imgui/backends/imgui_impl_wgpu.cpp

715 lines
31 KiB
C++
Raw Normal View History

// 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: Support for large meshes (64k+ vertices) with 16-bit indices.
// You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
2021-05-27 11:59:35 +00:00
// 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)
// 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: Fix 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);
// WebGPU data
static WGPUDevice g_wgpuDevice = nullptr;
static WGPUQueue g_defaultQueue = nullptr;
static WGPUTextureFormat g_renderTargetFormat = WGPUTextureFormat_Undefined;
static WGPURenderPipeline g_pipelineState = nullptr;
struct RenderResources
{
WGPUTexture FontTexture; // Font texture
WGPUTextureView FontTextureView; // Texture view for font texture
WGPUSampler Sampler; // Sampler for the font texture
WGPUBuffer Uniforms; // Shader uniforms
WGPUBindGroup CommonBindGroup; // 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; // Default font-resource of Dear ImGui
WGPUBindGroupLayout ImageBindGroupLayout; // Cache layout used for the image bind group. Avoids allocating unnecessary JS objects when working with WebASM
};
static RenderResources g_resources;
struct FrameResources
{
WGPUBuffer IndexBuffer;
WGPUBuffer VertexBuffer;
ImDrawIdx* IndexBufferHost;
ImDrawVert* VertexBufferHost;
int IndexBufferSize;
int VertexBufferSize;
};
static FrameResources* g_pFrameResources = nullptr;
static unsigned int g_numFramesInFlight = 0;
static unsigned int g_frameIndex = UINT_MAX;
struct Uniforms
{
float MVP[4][4];
};
//-----------------------------------------------------------------------------
// SHADERS
//-----------------------------------------------------------------------------
// glsl_shader.vert, compiled with:
// # glslangValidator -V -x -o glsl_shader.vert.u32 glsl_shader.vert
/*
#version 450 core
layout(location = 0) in vec2 aPos;
layout(location = 1) in vec2 aUV;
layout(location = 2) in vec4 aColor;
layout(set=0, binding = 0) uniform transform { mat4 mvp; };
out gl_PerVertex { vec4 gl_Position; };
layout(location = 0) out struct { vec4 Color; vec2 UV; } Out;
void main()
{
Out.Color = aColor;
Out.UV = aUV;
gl_Position = mvp * vec4(aPos, 0, 1);
}
*/
static uint32_t __glsl_shader_vert_spv[] =
{
0x07230203,0x00010000,0x00080007,0x0000002c,0x00000000,0x00020011,0x00000001,0x0006000b,
0x00000001,0x4c534c47,0x6474732e,0x3035342e,0x00000000,0x0003000e,0x00000000,0x00000001,
0x000a000f,0x00000000,0x00000004,0x6e69616d,0x00000000,0x0000000b,0x0000000f,0x00000015,
0x0000001b,0x00000023,0x00030003,0x00000002,0x000001c2,0x00040005,0x00000004,0x6e69616d,
0x00000000,0x00030005,0x00000009,0x00000000,0x00050006,0x00000009,0x00000000,0x6f6c6f43,
0x00000072,0x00040006,0x00000009,0x00000001,0x00005655,0x00030005,0x0000000b,0x0074754f,
0x00040005,0x0000000f,0x6c6f4361,0x0000726f,0x00030005,0x00000015,0x00565561,0x00060005,
0x00000019,0x505f6c67,0x65567265,0x78657472,0x00000000,0x00060006,0x00000019,0x00000000,
0x505f6c67,0x7469736f,0x006e6f69,0x00030005,0x0000001b,0x00000000,0x00050005,0x0000001d,
