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imgui/backends/imgui_impl_sdlgpu3.cpp

620 lines
28 KiB
C++

// dear imgui: Renderer Backend for SDL_GPU
// This needs to be used along with the SDL3 Platform Backend
// Implemented features:
// [X] Renderer: User texture binding. Use simply cast a reference to your SDL_GPUTextureSamplerBinding to ImTextureID.
// [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
// Missing features:
// [ ] Renderer: Multi-viewport support (multiple windows).
// The aim of imgui_impl_sdlgpu3.h/.cpp is to be usable in your engine without any modification.
// IF YOU FEEL YOU NEED TO MAKE ANY CHANGE TO THIS CODE, please share them and your feedback at https://github.com/ocornut/imgui/
// 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.
// Learn about Dear ImGui:
// - FAQ https://dearimgui.com/faq
// - Getting Started https://dearimgui.com/getting-started
// - Documentation https://dearimgui.com/docs (same as your local docs/ folder).
// - Introduction, links and more at the top of imgui.cpp
// Important note to the reader who wish to integrate imgui_impl_sdlgpu3.cpp/.h in their own engine/app.
// - Unlike other backends, the user must call the function Imgui_ImplSDLGPU3_PrepareDrawData() BEFORE issuing a SDL_GPURenderPass containing ImGui_ImplSDLGPU3_RenderDrawData.
// Calling the function is MANDATORY, otherwise the ImGui will not upload neither the vertex nor the index buffer for the GPU. See imgui_impl_sdlgpu3.cpp for more info.
// CHANGELOG
// 2025-01-09: SDL_Gpu: Added the SDL_GPU3 backend.
#include "imgui.h"
#ifndef IMGUI_DISABLE
#include "imgui_impl_sdlgpu3.h"
#include "imgui_impl_sdlgpu3_shaders.h"
// Reusable buffers used for rendering 1 current in-flight frame, for ImGui_ImplSDLGPU3_RenderDrawData()
struct ImGui_ImplSDLGPU3_FrameData
{
SDL_GPUBuffer* VertexBuffer = nullptr;
SDL_GPUBuffer* IndexBuffer = nullptr;
uint32_t VertexBufferSize = 0;
uint32_t IndexBufferSize = 0;
};
// SDL_GPU Data
struct ImGui_ImplSDLGPU3_Data
{
ImGui_ImplSDLGPU3_InitInfo GPUInitInfo;
// Graphics pipeline & shaders
SDL_GPUShader* VertexShader = nullptr;
SDL_GPUShader* FragmentShader = nullptr;
SDL_GPUGraphicsPipeline* Pipeline = nullptr;
// Font data
SDL_GPUSampler* FontSampler = nullptr;
SDL_GPUTexture* FontTexture = nullptr;
SDL_GPUTextureSamplerBinding FontBinding = { nullptr, nullptr };
// Frame data for main window
ImGui_ImplSDLGPU3_FrameData MainWindowFrameData;
};
// Forward Declarations
static bool ImGui_ImplSDLGPU3_CreateDeviceObjects();
static void ImGui_ImplSDLGPU3_DestroyDeviceObjects();
static void ImGui_ImplSDLGPU3_DestroyFrameData();
//-----------------------------------------------------------------------------
// FUNCTIONS
//-----------------------------------------------------------------------------
// 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.
// FIXME: multi-context support has never been tested.
