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1 // dear imgui: Renderer for DirectX12
2 // This needs to be used along with a Platform Binding (e.g. Win32)
3 
4 // Implemented features:
5 //  [X] Renderer: User texture binding. Use 'D3D12_GPU_DESCRIPTOR_HANDLE' as ImTextureID. Read the FAQ about ImTextureID in imgui.cpp.
6 // Issues:
7 //  [ ] 64-bit only for now! (Because sizeof(ImTextureId) == sizeof(void*)). See github.com/ocornut/imgui/pull/301
8 
9 // You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this.
10 // If you are new to dear imgui, read examples/README.txt and read the documentation at the top of imgui.cpp.
11 // https://github.com/ocornut/imgui
12 
13 // CHANGELOG
14 // (minor and older changes stripped away, please see git history for details)
15 //  2018-12-03: Misc: Added #pragma comment statement to automatically link with d3dcompiler.lib when using D3DCompile().
16 //  2018-11-30: Misc: Setting up io.BackendRendererName so it can be displayed in the About Window.
17 //  2018-06-12: DirectX12: Moved the ID3D12GraphicsCommandList* parameter from NewFrame() to RenderDrawData().
18 //  2018-06-08: Misc: Extracted imgui_impl_dx12.cpp/.h away from the old combined DX12+Win32 example.
19 //  2018-06-08: DirectX12: Use draw_data->DisplayPos and draw_data->DisplaySize to setup projection matrix and clipping rectangle (to ease support for future multi-viewport).
20 //  2018-02-22: Merged into master with all Win32 code synchronized to other examples.
21 
22 #include "imgui.h"
23 #include "imgui_impl_dx12.h"
24 
25 // DirectX
26 #include <d3d12.h>
27 #include <dxgi1_4.h>
28 #include <d3dcompiler.h>
29 #ifdef _MSC_VER
30 #pragma comment(lib, "d3dcompiler") // Automatically link with d3dcompiler.lib as we are using D3DCompile() below.
31 #endif
32 
33 // DirectX data
34 static ID3D12Device*                g_pd3dDevice = NULL;
35 static ID3D10Blob*                  g_pVertexShaderBlob = NULL;
36 static ID3D10Blob*                  g_pPixelShaderBlob = NULL;
37 static ID3D12RootSignature*         g_pRootSignature = NULL;
38 static ID3D12PipelineState*         g_pPipelineState = NULL;
39 static DXGI_FORMAT                  g_RTVFormat = DXGI_FORMAT_UNKNOWN;
40 static ID3D12Resource*              g_pFontTextureResource = NULL;
41 static D3D12_CPU_DESCRIPTOR_HANDLE  g_hFontSrvCpuDescHandle = {};
42 static D3D12_GPU_DESCRIPTOR_HANDLE  g_hFontSrvGpuDescHandle = {};
43 
44 struct FrameResources
45 {
46     ID3D12Resource* IB;
47     ID3D12Resource* VB;
48     int VertexBufferSize;
49     int IndexBufferSize;
50 };
51 static FrameResources*              g_pFrameResources = NULL;
52 static UINT                         g_numFramesInFlight = 0;
53 static UINT                         g_frameIndex = UINT_MAX;
54 
55 struct VERTEX_CONSTANT_BUFFER
56 {
57     float   mvp[4][4];
58 };
59 
60 // Render function
61 // (this used to be set in io.RenderDrawListsFn and called by ImGui::Render(), but you can now call this directly from your main loop)
ImGui_ImplDX12_RenderDrawData(ImDrawData * draw_data,ID3D12GraphicsCommandList * ctx)62 void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandList* ctx)
63 {
64     // FIXME: I'm assuming that this only gets called once per frame!
65     // If not, we can't just re-allocate the IB or VB, we'll have to do a proper allocator.