0x6e617274,0x726f6673,0x0000006d,0x00040006,0x0000001d,0x00000000,0x0070766d,0x00030005,
0x0000001f,0x00000000,0x00040005,0x00000023,0x736f5061,0x00000000,0x00040047,0x0000000b,
0x0000001e,0x00000000,0x00040047,0x0000000f,0x0000001e,0x00000002,0x00040047,0x00000015,
0x0000001e,0x00000001,0x00050048,0x00000019,0x00000000,0x0000000b,0x00000000,0x00030047,
0x00000019,0x00000002,0x00040048,0x0000001d,0x00000000,0x00000005,0x00050048,0x0000001d,
0x00000000,0x00000023,0x00000000,0x00050048,0x0000001d,0x00000000,0x00000007,0x00000010,
0x00030047,0x0000001d,0x00000002,0x00040047,0x0000001f,0x00000022,0x00000000,0x00040047,
0x0000001f,0x00000021,0x00000000,0x00040047,0x00000023,0x0000001e,0x00000000,0x00020013,
0x00000002,0x00030021,0x00000003,0x00000002,0x00030016,0x00000006,0x00000020,0x00040017,
0x00000007,0x00000006,0x00000004,0x00040017,0x00000008,0x00000006,0x00000002,0x0004001e,
0x00000009,0x00000007,0x00000008,0x00040020,0x0000000a,0x00000003,0x00000009,0x0004003b,
0x0000000a,0x0000000b,0x00000003,0x00040015,0x0000000c,0x00000020,0x00000001,0x0004002b,
0x0000000c,0x0000000d,0x00000000,0x00040020,0x0000000e,0x00000001,0x00000007,0x0004003b,
0x0000000e,0x0000000f,0x00000001,0x00040020,0x00000011,0x00000003,0x00000007,0x0004002b,
0x0000000c,0x00000013,0x00000001,0x00040020,0x00000014,0x00000001,0x00000008,0x0004003b,
0x00000014,0x00000015,0x00000001,0x00040020,0x00000017,0x00000003,0x00000008,0x0003001e,
0x00000019,0x00000007,0x00040020,0x0000001a,0x00000003,0x00000019,0x0004003b,0x0000001a,
0x0000001b,0x00000003,0x00040018,0x0000001c,0x00000007,0x00000004,0x0003001e,0x0000001d,
0x0000001c,0x00040020,0x0000001e,0x00000002,0x0000001d,0x0004003b,0x0000001e,0x0000001f,
0x00000002,0x00040020,0x00000020,0x00000002,0x0000001c,0x0004003b,0x00000014,0x00000023,
0x00000001,0x0004002b,0x00000006,0x00000025,0x00000000,0x0004002b,0x00000006,0x00000026,
0x3f800000,0x00050036,0x00000002,0x00000004,0x00000000,0x00000003,0x000200f8,0x00000005,
0x0004003d,0x00000007,0x00000010,0x0000000f,0x00050041,0x00000011,0x00000012,0x0000000b,
0x0000000d,0x0003003e,0x00000012,0x00000010,0x0004003d,0x00000008,0x00000016,0x00000015,
0x00050041,0x00000017,0x00000018,0x0000000b,0x00000013,0x0003003e,0x00000018,0x00000016,
0x00050041,0x00000020,0x00000021,0x0000001f,0x0000000d,0x0004003d,0x0000001c,0x00000022,
0x00000021,0x0004003d,0x00000008,0x00000024,0x00000023,0x00050051,0x00000006,0x00000027,
0x00000024,0x00000000,0x00050051,0x00000006,0x00000028,0x00000024,0x00000001,0x00070050,
0x00000007,0x00000029,0x00000027,0x00000028,0x00000025,0x00000026,0x00050091,0x00000007,
0x0000002a,0x00000022,0x00000029,0x00050041,0x00000011,0x0000002b,0x0000001b,0x0000000d,
0x0003003e,0x0000002b,0x0000002a,0x000100fd,0x00010038
};
// glsl_shader.frag, compiled with:
// # glslangValidator -V -x -o glsl_shader.frag.u32 glsl_shader.frag
/*
#version 450 core
layout(location = 0) out vec4 fColor;
layout(set=0, binding=1) uniform sampler s;
layout(set=1, binding=0) uniform texture2D t;
layout(location = 0) in struct { vec4 Color; vec2 UV; } In;
void main()
{
