imgui

FORK: Dear ImGui: Bloat-free Graphical User interface for C++ with minimal dependencies
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imgui_impl_wgpu.cpp (31399B)


      1 // dear imgui: Renderer for WebGPU
      2 // This needs to be used along with a Platform Binding (e.g. GLFW)
      3 // (Please note that WebGPU is currently experimental, will not run on non-beta browsers, and may break.)
      4 
      5 // Implemented features:
      6 //  [X] Renderer: User texture binding. Use 'WGPUTextureView' as ImTextureID. Read the FAQ about ImTextureID!
      7 //  [X] Renderer: Support for large meshes (64k+ vertices) with 16-bit indices.
      8 
      9 // You can copy and use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
     10 // If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
     11 // Read online: https://github.com/ocornut/imgui/tree/master/docs
     12 
     13 // CHANGELOG
     14 // (minor and older changes stripped away, please see git history for details)
     15 //  2021-05-24: Add support for draw_data->FramebufferScale.
     16 //  2021-05-19: Replaced direct access to ImDrawCmd::TextureId with a call to ImDrawCmd::GetTexID(). (will become a requirement)
     17 //  2021-05-16: Update to latest WebGPU specs (compatible with Emscripten 2.0.20 and Chrome Canary 92).
     18 //  2021-02-18: Change blending equation to preserve alpha in output buffer.
     19 //  2021-01-28: Initial version.
     20 
     21 #include "imgui.h"
     22 #include "imgui_impl_wgpu.h"
     23 #include <limits.h>
     24 #include <webgpu/webgpu.h>
     25 
     26 #define HAS_EMSCRIPTEN_VERSION(major, minor, tiny) (__EMSCRIPTEN_major__ > (major) || (__EMSCRIPTEN_major__ == (major) && __EMSCRIPTEN_minor__ > (minor)) || (__EMSCRIPTEN_major__ == (major) && __EMSCRIPTEN_minor__ == (minor) && __EMSCRIPTEN_tiny__ >= (tiny)))
     27 
     28 #if defined(__EMSCRIPTEN__) && !HAS_EMSCRIPTEN_VERSION(2, 0, 20)
     29 #error "Requires at least emscripten 2.0.20"
     30 #endif
     31 
     32 // Dear ImGui prototypes from imgui_internal.h
     33 extern ImGuiID ImHashData(const void* data_p, size_t data_size, ImU32 seed = 0);
     34 
     35 // WebGPU data
     36 static WGPUDevice               g_wgpuDevice = NULL;
     37 static WGPUQueue                g_defaultQueue = NULL;
     38 static WGPUTextureFormat        g_renderTargetFormat = WGPUTextureFormat_Undefined;
     39 static WGPURenderPipeline       g_pipelineState = NULL;
     40 
     41 struct RenderResources
     42 {
     43     WGPUTexture         FontTexture;            // Font texture
     44     WGPUTextureView     FontTextureView;        // Texture view for font texture
     45     WGPUSampler         Sampler;                // Sampler for the font texture
     46     WGPUBuffer          Uniforms;               // Shader uniforms
     47     WGPUBindGroup       CommonBindGroup;        // Resources bind-group to bind the common resources to pipeline
     48     ImGuiStorage        ImageBindGroups;        // Resources bind-group to bind the font/image resources to pipeline (this is a key->value map)
     49     WGPUBindGroup       ImageBindGroup;         // Default font-resource of Dear ImGui
     50     WGPUBindGroupLayout ImageBindGroupLayout;   // Cache layout used for the image bind group. Avoids allocating unnecessary JS objects when working with WebASM
     51 };
     52 static RenderResources  g_resources;
     53 
     54 struct FrameResources
     55 {
     56     WGPUBuffer  IndexBuffer;
     57     WGPUBuffer  VertexBuffer;
     58     ImDrawIdx*  IndexBufferHost;
     59     ImDrawVert* VertexBufferHost;
     60     int         IndexBufferSize;
     61     int         VertexBufferSize;
     62 };
     63 static FrameResources*  g_pFrameResources = NULL;
     64 static unsigned int     g_numFramesInFlight = 0;
     65 static unsigned int     g_frameIndex = UINT_MAX;
     66 
     67 struct Uniforms
     68 {
     69     float MVP[4][4];
     70 };
     71 
     72 //-----------------------------------------------------------------------------
     73 // SHADERS
     74 //-----------------------------------------------------------------------------
     75 
     76 // glsl_shader.vert, compiled with:
     77 // # glslangValidator -V -x -o glsl_shader.vert.u32 glsl_shader.vert
     78 /*
     79 #version 450 core
     80 layout(location = 0) in vec2 aPos;
     81 layout(location = 1) in vec2 aUV;
     82 layout(location = 2) in vec4 aColor;
     83 layout(set=0, binding = 0) uniform transform { mat4 mvp; };
     84 
