// dear imgui: Renderer for WebGPU
// This needs to be used along with a Platform Binding (e.g. GLFW)
// (Please note that WebGPU is currently experimental, will not run on non-beta browsers, and may break.)
// Implemented features:
// [X] Renderer: User texture binding. Use 'WGPUTextureView' as ImTextureID. Read the FAQ about ImTextureID!
// [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
// 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.
// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
// Read online: https://github.com/ocornut/imgui/tree/master/docs
// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
// 2023-04-11: Align buffer sizes. Use WGSL shaders instead of precompiled SPIR-V.
// 2023-04-11: Reorganized backend to pull data from a single structure to facilitate usage with multiple-contexts (all g_XXXX access changed to bd->XXXX).
// 2023-01-25: Revert automatic pipeline layout generation (see https://github.com/gpuweb/gpuweb/issues/2470)
// 2022-11-24: Fixed validation error with default depth buffer settings.
// 2022-11-10: Fixed rendering when a depth buffer is enabled. Added 'WGPUTextureFormat depth_format' parameter to ImGui_ImplWGPU_Init().
// 2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
// 2021-11-29: Passing explicit buffer sizes to wgpuRenderPassEncoderSetVertexBuffer()/wgpuRenderPassEncoderSetIndexBuffer().
// 2021-08-24: Fixed for latest specs.
// 2021-05-24: Add support for draw_data->FramebufferScale.
// 2021-05-19: Replaced direct access to ImDrawCmd::TextureId with a call to ImDrawCmd::GetTexID(). (will become a requirement)
// 2021-05-16: Update to latest WebGPU specs (compatible with Emscripten 2.0.20 and Chrome Canary 92).
// 2021-02-18: Change blending equation to preserve alpha in output buffer.
// 2021-01-28: Initial version.
#include "imgui.h"
#include "imgui_impl_wgpu.h"
#include <limits.h>
#include <webgpu/webgpu.h>
// Dear ImGui prototypes from imgui_internal.h
extern ImGuiID ImHashData(const void* data_p, size_t data_size, ImU32 seed = 0);
#define MEMALIGN(_SIZE,_ALIGN) (((_SIZE) + ((_ALIGN) - 1)) & ~((_ALIGN) - 1)) // Memory align (copied from IM_ALIGN() macro).
// WebGPU data
struct RenderResources
{
WGPUTexture FontTexture = nullptr; // Font texture
WGPUTextureView FontTextureView = nullptr; // Texture view for font texture
WGPUSampler Sampler = nullptr; // Sampler for the font texture
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)
WGPUBindGroup ImageBindGroup = nullptr; // Default font-resource of Dear ImGui
WGPUBindGroupLayout ImageBindGroupLayout = nullptr; // Cache layout used for the image bind group. Avoids allocating unnecessary JS objects when working with WebASM
};
struct FrameResources
{
WGPUBuffer IndexBuffer;
WGPUBuffer VertexBuffer;
ImDrawIdx* IndexBufferHost;
ImDrawVert* VertexBufferHost;
int IndexBufferSize;
int VertexBufferSize;
};
struct Uniforms
{
float MVP[4][4];
float Gamma;
};
struct ImGui_ImplWGPU_Data
{
WGPUDevice wgpuDevice = nullptr;
WGPUQueue defaultQueue = nullptr;
WGPUTextureFormat renderTargetFormat = WGPUTextureFormat_Undefined;
WGPUTextureFormat depthStencilFormat = WGPUTextureFormat_Undefined;
WGPURenderPipeline pipelineState = nullptr;
RenderResources renderResources;
FrameResources* pFrameResources = nullptr;
unsigned int numFramesInFlight = 0;
unsigned int frameIndex = UINT_MAX;
};
// Backend data stored in io.BackendRendererUserData to allow support for multiple Dear ImGui contexts
// It is STRONGLY preferred that you use docking branch with multi-viewports (== single Dear ImGui context + multiple windows) instead of multiple Dear ImGui contexts.