fColor = In.Color * texture(sampler2D(t, s), In.UV.st);
}
*/
static uint32_t __glsl_shader_frag_spv[] =
{
0x07230203,0x00010000,0x00080007,0x00000023,0x00000000,0x00020011,0x00000001,0x0006000b,
0x00000001,0x4c534c47,0x6474732e,0x3035342e,0x00000000,0x0003000e,0x00000000,0x00000001,
0x0007000f,0x00000004,0x00000004,0x6e69616d,0x00000000,0x00000009,0x0000000d,0x00030010,
0x00000004,0x00000007,0x00030003,0x00000002,0x000001c2,0x00040005,0x00000004,0x6e69616d,
0x00000000,0x00040005,0x00000009,0x6c6f4366,0x0000726f,0x00030005,0x0000000b,0x00000000,
0x00050006,0x0000000b,0x00000000,0x6f6c6f43,0x00000072,0x00040006,0x0000000b,0x00000001,
0x00005655,0x00030005,0x0000000d,0x00006e49,0x00030005,0x00000015,0x00000074,0x00030005,
0x00000019,0x00000073,0x00040047,0x00000009,0x0000001e,0x00000000,0x00040047,0x0000000d,
0x0000001e,0x00000000,0x00040047,0x00000015,0x00000022,0x00000001,0x00040047,0x00000015,
0x00000021,0x00000000,0x00040047,0x00000019,0x00000022,0x00000000,0x00040047,0x00000019,
0x00000021,0x00000001,0x00020013,0x00000002,0x00030021,0x00000003,0x00000002,0x00030016,
0x00000006,0x00000020,0x00040017,0x00000007,0x00000006,0x00000004,0x00040020,0x00000008,
0x00000003,0x00000007,0x0004003b,0x00000008,0x00000009,0x00000003,0x00040017,0x0000000a,
0x00000006,0x00000002,0x0004001e,0x0000000b,0x00000007,0x0000000a,0x00040020,0x0000000c,
0x00000001,0x0000000b,0x0004003b,0x0000000c,0x0000000d,0x00000001,0x00040015,0x0000000e,
0x00000020,0x00000001,0x0004002b,0x0000000e,0x0000000f,0x00000000,0x00040020,0x00000010,
0x00000001,0x00000007,0x00090019,0x00000013,0x00000006,0x00000001,0x00000000,0x00000000,
0x00000000,0x00000001,0x00000000,0x00040020,0x00000014,0x00000000,0x00000013,0x0004003b,
0x00000014,0x00000015,0x00000000,0x0002001a,0x00000017,0x00040020,0x00000018,0x00000000,
0x00000017,0x0004003b,0x00000018,0x00000019,0x00000000,0x0003001b,0x0000001b,0x00000013,
0x0004002b,0x0000000e,0x0000001d,0x00000001,0x00040020,0x0000001e,0x00000001,0x0000000a,
0x00050036,0x00000002,0x00000004,0x00000000,0x00000003,0x000200f8,0x00000005,0x00050041,
0x00000010,0x00000011,0x0000000d,0x0000000f,0x0004003d,0x00000007,0x00000012,0x00000011,
0x0004003d,0x00000013,0x00000016,0x00000015,0x0004003d,0x00000017,0x0000001a,0x00000019,
0x00050056,0x0000001b,0x0000001c,0x00000016,0x0000001a,0x00050041,0x0000001e,0x0000001f,
0x0000000d,0x0000001d,0x0004003d,0x0000000a,0x00000020,0x0000001f,0x00050057,0x00000007,
0x00000021,0x0000001c,0x00000020,0x00050085,0x00000007,0x00000022,0x00000012,0x00000021,
0x0003003e,0x00000009,0x00000022,0x000100fd,0x00010038
};
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(uint32_t* binary_data, uint32_t binary_data_size)
{
WGPUShaderModuleSPIRVDescriptor spirv_desc = {};
spirv_desc.chain.sType = WGPUSType_ShaderModuleSPIRVDescriptor;
spirv_desc.codeSize = binary_data_size;
spirv_desc.code = binary_data;
WGPUShaderModuleDescriptor desc = {};
desc.nextInChain = reinterpret_cast<WGPUChainedStruct*>(&spirv_desc);
WGPUProgrammableStageDescriptor stage_desc = {};
stage_desc.module = wgpuDeviceCreateShaderModule(g_wgpuDevice, &desc);