     85 out gl_PerVertex { vec4 gl_Position; };
     86 layout(location = 0) out struct { vec4 Color; vec2 UV; } Out;
     87 
     88 void main()
     89 {
     90     Out.Color = aColor;
     91     Out.UV = aUV;
     92     gl_Position = mvp * vec4(aPos, 0, 1);
     93 }
     94 */
     95 static uint32_t __glsl_shader_vert_spv[] =
     96 {
     97     0x07230203,0x00010000,0x00080007,0x0000002c,0x00000000,0x00020011,0x00000001,0x0006000b,
     98     0x00000001,0x4c534c47,0x6474732e,0x3035342e,0x00000000,0x0003000e,0x00000000,0x00000001,
     99     0x000a000f,0x00000000,0x00000004,0x6e69616d,0x00000000,0x0000000b,0x0000000f,0x00000015,
    100     0x0000001b,0x00000023,0x00030003,0x00000002,0x000001c2,0x00040005,0x00000004,0x6e69616d,
    101     0x00000000,0x00030005,0x00000009,0x00000000,0x00050006,0x00000009,0x00000000,0x6f6c6f43,
    102     0x00000072,0x00040006,0x00000009,0x00000001,0x00005655,0x00030005,0x0000000b,0x0074754f,
    103     0x00040005,0x0000000f,0x6c6f4361,0x0000726f,0x00030005,0x00000015,0x00565561,0x00060005,
    104     0x00000019,0x505f6c67,0x65567265,0x78657472,0x00000000,0x00060006,0x00000019,0x00000000,
    105     0x505f6c67,0x7469736f,0x006e6f69,0x00030005,0x0000001b,0x00000000,0x00050005,0x0000001d,
    106     0x6e617274,0x726f6673,0x0000006d,0x00040006,0x0000001d,0x00000000,0x0070766d,0x00030005,
    107     0x0000001f,0x00000000,0x00040005,0x00000023,0x736f5061,0x00000000,0x00040047,0x0000000b,
    108     0x0000001e,0x00000000,0x00040047,0x0000000f,0x0000001e,0x00000002,0x00040047,0x00000015,
    109     0x0000001e,0x00000001,0x00050048,0x00000019,0x00000000,0x0000000b,0x00000000,0x00030047,
    110     0x00000019,0x00000002,0x00040048,0x0000001d,0x00000000,0x00000005,0x00050048,0x0000001d,
    111     0x00000000,0x00000023,0x00000000,0x00050048,0x0000001d,0x00000000,0x00000007,0x00000010,
    112     0x00030047,0x0000001d,0x00000002,0x00040047,0x0000001f,0x00000022,0x00000000,0x00040047,
    113     0x0000001f,0x00000021,0x00000000,0x00040047,0x00000023,0x0000001e,0x00000000,0x00020013,
    114     0x00000002,0x00030021,0x00000003,0x00000002,0x00030016,0x00000006,0x00000020,0x00040017,
    115     0x00000007,0x00000006,0x00000004,0x00040017,0x00000008,0x00000006,0x00000002,0x0004001e,
    116     0x00000009,0x00000007,0x00000008,0x00040020,0x0000000a,0x00000003,0x00000009,0x0004003b,
    117     0x0000000a,0x0000000b,0x00000003,0x00040015,0x0000000c,0x00000020,0x00000001,0x0004002b,
    118     0x0000000c,0x0000000d,0x00000000,0x00040020,0x0000000e,0x00000001,0x00000007,0x0004003b,
    119     0x0000000e,0x0000000f,0x00000001,0x00040020,0x00000011,0x00000003,0x00000007,0x0004002b,
    120     0x0000000c,0x00000013,0x00000001,0x00040020,0x00000014,0x00000001,0x00000008,0x0004003b,
    121     0x00000014,0x00000015,0x00000001,0x00040020,0x00000017,0x00000003,0x00000008,0x0003001e,
    122     0x00000019,0x00000007,0x00040020,0x0000001a,0x00000003,0x00000019,0x0004003b,0x0000001a,
    123     0x0000001b,0x00000003,0x00040018,0x0000001c,0x00000007,0x00000004,0x0003001e,0x0000001d,
    124     0x0000001c,0x00040020,0x0000001e,0x00000002,0x0000001d,0x0004003b,0x0000001e,0x0000001f,
    125     0x00000002,0x00040020,0x00000020,0x00000002,0x0000001c,0x0004003b,0x00000014,0x00000023,
    126     0x00000001,0x0004002b,0x00000006,0x00000025,0x00000000,0x0004002b,0x00000006,0x00000026,
    127     0x3f800000,0x00050036,0x00000002,0x00000004,0x00000000,0x00000003,0x000200f8,0x00000005,
    128     0x0004003d,0x00000007,0x00000010,0x0000000f,0x00050041,0x00000011,0x00000012,0x0000000b,
    129     0x0000000d,0x0003003e,0x00000012,0x00000010,0x0004003d,0x00000008,0x00000016,0x00000015,
    130     0x00050041,0x00000017,0x00000018,0x0000000b,0x00000013,0x0003003e,0x00000018,0x00000016,
    131     0x00050041,0x00000020,0x00000021,0x0000001f,0x0000000d,0x0004003d,0x0000001c,0x00000022,
    132     0x00000021,0x0004003d,0x00000008,0x00000024,0x00000023,0x00050051,0x00000006,0x00000027,
    133     0x00000024,0x00000000,0x00050051,0x00000006,0x00000028,0x00000024,0x00000001,0x00070050,
    134     0x00000007,0x00000029,0x00000027,0x00000028,0x00000025,0x00000026,0x00050091,0x00000007,
    135     0x0000002a,0x00000022,0x00000029,0x00050041,0x00000011,0x0000002b,0x0000001b,0x0000000d,
    136     0x0003003e,0x0000002b,0x0000002a,0x000100fd,0x00010038
    137 };
    138 
    139 // glsl_shader.frag, compiled with:
    140 // # glslangValidator -V -x -o glsl_shader.frag.u32 glsl_shader.frag
    141 /*
    142 #version 450 core
    143 layout(location = 0) out vec4 fColor;
    144 layout(set=0, binding=1) uniform sampler s;