static ImGui_ImplSDLGPU3_Data* ImGui_ImplSDLGPU3_GetBackendData()
{
return ImGui::GetCurrentContext() ? (ImGui_ImplSDLGPU3_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
}
static void ImGui_ImplSDLGPU3_SetupRenderState(ImDrawData* draw_data, SDL_GPUGraphicsPipeline* pipeline, SDL_GPUCommandBuffer* command_buffer, SDL_GPURenderPass * render_pass, ImGui_ImplSDLGPU3_FrameData* fd, uint32_t fb_width, uint32_t fb_height)
{
//ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
// Bind graphics pipeline
SDL_BindGPUGraphicsPipeline(render_pass,pipeline);
// Bind Vertex And Index Buffers
if (draw_data->TotalVtxCount > 0)
{
SDL_GPUBufferBinding vertex_buffer_binding = {};
vertex_buffer_binding.buffer = fd->VertexBuffer;
vertex_buffer_binding.offset = 0;
SDL_GPUBufferBinding index_buffer_binding = {};
index_buffer_binding.buffer = fd->IndexBuffer;
index_buffer_binding.offset = 0;
SDL_BindGPUVertexBuffers(render_pass,0,&vertex_buffer_binding,1);
SDL_BindGPUIndexBuffer(render_pass,&index_buffer_binding,sizeof(ImDrawIdx) == 2 ? SDL_GPU_INDEXELEMENTSIZE_16BIT : SDL_GPU_INDEXELEMENTSIZE_32BIT);
}
// Setup viewport
SDL_GPUViewport viewport = {};
viewport.x = 0;
viewport.y = 0;
viewport.w = (float)fb_width;
viewport.h = (float)fb_height;
viewport.min_depth = 0.0f;
viewport.min_depth = 1.0f;
SDL_SetGPUViewport(render_pass,&viewport);
// Setup scale and translation
// Our visible imgui space lies from draw_data->DisplayPps (top left) to draw_data->DisplayPos+data_data->DisplaySize (bottom right). DisplayPos is (0,0) for single viewport apps.
struct UBO { float scale[2]; float translation[2]; } ubo;
ubo.scale[0] = 2.0f / draw_data->DisplaySize.x;
ubo.scale[1] = 2.0f / draw_data->DisplaySize.y;
ubo.translation[0] = -1.0f - draw_data->DisplayPos.x * ubo.scale[0];
ubo.translation[1] = -1.0f - draw_data->DisplayPos.y * ubo.scale[1];
SDL_PushGPUVertexUniformData(command_buffer, 0, &ubo, sizeof(UBO));
}
static void CreateOrResizeBuffer(SDL_GPUBuffer** buffer, uint32_t* old_size, uint32_t new_size, SDL_GPUBufferUsageFlags usage)
{
ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
ImGui_ImplSDLGPU3_InitInfo* v = &bd->GPUInitInfo;
SDL_WaitForGPUIdle(v->GpuDevice);
SDL_ReleaseGPUBuffer(v->GpuDevice, *buffer);
SDL_GPUBufferCreateInfo buffer_info = {};
buffer_info.usage = usage;
buffer_info.size = new_size;
buffer_info.props = 0;
*buffer = SDL_CreateGPUBuffer(v->GpuDevice, &buffer_info);
*old_size = new_size;
IM_ASSERT(*buffer != nullptr && "Failed to create GPU Buffer, call SDL_GetError() for more information");
}
// SDL_GPU doesn't allow copy passes to occur while a render or compute pass is bound!
// The only way to allow a user to supply their own RenderPass (to render to a texture instead of the window for example),
// is to split the upload part of ImGui_ImplSDLGPU3_RenderDrawData() to another function that needs to be called by the user before rendering.
void Imgui_ImplSDLGPU3_PrepareDrawData(ImDrawData* draw_data, SDL_GPUCommandBuffer* command_buffer)
{
// Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
int fb_width = (int)(draw_data->DisplaySize.x * draw_data->FramebufferScale.x);
int fb_height = (int)(draw_data->DisplaySize.y * draw_data->FramebufferScale.y);
if (fb_width <= 0 || fb_height <= 0 || draw_data->TotalVtxCount <= 0)
return;
ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
ImGui_ImplSDLGPU3_InitInfo* v = &bd->GPUInitInfo;
ImGui_ImplSDLGPU3_FrameData* fd = &bd->MainWindowFrameData;
uint32_t vertex_size = draw_data->TotalVtxCount * sizeof(ImDrawVert);
uint32_t index_size = draw_data->TotalIdxCount * sizeof(ImDrawIdx);
if (fd->VertexBuffer == nullptr || fd->VertexBufferSize < vertex_size)
CreateOrResizeBuffer(&fd->VertexBuffer, &fd->VertexBufferSize, vertex_size, SDL_GPU_BUFFERUSAGE_VERTEX);
if (fd->IndexBuffer == nullptr || fd->IndexBufferSize < index_size)
CreateOrResizeBuffer(&fd->IndexBuffer, &fd->IndexBufferSize, index_size, SDL_GPU_BUFFERUSAGE_INDEX);
// FIXME: It feels like more code could be shared there.