stage_desc.entryPoint = "main";
return stage_desc;
}
static WGPUBindGroup ImGui_ImplWGPU_CreateImageBindGroup(WGPUBindGroupLayout layout, WGPUTextureView texture)
{
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(g_wgpuDevice, &image_bg_descriptor);
}
static void ImGui_ImplWGPU_SetupRenderState(ImDrawData* draw_data, WGPURenderPassEncoder ctx, FrameResources* fr)
{
// 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(g_defaultQueue, g_resources.Uniforms, 0, mvp, sizeof(mvp));
}
// 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, g_pipelineState);
wgpuRenderPassEncoderSetBindGroup(ctx, 0, g_resources.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.
g_frameIndex = g_frameIndex + 1;
FrameResources* fr = &g_pFrameResources[g_frameIndex % g_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,
fr->VertexBufferSize * sizeof(ImDrawVert),
false
};
fr->VertexBuffer = wgpuDeviceCreateBuffer(g_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,
fr->IndexBufferSize * sizeof(ImDrawIdx),
false
};
fr->IndexBuffer = wgpuDeviceCreateBuffer(g_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 = ((char*)vtx_dst - (char*)fr->VertexBufferHost + 3) & ~3;
int64_t ib_write_size = ((char*)idx_dst - (char*)fr->IndexBufferHost + 3) & ~3;
wgpuQueueWriteBuffer(g_defaultQueue, fr->VertexBuffer, 0, fr->VertexBufferHost, vb_write_size);
wgpuQueueWriteBuffer(g_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 = g_resources.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(g_resources.ImageBindGroupLayout, (WGPUTextureView)tex_id);
g_resources.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
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;
g_resources.FontTexture = wgpuDeviceCreateTexture(g_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;
g_resources.FontTextureView = wgpuTextureCreateView(g_resources.FontTexture, &tex_view_desc);
}
// Upload texture data
{
WGPUImageCopyTexture dst_view = {};
dst_view.texture = g_resources.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(g_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;
g_resources.Sampler = wgpuDeviceCreateSampler(g_wgpuDevice, &sampler_desc);
}
// Store our identifier
static_assert(sizeof(ImTextureID) >= sizeof(g_resources.FontTexture), "Can't pack descriptor handle into TexID, 32-bit not supported yet.");
io.Fonts->SetTexID((ImTextureID)g_resources.FontTextureView);
}
static void ImGui_ImplWGPU_CreateUniformBuffer()
{
WGPUBufferDescriptor ub_desc =
{
nullptr,
"Dear ImGui Uniform buffer",
WGPUBufferUsage_CopyDst | WGPUBufferUsage_Uniform,
sizeof(Uniforms),
false
};
g_resources.Uniforms = wgpuDeviceCreateBuffer(g_wgpuDevice, &ub_desc);
}
bool ImGui_ImplWGPU_CreateDeviceObjects()
{
if (!g_wgpuDevice)
return false;
if (g_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;
graphics_pipeline_desc.layout = nullptr; // Use automatic layout generation
// Create the vertex shader
WGPUProgrammableStageDescriptor vertex_shader_desc = ImGui_ImplWGPU_CreateShaderModule(__glsl_shader_vert_spv, sizeof(__glsl_shader_vert_spv) / sizeof(uint32_t));