    145 layout(set=1, binding=0) uniform texture2D t;
    146 layout(location = 0) in struct { vec4 Color; vec2 UV; } In;
    147 void main()
    148 {
    149     fColor = In.Color * texture(sampler2D(t, s), In.UV.st);
    150 }
    151 */
    152 static uint32_t __glsl_shader_frag_spv[] =
    153 {
    154     0x07230203,0x00010000,0x00080007,0x00000023,0x00000000,0x00020011,0x00000001,0x0006000b,
    155     0x00000001,0x4c534c47,0x6474732e,0x3035342e,0x00000000,0x0003000e,0x00000000,0x00000001,
    156     0x0007000f,0x00000004,0x00000004,0x6e69616d,0x00000000,0x00000009,0x0000000d,0x00030010,
    157     0x00000004,0x00000007,0x00030003,0x00000002,0x000001c2,0x00040005,0x00000004,0x6e69616d,
    158     0x00000000,0x00040005,0x00000009,0x6c6f4366,0x0000726f,0x00030005,0x0000000b,0x00000000,
    159     0x00050006,0x0000000b,0x00000000,0x6f6c6f43,0x00000072,0x00040006,0x0000000b,0x00000001,
    160     0x00005655,0x00030005,0x0000000d,0x00006e49,0x00030005,0x00000015,0x00000074,0x00030005,
    161     0x00000019,0x00000073,0x00040047,0x00000009,0x0000001e,0x00000000,0x00040047,0x0000000d,
    162     0x0000001e,0x00000000,0x00040047,0x00000015,0x00000022,0x00000001,0x00040047,0x00000015,
    163     0x00000021,0x00000000,0x00040047,0x00000019,0x00000022,0x00000000,0x00040047,0x00000019,
    164     0x00000021,0x00000001,0x00020013,0x00000002,0x00030021,0x00000003,0x00000002,0x00030016,
    165     0x00000006,0x00000020,0x00040017,0x00000007,0x00000006,0x00000004,0x00040020,0x00000008,
    166     0x00000003,0x00000007,0x0004003b,0x00000008,0x00000009,0x00000003,0x00040017,0x0000000a,
    167     0x00000006,0x00000002,0x0004001e,0x0000000b,0x00000007,0x0000000a,0x00040020,0x0000000c,
    168     0x00000001,0x0000000b,0x0004003b,0x0000000c,0x0000000d,0x00000001,0x00040015,0x0000000e,
    169     0x00000020,0x00000001,0x0004002b,0x0000000e,0x0000000f,0x00000000,0x00040020,0x00000010,
    170     0x00000001,0x00000007,0x00090019,0x00000013,0x00000006,0x00000001,0x00000000,0x00000000,
    171     0x00000000,0x00000001,0x00000000,0x00040020,0x00000014,0x00000000,0x00000013,0x0004003b,
    172     0x00000014,0x00000015,0x00000000,0x0002001a,0x00000017,0x00040020,0x00000018,0x00000000,
    173     0x00000017,0x0004003b,0x00000018,0x00000019,0x00000000,0x0003001b,0x0000001b,0x00000013,
    174     0x0004002b,0x0000000e,0x0000001d,0x00000001,0x00040020,0x0000001e,0x00000001,0x0000000a,
    175     0x00050036,0x00000002,0x00000004,0x00000000,0x00000003,0x000200f8,0x00000005,0x00050041,
    176     0x00000010,0x00000011,0x0000000d,0x0000000f,0x0004003d,0x00000007,0x00000012,0x00000011,
    177     0x0004003d,0x00000013,0x00000016,0x00000015,0x0004003d,0x00000017,0x0000001a,0x00000019,
    178     0x00050056,0x0000001b,0x0000001c,0x00000016,0x0000001a,0x00050041,0x0000001e,0x0000001f,
    179     0x0000000d,0x0000001d,0x0004003d,0x0000000a,0x00000020,0x0000001f,0x00050057,0x00000007,
    180     0x00000021,0x0000001c,0x00000020,0x00050085,0x00000007,0x00000022,0x00000012,0x00000021,
    181     0x0003003e,0x00000009,0x00000022,0x000100fd,0x00010038
    182 };
    183 
    184 static void SafeRelease(ImDrawIdx*& res)
    185 {
    186     if (res)
    187         delete[] res;
    188     res = NULL;
    189 }
    190 static void SafeRelease(ImDrawVert*& res)
    191 {
    192     if (res)
    193         delete[] res;
    194     res = NULL;
    195 }
    196 static void SafeRelease(WGPUBindGroupLayout& res)
    197 {
    198     if (res)
    199         wgpuBindGroupLayoutRelease(res);
    200     res = NULL;
    201 }
    202 static void SafeRelease(WGPUBindGroup& res)
    203 {
    204     if (res)
    205         wgpuBindGroupRelease(res);
    206     res = NULL;
    207 }
    208 static void SafeRelease(WGPUBuffer& res)
    209 {
    210     if (res)
    211         wgpuBufferRelease(res);
    212     res = NULL;
    213 }
    214 static void SafeRelease(WGPURenderPipeline& res)
    215 {
    216     if (res)
    217         wgpuRenderPipelineRelease(res);
    218     res = NULL;
    219 }
    220 static void SafeRelease(WGPUSampler& res)
    221 {
    222     if (res)
    223         wgpuSamplerRelease(res);
    224     res = NULL;
    225 }
    226 static void SafeRelease(WGPUShaderModule& res)
    227 {
    228     if (res)
    229         wgpuShaderModuleRelease(res);
    230     res = NULL;
    231 }
    232 static void SafeRelease(WGPUTextureView& res)
    233 {
    234     if (res)
    235         wgpuTextureViewRelease(res);
    236     res = NULL;
    237 }
    238 static void SafeRelease(WGPUTexture& res)
