@ -295,17 +346,23 @@ void DrawPrimitive()
     devcon->DrawIndexed((UINT)std::size(indices), 0u, 0u);
 }
 
-void drawTriangle()
+void drawSingleTriangle(float angle, float z)
 {
     DefineShader();
     DefineVertexBuffer();
     DefineIndexBuffer();
-    DefineConstantBuffer(timer.Peek());
+    DefineConstantBuffer(angle, z);
     DefineColorConstantBuffer();
     DefineInputLayout();
     DrawPrimitive();
 }
 
+void drawTriangle()
+{
+    drawSingleTriangle(timer.Peek(), 4.0f);
+    drawSingleTriangle(-timer.Peek(), 4.5f);
+}
+
 // this function initializes and prepares Direct3D for use
 void InitD3D(HWND hWnd)
 {
@@ -317,10 +374,10 @@ void InitD3D(HWND hWnd)
 
     // fill the swap chain description struct
     scd.BufferCount = 1;                                    // one back buffer
-    scd.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;     // use 32-bit color
+    scd.BufferDesc.Format = DXGI_FORMAT_B8G8R8A8_UNORM;     // use 32-bit color
     scd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;      // how swap chain is to be used
     scd.OutputWindow = hWnd;                                // the window to be used
-    scd.SampleDesc.Count = 4;                               // how many multisamples
+    scd.SampleDesc.Count = 1;                               // how many multisamples
     scd.Windowed = TRUE;                                    // windowed/full-screen mode
 
     // create a device, device context and swap chain using the information in the scd struct
@@ -344,8 +401,11 @@ void InitD3D(HWND hWnd)
     // 根据back buffer，创建新的View Target
     dev->CreateRenderTargetView(pBackBuffer.Get(), NULL, &targetView);
 
+    DefineDepthStencilBuffer();
+
     // 将渲染目标设置成我们新创建的View Target
-    devcon->OMSetRenderTargets(1, targetView.GetAddressOf(), NULL);
+    //devcon->OMSetRenderTargets(1u, targetView.GetAddressOf(), NULL);
+    devcon->OMSetRenderTargets(1u, targetView.GetAddressOf(), pDSView.Get());
 
     // 指定View Port
     D3D11_VIEWPORT viewport;
@@ -355,6 +415,8 @@ void InitD3D(HWND hWnd)
     viewport.TopLeftY = 0;
     viewport.Width = 800;
     viewport.Height = 600;
+    viewport.MinDepth = 0;
+    viewport.MaxDepth = 1;
 
     devcon->RSSetViewports(1, &viewport);
 }
@@ -366,6 +428,9 @@ void RenderFrame(void)
     const float color[] = { 0.0f, 0.2f, 0.4f, 1.0f };
     devcon->ClearRenderTargetView(targetView.Get(), color);
 
+    // clear the depth stencil view
+    devcon->ClearDepthStencilView(pDSView.Get(), D3D11_CLEAR_DEPTH, 1.0f, 0u);
+
     // do 3D rendering on the back buffer here
     drawTriangle();