static ImGui_ImplWGPU_Data* ImGui_ImplWGPU_GetBackendData()
{
return ImGui::GetCurrentContext() ? (ImGui_ImplWGPU_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
}
//-----------------------------------------------------------------------------
// SHADERS
//-----------------------------------------------------------------------------
static const char __shader_vert_wgsl[] = R"(
struct VertexInput {
@location(0) position: vec2<f32>,
@location(1) uv: vec2<f32>,
@location(2) color: vec4<f32>,
};
struct VertexOutput {
@builtin(position) position: vec4<f32>,
@location(0) color: vec4<f32>,
@location(1) uv: vec2<f32>,
};
struct Uniforms {
mvp: mat4x4<f32>,
gamma: f32,
};
@group(0) @binding(0) var<uniform> uniforms: Uniforms;
@vertex
fn main(in: VertexInput) -> VertexOutput {
var out: VertexOutput;
out.position = uniforms.mvp * vec4<f32>(in.position, 0.0, 1.0);
out.color = in.color;
out.uv = in.uv;
return out;
}
)";
static const char __shader_frag_wgsl[] = R"(
struct VertexOutput {
@builtin(position) position: vec4<f32>,
@location(0) color: vec4<f32>,
@location(1) uv: vec2<f32>,
};
struct Uniforms {
mvp: mat4x4<f32>,
gamma: f32,
};
@group(0) @binding(0) var<uniform> uniforms: Uniforms;
@group(0) @binding(1) var s: sampler;
@group(1) @binding(0) var t: texture_2d<f32>;
@fragment
fn main(in: VertexOutput) -> @location(0) vec4<f32> {
let color = in.color * textureSample(t, s, in.uv);
let corrected_color = pow(color.rgb, vec3<f32>(uniforms.gamma));
return vec4<f32>(corrected_color, color.a);
}
)";
static void SafeRelease(ImDrawIdx*& res)
{
if (res)
delete[] res;
res = nullptr;
}
static void SafeRelease(ImDrawVert*& res)
{
if (res)
delete[] res;
res = nullptr;
}
static void SafeRelease(WGPUBindGroupLayout& res)
{
if (res)
wgpuBindGroupLayoutRelease(res);
res = nullptr;
}
static void SafeRelease(WGPUBindGroup& res)
{
if (res)
wgpuBindGroupRelease(res);
res = nullptr;
}
static void SafeRelease(WGPUBuffer& res)
{
if (res)
wgpuBufferRelease(res);
res = nullptr;
}
static void SafeRelease(WGPURenderPipeline& res)
{
if (res)
wgpuRenderPipelineRelease(res);
res = nullptr;
}
static void SafeRelease(WGPUSampler& res)
{
if (res)
wgpuSamplerRelease(res);
res = nullptr;
}
static void SafeRelease(WGPUShaderModule& res)
{
if (res)
wgpuShaderModuleRelease(res);
res = nullptr;
}
static void SafeRelease(WGPUTextureView& res)
{
if (res)
wgpuTextureViewRelease(res);
res = nullptr;
}
static void SafeRelease(WGPUTexture& res)
{
if (res)
wgpuTextureRelease(res);
res = nullptr;
}
static void SafeRelease(RenderResources& res)
{
SafeRelease(res.FontTexture);
SafeRelease(res.FontTextureView);
SafeRelease(res.Sampler);
SafeRelease(res.Uniforms);
SafeRelease(res.CommonBindGroup);
SafeRelease(res.ImageBindGroup);
SafeRelease(res.ImageBindGroupLayout);
};
static void SafeRelease(FrameResources& res)
{
SafeRelease(res.IndexBuffer);
SafeRelease(res.VertexBuffer);
SafeRelease(res.IndexBufferHost);
SafeRelease(res.VertexBufferHost);
}
static WGPUProgrammableStageDescriptor ImGui_ImplWGPU_CreateShaderModule(const char* wgsl_source)
{
ImGui_ImplWGPU_Data* bd = ImGui_ImplWGPU_GetBackendData();
WGPUShaderModuleWGSLDescriptor wgsl_desc = {};
wgsl_desc.chain.sType = WGPUSType_ShaderModuleWGSLDescriptor;
wgsl_desc.source = wgsl_source;
WGPUShaderModuleDescriptor desc = {};
desc.nextInChain = reinterpret_cast<WGPUChainedStruct*>(&wgsl_desc);
WGPUProgrammableStageDescriptor stage_desc = {};
stage_desc.module = wgpuDeviceCreateShaderModule(bd->wgpuDevice, &desc);
stage_desc.entryPoint = "main";
return stage_desc;
}
static WGPUBindGroup ImGui_ImplWGPU_CreateImageBindGroup(WGPUBindGroupLayout layout, WGPUTextureView texture)
{
ImGui_ImplWGPU_Data* bd = ImGui_ImplWGPU_GetBackendData();
WGPUBindGroupEntry image_bg_entries[] = { { nullptr, 0, 0, 0, 0, 0, texture } };
WGPUBindGroupDescriptor image_bg_descriptor = {};
image_bg_descriptor.layout = layout;
image_bg_descriptor.entryCount = sizeof(image_bg_entries) / sizeof(WGPUBindGroupEntry);
image_bg_descriptor.entries = image_bg_entries;
return wgpuDeviceCreateBindGroup(bd->wgpuDevice, &image_bg_descriptor);
}
static void ImGui_ImplWGPU_SetupRenderState(ImDrawData* draw_data, WGPURenderPassEncoder ctx, FrameResources* fr)
{
ImGui_ImplWGPU_Data* bd = ImGui_ImplWGPU_GetBackendData();
// 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).
