Examples: DirectX12: Various tidying up.

examples/imgui_impl_dx11.cpp

@@ -90,7 +90,7 @@ void ImGui_ImplDX11_RenderDrawData(ImDrawData* draw_data)
             return;
     }
 
-    // Copy and convert all vertices into a single contiguous buffer
+    // Upload vertex/index data into a single contiguous GPU buffer
     D3D11_MAPPED_SUBRESOURCE vtx_resource, idx_resource;
     if (ctx->Map(g_pVB, 0, D3D11_MAP_WRITE_DISCARD, 0, &vtx_resource) != S_OK)
         return;

examples/imgui_impl_dx12.cpp

@@ -12,6 +12,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2019-03-29: Misc: Various minor tidying up.
 //  2018-12-03: Misc: Added #pragma comment statement to automatically link with d3dcompiler.lib when using D3DCompile().
 //  2018-11-30: Misc: Setting up io.BackendRendererName so it can be displayed in the About Window.
 //  2018-06-12: DirectX12: Moved the ID3D12GraphicsCommandList* parameter from NewFrame() to RenderDrawData().
@@ -43,14 +44,14 @@ static D3D12_GPU_DESCRIPTOR_HANDLE  g_hFontSrvGpuDescHandle = {};
 
 struct FrameResources
 {
-    ID3D12Resource* IB;
-    ID3D12Resource* VB;
-    int VertexBufferSize;
-    int IndexBufferSize;
+    ID3D12Resource*     IndexBuffer;
+    ID3D12Resource*     VertexBuffer;
+    int                 IndexBufferSize;
+    int                 VertexBufferSize;
 };
-static FrameResources*              g_pFrameResources = NULL;
-static UINT                         g_numFramesInFlight = 0;
-static UINT                         g_frameIndex = UINT_MAX;
+static FrameResources*  g_pFrameResources = NULL;
+static UINT             g_numFramesInFlight = 0;
+static UINT             g_frameIndex = UINT_MAX;
 
 struct VERTEX_CONSTANT_BUFFER
 {
@@ -64,17 +65,13 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
     // FIXME: I'm assuming that this only gets called once per frame!
     // If not, we can't just re-allocate the IB or VB, we'll have to do a proper allocator.
     g_frameIndex = g_frameIndex + 1;
-    FrameResources* frameResources = &g_pFrameResources[g_frameIndex % g_numFramesInFlight];
-    ID3D12Resource* g_pVB = frameResources->VB;
-    ID3D12Resource* g_pIB = frameResources->IB;
-    int g_VertexBufferSize = frameResources->VertexBufferSize;
-    int g_IndexBufferSize = frameResources->IndexBufferSize;
+    FrameResources* fr = &g_pFrameResources[g_frameIndex % g_numFramesInFlight];
 
