From dfe6f9ebca22dadea98319e0c4602df2084bde4b Mon Sep 17 00:00:00 2001 From: ocornut Date: Thu, 23 Apr 2026 19:22:04 +0200 Subject: [PATCH] Backends: WebGPU: added SetSamplerLinear/Nearest draw callbacks. (#9378) --- backends/imgui_impl_wgpu.cpp | 55 +++++++++++++++++++++--------------- backends/imgui_impl_wgpu.h | 2 +- docs/CHANGELOG.txt | 2 +- 3 files changed, 35 insertions(+), 24 deletions(-) diff --git a/backends/imgui_impl_wgpu.cpp b/backends/imgui_impl_wgpu.cpp index 0b89abe8f..fe01dcf43 100644 --- a/backends/imgui_impl_wgpu.cpp +++ b/backends/imgui_impl_wgpu.cpp @@ -8,7 +8,7 @@ // [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'. // [X] Renderer: Texture updates support for dynamic font system (ImGuiBackendFlags_RendererHasTextures). // Missing features or Issues: -// [ ] Renderer: Missing support for DrawCallback_SetSamplerLinear, DrawCallback_SetSamplerNearest, DrawCallback_SetSamplerCustom callbacks. +// [ ] Renderer: Missing support for DrawCallback_SetSamplerCustom. // Read imgui_impl_wgpu.h about how to use the IMGUI_IMPL_WEBGPU_BACKEND_WGPU or IMGUI_IMPL_WEBGPU_BACKEND_DAWN flags. @@ -22,7 +22,7 @@ // CHANGELOG // (minor and older changes stripped away, please see git history for details) -// 2026-XX-XX: Added support for standard draw callbacks (in platform_io): DrawCallback_ResetRenderState (others are not yet supported). +// 2026-XX-XX: Added support for standard draw callbacks (in platform_io): DrawCallback_ResetRenderState, DrawCallback_SetSamplerLinear, DrawCallback_SetSamplerNearest. // 2026-03-25: Added support for WGVK native backend via IMGUI_IMPL_WEBGPU_BACKEND_WGVK define, with SPIRV shaders if WGSL is not available. (#9316, #9246, #9257) // 2026-03-09: Removed support for Emscripten < 4.0.10. (#9281) // 2025-10-16: Update to compile with Dawn and Emscripten's 4.0.10+ '--use-port=emdawnwebgpu' ports. (#8381, #8898) @@ -86,11 +86,13 @@ struct ImGui_ImplWGPU_Texture struct RenderResources { - WGPUSampler SamplerLinear = nullptr; // Sampler for textures - WGPUBuffer Uniforms = nullptr; // Shader uniforms - WGPUBindGroup CommonBindGroup = nullptr; // Resources bind-group to bind the common resources to pipeline - ImGuiStorage ImageBindGroups; // Resources bind-group to bind the font/image resources to pipeline (this is a key->value map) - WGPUBindGroupLayout ImageBindGroupLayout = nullptr; // Cache layout used for the image bind group. Avoids allocating unnecessary JS objects when working with WebASM + WGPUSampler SamplerLinear = nullptr; // Bilinear sampler + WGPUSampler SamplerNearest = nullptr; // Nearest/point sampler + WGPUBuffer Uniforms = nullptr; // Shader uniforms + WGPUBindGroup CommonBindGroupLinear = nullptr; // Common bind-group bound to group 0 (uniforms + SamplerLinear) + WGPUBindGroup CommonBindGroupNearest = nullptr; // Common bind-group bound to group 0 (uniforms + SamplerNearest) + ImGuiStorage ImageBindGroups; // Resources bind-group to bind the font/image resources to pipeline (this is a key->value map) + WGPUBindGroupLayout ImageBindGroupLayout = nullptr; // Cache layout used for the image bind group. Avoids allocating unnecessary JS objects when working with WebASM }; struct FrameResources @@ -117,6 +119,7 @@ struct ImGui_ImplWGPU_Data WGPUTextureFormat renderTargetFormat = WGPUTextureFormat_Undefined; WGPUTextureFormat depthStencilFormat = WGPUTextureFormat_Undefined; WGPURenderPipeline pipelineState = nullptr; + ImGui_ImplWGPU_RenderState* RenderState = nullptr; // == ImGui::GetPlatformIO().Renderer_RenderState during rendering. RenderResources renderResources; FrameResources* pFrameResources = nullptr; @@ -300,8 +303,10 @@ static void SafeRelease(WGPUShaderModule& res) static void