{
float L = draw_data->DisplayPos.x;
float R = draw_data->DisplayPos.x + draw_data->DisplaySize.x;
float T = draw_data->DisplayPos.y;
float B = draw_data->DisplayPos.y + draw_data->DisplaySize.y;
float mvp[4][4] =
{
{ 2.0f/(R-L), 0.0f, 0.0f, 0.0f },
{ 0.0f, 2.0f/(T-B), 0.0f, 0.0f },
{ 0.0f, 0.0f, 0.5f, 0.0f },
{ (R+L)/(L-R), (T+B)/(B-T), 0.5f, 1.0f },
};
wgpuQueueWriteBuffer(bd->defaultQueue, bd->renderResources.Uniforms, offsetof(Uniforms, MVP), mvp, sizeof(Uniforms::MVP));
float gamma;
switch (bd->renderTargetFormat)
{
case WGPUTextureFormat_ASTC10x10UnormSrgb:
case WGPUTextureFormat_ASTC10x5UnormSrgb:
case WGPUTextureFormat_ASTC10x6UnormSrgb:
case WGPUTextureFormat_ASTC10x8UnormSrgb:
case WGPUTextureFormat_ASTC12x10UnormSrgb:
case WGPUTextureFormat_ASTC12x12UnormSrgb:
case WGPUTextureFormat_ASTC4x4UnormSrgb:
case WGPUTextureFormat_ASTC5x5UnormSrgb:
case WGPUTextureFormat_ASTC6x5UnormSrgb:
case WGPUTextureFormat_ASTC6x6UnormSrgb:
case WGPUTextureFormat_ASTC8x5UnormSrgb:
case WGPUTextureFormat_ASTC8x6UnormSrgb:
case WGPUTextureFormat_ASTC8x8UnormSrgb:
case WGPUTextureFormat_BC1RGBAUnormSrgb:
case WGPUTextureFormat_BC2RGBAUnormSrgb:
case WGPUTextureFormat_BC3RGBAUnormSrgb:
case WGPUTextureFormat_BC7RGBAUnormSrgb:
case WGPUTextureFormat_BGRA8UnormSrgb:
case WGPUTextureFormat_ETC2RGB8A1UnormSrgb:
case WGPUTextureFormat_ETC2RGB8UnormSrgb:
case WGPUTextureFormat_ETC2RGBA8UnormSrgb:
case WGPUTextureFormat_RGBA8UnormSrgb:
gamma = 2.2f;
break;
default:
gamma = 1.0f;
}
wgpuQueueWriteBuffer(bd->defaultQueue, bd->renderResources.Uniforms, offsetof(Uniforms, Gamma), &gamma, sizeof(Uniforms::Gamma));
}
// Setup viewport
wgpuRenderPassEncoderSetViewport(ctx, 0, 0, draw_data->FramebufferScale.x * draw_data->DisplaySize.x, draw_data->FramebufferScale.y * draw_data->DisplaySize.y, 0, 1);
// Bind shader and vertex buffers
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);
// Setup blend factor
WGPUColor blend_color = { 0.f, 0.f, 0.f, 0.f };
wgpuRenderPassEncoderSetBlendConstant(ctx, &blend_color);
}
// Render function
// (this used to be set in io.RenderDrawListsFn and called by ImGui::Render(), but you can now call this directly from your main loop)
void ImGui_ImplWGPU_RenderDrawData(ImDrawData* draw_data, WGPURenderPassEncoder pass_encoder)
{
// Avoid rendering when minimized
if (draw_data->DisplaySize.x <= 0.0f || draw_data->DisplaySize.y <= 0.0f)
return;
// FIXME: 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.