     // Create and grow vertex/index buffers if needed
-    if (!g_pVB || g_VertexBufferSize < draw_data->TotalVtxCount)
+    if (fr->VertexBuffer == NULL || fr->VertexBufferSize < draw_data->TotalVtxCount)
     {
-        if (g_pVB) { g_pVB->Release(); g_pVB = NULL; }
-        g_VertexBufferSize = draw_data->TotalVtxCount + 5000;
+        if (fr->VertexBuffer != NULL) { fr->VertexBuffer->Release(); fr->VertexBuffer = NULL; }
+        fr->VertexBufferSize = draw_data->TotalVtxCount + 5000;
         D3D12_HEAP_PROPERTIES props;
         memset(&props, 0, sizeof(D3D12_HEAP_PROPERTIES));
         props.Type = D3D12_HEAP_TYPE_UPLOAD;
@@ -83,7 +80,7 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
         D3D12_RESOURCE_DESC desc;
         memset(&desc, 0, sizeof(D3D12_RESOURCE_DESC));
         desc.Dimension = D3D12_RESOURCE_DIMENSION_BUFFER;
-        desc.Width = g_VertexBufferSize * sizeof(ImDrawVert);
+        desc.Width = fr->VertexBufferSize * sizeof(ImDrawVert);
         desc.Height = 1;
         desc.DepthOrArraySize = 1;
         desc.MipLevels = 1;
@@ -91,15 +88,13 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
         desc.SampleDesc.Count = 1;
         desc.Layout = D3D12_TEXTURE_LAYOUT_ROW_MAJOR;
         desc.Flags = D3D12_RESOURCE_FLAG_NONE;
-        if (g_pd3dDevice->CreateCommittedResource(&props, D3D12_HEAP_FLAG_NONE, &desc, D3D12_RESOURCE_STATE_GENERIC_READ, NULL, IID_PPV_ARGS(&g_pVB)) < 0)
+        if (g_pd3dDevice->CreateCommittedResource(&props, D3D12_HEAP_FLAG_NONE, &desc, D3D12_RESOURCE_STATE_GENERIC_READ, NULL, IID_PPV_ARGS(&fr->VertexBuffer)) < 0)
             return;
-        frameResources->VB = g_pVB;
-        frameResources->VertexBufferSize = g_VertexBufferSize;
     }
-    if (!g_pIB || g_IndexBufferSize < draw_data->TotalIdxCount)
+    if (fr->IndexBuffer == NULL || fr->IndexBufferSize < draw_data->TotalIdxCount)
     {
-        if (g_pIB) { g_pIB->Release(); g_pIB = NULL; }
-        g_IndexBufferSize = draw_data->TotalIdxCount + 10000;
+        if (fr->IndexBuffer != NULL) { fr->IndexBuffer->Release(); fr->IndexBuffer = NULL; }
+        fr->IndexBufferSize = draw_data->TotalIdxCount + 10000;
         D3D12_HEAP_PROPERTIES props;
         memset(&props, 0, sizeof(D3D12_HEAP_PROPERTIES));
         props.Type = D3D12_HEAP_TYPE_UPLOAD;
@@ -108,7 +103,7 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
         D3D12_RESOURCE_DESC desc;
         memset(&desc, 0, sizeof(D3D12_RESOURCE_DESC));
         desc.Dimension = D3D12_RESOURCE_DIMENSION_BUFFER;
-        desc.Width = g_IndexBufferSize * sizeof(ImDrawIdx);
+        desc.Width = fr->IndexBufferSize * sizeof(ImDrawIdx);
         desc.Height = 1;
         desc.DepthOrArraySize = 1;
         desc.MipLevels = 1;
@@ -116,19 +111,17 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
         desc.SampleDesc.Count = 1;
         desc.Layout = D3D12_TEXTURE_LAYOUT_ROW_MAJOR;
         desc.Flags = D3D12_RESOURCE_FLAG_NONE;
-        if (g_pd3dDevice->CreateCommittedResource(&props, D3D12_HEAP_FLAG_NONE, &desc, D3D12_RESOURCE_STATE_GENERIC_READ, NULL, IID_PPV_ARGS(&g_pIB)) < 0)
+        if (g_pd3dDevice->CreateCommittedResource(&props, D3D12_HEAP_FLAG_NONE, &desc, D3D12_RESOURCE_STATE_GENERIC_READ, NULL, IID_PPV_ARGS(&fr->IndexBuffer)) < 0)
             return;
-        frameResources->IB = g_pIB;
-        frameResources->IndexBufferSize = g_IndexBufferSize;
     }
 
-    // Copy and convert all vertices into a single contiguous buffer
+    // Upload vertex/index data into a single contiguous GPU buffer
     void* vtx_resource, *idx_resource;
     D3D12_RANGE range;
     memset(&range, 0, sizeof(D3D12_RANGE));
-    if (g_pVB->Map(0, &range, &vtx_resource) != S_OK)
+    if (fr->VertexBuffer->Map(0, &range, &vtx_resource) != S_OK)
         return;
-    if (g_pIB->Map(0, &range, &idx_resource) != S_OK)
+    if (fr->IndexBuffer->Map(0, &range, &idx_resource) != S_OK)
         return;
     ImDrawVert* vtx_dst = (ImDrawVert*)vtx_resource;
     ImDrawIdx* idx_dst = (ImDrawIdx*)idx_resource;
@@ -140,14 +133,13 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
         vtx_dst += cmd_list->VtxBuffer.Size;
         idx_dst += cmd_list->IdxBuffer.Size;
     }
-    g_pVB->Unmap(0, &range);
-    g_pIB->Unmap(0, &range);
+    fr->VertexBuffer->Unmap(0, &range);
+    fr->IndexBuffer->Unmap(0, &range);
 