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(__glsl_shader_frag_spv, sizeof(__glsl_shader_frag_spv) / sizeof(uint32_t));
// 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 = g_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.depthBias = 0;
depth_stencil_state.depthBiasClamp = 0;
depth_stencil_state.depthBiasSlopeScale = 0;
// Configure disabled depth-stencil state
graphics_pipeline_desc.depthStencil = nullptr;
g_pipelineState = wgpuDeviceCreateRenderPipeline(g_wgpuDevice, &graphics_pipeline_desc);
ImGui_ImplWGPU_CreateFontsTexture();
ImGui_ImplWGPU_CreateUniformBuffer();
// Create resource bind group
WGPUBindGroupLayout bg_layouts[2];
bg_layouts[0] = wgpuRenderPipelineGetBindGroupLayout(g_pipelineState, 0);
bg_layouts[1] = wgpuRenderPipelineGetBindGroupLayout(g_pipelineState, 1);
WGPUBindGroupEntry common_bg_entries[] =
{
{ nullptr, 0, g_resources.Uniforms, 0, sizeof(Uniforms), 0, 0 },
{ nullptr, 1, 0, 0, 0, g_resources.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;
g_resources.CommonBindGroup = wgpuDeviceCreateBindGroup(g_wgpuDevice, &common_bg_descriptor);
WGPUBindGroup image_bind_group = ImGui_ImplWGPU_CreateImageBindGroup(bg_layouts[1], g_resources.FontTextureView);
g_resources.ImageBindGroup = image_bind_group;
g_resources.ImageBindGroupLayout = bg_layouts[1];
g_resources.ImageBindGroups.SetVoidPtr(ImHashData(&g_resources.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()
{
if (!g_wgpuDevice)
return;
SafeRelease(g_pipelineState);
SafeRelease(g_resources);
ImGuiIO& io = ImGui::GetIO();
io.Fonts->SetTexID(nullptr); // We copied g_pFontTextureView to io.Fonts->TexID so let's clear that as well.
for (unsigned int i = 0; i < g_numFramesInFlight; i++)
SafeRelease(g_pFrameResources[i]);
}
bool ImGui_ImplWGPU_Init(WGPUDevice device, int num_frames_in_flight, WGPUTextureFormat rt_format)
{
// Setup backend capabilities flags
ImGuiIO& io = ImGui::GetIO();
io.BackendRendererName = "imgui_impl_webgpu";
io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset; // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
g_wgpuDevice = device;
g_defaultQueue = wgpuDeviceGetQueue(g_wgpuDevice);
g_renderTargetFormat = rt_format;
g_pFrameResources = new FrameResources[num_frames_in_flight];
g_numFramesInFlight = num_frames_in_flight;
g_frameIndex = UINT_MAX;
g_resources.FontTexture = nullptr;
g_resources.FontTextureView = nullptr;
g_resources.Sampler = nullptr;
g_resources.Uniforms = nullptr;
g_resources.CommonBindGroup = nullptr;
g_resources.ImageBindGroups.Data.reserve(100);
g_resources.ImageBindGroup = nullptr;
g_resources.ImageBindGroupLayout = nullptr;
// Create buffers with a default size (they will later be grown as needed)
for (int i = 0; i < num_frames_in_flight; i++)
{
FrameResources* fr = &g_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_InvalidateDeviceObjects();
delete[] g_pFrameResources;
g_pFrameResources = nullptr;
wgpuQueueRelease(g_defaultQueue);
g_wgpuDevice = nullptr;
g_numFramesInFlight = 0;
g_frameIndex = UINT_MAX;
}
void ImGui_ImplWGPU_NewFrame()
{
if (!g_pipelineState)
ImGui_ImplWGPU_CreateDeviceObjects();
}