ImGui_ImplWGPU_Data* bd = ImGui_ImplWGPU_GetBackendData();
bd->frameIndex = bd->frameIndex + 1;
FrameResources* fr = &bd->pFrameResources[bd->frameIndex % bd->numFramesInFlight];
// Create and grow vertex/index buffers if needed
if (fr->VertexBuffer == nullptr || fr->VertexBufferSize < draw_data->TotalVtxCount)
{
if (fr->VertexBuffer)
{
wgpuBufferDestroy(fr->VertexBuffer);
wgpuBufferRelease(fr->VertexBuffer);
}
SafeRelease(fr->VertexBufferHost);
fr->VertexBufferSize = draw_data->TotalVtxCount + 5000;
WGPUBufferDescriptor vb_desc =
{
nullptr,
"Dear ImGui Vertex buffer",
WGPUBufferUsage_CopyDst | WGPUBufferUsage_Vertex,
MEMALIGN(fr->VertexBufferSize * sizeof(ImDrawVert), 4),
false
};
fr->VertexBuffer = wgpuDeviceCreateBuffer(bd->wgpuDevice, &vb_desc);
if (!fr->VertexBuffer)
return;
fr->VertexBufferHost = new ImDrawVert[fr->VertexBufferSize];
}
if (fr->IndexBuffer == nullptr || fr->IndexBufferSize < draw_data->TotalIdxCount)
{
if (fr->IndexBuffer)
{
wgpuBufferDestroy(fr->IndexBuffer);
wgpuBufferRelease(fr->IndexBuffer);
}
SafeRelease(fr->IndexBufferHost);
fr->IndexBufferSize = draw_data->TotalIdxCount + 10000;
WGPUBufferDescriptor ib_desc =
{
nullptr,
"Dear ImGui Index buffer",
WGPUBufferUsage_CopyDst | WGPUBufferUsage_Index,
MEMALIGN(fr->IndexBufferSize * sizeof(ImDrawIdx), 4),
false
};
fr->IndexBuffer = wgpuDeviceCreateBuffer(bd->wgpuDevice, &ib_desc);
if (!fr->IndexBuffer)
return;
fr->IndexBufferHost = new ImDrawIdx[fr->IndexBufferSize];
}
// Upload vertex/index data into a single contiguous GPU buffer
ImDrawVert* vtx_dst = (ImDrawVert*)fr->VertexBufferHost;
ImDrawIdx* idx_dst = (ImDrawIdx*)fr->IndexBufferHost;
for (int n = 0; n < draw_data->CmdListsCount; n++)
{
const ImDrawList* cmd_list = draw_data->CmdLists[n];
memcpy(vtx_dst, cmd_list->VtxBuffer.Data, cmd_list->VtxBuffer.Size * sizeof(ImDrawVert));
memcpy(idx_dst, cmd_list->IdxBuffer.Data, cmd_list->IdxBuffer.Size * sizeof(ImDrawIdx));
vtx_dst += cmd_list->VtxBuffer.Size;
idx_dst += cmd_list->IdxBuffer.Size;
}
int64_t vb_write_size = MEMALIGN((char*)vtx_dst - (char*)fr->VertexBufferHost, 4);
int64_t ib_write_size = MEMALIGN((char*)idx_dst - (char*)fr->IndexBufferHost, 4);
wgpuQueueWriteBuffer(bd->defaultQueue, fr->VertexBuffer, 0, fr->VertexBufferHost, vb_write_size);
wgpuQueueWriteBuffer(bd->defaultQueue, fr->IndexBuffer, 0, fr->IndexBufferHost, ib_write_size);
// Setup desired render state
ImGui_ImplWGPU_SetupRenderState(draw_data, pass_encoder, fr);
// Render command lists
// (Because we merged all buffers into a single one, we maintain our own offset into them)
int global_vtx_offset = 0;
int global_idx_offset = 0;
ImVec2 clip_scale = draw_data->FramebufferScale;
ImVec2 clip_off = draw_data->DisplayPos;
for (int n = 0; n < draw_data->CmdListsCount; n++)
{
const ImDrawList* cmd_list = draw_data->CmdLists[n];
for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
{
const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
if (pcmd->UserCallback != nullptr)
{
// User callback, registered via ImDrawList::AddCallback()
// (ImDrawCallback_ResetRenderState is a special callback value used by the user to request the renderer to reset render state.)