    239 {
    240     if (res)
    241         wgpuTextureRelease(res);
    242     res = NULL;
    243 }
    244 
    245 static void SafeRelease(RenderResources& res)
    246 {
    247     SafeRelease(res.FontTexture);
    248     SafeRelease(res.FontTextureView);
    249     SafeRelease(res.Sampler);
    250     SafeRelease(res.Uniforms);
    251     SafeRelease(res.CommonBindGroup);
    252     SafeRelease(res.ImageBindGroup);
    253     SafeRelease(res.ImageBindGroupLayout);
    254 };
    255 
    256 static void SafeRelease(FrameResources& res)
    257 {
    258     SafeRelease(res.IndexBuffer);
    259     SafeRelease(res.VertexBuffer);
    260     SafeRelease(res.IndexBufferHost);
    261     SafeRelease(res.VertexBufferHost);
    262 }
    263 
    264 static WGPUProgrammableStageDescriptor ImGui_ImplWGPU_CreateShaderModule(uint32_t* binary_data, uint32_t binary_data_size)
    265 {
    266     WGPUShaderModuleSPIRVDescriptor spirv_desc = {};
    267     spirv_desc.chain.sType = WGPUSType_ShaderModuleSPIRVDescriptor;
    268     spirv_desc.codeSize = binary_data_size;
    269     spirv_desc.code = binary_data;
    270 
    271     WGPUShaderModuleDescriptor desc;
    272     desc.nextInChain = reinterpret_cast<WGPUChainedStruct*>(&spirv_desc);
    273 
    274     WGPUProgrammableStageDescriptor stage_desc = {};
    275     stage_desc.module = wgpuDeviceCreateShaderModule(g_wgpuDevice, &desc);
    276     stage_desc.entryPoint = "main";
    277     return stage_desc;
    278 }
    279 
    280 static WGPUBindGroup ImGui_ImplWGPU_CreateImageBindGroup(WGPUBindGroupLayout layout, WGPUTextureView texture)
    281 {
    282     WGPUBindGroupEntry image_bg_entries[] = { { 0, 0, 0, 0, 0, texture } };
    283 
    284     WGPUBindGroupDescriptor image_bg_descriptor = {};
    285     image_bg_descriptor.layout = layout;
    286     image_bg_descriptor.entryCount = sizeof(image_bg_entries) / sizeof(WGPUBindGroupEntry);
    287     image_bg_descriptor.entries = image_bg_entries;
    288     return wgpuDeviceCreateBindGroup(g_wgpuDevice, &image_bg_descriptor);
    289 }
    290 
    291 static void ImGui_ImplWGPU_SetupRenderState(ImDrawData* draw_data, WGPURenderPassEncoder ctx, FrameResources* fr)
    292 {
    293     // Setup orthographic projection matrix into our constant buffer
    294     // Our visible imgui space lies from draw_data->DisplayPos (top left) to draw_data->DisplayPos+data_data->DisplaySize (bottom right).
    295     {
    296         float L = draw_data->DisplayPos.x;
    297         float R = draw_data->DisplayPos.x + draw_data->DisplaySize.x;
    298         float T = draw_data->DisplayPos.y;
    299         float B = draw_data->DisplayPos.y + draw_data->DisplaySize.y;
    300         float mvp[4][4] =
    301         {
    302             { 2.0f/(R-L),   0.0f,           0.0f,       0.0f },
    303             { 0.0f,         2.0f/(T-B),     0.0f,       0.0f },
    304             { 0.0f,         0.0f,           0.5f,       0.0f },
    305             { (R+L)/(L-R),  (T+B)/(B-T),    0.5f,       1.0f },
    306         };
    307         wgpuQueueWriteBuffer(g_defaultQueue, g_resources.Uniforms, 0, mvp, sizeof(mvp));
    308     }
    309 
    310     // Setup viewport
    311     wgpuRenderPassEncoderSetViewport(ctx, 0, 0, draw_data->FramebufferScale.x * draw_data->DisplaySize.x, draw_data->FramebufferScale.y * draw_data->DisplaySize.y, 0, 1);
    312 
    313     // Bind shader and vertex buffers
    314     wgpuRenderPassEncoderSetVertexBuffer(ctx, 0, fr->VertexBuffer, 0, 0);
    315     wgpuRenderPassEncoderSetIndexBuffer(ctx, fr->IndexBuffer, sizeof(ImDrawIdx) == 2 ? WGPUIndexFormat_Uint16 : WGPUIndexFormat_Uint32, 0, 0);
    316     wgpuRenderPassEncoderSetPipeline(ctx, g_pipelineState);
    317     wgpuRenderPassEncoderSetBindGroup(ctx, 0, g_resources.CommonBindGroup, 0, NULL);
    318 
    319     // Setup blend factor
    320     WGPUColor blend_color = { 0.f, 0.f, 0.f, 0.f };
    321     wgpuRenderPassEncoderSetBlendConstant(ctx, &blend_color);
    322 }
    323 
    324 // Render function
    325 // (this used to be set in io.RenderDrawListsFn and called by ImGui::Render(), but you can now call this directly from your main loop)
    326 void ImGui_ImplWGPU_RenderDrawData(ImDrawData* draw_data, WGPURenderPassEncoder pass_encoder)
    327 {
    328     // Avoid rendering when minimized
    329     if (draw_data->DisplaySize.x <= 0.0f || draw_data->DisplaySize.y <= 0.0f)
    330         return;
    331 
    332     // FIXME: Assuming that this only gets called once per frame!