     // Setup orthographic projection matrix into our constant buffer
     // Our visible imgui space lies from draw_data->DisplayPos (top left) to draw_data->DisplayPos+data_data->DisplaySize (bottom right).
     VERTEX_CONSTANT_BUFFER vertex_constant_buffer;
     {
-        VERTEX_CONSTANT_BUFFER* constant_buffer = &vertex_constant_buffer;
         float L = draw_data->DisplayPos.x;
         float R = draw_data->DisplayPos.x + draw_data->DisplaySize.x;
         float T = draw_data->DisplayPos.y;
@@ -159,7 +151,7 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
             { 0.0f,         0.0f,           0.5f,       0.0f },
             { (R+L)/(L-R),  (T+B)/(B-T),    0.5f,       1.0f },
         };
-        memcpy(&constant_buffer->mvp, mvp, sizeof(mvp));
+        memcpy(&vertex_constant_buffer.mvp, mvp, sizeof(mvp));
     }
 
     // Setup viewport
@@ -177,14 +169,14 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
     unsigned int offset = 0;
     D3D12_VERTEX_BUFFER_VIEW vbv;
     memset(&vbv, 0, sizeof(D3D12_VERTEX_BUFFER_VIEW));
-    vbv.BufferLocation = g_pVB->GetGPUVirtualAddress() + offset;
-    vbv.SizeInBytes = g_VertexBufferSize * stride;
+    vbv.BufferLocation = fr->VertexBuffer->GetGPUVirtualAddress() + offset;
+    vbv.SizeInBytes = fr->VertexBufferSize * stride;
     vbv.StrideInBytes = stride;
     ctx->IASetVertexBuffers(0, 1, &vbv);
     D3D12_INDEX_BUFFER_VIEW ibv;
     memset(&ibv, 0, sizeof(D3D12_INDEX_BUFFER_VIEW));
-    ibv.BufferLocation = g_pIB->GetGPUVirtualAddress();
-    ibv.SizeInBytes = g_IndexBufferSize * sizeof(ImDrawIdx);
+    ibv.BufferLocation = fr->IndexBuffer->GetGPUVirtualAddress();
+    ibv.SizeInBytes = fr->IndexBufferSize * sizeof(ImDrawIdx);
     ibv.Format = sizeof(ImDrawIdx) == 2 ? DXGI_FORMAT_R16_UINT : DXGI_FORMAT_R32_UINT;
     ctx->IASetIndexBuffer(&ibv);
     ctx->IASetPrimitiveTopology(D3D_PRIMITIVE_TOPOLOGY_TRIANGLELIST);
@@ -192,7 +184,7 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
     ctx->SetGraphicsRootSignature(g_pRootSignature);
     ctx->SetGraphicsRoot32BitConstants(0, 16, &vertex_constant_buffer, 0);
 
-    // Setup render state
+    // Setup blend factor
     const float blend_factor[4] = { 0.f, 0.f, 0.f, 0.f };
     ctx->OMSetBlendFactor(blend_factor);
 
@@ -208,10 +200,12 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
             const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
             if (pcmd->UserCallback)
             {
+                // User callback (registered via ImDrawList::AddCallback)
                 pcmd->UserCallback(cmd_list, pcmd);
             }
             else
             {
+                // Apply Scissor, Bind texture, Draw
                 const D3D12_RECT r = { (LONG)(pcmd->ClipRect.x - clip_off.x), (LONG)(pcmd->ClipRect.y - clip_off.y), (LONG)(pcmd->ClipRect.z - clip_off.x), (LONG)(pcmd->ClipRect.w - clip_off.y) };
                 ctx->SetGraphicsRootDescriptorTable(1, *(D3D12_GPU_DESCRIPTOR_HANDLE*)&pcmd->TextureId);
                 ctx->RSSetScissorRects(1, &r);
@@ -490,9 +484,9 @@ bool    ImGui_ImplDX12_CreateDeviceObjects()
 