if (pcmd->UserCallback == ImDrawCallback_ResetRenderState)
ImGui_ImplWGPU_SetupRenderState(draw_data, pass_encoder, fr);
else
pcmd->UserCallback(cmd_list, pcmd);
}
else
{
// Bind custom texture
ImTextureID tex_id = pcmd->GetTexID();
ImGuiID tex_id_hash = ImHashData(&tex_id, sizeof(tex_id));
auto bind_group = bd->renderResources.ImageBindGroups.GetVoidPtr(tex_id_hash);
if (bind_group)
{
wgpuRenderPassEncoderSetBindGroup(pass_encoder, 1, (WGPUBindGroup)bind_group, 0, nullptr);
}
else
{
WGPUBindGroup image_bind_group = ImGui_ImplWGPU_CreateImageBindGroup(bd->renderResources.ImageBindGroupLayout, (WGPUTextureView)tex_id);
bd->renderResources.ImageBindGroups.SetVoidPtr(tex_id_hash, image_bind_group);
wgpuRenderPassEncoderSetBindGroup(pass_encoder, 1, image_bind_group, 0, nullptr);
}
// Project scissor/clipping rectangles into framebuffer space
ImVec2 clip_min((pcmd->ClipRect.x - clip_off.x) * clip_scale.x, (pcmd->ClipRect.y - clip_off.y) * clip_scale.y);
ImVec2 clip_max((pcmd->ClipRect.z - clip_off.x) * clip_scale.x, (pcmd->ClipRect.w - clip_off.y) * clip_scale.y);
if (clip_max.x <= clip_min.x || clip_max.y <= clip_min.y)
continue;
// Apply scissor/clipping rectangle, Draw
wgpuRenderPassEncoderSetScissorRect(pass_encoder, (uint32_t)clip_min.x, (uint32_t)clip_min.y, (uint32_t)(clip_max.x - clip_min.x), (uint32_t)(clip_max.y - clip_min.y));
wgpuRenderPassEncoderDrawIndexed(pass_encoder, pcmd->ElemCount, 1, pcmd->IdxOffset + global_idx_offset, pcmd->VtxOffset + global_vtx_offset, 0);
}
}
global_idx_offset += cmd_list->IdxBuffer.Size;
global_vtx_offset += cmd_list->VtxBuffer.Size;
}
}
static void ImGui_ImplWGPU_CreateFontsTexture()
{
// Build texture atlas
ImGui_ImplWGPU_Data* bd = ImGui_ImplWGPU_GetBackendData();
ImGuiIO& io = ImGui::GetIO();
unsigned char* pixels;
int width, height, size_pp;
io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height, &size_pp);
// Upload texture to graphics system
{
WGPUTextureDescriptor tex_desc = {};
tex_desc.label = "Dear ImGui Font Texture";
tex_desc.dimension = WGPUTextureDimension_2D;
tex_desc.size.width = width;
tex_desc.size.height = height;
tex_desc.size.depthOrArrayLayers = 1;
tex_desc.sampleCount = 1;
tex_desc.format = WGPUTextureFormat_RGBA8Unorm;
tex_desc.mipLevelCount = 1;
tex_desc.usage = WGPUTextureUsage_CopyDst | WGPUTextureUsage_TextureBinding;
bd->renderResources.FontTexture = wgpuDeviceCreateTexture(bd->wgpuDevice, &tex_desc);
WGPUTextureViewDescriptor tex_view_desc = {};
tex_view_desc.format = WGPUTextureFormat_RGBA8Unorm;
tex_view_desc.dimension = WGPUTextureViewDimension_2D;
tex_view_desc.baseMipLevel = 0;
tex_view_desc.mipLevelCount = 1;
tex_view_desc.baseArrayLayer = 0;
tex_view_desc.arrayLayerCount = 1;
tex_view_desc.aspect = WGPUTextureAspect_All;
bd->renderResources.FontTextureView = wgpuTextureCreateView(bd->renderResources.FontTexture, &tex_view_desc);
}
// Upload texture data
{
WGPUImageCopyTexture dst_view = {};
dst_view.texture = bd->renderResources.FontTexture;
dst_view.mipLevel = 0;
dst_view.origin = { 0, 0, 0 };
dst_view.aspect = WGPUTextureAspect_All;
WGPUTextureDataLayout layout = {};
layout.offset = 0;
layout.bytesPerRow = width * size_pp;
layout.rowsPerImage = height;
WGPUExtent3D size = { (uint32_t)width, (uint32_t)height, 1 };
wgpuQueueWriteTexture(bd->defaultQueue, &dst_view, pixels, (uint32_t)(width * size_pp * height), &layout, &size);
}
// Create the associated sampler
// (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 = WGPUFilterMode_Linear;