66     g_frameIndex = g_frameIndex + 1;
67     FrameResources* frameResources = &g_pFrameResources[g_frameIndex % g_numFramesInFlight];
68     ID3D12Resource* g_pVB = frameResources->VB;
69     ID3D12Resource* g_pIB = frameResources->IB;
70     int g_VertexBufferSize = frameResources->VertexBufferSize;
71     int g_IndexBufferSize = frameResources->IndexBufferSize;
72 
73     // Create and grow vertex/index buffers if needed
74     if (!g_pVB || g_VertexBufferSize < draw_data->TotalVtxCount)
75     {
76         if (g_pVB) { g_pVB->Release(); g_pVB = NULL; }
77         g_VertexBufferSize = draw_data->TotalVtxCount + 5000;
78         D3D12_HEAP_PROPERTIES props;
79         memset(&props, 0, sizeof(D3D12_HEAP_PROPERTIES));
80         props.Type = D3D12_HEAP_TYPE_UPLOAD;
81         props.CPUPageProperty = D3D12_CPU_PAGE_PROPERTY_UNKNOWN;
82         props.MemoryPoolPreference = D3D12_MEMORY_POOL_UNKNOWN;
83         D3D12_RESOURCE_DESC desc;
84         memset(&desc, 0, sizeof(D3D12_RESOURCE_DESC));
85         desc.Dimension = D3D12_RESOURCE_DIMENSION_BUFFER;
86         desc.Width = g_VertexBufferSize * sizeof(ImDrawVert);
87         desc.Height = 1;
88         desc.DepthOrArraySize = 1;
89         desc.MipLevels = 1;
90         desc.Format = DXGI_FORMAT_UNKNOWN;
91         desc.SampleDesc.Count = 1;
92         desc.Layout = D3D12_TEXTURE_LAYOUT_ROW_MAJOR;
93         desc.Flags = D3D12_RESOURCE_FLAG_NONE;
94         if (g_pd3dDevice->CreateCommittedResource(&props, D3D12_HEAP_FLAG_NONE, &desc, D3D12_RESOURCE_STATE_GENERIC_READ, NULL, IID_PPV_ARGS(&g_pVB)) < 0)
95             return;
96         frameResources->VB = g_pVB;
97         frameResources->VertexBufferSize = g_VertexBufferSize;
98     }
99     if (!g_pIB || g_IndexBufferSize < draw_data->TotalIdxCount)
100     {
101         if (g_pIB) { g_pIB->Release(); g_pIB = NULL; }
102         g_IndexBufferSize = draw_data->TotalIdxCount + 10000;
103         D3D12_HEAP_PROPERTIES props;
104         memset(&props, 0, sizeof(D3D12_HEAP_PROPERTIES));
105         props.Type = D3D12_HEAP_TYPE_UPLOAD;
106         props.CPUPageProperty = D3D12_CPU_PAGE_PROPERTY_UNKNOWN;
107         props.MemoryPoolPreference = D3D12_MEMORY_POOL_UNKNOWN;
108         D3D12_RESOURCE_DESC desc;
109         memset(&desc, 0, sizeof(D3D12_RESOURCE_DESC));
110         desc.Dimension = D3D12_RESOURCE_DIMENSION_BUFFER;
111         desc.Width = g_IndexBufferSize * sizeof(ImDrawIdx);
112         desc.Height = 1;
113         desc.DepthOrArraySize = 1;
114         desc.MipLevels = 1;
115         desc.Format = DXGI_FORMAT_UNKNOWN;
116         desc.SampleDesc.Count = 1;
117         desc.Layout = D3D12_TEXTURE_LAYOUT_ROW_MAJOR;
118         desc.Flags = D3D12_RESOURCE_FLAG_NONE;
119         if (g_pd3dDevice->CreateCommittedResource(&props, D3D12_HEAP_FLAG_NONE, &desc, D3D12_RESOURCE_STATE_GENERIC_READ, NULL, IID_PPV_ARGS(&g_pIB)) < 0)
120             return;
121         frameResources->IB = g_pIB;
122         frameResources->IndexBufferSize = g_IndexBufferSize;
123     }
124 
125     // Copy and convert all vertices into a single contiguous buffer
126     void* vtx_resource, *idx_resource;
127     D3D12_RANGE range;
128     memset(&range, 0, sizeof(D3D12_RANGE));
129     if (g_pVB->Map(0, &range, &vtx_resource) != S_OK)
130         return;
131     if (g_pIB->Map(0, &range, &idx_resource) != S_OK)
132         return;
133     ImDrawVert* vtx_dst = (ImDrawVert*)vtx_resource;
134     ImDrawIdx* idx_dst = (ImDrawIdx*)idx_resource;
135     for (int n = 0; n < draw_data->CmdListsCount; n++)
136     {
137         const ImDrawList* cmd_list = draw_data->CmdLists[n];
138         memcpy(vtx_dst, cmd_list->VtxBuffer.Data, cmd_list->VtxBuffer.Size * sizeof(ImDrawVert));
139         memcpy(idx_dst, cmd_list->IdxBuffer.Data, cmd_list->IdxBuffer.Size * sizeof(ImDrawIdx));
140         vtx_dst += cmd_list->VtxBuffer.Size;
141         idx_dst += cmd_list->IdxBuffer.Size;
142     }
143     g_pVB->Unmap(0, &range);
144     g_pIB->Unmap(0, &range);
145 
146     // Setup orthographic projection matrix into our constant buffer
147     // Our visible imgui space lies from draw_data->DisplayPos (top left) to draw_data->DisplayPos+data_data->DisplaySize (bottom right).