SDL_GPUTransferBufferCreateInfo vertex_transferbuffer_info = {};
vertex_transferbuffer_info.usage = SDL_GPU_TRANSFERBUFFERUSAGE_UPLOAD;
vertex_transferbuffer_info.size = vertex_size;
SDL_GPUTransferBufferCreateInfo index_transferbuffer_info = {};
index_transferbuffer_info.usage = SDL_GPU_TRANSFERBUFFERUSAGE_UPLOAD;
index_transferbuffer_info.size = index_size;
SDL_GPUTransferBuffer* vertex_transferbuffer = SDL_CreateGPUTransferBuffer(v->GpuDevice, &vertex_transferbuffer_info);
IM_ASSERT(vertex_transferbuffer != nullptr && "Failed to create the vertex transfer buffer, call SDL_GetError() for more information");
SDL_GPUTransferBuffer* index_transferbuffer = SDL_CreateGPUTransferBuffer(v->GpuDevice, &index_transferbuffer_info);
IM_ASSERT(index_transferbuffer != nullptr && "Failed to create the index transfer buffer, call SDL_GetError() for more information");
ImDrawVert* vtx_dst = (ImDrawVert*)SDL_MapGPUTransferBuffer(v->GpuDevice, vertex_transferbuffer, true);
ImDrawIdx* idx_dst = (ImDrawIdx*)SDL_MapGPUTransferBuffer(v->GpuDevice, index_transferbuffer, true);
for (int n = 0; n < draw_data->CmdListsCount; n++)
{
const ImDrawList* draw_list = draw_data->CmdLists[n];
memcpy(vtx_dst, draw_list->VtxBuffer.Data, draw_list->VtxBuffer.Size * sizeof(ImDrawVert));
memcpy(idx_dst, draw_list->IdxBuffer.Data, draw_list->IdxBuffer.Size * sizeof(ImDrawIdx));
vtx_dst += draw_list->VtxBuffer.Size;
idx_dst += draw_list->IdxBuffer.Size;
}
SDL_UnmapGPUTransferBuffer(v->GpuDevice, vertex_transferbuffer);
SDL_UnmapGPUTransferBuffer(v->GpuDevice, index_transferbuffer);
SDL_GPUTransferBufferLocation vertex_buffer_location = {};
vertex_buffer_location.offset = 0;
vertex_buffer_location.transfer_buffer = vertex_transferbuffer;
SDL_GPUTransferBufferLocation index_buffer_location = {};
index_buffer_location.offset = 0;
index_buffer_location.transfer_buffer = index_transferbuffer;
SDL_GPUBufferRegion vertex_buffer_region = {};
vertex_buffer_region.buffer = fd->VertexBuffer;
vertex_buffer_region.offset = 0;
vertex_buffer_region.size = vertex_size;
SDL_GPUBufferRegion index_buffer_region = {};
index_buffer_region.buffer = fd->IndexBuffer;
index_buffer_region.offset = 0;
index_buffer_region.size = index_size;
SDL_GPUCopyPass* copy_pass = SDL_BeginGPUCopyPass(command_buffer);
SDL_UploadToGPUBuffer(copy_pass, &vertex_buffer_location, &vertex_buffer_region,true);
SDL_UploadToGPUBuffer(copy_pass, &index_buffer_location, &index_buffer_region,true);
SDL_EndGPUCopyPass(copy_pass);
SDL_ReleaseGPUTransferBuffer(v->GpuDevice, index_transferbuffer);
SDL_ReleaseGPUTransferBuffer(v->GpuDevice, vertex_transferbuffer);
}
void ImGui_ImplSDLGPU3_RenderDrawData(ImDrawData* draw_data, SDL_GPUCommandBuffer* command_buffer, SDL_GPURenderPass* render_pass, SDL_GPUGraphicsPipeline* pipeline)
{
// Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
int fb_width = (int)(draw_data->DisplaySize.x * draw_data->FramebufferScale.x);
int fb_height = (int)(draw_data->DisplaySize.y * draw_data->FramebufferScale.y);
if (fb_width <= 0 || fb_height <= 0)
return;
ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
ImGui_ImplSDLGPU3_FrameData* fd = &bd->MainWindowFrameData;
if (pipeline == nullptr)
pipeline = bd->Pipeline;