    333     // If not, we can't just re-allocate the IB or VB, we'll have to do a proper allocator.
    334     g_frameIndex = g_frameIndex + 1;
    335     FrameResources* fr = &g_pFrameResources[g_frameIndex % g_numFramesInFlight];
    336 
    337     // Create and grow vertex/index buffers if needed
    338     if (fr->VertexBuffer == NULL || fr->VertexBufferSize < draw_data->TotalVtxCount)
    339     {
    340         if (fr->VertexBuffer)
    341         {
    342             wgpuBufferDestroy(fr->VertexBuffer);
    343             wgpuBufferRelease(fr->VertexBuffer);
    344         }
    345         SafeRelease(fr->VertexBufferHost);
    346         fr->VertexBufferSize = draw_data->TotalVtxCount + 5000;
    347 
    348         WGPUBufferDescriptor vb_desc =
    349         {
    350             NULL,
    351             "Dear ImGui Vertex buffer",
    352             WGPUBufferUsage_CopyDst | WGPUBufferUsage_Vertex,
    353             fr->VertexBufferSize * sizeof(ImDrawVert),
    354             false
    355         };
    356         fr->VertexBuffer = wgpuDeviceCreateBuffer(g_wgpuDevice, &vb_desc);
    357         if (!fr->VertexBuffer)
    358             return;
    359 
    360         fr->VertexBufferHost = new ImDrawVert[fr->VertexBufferSize];
    361     }
    362     if (fr->IndexBuffer == NULL || fr->IndexBufferSize < draw_data->TotalIdxCount)
    363     {
    364         if (fr->IndexBuffer)
    365         {
    366             wgpuBufferDestroy(fr->IndexBuffer);
    367             wgpuBufferRelease(fr->IndexBuffer);
    368         }
    369         SafeRelease(fr->IndexBufferHost);
    370         fr->IndexBufferSize = draw_data->TotalIdxCount + 10000;
    371 
    372         WGPUBufferDescriptor ib_desc =
    373         {
    374             NULL,
    375             "Dear ImGui Index buffer",
    376             WGPUBufferUsage_CopyDst | WGPUBufferUsage_Index,
    377             fr->IndexBufferSize * sizeof(ImDrawIdx),
    378             false
    379         };
    380         fr->IndexBuffer = wgpuDeviceCreateBuffer(g_wgpuDevice, &ib_desc);
    381         if (!fr->IndexBuffer)
    382             return;
    383 
    384         fr->IndexBufferHost = new ImDrawIdx[fr->IndexBufferSize];
    385     }
    386 
    387     // Upload vertex/index data into a single contiguous GPU buffer
    388     ImDrawVert* vtx_dst = (ImDrawVert*)fr->VertexBufferHost;
    389     ImDrawIdx* idx_dst = (ImDrawIdx*)fr->IndexBufferHost;
    390     for (int n = 0; n < draw_data->CmdListsCount; n++)
    391     {
    392         const ImDrawList* cmd_list = draw_data->CmdLists[n];
    393         memcpy(vtx_dst, cmd_list->VtxBuffer.Data, cmd_list->VtxBuffer.Size * sizeof(ImDrawVert));
    394         memcpy(idx_dst, cmd_list->IdxBuffer.Data, cmd_list->IdxBuffer.Size * sizeof(ImDrawIdx));
    395         vtx_dst += cmd_list->VtxBuffer.Size;
    396         idx_dst += cmd_list->IdxBuffer.Size;
    397     }
    398     int64_t vb_write_size = ((char*)vtx_dst - (char*)fr->VertexBufferHost + 3) & ~3;
    399     int64_t ib_write_size = ((char*)idx_dst - (char*)fr->IndexBufferHost  + 3) & ~3;
    400     wgpuQueueWriteBuffer(g_defaultQueue, fr->VertexBuffer, 0, fr->VertexBufferHost, vb_write_size);
    401     wgpuQueueWriteBuffer(g_defaultQueue, fr->IndexBuffer,  0, fr->IndexBufferHost,  ib_write_size);
    402 
    403     // Setup desired render state
    404     ImGui_ImplWGPU_SetupRenderState(draw_data, pass_encoder, fr);
    405 
    406     // Render command lists
    407     // (Because we merged all buffers into a single one, we maintain our own offset into them)
    408     int global_vtx_offset = 0;
    409     int global_idx_offset = 0;
    410     ImVec2 clip_scale = draw_data->FramebufferScale;
    411     ImVec2 clip_off = draw_data->DisplayPos;
    412     for (int n = 0; n < draw_data->CmdListsCount; n++)
    413     {
    414         const ImDrawList* cmd_list = draw_data->CmdLists[n];
    415         for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
    416         {
    417             const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
    418             if (pcmd->UserCallback != NULL)
    419             {
    420                 // User callback, registered via ImDrawList::AddCallback()
    421                 // (ImDrawCallback_ResetRenderState is a special callback value used by the user to request the renderer to reset render state.)