148     VERTEX_CONSTANT_BUFFER vertex_constant_buffer;
149     {
150         VERTEX_CONSTANT_BUFFER* constant_buffer = &vertex_constant_buffer;
151         float L = draw_data->DisplayPos.x;
152         float R = draw_data->DisplayPos.x + draw_data->DisplaySize.x;
153         float T = draw_data->DisplayPos.y;
154         float B = draw_data->DisplayPos.y + draw_data->DisplaySize.y;
155         float mvp[4][4] =
156         {
157             { 2.0f/(R-L),   0.0f,           0.0f,       0.0f },
158             { 0.0f,         2.0f/(T-B),     0.0f,       0.0f },
159             { 0.0f,         0.0f,           0.5f,       0.0f },
160             { (R+L)/(L-R),  (T+B)/(B-T),    0.5f,       1.0f },
161         };
162         memcpy(&constant_buffer->mvp, mvp, sizeof(mvp));
163     }
164 
165     // Setup viewport
166     D3D12_VIEWPORT vp;
167     memset(&vp, 0, sizeof(D3D12_VIEWPORT));
168     vp.Width = draw_data->DisplaySize.x;
169     vp.Height = draw_data->DisplaySize.y;
170     vp.MinDepth = 0.0f;
171     vp.MaxDepth = 1.0f;
172     vp.TopLeftX = vp.TopLeftY = 0.0f;
173     ctx->RSSetViewports(1, &vp);
174 
175     // Bind shader and vertex buffers
176     unsigned int stride = sizeof(ImDrawVert);
177     unsigned int offset = 0;
178     D3D12_VERTEX_BUFFER_VIEW vbv;
179     memset(&vbv, 0, sizeof(D3D12_VERTEX_BUFFER_VIEW));
180     vbv.BufferLocation = g_pVB->GetGPUVirtualAddress() + offset;
181     vbv.SizeInBytes = g_VertexBufferSize * stride;
182     vbv.StrideInBytes = stride;
183     ctx->IASetVertexBuffers(0, 1, &vbv);
184     D3D12_INDEX_BUFFER_VIEW ibv;
185     memset(&ibv, 0, sizeof(D3D12_INDEX_BUFFER_VIEW));
186     ibv.BufferLocation = g_pIB->GetGPUVirtualAddress();
187     ibv.SizeInBytes = g_IndexBufferSize * sizeof(ImDrawIdx);
188     ibv.Format = sizeof(ImDrawIdx) == 2 ? DXGI_FORMAT_R16_UINT : DXGI_FORMAT_R32_UINT;
189     ctx->IASetIndexBuffer(&ibv);
190     ctx->IASetPrimitiveTopology(D3D_PRIMITIVE_TOPOLOGY_TRIANGLELIST);
191     ctx->SetPipelineState(g_pPipelineState);
192     ctx->SetGraphicsRootSignature(g_pRootSignature);
193     ctx->SetGraphicsRoot32BitConstants(0, 16, &vertex_constant_buffer, 0);
194 
195     // Setup render state
196     const float blend_factor[4] = { 0.f, 0.f, 0.f, 0.f };
197     ctx->OMSetBlendFactor(blend_factor);
198 
199     // Render command lists
200     int vtx_offset = 0;
201     int idx_offset = 0;
202     ImVec2 pos = draw_data->DisplayPos;
203     for (int n = 0; n < draw_data->CmdListsCount; n++)
204     {
205         const ImDrawList* cmd_list = draw_data->CmdLists[n];
206         for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
207         {
208             const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
209             if (pcmd->UserCallback)
210             {
211                 pcmd->UserCallback(cmd_list, pcmd);
212             }
213             else
214             {
215                 const D3D12_RECT r = { (LONG)(pcmd->ClipRect.x - pos.x), (LONG)(pcmd->ClipRect.y - pos.y), (LONG)(pcmd->ClipRect.z - pos.x), (LONG)(pcmd->ClipRect.w - pos.y) };
216                 ctx->SetGraphicsRootDescriptorTable(1, *(D3D12_GPU_DESCRIPTOR_HANDLE*)&pcmd->TextureId);
217                 ctx->RSSetScissorRects(1, &r);
218                 ctx->DrawIndexedInstanced(pcmd->ElemCount, 1, idx_offset, vtx_offset, 0);
219             }
220             idx_offset += pcmd->ElemCount;
221         }
222         vtx_offset += cmd_list->VtxBuffer.Size;
223     }
224 }
225 
ImGui_ImplDX12_CreateFontsTexture()226 static void ImGui_ImplDX12_CreateFontsTexture()
227 {
228     // Build texture atlas
229     ImGuiIO& io = ImGui::GetIO();
230     unsigned char* pixels;
231     int width, height;
232     io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);
233 
234     // Upload texture to graphics system
235     {
236         D3D12_HEAP_PROPERTIES props;
237         memset(&props, 0, sizeof(D3D12_HEAP_PROPERTIES));
238         props.Type = D3D12_HEAP_TYPE_DEFAULT;