ImGui_ImplSDLGPU3_SetupRenderState(draw_data, pipeline, command_buffer, render_pass, fd, fb_width, fb_height);
// Will project scissor/clipping rectangles into framebuffer space
ImVec2 clip_off = draw_data->DisplayPos; // (0,0) unless using multi-viewports
ImVec2 clip_scale = draw_data->FramebufferScale; // (1,1) unless using retina display which are often (2,2)
// 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;
for (int n = 0; n < draw_data->CmdListsCount; n++)
{
const ImDrawList* draw_list = draw_data->CmdLists[n];
for (int cmd_i = 0; cmd_i < draw_list->CmdBuffer.Size; cmd_i++)
{
const ImDrawCmd* pcmd = &draw_list->CmdBuffer[cmd_i];
if (pcmd->UserCallback != nullptr)
{
pcmd->UserCallback(draw_list, pcmd);
}
else
{
// 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);
// Clamp to viewport as SDL_SetGPUScissor() won't accept values that are off bounds
if (clip_min.x < 0.0f) { clip_min.x = 0.0f; }
if (clip_min.y < 0.0f) { clip_min.y = 0.0f; }
if (clip_max.x > fb_width) { clip_max.x = (float)fb_width; }
if (clip_max.y > fb_height) { clip_max.y = (float)fb_height; }
if (clip_max.x <= clip_min.x || clip_max.y <= clip_min.y)
continue;
// Apply scissor/clipping rectangle
SDL_Rect scissor_rect = {};
scissor_rect.x = (int)clip_min.x;
scissor_rect.y = (int)clip_min.y;
scissor_rect.w = (int)(clip_max.x - clip_min.x);
scissor_rect.h = (int)(clip_max.y - clip_min.y);
SDL_SetGPUScissor(render_pass,&scissor_rect);
// Bind DescriptorSet with font or user texture
SDL_BindGPUFragmentSamplers(render_pass, 0, (SDL_GPUTextureSamplerBinding*)pcmd->GetTexID(), 1);
// Draw
SDL_DrawGPUIndexedPrimitives(render_pass, pcmd->ElemCount, 1, pcmd->IdxOffset + global_idx_offset, pcmd->VtxOffset + global_vtx_offset, 0);
}
}
global_idx_offset += draw_list->IdxBuffer.Size;
global_vtx_offset += draw_list->VtxBuffer.Size;
}
// Note: at this point both SDL_SetGPUViewport() and SDL_SetGPUScissor() have been called.
// Our last values will leak into user/application rendering if you forgot to call SDL_SetGPUViewport() and SDL_SetGPUScissor() yourself to explicitly set that state
// In theory we should aim to backup/restore those values but I am not sure this is possible.
// We perform a call to SDL_SetGPUScissor() to set back a full viewport which is likely to fix things for 99% users but technically this is not perfect. (See github #4644)
SDL_Rect scissor_rect { 0, 0, fb_width, fb_height };
SDL_SetGPUScissor(render_pass, &scissor_rect);
}
bool ImGui_ImplSDLGPU3_CreateFontsTexture()
{
ImGuiIO& io = ImGui::GetIO();
ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
ImGui_ImplSDLGPU3_InitInfo* v = &bd->GPUInitInfo;
// Destroy existing texture (if any)
if (bd->FontTexture)
{
SDL_WaitForGPUIdle(v->GpuDevice);
ImGui_ImplSDLGPU3_DestroyFontsTexture();
}
unsigned char* pixels;
int width, height;
io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);
uint32_t upload_size = width * height * 4 * sizeof(char);
// Create the Image:
{
SDL_GPUTextureCreateInfo texture_info = {};
texture_info.type = SDL_GPU_TEXTURETYPE_2D;
texture_info.format = SDL_GPU_TEXTUREFORMAT_R8G8B8A8_UNORM;
texture_info.usage = SDL_GPU_TEXTUREUSAGE_SAMPLER;
texture_info.width = width;
texture_info.height = height;