         // Create the input layout
         static D3D12_INPUT_ELEMENT_DESC local_layout[] = {
-            { "POSITION", 0, DXGI_FORMAT_R32G32_FLOAT,   0, (size_t)(&((ImDrawVert*)0)->pos), D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
-            { "TEXCOORD", 0, DXGI_FORMAT_R32G32_FLOAT,   0, (size_t)(&((ImDrawVert*)0)->uv),  D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
-            { "COLOR",    0, DXGI_FORMAT_R8G8B8A8_UNORM, 0, (size_t)(&((ImDrawVert*)0)->col), D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
+            { "POSITION", 0, DXGI_FORMAT_R32G32_FLOAT,   0, IM_OFFSETOF(ImDrawVert, pos), D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
+            { "TEXCOORD", 0, DXGI_FORMAT_R32G32_FLOAT,   0, IM_OFFSETOF(ImDrawVert, uv),  D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
+            { "COLOR",    0, DXGI_FORMAT_R8G8B8A8_UNORM, 0, IM_OFFSETOF(ImDrawVert, col), D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
         };
         psoDesc.InputLayout = { local_layout, 3 };
     }
@@ -576,15 +570,17 @@ void    ImGui_ImplDX12_InvalidateDeviceObjects()
     if (!g_pd3dDevice)
         return;
 
+    ImGuiIO& io = ImGui::GetIO();
     if (g_pVertexShaderBlob) { g_pVertexShaderBlob->Release(); g_pVertexShaderBlob = NULL; }
     if (g_pPixelShaderBlob) { g_pPixelShaderBlob->Release(); g_pPixelShaderBlob = NULL; }
     if (g_pRootSignature) { g_pRootSignature->Release(); g_pRootSignature = NULL; }
     if (g_pPipelineState) { g_pPipelineState->Release(); g_pPipelineState = NULL; }
-    if (g_pFontTextureResource) { g_pFontTextureResource->Release(); g_pFontTextureResource = NULL; ImGui::GetIO().Fonts->TexID = NULL; } // We copied g_pFontTextureView to io.Fonts->TexID so let's clear that as well.
+    if (g_pFontTextureResource) { g_pFontTextureResource->Release(); g_pFontTextureResource = NULL; io.Fonts->TexID = NULL; } // We copied g_pFontTextureView to io.Fonts->TexID so let's clear that as well.
     for (UINT i = 0; i < g_numFramesInFlight; i++)
     {
-        if (g_pFrameResources[i].IB) { g_pFrameResources[i].IB->Release(); g_pFrameResources[i].IB = NULL; }
-        if (g_pFrameResources[i].VB) { g_pFrameResources[i].VB->Release(); g_pFrameResources[i].VB = NULL; }
+        FrameResources* fr = &g_pFrameResources[i];
+        if (fr->IndexBuffer)  { fr->IndexBuffer->Release();  fr->IndexBuffer = NULL; }
+        if (fr->VertexBuffer) { fr->VertexBuffer->Release(); fr->VertexBuffer = NULL; }
     }
 }
 
@@ -605,10 +601,11 @@ bool ImGui_ImplDX12_Init(ID3D12Device* device, int num_frames_in_flight, DXGI_FO
     // Create buffers with a default size (they will later be grown as needed)
     for (int i = 0; i < num_frames_in_flight; i++)
     {
-        g_pFrameResources[i].IB = NULL;
-        g_pFrameResources[i].VB = NULL;
-        g_pFrameResources[i].VertexBufferSize = 5000;
-        g_pFrameResources[i].IndexBufferSize = 10000;
+        FrameResources* fr = &g_pFrameResources[i];
+        fr->IndexBuffer = NULL;
+        fr->VertexBuffer = NULL;
+        fr->IndexBufferSize = 10000;
+        fr->VertexBufferSize = 5000;
     }
 
     return true;
@@ -618,10 +615,10 @@ void ImGui_ImplDX12_Shutdown()
 {
     ImGui_ImplDX12_InvalidateDeviceObjects();
     delete[] g_pFrameResources;
+    g_pFrameResources = NULL;
     g_pd3dDevice = NULL;
     g_hFontSrvCpuDescHandle.ptr = 0;
     g_hFontSrvGpuDescHandle.ptr = 0;
-    g_pFrameResources = NULL;
     g_numFramesInFlight = 0;
     g_frameIndex = UINT_MAX;
 }