sampler_desc.addressModeU = WGPUAddressMode_Repeat;
sampler_desc.addressModeV = WGPUAddressMode_Repeat;
sampler_desc.addressModeW = WGPUAddressMode_Repeat;
sampler_desc.maxAnisotropy = 1;
bd->renderResources.Sampler = wgpuDeviceCreateSampler(bd->wgpuDevice, &sampler_desc);
}
// Store our identifier
static_assert(sizeof(ImTextureID) >= sizeof(bd->renderResources.FontTexture), "Can't pack descriptor handle into TexID, 32-bit not supported yet.");
io.Fonts->SetTexID((ImTextureID)bd->renderResources.FontTextureView);
}
static void ImGui_ImplWGPU_CreateUniformBuffer()
{
ImGui_ImplWGPU_Data* bd = ImGui_ImplWGPU_GetBackendData();
WGPUBufferDescriptor ub_desc =
{
nullptr,
"Dear ImGui Uniform buffer",
WGPUBufferUsage_CopyDst | WGPUBufferUsage_Uniform,
MEMALIGN(sizeof(Uniforms), 16),
false
};
bd->renderResources.Uniforms = wgpuDeviceCreateBuffer(bd->wgpuDevice, &ub_desc);
}
bool ImGui_ImplWGPU_CreateDeviceObjects()
{
ImGui_ImplWGPU_Data* bd = ImGui_ImplWGPU_GetBackendData();
if (!bd->wgpuDevice)
return false;
if (bd->pipelineState)
ImGui_ImplWGPU_InvalidateDeviceObjects();
// Create render pipeline
WGPURenderPipelineDescriptor graphics_pipeline_desc = {};
graphics_pipeline_desc.primitive.topology = WGPUPrimitiveTopology_TriangleList;
graphics_pipeline_desc.primitive.stripIndexFormat = WGPUIndexFormat_Undefined;
graphics_pipeline_desc.primitive.frontFace = WGPUFrontFace_CW;
graphics_pipeline_desc.primitive.cullMode = WGPUCullMode_None;
graphics_pipeline_desc.multisample.count = 1;
graphics_pipeline_desc.multisample.mask = UINT_MAX;
graphics_pipeline_desc.multisample.alphaToCoverageEnabled = false;
// Bind group layouts
WGPUBindGroupLayoutEntry common_bg_layout_entries[2] = {};
common_bg_layout_entries[0].binding = 0;
common_bg_layout_entries[0].visibility = WGPUShaderStage_Vertex | WGPUShaderStage_Fragment;
common_bg_layout_entries[0].buffer.type = WGPUBufferBindingType_Uniform;
common_bg_layout_entries[1].binding = 1;
common_bg_layout_entries[1].visibility = WGPUShaderStage_Fragment;
common_bg_layout_entries[1].sampler.type = WGPUSamplerBindingType_Filtering;
WGPUBindGroupLayoutEntry image_bg_layout_entries[1] = {};
image_bg_layout_entries[0].binding = 0;
image_bg_layout_entries[0].visibility = WGPUShaderStage_Fragment;
image_bg_layout_entries[0].texture.sampleType = WGPUTextureSampleType_Float;
image_bg_layout_entries[0].texture.viewDimension = WGPUTextureViewDimension_2D;
WGPUBindGroupLayoutDescriptor common_bg_layout_desc = {};
common_bg_layout_desc.entryCount = 2;
common_bg_layout_desc.entries = common_bg_layout_entries;
WGPUBindGroupLayoutDescriptor image_bg_layout_desc = {};
image_bg_layout_desc.entryCount = 1;
image_bg_layout_desc.entries = image_bg_layout_entries;
WGPUBindGroupLayout bg_layouts[2];
bg_layouts[0] = wgpuDeviceCreateBindGroupLayout(bd->wgpuDevice, &common_bg_layout_desc);
bg_layouts[1] = wgpuDeviceCreateBindGroupLayout(bd->wgpuDevice, &image_bg_layout_desc);
WGPUPipelineLayoutDescriptor layout_desc = {};
layout_desc.bindGroupLayoutCount = 2;
layout_desc.bindGroupLayouts = bg_layouts;
graphics_pipeline_desc.layout = wgpuDeviceCreatePipelineLayout(bd->wgpuDevice, &layout_desc);
// Create the vertex shader
WGPUProgrammableStageDescriptor vertex_shader_desc = ImGui_ImplWGPU_CreateShaderModule(__shader_vert_wgsl);
graphics_pipeline_desc.vertex.module = vertex_shader_desc.module;
graphics_pipeline_desc.vertex.entryPoint = vertex_shader_desc.entryPoint;
// Vertex input configuration