239         props.CPUPageProperty = D3D12_CPU_PAGE_PROPERTY_UNKNOWN;
240         props.MemoryPoolPreference = D3D12_MEMORY_POOL_UNKNOWN;
241 
242         D3D12_RESOURCE_DESC desc;
243         ZeroMemory(&desc, sizeof(desc));
244         desc.Dimension = D3D12_RESOURCE_DIMENSION_TEXTURE2D;
245         desc.Alignment = 0;
246         desc.Width = width;
247         desc.Height = height;
248         desc.DepthOrArraySize = 1;
249         desc.MipLevels = 1;
250         desc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
251         desc.SampleDesc.Count = 1;
252         desc.SampleDesc.Quality = 0;
253         desc.Layout = D3D12_TEXTURE_LAYOUT_UNKNOWN;
254         desc.Flags = D3D12_RESOURCE_FLAG_NONE;
255 
256         ID3D12Resource* pTexture = NULL;
257         g_pd3dDevice->CreateCommittedResource(&props, D3D12_HEAP_FLAG_NONE, &desc,
258             D3D12_RESOURCE_STATE_COPY_DEST, NULL, IID_PPV_ARGS(&pTexture));
259 
260         UINT uploadPitch = (width * 4 + D3D12_TEXTURE_DATA_PITCH_ALIGNMENT - 1u) & ~(D3D12_TEXTURE_DATA_PITCH_ALIGNMENT - 1u);
261         UINT uploadSize = height * uploadPitch;
262         desc.Dimension = D3D12_RESOURCE_DIMENSION_BUFFER;
263         desc.Alignment = 0;
264         desc.Width = uploadSize;
265         desc.Height = 1;
266         desc.DepthOrArraySize = 1;
267         desc.MipLevels = 1;
268         desc.Format = DXGI_FORMAT_UNKNOWN;
269         desc.SampleDesc.Count = 1;
270         desc.SampleDesc.Quality = 0;
271         desc.Layout = D3D12_TEXTURE_LAYOUT_ROW_MAJOR;
272         desc.Flags = D3D12_RESOURCE_FLAG_NONE;
273 
274         props.Type = D3D12_HEAP_TYPE_UPLOAD;
275         props.CPUPageProperty = D3D12_CPU_PAGE_PROPERTY_UNKNOWN;
276         props.MemoryPoolPreference = D3D12_MEMORY_POOL_UNKNOWN;
277 
278         ID3D12Resource* uploadBuffer = NULL;
279         HRESULT hr = g_pd3dDevice->CreateCommittedResource(&props, D3D12_HEAP_FLAG_NONE, &desc,
280             D3D12_RESOURCE_STATE_GENERIC_READ, NULL, IID_PPV_ARGS(&uploadBuffer));
281         IM_ASSERT(SUCCEEDED(hr));
282 
283         void* mapped = NULL;
284         D3D12_RANGE range = { 0, uploadSize };
285         hr = uploadBuffer->Map(0, &range, &mapped);
286         IM_ASSERT(SUCCEEDED(hr));
287         for (int y = 0; y < height; y++)
288             memcpy((void*) ((uintptr_t) mapped + y * uploadPitch), pixels + y * width * 4, width * 4);
289         uploadBuffer->Unmap(0, &range);
290 
291         D3D12_TEXTURE_COPY_LOCATION srcLocation = {};
292         srcLocation.pResource = uploadBuffer;
293         srcLocation.Type = D3D12_TEXTURE_COPY_TYPE_PLACED_FOOTPRINT;
294         srcLocation.PlacedFootprint.Footprint.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
295         srcLocation.PlacedFootprint.Footprint.Width = width;
296         srcLocation.PlacedFootprint.Footprint.Height = height;
297         srcLocation.PlacedFootprint.Footprint.Depth = 1;
298         srcLocation.PlacedFootprint.Footprint.RowPitch = uploadPitch;
299 
300         D3D12_TEXTURE_COPY_LOCATION dstLocation = {};
301         dstLocation.pResource = pTexture;
302         dstLocation.Type = D3D12_TEXTURE_COPY_TYPE_SUBRESOURCE_INDEX;
303         dstLocation.SubresourceIndex = 0;
304 
305         D3D12_RESOURCE_BARRIER barrier = {};
306         barrier.Type = D3D12_RESOURCE_BARRIER_TYPE_TRANSITION;
307         barrier.Flags = D3D12_RESOURCE_BARRIER_FLAG_NONE;
308         barrier.Transition.pResource   = pTexture;
309         barrier.Transition.Subresource = D3D12_RESOURCE_BARRIER_ALL_SUBRESOURCES;
310         barrier.Transition.StateBefore = D3D12_RESOURCE_STATE_COPY_DEST;
311         barrier.Transition.StateAfter  = D3D12_RESOURCE_STATE_PIXEL_SHADER_RESOURCE;
312 
313         ID3D12Fence* fence = NULL;
314         hr = g_pd3dDevice->CreateFence(0, D3D12_FENCE_FLAG_NONE, IID_PPV_ARGS(&fence));
315         IM_ASSERT(SUCCEEDED(hr));
316 
317         HANDLE event = CreateEvent(0, 0, 0, 0);
318         IM_ASSERT(event != NULL);