SafeRelease(RenderResources& res) { SafeRelease(res.SamplerLinear); + SafeRelease(res.SamplerNearest); SafeRelease(res.Uniforms); - SafeRelease(res.CommonBindGroup); + SafeRelease(res.CommonBindGroupLinear); + SafeRelease(res.CommonBindGroupNearest); SafeRelease(res.ImageBindGroupLayout); }; @@ -423,7 +428,7 @@ static void ImGui_ImplWGPU_SetupRenderState(ImDrawData* draw_data, WGPURenderPas wgpuRenderPassEncoderSetVertexBuffer(ctx, 0, fr->VertexBuffer, 0, fr->VertexBufferSize * sizeof(ImDrawVert)); wgpuRenderPassEncoderSetIndexBuffer(ctx, fr->IndexBuffer, sizeof(ImDrawIdx) == 2 ? WGPUIndexFormat_Uint16 : WGPUIndexFormat_Uint32, 0, fr->IndexBufferSize * sizeof(ImDrawIdx)); wgpuRenderPassEncoderSetPipeline(ctx, bd->pipelineState); - wgpuRenderPassEncoderSetBindGroup(ctx, 0, bd->renderResources.CommonBindGroup, 0, nullptr); + wgpuRenderPassEncoderSetBindGroup(ctx, 0, bd->renderResources.CommonBindGroupLinear, 0, nullptr); // Setup blend factor WGPUColor blend_color = { 0.f, 0.f, 0.f, 0.f }; @@ -431,7 +436,9 @@ static void ImGui_ImplWGPU_SetupRenderState(ImDrawData* draw_data, WGPURenderPas } // Draw callbacks -static void ImGui_ImplWGPU_DrawCallback_ResetRenderState(const ImDrawList*, const ImDrawCmd*) {} // Intentionally empty. Used as an identifier for rendering loop to call its code. Simpler to implement this way. +static void ImGui_ImplWGPU_DrawCallback_ResetRenderState(const ImDrawList*, const ImDrawCmd*) {} // Intentionally empty. Used as an identifier for rendering loop to call its code. Simpler to implement this way. +static void ImGui_ImplWGPU_DrawCallback_SetSamplerLinear(const ImDrawList*, const ImDrawCmd*) { ImGui_ImplWGPU_Data* bd = ImGui_ImplWGPU_GetBackendData(); wgpuRenderPassEncoderSetBindGroup(bd->RenderState->RenderPassEncoder, 0, bd->renderResources.CommonBindGroupLinear, 0, nullptr); } +static void ImGui_ImplWGPU_DrawCallback_SetSamplerNearest(const ImDrawList*, const ImDrawCmd*) { ImGui_ImplWGPU_Data* bd = ImGui_ImplWGPU_GetBackendData(); wgpuRenderPassEncoderSetBindGroup(bd->RenderState->RenderPassEncoder, 0, bd->renderResources.CommonBindGroupNearest, 0, nullptr); } // Render function void ImGui_ImplWGPU_RenderDrawData(ImDrawData* draw_data, WGPURenderPassEncoder pass_encoder) @@ -528,7 +535,7 @@ void ImGui_ImplWGPU_RenderDrawData(ImDrawData* draw_data, WGPURenderPassEncoder ImGui_ImplWGPU_RenderState render_state; render_state.Device = bd->wgpuDevice; render_state.RenderPassEncoder = pass_encoder; - platform_io.Renderer_RenderState = &render_state; + platform_io.Renderer_RenderState = bd->RenderState = &render_state; // Render command lists // (Because we merged all buffers into a single one, we maintain our own offset into them) @@ -591,7 +598,7 @@ void ImGui_ImplWGPU_RenderDrawData(ImDrawData* draw_data, WGPURenderPassEncoder } image_bind_groups.Data.resize(0); - platform_io.Renderer_RenderState = nullptr; + platform_io.Renderer_RenderState = bd->RenderState = nullptr; } static void ImGui_ImplWGPU_DestroyTexture(ImTextureData* tex) @@ -819,19 +826,23 @@ bool ImGui_ImplWGPU_CreateDeviceObjects() ImGui_ImplWGPU_CreateUniformBuffer(); - // Create sampler + // Create samplers (Linear/Nearest) // (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling) WGPUSamplerDescriptor sampler_desc = {}; - sampler_desc.minFilter = WGPUFilterMode_Linear; - sampler_desc.magFilter = WGPUFilterMode_Linear; - sampler_desc.mipmapFilter = WGPUMipmapFilterMode_Linear; sampler_desc.addressModeU = WGPUAddressMode_ClampToEdge; sampler_desc.addressModeV = WGPUAddressMode_ClampToEdge; sampler_desc.addressModeW = WGPUAddressMode_ClampToEdge; sampler_desc.maxAnisotropy = 1; + sampler_desc.minFilter = WGPUFilterMode_Linear; + sampler_desc.magFilter = WGPUFilterMode_Linear; + sampler_desc.mipmapFilter = WGPUMipmapFilterMode_Linear; bd->renderResources.SamplerLinear = wgpuDeviceCreateSampler(bd->wgpuDevice, &sampler_desc); + sampler_desc.minFilter = WGPUFilterMode_Nearest; + sampler_desc.magFilter = WGPUFilterMode_Nearest; + sampler_desc.mipmapFilter = WGPUMipmapFilterMode_Nearest; + bd->renderResources.SamplerNearest = wgpuDeviceCreateSampler(bd->wgpuDevice, &sampler_desc); - // Create resource bind group + // Create resource bind groups (one per sampler, otherwise identical) WGPUBindGroupEntry common_bg_entries[] = { { nullptr, 0, bd->renderResources.Uniforms, 0, MEMALIGN(sizeof(Uniforms), 16), 0, 0 }, @@ -841,7 +852,9 @@ bool ImGui_ImplWGPU_CreateDeviceObjects() common_bg_descriptor.layout = bg_layouts[0]; common_bg_descriptor.entryCount = sizeof(common_bg_entries) / sizeof(WGPUBindGroupEntry); common_bg_descriptor.entries = common_bg_entries; - bd->renderResources.CommonBindGroup = wgpuDeviceCreateBindGroup(bd->wgpuDevice, &common_bg_descriptor); + bd->renderResources.CommonBindGroupLinear = wgpuDeviceCreateBindGroup(bd->wgpuDevice, &common_bg_descriptor); + common_bg_entries[1].sampler = bd->renderResources.SamplerNearest; + bd->renderResources.CommonBindGroupNearest = wgpuDeviceCreateBindGroup(bd->wgpuDevice, &common_bg_descriptor); bd->renderResources.ImageBindGroupLayout = bg_layouts[1]; SafeRelease(vertex_shader_desc.module); @@ -895,6 +908,8 @@ bool ImGui_ImplWGPU_Init(ImGui_ImplWGPU_InitInfo* init_info) ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO(); platform_io.DrawCallback_ResetRenderState = ImGui_ImplWGPU_DrawCallback_ResetRenderState; + platform_io.DrawCallback_SetSamplerLinear = ImGui_ImplWGPU_DrawCallback_SetSamplerLinear; + platform_io.DrawCallback_SetSamplerNearest = ImGui_ImplWGPU_DrawCallback_SetSamplerNearest; bd->initInfo = *init_info; bd->wgpuDevice = init_info->Device; @@ -904,11 +919,7 @@ bool ImGui_ImplWGPU_Init(ImGui_ImplWGPU_InitInfo* init_info) bd->numFramesInFlight = init_info->NumFramesInFlight; bd->frameIndex = UINT_MAX; - bd->renderResources.SamplerLinear = nullptr; - bd->renderResources.Uniforms = nullptr; - bd->renderResources.CommonBindGroup = nullptr; bd->renderResources.ImageBindGroups.Data.reserve(100); - bd->renderResources.ImageBindGroupLayout = nullptr; // Create buffers with a default size (they will later be grown as needed) bd->pFrameResources = new FrameResources[bd->numFramesInFlight]; diff --git a/backends/imgui_impl_wgpu.h b/backends/imgui_impl_wgpu.h index 2e4ea92e4..e1bbf9d85 100644 --- a/backends/imgui_impl_wgpu.h +++ b/backends/imgui_impl_wgpu.h @@ -20,7 +20,7 @@ // [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'. // [X] Renderer: Texture updates support for dynamic font system (ImGuiBackendFlags_RendererHasTextures). // Missing features or Issues: -// [ ] Renderer: Missing support for DrawCallback_SetSamplerLinear, DrawCallback_SetSamplerNearest, DrawCallback_SetSamplerCustom callbacks. +// [ ] Renderer: Missing support for DrawCallback_SetSamplerCustom. // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this. // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need. diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt index 3df412006..658d895a2 100644 --- a/docs/CHANGELOG.txt +++ b/docs/CHANGELOG.txt @@ -145,7 +145,7 @@ Other Changes: - SDLRenderer2: Reset n/a n/a n/a - SDLRenderer3: Reset SetSamplerLinear SetSamplerNearest n/a - Vulkan: Reset SetSamplerLinear SetSamplerNearest SetSamplerCustom - - WebGPU: Reset *missing* *missing* *missing* + - WebGPU: Reset SetSamplerLinear SetSamplerNearest *missing* (Vulkan backend by @yaz0r, others by @ocornut) - GLFW: added a Win32-specific implementation of `ImGui_ImplGlfw_GetContentScaleXXXX` functions for legacy GLFW 3.2. (#9003)