    422                 if (pcmd->UserCallback == ImDrawCallback_ResetRenderState)
    423                     ImGui_ImplWGPU_SetupRenderState(draw_data, pass_encoder, fr);
    424                 else
    425                     pcmd->UserCallback(cmd_list, pcmd);
    426             }
    427             else
    428             {
    429                 // Bind custom texture
    430                 ImTextureID tex_id = pcmd->GetTexID();
    431                 ImGuiID tex_id_hash = ImHashData(&tex_id, sizeof(tex_id));
    432                 auto bind_group = g_resources.ImageBindGroups.GetVoidPtr(tex_id_hash);
    433                 if (bind_group)
    434                 {
    435                     wgpuRenderPassEncoderSetBindGroup(pass_encoder, 1, (WGPUBindGroup)bind_group, 0, NULL);
    436                 }
    437                 else
    438                 {
    439                     WGPUBindGroup image_bind_group = ImGui_ImplWGPU_CreateImageBindGroup(g_resources.ImageBindGroupLayout, (WGPUTextureView)tex_id);
    440                     g_resources.ImageBindGroups.SetVoidPtr(tex_id_hash, image_bind_group);
    441                     wgpuRenderPassEncoderSetBindGroup(pass_encoder, 1, image_bind_group, 0, NULL);
    442                 }
    443 
    444                 // Apply Scissor, Bind texture, Draw
    445                 uint32_t clip_rect[4];
    446                 clip_rect[0] = (uint32_t)(clip_scale.x * (pcmd->ClipRect.x - clip_off.x));
    447                 clip_rect[1] = (uint32_t)(clip_scale.y * (pcmd->ClipRect.y - clip_off.y));
    448                 clip_rect[2] = (uint32_t)(clip_scale.x * (pcmd->ClipRect.z - clip_off.x));
    449                 clip_rect[3] = (uint32_t)(clip_scale.y * (pcmd->ClipRect.w - clip_off.y));
    450                 wgpuRenderPassEncoderSetScissorRect(pass_encoder, clip_rect[0], clip_rect[1], clip_rect[2] - clip_rect[0], clip_rect[3] - clip_rect[1]);
    451                 wgpuRenderPassEncoderDrawIndexed(pass_encoder, pcmd->ElemCount, 1, pcmd->IdxOffset + global_idx_offset, pcmd->VtxOffset + global_vtx_offset, 0);
    452             }
    453         }
    454         global_idx_offset += cmd_list->IdxBuffer.Size;
    455         global_vtx_offset += cmd_list->VtxBuffer.Size;
    456     }
    457 }
    458 
    459 static void ImGui_ImplWGPU_CreateFontsTexture()
    460 {
    461     // Build texture atlas
    462     ImGuiIO& io = ImGui::GetIO();
    463     unsigned char* pixels;
    464     int width, height, size_pp;
    465     io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height, &size_pp);
    466 
    467     // Upload texture to graphics system
    468     {
    469         WGPUTextureDescriptor tex_desc = {};
    470         tex_desc.label = "Dear ImGui Font Texture";
    471         tex_desc.dimension = WGPUTextureDimension_2D;
    472         tex_desc.size.width = width;
    473         tex_desc.size.height = height;
    474         tex_desc.size.depthOrArrayLayers = 1;
    475         tex_desc.sampleCount = 1;
    476         tex_desc.format = WGPUTextureFormat_RGBA8Unorm;
    477         tex_desc.mipLevelCount = 1;
    478         tex_desc.usage = WGPUTextureUsage_CopyDst | WGPUTextureUsage_Sampled;
    479         g_resources.FontTexture = wgpuDeviceCreateTexture(g_wgpuDevice, &tex_desc);
    480 
    481         WGPUTextureViewDescriptor tex_view_desc = {};
    482         tex_view_desc.format = WGPUTextureFormat_RGBA8Unorm;
    483         tex_view_desc.dimension = WGPUTextureViewDimension_2D;
    484         tex_view_desc.baseMipLevel = 0;
    485         tex_view_desc.mipLevelCount = 1;
    486         tex_view_desc.baseArrayLayer = 0;
    487         tex_view_desc.arrayLayerCount = 1;
    488         tex_view_desc.aspect = WGPUTextureAspect_All;
    489         g_resources.FontTextureView = wgpuTextureCreateView(g_resources.FontTexture, &tex_view_desc);
    490     }
    491 
    492     // Upload texture data
    493     {
    494         WGPUImageCopyTexture dst_view = {};
    495         dst_view.texture = g_resources.FontTexture;
    496         dst_view.mipLevel = 0;
    497         dst_view.origin = { 0, 0, 0 };
    498         dst_view.aspect = WGPUTextureAspect_All;
    499         WGPUTextureDataLayout layout = {};
    500         layout.offset = 0;
    501         layout.bytesPerRow = width * size_pp;
    502         layout.rowsPerImage = height;
    503         WGPUExtent3D size = { (uint32_t)width, (uint32_t)height, 1 };
    504         wgpuQueueWriteTexture(g_defaultQueue, &dst_view, pixels, (uint32_t)(width * size_pp * height), &layout, &size);
    505     }
    506 
    507     // Create the associated sampler
    508     {
    509         WGPUSamplerDescriptor sampler_desc = {};