319 
320         D3D12_COMMAND_QUEUE_DESC queueDesc = {};
321         queueDesc.Type     = D3D12_COMMAND_LIST_TYPE_DIRECT;
322         queueDesc.Flags    = D3D12_COMMAND_QUEUE_FLAG_NONE;
323         queueDesc.NodeMask = 1;
324 
325         ID3D12CommandQueue* cmdQueue = NULL;
326         hr = g_pd3dDevice->CreateCommandQueue(&queueDesc, IID_PPV_ARGS(&cmdQueue));
327         IM_ASSERT(SUCCEEDED(hr));
328 
329         ID3D12CommandAllocator* cmdAlloc = NULL;
330         hr = g_pd3dDevice->CreateCommandAllocator(D3D12_COMMAND_LIST_TYPE_DIRECT, IID_PPV_ARGS(&cmdAlloc));
331         IM_ASSERT(SUCCEEDED(hr));
332 
333         ID3D12GraphicsCommandList* cmdList = NULL;
334         hr = g_pd3dDevice->CreateCommandList(0, D3D12_COMMAND_LIST_TYPE_DIRECT, cmdAlloc, NULL, IID_PPV_ARGS(&cmdList));
335         IM_ASSERT(SUCCEEDED(hr));
336 
337         cmdList->CopyTextureRegion(&dstLocation, 0, 0, 0, &srcLocation, NULL);
338         cmdList->ResourceBarrier(1, &barrier);
339 
340         hr = cmdList->Close();
341         IM_ASSERT(SUCCEEDED(hr));
342 
343         cmdQueue->ExecuteCommandLists(1, (ID3D12CommandList* const*) &cmdList);
344         hr = cmdQueue->Signal(fence, 1);
345         IM_ASSERT(SUCCEEDED(hr));
346 
347         fence->SetEventOnCompletion(1, event);
348         WaitForSingleObject(event, INFINITE);
349 
350         cmdList->Release();
351         cmdAlloc->Release();
352         cmdQueue->Release();
353         CloseHandle(event);
354         fence->Release();
355         uploadBuffer->Release();
356 
357         // Create texture view
358         D3D12_SHADER_RESOURCE_VIEW_DESC srvDesc;
359         ZeroMemory(&srvDesc, sizeof(srvDesc));
360         srvDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
361         srvDesc.ViewDimension = D3D12_SRV_DIMENSION_TEXTURE2D;
362         srvDesc.Texture2D.MipLevels = desc.MipLevels;
363         srvDesc.Texture2D.MostDetailedMip = 0;
364         srvDesc.Shader4ComponentMapping = D3D12_DEFAULT_SHADER_4_COMPONENT_MAPPING;
365         g_pd3dDevice->CreateShaderResourceView(pTexture, &srvDesc, g_hFontSrvCpuDescHandle);
366         if (g_pFontTextureResource != NULL)
367             g_pFontTextureResource->Release();
368         g_pFontTextureResource = pTexture;
369     }
370 
371     // Store our identifier
372     static_assert(sizeof(ImTextureID) >= sizeof(g_hFontSrvGpuDescHandle.ptr), "Can't pack descriptor handle into TexID, 32-bit not supported yet.");
373     io.Fonts->TexID = (ImTextureID)g_hFontSrvGpuDescHandle.ptr;
374 }
375 
ImGui_ImplDX12_CreateDeviceObjects()376 bool    ImGui_ImplDX12_CreateDeviceObjects()
377 {
378     if (!g_pd3dDevice)
379         return false;
380     if (g_pPipelineState)
381         ImGui_ImplDX12_InvalidateDeviceObjects();
382 
383     // Create the root signature
384     {
385         D3D12_DESCRIPTOR_RANGE descRange = {};
386         descRange.RangeType = D3D12_DESCRIPTOR_RANGE_TYPE_SRV;
387         descRange.NumDescriptors = 1;
388         descRange.BaseShaderRegister = 0;
389         descRange.RegisterSpace = 0;
390         descRange.OffsetInDescriptorsFromTableStart = 0;
391 
392         D3D12_ROOT_PARAMETER param[2] = {};
393 
394         param[0].ParameterType = D3D12_ROOT_PARAMETER_TYPE_32BIT_CONSTANTS;
395         param[0].Constants.ShaderRegister = 0;
396         param[0].Constants.RegisterSpace = 0;
397         param[0].Constants.Num32BitValues = 16;
398         param[0].ShaderVisibility = D3D12_SHADER_VISIBILITY_VERTEX;
399 
400         param[1].ParameterType = D3D12_ROOT_PARAMETER_TYPE_DESCRIPTOR_TABLE;
401         param[1].DescriptorTable.NumDescriptorRanges = 1;
402         param[1].DescriptorTable.pDescriptorRanges = &descRange;
403         param[1].ShaderVisibility = D3D12_SHADER_VISIBILITY_PIXEL;
404 
405         D3D12_STATIC_SAMPLER_DESC staticSampler = {};
406         staticSampler.Filter = D3D12_FILTER_MIN_MAG_MIP_LINEAR;
407         staticSampler.AddressU = D3D12_TEXTURE_ADDRESS_MODE_WRAP;