WGPUVertexAttribute attribute_desc[] =
{
{ WGPUVertexFormat_Float32x2, (uint64_t)IM_OFFSETOF(ImDrawVert, pos), 0 },
{ WGPUVertexFormat_Float32x2, (uint64_t)IM_OFFSETOF(ImDrawVert, uv), 1 },
{ WGPUVertexFormat_Unorm8x4, (uint64_t)IM_OFFSETOF(ImDrawVert, col), 2 },
};
WGPUVertexBufferLayout buffer_layouts[1];
buffer_layouts[0].arrayStride = sizeof(ImDrawVert);
buffer_layouts[0].stepMode = WGPUVertexStepMode_Vertex;
buffer_layouts[0].attributeCount = 3;
buffer_layouts[0].attributes = attribute_desc;
graphics_pipeline_desc.vertex.bufferCount = 1;
graphics_pipeline_desc.vertex.buffers = buffer_layouts;
// Create the pixel shader
WGPUProgrammableStageDescriptor pixel_shader_desc = ImGui_ImplWGPU_CreateShaderModule(__shader_frag_wgsl);
// Create the blending setup
WGPUBlendState blend_state = {};
blend_state.alpha.operation = WGPUBlendOperation_Add;
blend_state.alpha.srcFactor = WGPUBlendFactor_One;
blend_state.alpha.dstFactor = WGPUBlendFactor_OneMinusSrcAlpha;
blend_state.color.operation = WGPUBlendOperation_Add;
blend_state.color.srcFactor = WGPUBlendFactor_SrcAlpha;
blend_state.color.dstFactor = WGPUBlendFactor_OneMinusSrcAlpha;
WGPUColorTargetState color_state = {};
color_state.format = bd->renderTargetFormat;
color_state.blend = &blend_state;
color_state.writeMask = WGPUColorWriteMask_All;
WGPUFragmentState fragment_state = {};
fragment_state.module = pixel_shader_desc.module;
fragment_state.entryPoint = pixel_shader_desc.entryPoint;
fragment_state.targetCount = 1;
fragment_state.targets = &color_state;
graphics_pipeline_desc.fragment = &fragment_state;
// Create depth-stencil State
WGPUDepthStencilState depth_stencil_state = {};
depth_stencil_state.format = bd->depthStencilFormat;
depth_stencil_state.depthWriteEnabled = false;
depth_stencil_state.depthCompare = WGPUCompareFunction_Always;
depth_stencil_state.stencilFront.compare = WGPUCompareFunction_Always;
depth_stencil_state.stencilBack.compare = WGPUCompareFunction_Always;
// Configure disabled depth-stencil state
graphics_pipeline_desc.depthStencil = (bd->depthStencilFormat == WGPUTextureFormat_Undefined) ? nullptr : &depth_stencil_state;
bd->pipelineState = wgpuDeviceCreateRenderPipeline(bd->wgpuDevice, &graphics_pipeline_desc);
ImGui_ImplWGPU_CreateFontsTexture();
ImGui_ImplWGPU_CreateUniformBuffer();
// Create resource bind group
WGPUBindGroupEntry common_bg_entries[] =
{
{ nullptr, 0, bd->renderResources.Uniforms, 0, MEMALIGN(sizeof(Uniforms), 16), 0, 0 },
{ nullptr, 1, 0, 0, 0, bd->renderResources.Sampler, 0 },
};
WGPUBindGroupDescriptor common_bg_descriptor = {};
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);
WGPUBindGroup image_bind_group = ImGui_ImplWGPU_CreateImageBindGroup(bg_layouts[1], bd->renderResources.FontTextureView);
bd->renderResources.ImageBindGroup = image_bind_group;
bd->renderResources.ImageBindGroupLayout = bg_layouts[1];
bd->renderResources.ImageBindGroups.SetVoidPtr(ImHashData(&bd->renderResources.FontTextureView, sizeof(ImTextureID)), image_bind_group);
SafeRelease(vertex_shader_desc.module);
SafeRelease(pixel_shader_desc.module);
SafeRelease(bg_layouts[0]);
return true;
}
void ImGui_ImplWGPU_InvalidateDeviceObjects()
{
ImGui_ImplWGPU_Data* bd = ImGui_ImplWGPU_GetBackendData();
if (!bd->wgpuDevice)
return;
SafeRelease(bd->pipelineState);
SafeRelease(bd->renderResources);
ImGuiIO& io = ImGui::GetIO();
io.Fonts->SetTexID(0); // We copied g_pFontTextureView to io.Fonts->TexID so let's clear that as well.