    510         sampler_desc.minFilter = WGPUFilterMode_Linear;
    511         sampler_desc.magFilter = WGPUFilterMode_Linear;
    512         sampler_desc.mipmapFilter = WGPUFilterMode_Linear;
    513         sampler_desc.addressModeU = WGPUAddressMode_Repeat;
    514         sampler_desc.addressModeV = WGPUAddressMode_Repeat;
    515         sampler_desc.addressModeW = WGPUAddressMode_Repeat;
    516         sampler_desc.maxAnisotropy = 1;
    517         g_resources.Sampler = wgpuDeviceCreateSampler(g_wgpuDevice, &sampler_desc);
    518     }
    519 
    520     // Store our identifier
    521     static_assert(sizeof(ImTextureID) >= sizeof(g_resources.FontTexture), "Can't pack descriptor handle into TexID, 32-bit not supported yet.");
    522     io.Fonts->SetTexID((ImTextureID)g_resources.FontTextureView);
    523 }
    524 
    525 static void ImGui_ImplWGPU_CreateUniformBuffer()
    526 {
    527     WGPUBufferDescriptor ub_desc =
    528     {
    529         NULL,
    530         "Dear ImGui Uniform buffer",
    531         WGPUBufferUsage_CopyDst | WGPUBufferUsage_Uniform,
    532         sizeof(Uniforms),
    533         false
    534     };
    535     g_resources.Uniforms = wgpuDeviceCreateBuffer(g_wgpuDevice, &ub_desc);
    536 }
    537 
    538 bool ImGui_ImplWGPU_CreateDeviceObjects()
    539 {
    540     if (!g_wgpuDevice)
    541         return false;
    542     if (g_pipelineState)
    543         ImGui_ImplWGPU_InvalidateDeviceObjects();
    544 
    545     // Create render pipeline
    546     WGPURenderPipelineDescriptor2 graphics_pipeline_desc = {};
    547     graphics_pipeline_desc.primitive.topology = WGPUPrimitiveTopology_TriangleList;
    548     graphics_pipeline_desc.primitive.stripIndexFormat = WGPUIndexFormat_Undefined;
    549     graphics_pipeline_desc.primitive.frontFace = WGPUFrontFace_CW;
    550     graphics_pipeline_desc.primitive.cullMode = WGPUCullMode_None;
    551     graphics_pipeline_desc.multisample.count = 1;
    552     graphics_pipeline_desc.multisample.mask = UINT_MAX;
    553     graphics_pipeline_desc.multisample.alphaToCoverageEnabled = false;
    554     graphics_pipeline_desc.layout = nullptr; // Use automatic layout generation
    555 
    556     // Create the vertex shader
    557     WGPUProgrammableStageDescriptor vertex_shader_desc = ImGui_ImplWGPU_CreateShaderModule(__glsl_shader_vert_spv, sizeof(__glsl_shader_vert_spv) / sizeof(uint32_t));
    558     graphics_pipeline_desc.vertex.module = vertex_shader_desc.module;
    559     graphics_pipeline_desc.vertex.entryPoint = vertex_shader_desc.entryPoint;
    560 
    561     // Vertex input configuration
    562     WGPUVertexAttribute attribute_desc[] =
    563     {
    564         { WGPUVertexFormat_Float32x2, (uint64_t)IM_OFFSETOF(ImDrawVert, pos), 0 },
    565         { WGPUVertexFormat_Float32x2, (uint64_t)IM_OFFSETOF(ImDrawVert, uv),  1 },
    566         { WGPUVertexFormat_Unorm8x4,  (uint64_t)IM_OFFSETOF(ImDrawVert, col), 2 },
    567     };
    568 
    569     WGPUVertexBufferLayout buffer_layouts[1];
    570     buffer_layouts[0].arrayStride = sizeof(ImDrawVert);
    571     buffer_layouts[0].stepMode = WGPUInputStepMode_Vertex;
    572     buffer_layouts[0].attributeCount = 3;
    573     buffer_layouts[0].attributes = attribute_desc;
    574 
    575     graphics_pipeline_desc.vertex.bufferCount = 1;
    576     graphics_pipeline_desc.vertex.buffers = buffer_layouts;
    577 
    578     // Create the pixel shader
    579     WGPUProgrammableStageDescriptor pixel_shader_desc = ImGui_ImplWGPU_CreateShaderModule(__glsl_shader_frag_spv, sizeof(__glsl_shader_frag_spv) / sizeof(uint32_t));
    580 
    581     // Create the blending setup
    582     WGPUBlendState blend_state = {};
    583     blend_state.alpha.operation = WGPUBlendOperation_Add;
    584     blend_state.alpha.srcFactor = WGPUBlendFactor_One;
    585     blend_state.alpha.dstFactor = WGPUBlendFactor_OneMinusSrcAlpha;
    586     blend_state.color.operation = WGPUBlendOperation_Add;
    587     blend_state.color.srcFactor = WGPUBlendFactor_SrcAlpha;
    588     blend_state.color.dstFactor = WGPUBlendFactor_OneMinusSrcAlpha;
    589 
    590     WGPUColorTargetState color_state = {};
    591     color_state.format = g_renderTargetFormat;
    592     color_state.blend = &blend_state;
    593     color_state.writeMask = WGPUColorWriteMask_All;
    594 
    595     WGPUFragmentState fragment_state = {};
    596     fragment_state.module = pixel_shader_desc.module;
    597     fragment_state.entryPoint = pixel_shader_desc.entryPoint;
    598     fragment_state.targetCount = 1;
    599     fragment_state.targets = &color_state;
    600 