408         staticSampler.AddressV = D3D12_TEXTURE_ADDRESS_MODE_WRAP;
409         staticSampler.AddressW = D3D12_TEXTURE_ADDRESS_MODE_WRAP;
410         staticSampler.MipLODBias = 0.f;
411         staticSampler.MaxAnisotropy = 0;
412         staticSampler.ComparisonFunc = D3D12_COMPARISON_FUNC_ALWAYS;
413         staticSampler.BorderColor = D3D12_STATIC_BORDER_COLOR_TRANSPARENT_BLACK;
414         staticSampler.MinLOD = 0.f;
415         staticSampler.MaxLOD = 0.f;
416         staticSampler.ShaderRegister = 0;
417         staticSampler.RegisterSpace = 0;
418         staticSampler.ShaderVisibility = D3D12_SHADER_VISIBILITY_PIXEL;
419 
420         D3D12_ROOT_SIGNATURE_DESC desc = {};
421         desc.NumParameters = _countof(param);
422         desc.pParameters = param;
423         desc.NumStaticSamplers = 1;
424         desc.pStaticSamplers = &staticSampler;
425         desc.Flags =
426             D3D12_ROOT_SIGNATURE_FLAG_ALLOW_INPUT_ASSEMBLER_INPUT_LAYOUT |
427             D3D12_ROOT_SIGNATURE_FLAG_DENY_HULL_SHADER_ROOT_ACCESS |
428             D3D12_ROOT_SIGNATURE_FLAG_DENY_DOMAIN_SHADER_ROOT_ACCESS |
429             D3D12_ROOT_SIGNATURE_FLAG_DENY_GEOMETRY_SHADER_ROOT_ACCESS;
430 
431         ID3DBlob* blob = NULL;
432         if (D3D12SerializeRootSignature(&desc, D3D_ROOT_SIGNATURE_VERSION_1, &blob, NULL) != S_OK)
433             return false;
434 
435         g_pd3dDevice->CreateRootSignature(0, blob->GetBufferPointer(), blob->GetBufferSize(), IID_PPV_ARGS(&g_pRootSignature));
436         blob->Release();
437     }
438 
439     // By using D3DCompile() from <d3dcompiler.h> / d3dcompiler.lib, we introduce a dependency to a given version of d3dcompiler_XX.dll (see D3DCOMPILER_DLL_A)
440     // If you would like to use this DX12 sample code but remove this dependency you can:
441     //  1) compile once, save the compiled shader blobs into a file or source code and pass them to CreateVertexShader()/CreatePixelShader() [preferred solution]
442     //  2) use code to detect any version of the DLL and grab a pointer to D3DCompile from the DLL.
443     // See https://github.com/ocornut/imgui/pull/638 for sources and details.
444 
445     D3D12_GRAPHICS_PIPELINE_STATE_DESC psoDesc;
446     memset(&psoDesc, 0, sizeof(D3D12_GRAPHICS_PIPELINE_STATE_DESC));
447     psoDesc.NodeMask = 1;
448     psoDesc.PrimitiveTopologyType = D3D12_PRIMITIVE_TOPOLOGY_TYPE_TRIANGLE;
449     psoDesc.pRootSignature = g_pRootSignature;
450     psoDesc.SampleMask = UINT_MAX;
451     psoDesc.NumRenderTargets = 1;
452     psoDesc.RTVFormats[0] = g_RTVFormat;
453     psoDesc.SampleDesc.Count = 1;
454     psoDesc.Flags = D3D12_PIPELINE_STATE_FLAG_NONE;
455 
456     // Create the vertex shader
457     {
458         static const char* vertexShader =
459             "cbuffer vertexBuffer : register(b0) \
460             {\
461               float4x4 ProjectionMatrix; \
462             };\
463             struct VS_INPUT\
464             {\
465               float2 pos : POSITION;\
466               float4 col : COLOR0;\
467               float2 uv  : TEXCOORD0;\
468             };\
469             \
470             struct PS_INPUT\
471             {\
472               float4 pos : SV_POSITION;\
473               float4 col : COLOR0;\
474               float2 uv  : TEXCOORD0;\
475             };\
476             \
477             PS_INPUT main(VS_INPUT input)\
478             {\
479               PS_INPUT output;\
480               output.pos = mul( ProjectionMatrix, float4(input.pos.xy, 0.f, 1.f));\
481               output.col = input.col;\
482               output.uv  = input.uv;\
483               return output;\
484             }";
485 
486         D3DCompile(vertexShader, strlen(vertexShader), NULL, NULL, NULL, "main", "vs_5_0", 0, 0, &g_pVertexShaderBlob, NULL);
487         if (g_pVertexShaderBlob == NULL) // NB: Pass ID3D10Blob* pErrorBlob to D3DCompile() to get error showing in (const char*)pErrorBlob->GetBufferPointer(). Make sure to Release() the blob!