for (unsigned int i = 0; i < bd->numFramesInFlight; i++)
SafeRelease(bd->pFrameResources[i]);
}
bool ImGui_ImplWGPU_Init(WGPUDevice device, int num_frames_in_flight, WGPUTextureFormat rt_format, WGPUTextureFormat depth_format)
{
ImGuiIO& io = ImGui::GetIO();
IM_ASSERT(io.BackendRendererUserData == nullptr && "Already initialized a renderer backend!");
// Setup backend capabilities flags
ImGui_ImplWGPU_Data* bd = IM_NEW(ImGui_ImplWGPU_Data)();
io.BackendRendererUserData = (void*)bd;
io.BackendRendererName = "imgui_impl_webgpu";
io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset; // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
bd->wgpuDevice = device;
bd->defaultQueue = wgpuDeviceGetQueue(bd->wgpuDevice);
bd->renderTargetFormat = rt_format;
bd->depthStencilFormat = depth_format;
bd->numFramesInFlight = num_frames_in_flight;
bd->frameIndex = UINT_MAX;
bd->renderResources.FontTexture = nullptr;
bd->renderResources.FontTextureView = nullptr;
bd->renderResources.Sampler = nullptr;
bd->renderResources.Uniforms = nullptr;
bd->renderResources.CommonBindGroup = nullptr;
bd->renderResources.ImageBindGroups.Data.reserve(100);
bd->renderResources.ImageBindGroup = nullptr;
bd->renderResources.ImageBindGroupLayout = nullptr;
// Create buffers with a default size (they will later be grown as needed)
bd->pFrameResources = new FrameResources[num_frames_in_flight];
for (int i = 0; i < num_frames_in_flight; i++)
{
FrameResources* fr = &bd->pFrameResources[i];
fr->IndexBuffer = nullptr;
fr->VertexBuffer = nullptr;
fr->IndexBufferHost = nullptr;
fr->VertexBufferHost = nullptr;
fr->IndexBufferSize = 10000;
fr->VertexBufferSize = 5000;
}
return true;
}
void ImGui_ImplWGPU_Shutdown()
{
ImGui_ImplWGPU_Data* bd = ImGui_ImplWGPU_GetBackendData();
IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
ImGuiIO& io = ImGui::GetIO();
ImGui_ImplWGPU_InvalidateDeviceObjects();
delete[] bd->pFrameResources;
bd->pFrameResources = nullptr;
wgpuQueueRelease(bd->defaultQueue);
bd->wgpuDevice = nullptr;
bd->numFramesInFlight = 0;
bd->frameIndex = UINT_MAX;
io.BackendRendererName = nullptr;
io.BackendRendererUserData = nullptr;
io.BackendFlags &= ~ImGuiBackendFlags_RendererHasVtxOffset;
IM_DELETE(bd);
}
void ImGui_ImplWGPU_NewFrame()
{
ImGui_ImplWGPU_Data* bd = ImGui_ImplWGPU_GetBackendData();
if (!bd->pipelineState)
ImGui_ImplWGPU_CreateDeviceObjects();
}