    601     graphics_pipeline_desc.fragment = &fragment_state;
    602 
    603     // Create depth-stencil State
    604     WGPUDepthStencilState depth_stencil_state = {};
    605     depth_stencil_state.depthBias = 0;
    606     depth_stencil_state.depthBiasClamp = 0;
    607     depth_stencil_state.depthBiasSlopeScale = 0;
    608 
    609     // Configure disabled depth-stencil state
    610     graphics_pipeline_desc.depthStencil = nullptr;
    611 
    612     g_pipelineState = wgpuDeviceCreateRenderPipeline2(g_wgpuDevice, &graphics_pipeline_desc);
    613 
    614     ImGui_ImplWGPU_CreateFontsTexture();
    615     ImGui_ImplWGPU_CreateUniformBuffer();
    616 
    617     // Create resource bind group
    618     WGPUBindGroupLayout bg_layouts[2];
    619     bg_layouts[0] = wgpuRenderPipelineGetBindGroupLayout(g_pipelineState, 0);
    620     bg_layouts[1] = wgpuRenderPipelineGetBindGroupLayout(g_pipelineState, 1);
    621 
    622     WGPUBindGroupEntry common_bg_entries[] =
    623     {
    624         { 0, g_resources.Uniforms, 0, sizeof(Uniforms), 0, 0 },
    625         { 1, 0, 0, 0, g_resources.Sampler, 0 },
    626     };
    627 
    628     WGPUBindGroupDescriptor common_bg_descriptor = {};
    629     common_bg_descriptor.layout = bg_layouts[0];
    630     common_bg_descriptor.entryCount = sizeof(common_bg_entries) / sizeof(WGPUBindGroupEntry);
    631     common_bg_descriptor.entries = common_bg_entries;
    632     g_resources.CommonBindGroup = wgpuDeviceCreateBindGroup(g_wgpuDevice, &common_bg_descriptor);
    633 
    634     WGPUBindGroup image_bind_group = ImGui_ImplWGPU_CreateImageBindGroup(bg_layouts[1], g_resources.FontTextureView);
    635     g_resources.ImageBindGroup = image_bind_group;
    636     g_resources.ImageBindGroupLayout = bg_layouts[1];
    637     g_resources.ImageBindGroups.SetVoidPtr(ImHashData(&g_resources.FontTextureView, sizeof(ImTextureID)), image_bind_group);
    638 
    639     SafeRelease(vertex_shader_desc.module);
    640     SafeRelease(pixel_shader_desc.module);
    641     SafeRelease(bg_layouts[0]);
    642 
    643     return true;
    644 }
    645 
    646 void ImGui_ImplWGPU_InvalidateDeviceObjects()
    647 {
    648     if (!g_wgpuDevice)
    649         return;
    650 
    651     SafeRelease(g_pipelineState);
    652     SafeRelease(g_resources);
    653 
    654     ImGuiIO& io = ImGui::GetIO();
    655     io.Fonts->SetTexID(NULL); // We copied g_pFontTextureView to io.Fonts->TexID so let's clear that as well.
    656 
    657     for (unsigned int i = 0; i < g_numFramesInFlight; i++)
    658         SafeRelease(g_pFrameResources[i]);
    659 }
    660 
    661 bool ImGui_ImplWGPU_Init(WGPUDevice device, int num_frames_in_flight, WGPUTextureFormat rt_format)
    662 {
    663     // Setup backend capabilities flags
    664     ImGuiIO& io = ImGui::GetIO();
    665     io.BackendRendererName = "imgui_impl_webgpu";
    666     io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
    667 
    668     g_wgpuDevice = device;
    669     g_defaultQueue = wgpuDeviceGetQueue(g_wgpuDevice);
    670     g_renderTargetFormat = rt_format;
    671     g_pFrameResources = new FrameResources[num_frames_in_flight];
    672     g_numFramesInFlight = num_frames_in_flight;
    673     g_frameIndex = UINT_MAX;
    674 
    675     g_resources.FontTexture = NULL;
    676     g_resources.FontTextureView = NULL;
    677     g_resources.Sampler = NULL;
    678     g_resources.Uniforms = NULL;
    679     g_resources.CommonBindGroup = NULL;
    680     g_resources.ImageBindGroups.Data.reserve(100);
    681     g_resources.ImageBindGroup = NULL;
    682     g_resources.ImageBindGroupLayout = NULL;
    683 
    684     // Create buffers with a default size (they will later be grown as needed)
    685     for (int i = 0; i < num_frames_in_flight; i++)
    686     {
    687         FrameResources* fr = &g_pFrameResources[i];
    688         fr->IndexBuffer = NULL;
    689         fr->VertexBuffer = NULL;
    690         fr->IndexBufferHost = NULL;
    691         fr->VertexBufferHost = NULL;
    692         fr->IndexBufferSize = 10000;
    693         fr->VertexBufferSize = 5000;
    694     }
    695 
    696     return true;
    697 }
    698 
    699 void ImGui_ImplWGPU_Shutdown()
    700 {
    701     ImGui_ImplWGPU_InvalidateDeviceObjects();
    702     delete[] g_pFrameResources;
    703     g_pFrameResources = NULL;
    704     wgpuQueueRelease(g_defaultQueue);
    705     g_wgpuDevice = NULL;
    706     g_numFramesInFlight = 0;
    707     g_frameIndex = UINT_MAX;
    708 }
    709 
    710 void ImGui_ImplWGPU_NewFrame()
    711 {
    712     if (!g_pipelineState)
    713         ImGui_ImplWGPU_CreateDeviceObjects();
    714 }