488             return false;
489         psoDesc.VS = { g_pVertexShaderBlob->GetBufferPointer(), g_pVertexShaderBlob->GetBufferSize() };
490 
491         // Create the input layout
492         static D3D12_INPUT_ELEMENT_DESC local_layout[] = {
493             { "POSITION", 0, DXGI_FORMAT_R32G32_FLOAT,   0, (size_t)(&((ImDrawVert*)0)->pos), D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
494             { "TEXCOORD", 0, DXGI_FORMAT_R32G32_FLOAT,   0, (size_t)(&((ImDrawVert*)0)->uv),  D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
495             { "COLOR",    0, DXGI_FORMAT_R8G8B8A8_UNORM, 0, (size_t)(&((ImDrawVert*)0)->col), D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
496         };
497         psoDesc.InputLayout = { local_layout, 3 };
498     }
499 
500     // Create the pixel shader
501     {
502         static const char* pixelShader =
503             "struct PS_INPUT\
504             {\
505               float4 pos : SV_POSITION;\
506               float4 col : COLOR0;\
507               float2 uv  : TEXCOORD0;\
508             };\
509             SamplerState sampler0 : register(s0);\
510             Texture2D texture0 : register(t0);\
511             \
512             float4 main(PS_INPUT input) : SV_Target\
513             {\
514               float4 out_col = input.col * texture0.Sample(sampler0, input.uv); \
515               return out_col; \
516             }";
517 
518         D3DCompile(pixelShader, strlen(pixelShader), NULL, NULL, NULL, "main", "ps_5_0", 0, 0, &g_pPixelShaderBlob, NULL);
519         if (g_pPixelShaderBlob == NULL)  // NB: Pass ID3D10Blob* pErrorBlob to D3DCompile() to get error showing in (const char*)pErrorBlob->GetBufferPointer(). Make sure to Release() the blob!
520             return false;
521         psoDesc.PS = { g_pPixelShaderBlob->GetBufferPointer(), g_pPixelShaderBlob->GetBufferSize() };
522     }
523 
524     // Create the blending setup
525     {
526         D3D12_BLEND_DESC& desc = psoDesc.BlendState;
527         desc.AlphaToCoverageEnable = false;
528         desc.RenderTarget[0].BlendEnable = true;
529         desc.RenderTarget[0].SrcBlend = D3D12_BLEND_SRC_ALPHA;
530         desc.RenderTarget[0].DestBlend = D3D12_BLEND_INV_SRC_ALPHA;
531         desc.RenderTarget[0].BlendOp = D3D12_BLEND_OP_ADD;
532         desc.RenderTarget[0].SrcBlendAlpha = D3D12_BLEND_INV_SRC_ALPHA;
533         desc.RenderTarget[0].DestBlendAlpha = D3D12_BLEND_ZERO;
534         desc.RenderTarget[0].BlendOpAlpha = D3D12_BLEND_OP_ADD;
535         desc.RenderTarget[0].RenderTargetWriteMask = D3D12_COLOR_WRITE_ENABLE_ALL;
536     }
537 
538     // Create the rasterizer state
539     {
540         D3D12_RASTERIZER_DESC& desc = psoDesc.RasterizerState;
541         desc.FillMode = D3D12_FILL_MODE_SOLID;
542         desc.CullMode = D3D12_CULL_MODE_NONE;
543         desc.FrontCounterClockwise = FALSE;
544         desc.DepthBias = D3D12_DEFAULT_DEPTH_BIAS;
545         desc.DepthBiasClamp = D3D12_DEFAULT_DEPTH_BIAS_CLAMP;
546         desc.SlopeScaledDepthBias = D3D12_DEFAULT_SLOPE_SCALED_DEPTH_BIAS;
547         desc.DepthClipEnable = true;
548         desc.MultisampleEnable = FALSE;
549         desc.AntialiasedLineEnable = FALSE;
550         desc.ForcedSampleCount = 0;
551         desc.ConservativeRaster = D3D12_CONSERVATIVE_RASTERIZATION_MODE_OFF;
552     }
553 
554     // Create depth-stencil State
555     {
556         D3D12_DEPTH_STENCIL_DESC& desc = psoDesc.DepthStencilState;
557         desc.DepthEnable = false;
558         desc.DepthWriteMask = D3D12_DEPTH_WRITE_MASK_ALL;
559         desc.DepthFunc = D3D12_COMPARISON_FUNC_ALWAYS;
560         desc.StencilEnable = false;
561         desc.FrontFace.StencilFailOp = desc.FrontFace.StencilDepthFailOp = desc.FrontFace.StencilPassOp = D3D12_STENCIL_OP_KEEP;
562         desc.FrontFace.StencilFunc = D3D12_COMPARISON_FUNC_ALWAYS;
563         desc.BackFace = desc.FrontFace;
564     }
565 
566     if (g_pd3dDevice->CreateGraphicsPipelineState(&psoDesc, IID_PPV_ARGS(&g_pPipelineState)) != S_OK)
567         return false;
568 
569     ImGui_ImplDX12_CreateFontsTexture();
570 
571     return true;
572 }
573 
ImGui_ImplDX12_InvalidateDeviceObjects()574 void    ImGui_ImplDX12_InvalidateDeviceObjects()
575 {
576     if (!g_pd3dDevice)
577         return;
578 
579     if (g_pVertexShaderBlob) { g_pVertexShaderBlob->Release(); g_pVertexShaderBlob = NULL; }
580     if (g_pPixelShaderBlob) { g_pPixelShaderBlob->Release(); g_pPixelShaderBlob = NULL; }
581     if (g_pRootSignature) { g_pRootSignature->Release(); g_pRootSignature = NULL; }
582     if (g_pPipelineState) { g_pPipelineState->Release(); g_pPipelineState = NULL; }
583     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.
584     for (UINT i = 0; i < g_numFramesInFlight; i++)
585     {
586         if (g_pFrameResources[i].IB) { g_pFrameResources[i].IB->Release(); g_pFrameResources[i].IB = NULL; }
587         if (g_pFrameResources[i].VB) { g_pFrameResources[i].VB->Release(); g_pFrameResources[i].VB = NULL; }
588     }
589 }
590 
ImGui_ImplDX12_Init(ID3D12Device * device,int num_frames_in_flight,DXGI_FORMAT rtv_format,D3D12_CPU_DESCRIPTOR_HANDLE font_srv_cpu_desc_handle,D3D12_GPU_DESCRIPTOR_HANDLE font_srv_gpu_desc_handle)591 bool ImGui_ImplDX12_Init(ID3D12Device* device, int num_frames_in_flight, DXGI_FORMAT rtv_format,
592                          D3D12_CPU_DESCRIPTOR_HANDLE font_srv_cpu_desc_handle, D3D12_GPU_DESCRIPTOR_HANDLE font_srv_gpu_desc_handle)
593 {
594     ImGuiIO& io = ImGui::GetIO();
595     io.BackendRendererName = "imgui_impl_dx12";
596 
597     g_pd3dDevice = device;
598     g_RTVFormat = rtv_format;
599     g_hFontSrvCpuDescHandle = font_srv_cpu_desc_handle;
600     g_hFontSrvGpuDescHandle = font_srv_gpu_desc_handle;
601     g_pFrameResources = new FrameResources[num_frames_in_flight];
602     g_numFramesInFlight = num_frames_in_flight;
603     g_frameIndex = UINT_MAX;
604 
605     // Create buffers with a default size (they will later be grown as needed)
606     for (int i = 0; i < num_frames_in_flight; i++)
607     {
608         g_pFrameResources[i].IB = NULL;
609         g_pFrameResources[i].VB = NULL;
610         g_pFrameResources[i].VertexBufferSize = 5000;
611         g_pFrameResources[i].IndexBufferSize = 10000;
612     }
613 
614     return true;
615 }
616 
ImGui_ImplDX12_Shutdown()617 void ImGui_ImplDX12_Shutdown()
618 {
619     ImGui_ImplDX12_InvalidateDeviceObjects();
620     delete[] g_pFrameResources;
621     g_pd3dDevice = NULL;
622     g_hFontSrvCpuDescHandle.ptr = 0;
623     g_hFontSrvGpuDescHandle.ptr = 0;
624     g_pFrameResources = NULL;
625     g_numFramesInFlight = 0;
626     g_frameIndex = UINT_MAX;
627 }
628 
ImGui_ImplDX12_NewFrame()629 void ImGui_ImplDX12_NewFrame()
630 {
631     if (!g_pPipelineState)
632         ImGui_ImplDX12_CreateDeviceObjects();
633 }
634