texture_info.layer_count_or_depth = 1;
texture_info.num_levels = 1;
texture_info.sample_count = SDL_GPU_SAMPLECOUNT_1;
bd->FontTexture = SDL_CreateGPUTexture(v->GpuDevice, &texture_info);
IM_ASSERT(bd->FontTexture && "Failed to create font texture, call SDL_GetError() for more info");
}
// Assign the texture to the TextureSamplerBinding
bd->FontBinding.texture = bd->FontTexture;
// Create all the upload structures and upload:
{
SDL_GPUTransferBufferCreateInfo font_transferbuffer_info = {};
font_transferbuffer_info.usage = SDL_GPU_TRANSFERBUFFERUSAGE_UPLOAD;
font_transferbuffer_info.size = upload_size;
SDL_GPUTransferBuffer* font_transferbuffer = SDL_CreateGPUTransferBuffer(v->GpuDevice, &font_transferbuffer_info);
IM_ASSERT(font_transferbuffer != nullptr && "Failed to create font transfer buffer, call SDL_GetError() for more information");
void* texture_ptr = SDL_MapGPUTransferBuffer(v->GpuDevice, font_transferbuffer, false);
memcpy(texture_ptr, pixels, upload_size);
SDL_UnmapGPUTransferBuffer(v->GpuDevice, font_transferbuffer);
SDL_GPUTextureTransferInfo font_transfer_info = {};
font_transfer_info.offset = 0;
font_transfer_info.transfer_buffer = font_transferbuffer;
SDL_GPUTextureRegion font_texture_region = {};
font_texture_region.texture = bd->FontTexture;
font_texture_region.w = width;
font_texture_region.h = height;
font_texture_region.d = 1;
SDL_GPUCommandBuffer* cmd = SDL_AcquireGPUCommandBuffer(v->GpuDevice);
SDL_GPUCopyPass* copy_pass = SDL_BeginGPUCopyPass(cmd);
SDL_UploadToGPUTexture(copy_pass, &font_transfer_info, &font_texture_region, false);
SDL_EndGPUCopyPass(copy_pass);
SDL_SubmitGPUCommandBuffer(cmd);
SDL_ReleaseGPUTransferBuffer(v->GpuDevice, font_transferbuffer);
}
// Store our identifier
io.Fonts->SetTexID((ImTextureID)&bd->FontBinding);
return true;
}
// You probably never need to call this, as it is called by ImGui_ImplSDLGPU3_CreateFontsTexture() and ImGui_ImplSDLGPU3_Shutdown().
void ImGui_ImplSDLGPU3_DestroyFontsTexture()
{
ImGuiIO& io = ImGui::GetIO();
ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
ImGui_ImplSDLGPU3_InitInfo* v = &bd->GPUInitInfo;
if (bd->FontTexture)
{
SDL_ReleaseGPUTexture(v->GpuDevice, bd->FontTexture);
bd->FontBinding.texture = nullptr;
bd->FontTexture = nullptr;
}
io.Fonts->SetTexID(0);
}
static void Imgui_ImplSDLGPU3_CreateShaders()
{
// Create the shader modules
ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
ImGui_ImplSDLGPU3_InitInfo* v = &bd->GPUInitInfo;
const char* driver = SDL_GetGPUDeviceDriver(v->GpuDevice);
SDL_GPUShaderCreateInfo vertex_shader_info = {};
vertex_shader_info.entrypoint = "main";
vertex_shader_info.stage = SDL_GPU_SHADERSTAGE_VERTEX;
vertex_shader_info.num_uniform_buffers = 1;
vertex_shader_info.num_storage_buffers = 0;
vertex_shader_info.num_storage_textures = 0;
vertex_shader_info.num_samplers = 0;
SDL_GPUShaderCreateInfo fragment_shader_info = {};
fragment_shader_info.entrypoint = "main";
fragment_shader_info.stage = SDL_GPU_SHADERSTAGE_FRAGMENT;
fragment_shader_info.num_samplers = 1;
fragment_shader_info.num_storage_buffers = 0;
fragment_shader_info.num_storage_textures = 0;
fragment_shader_info.num_uniform_buffers = 0;
if (strcmp(driver, "vulkan") == 0)
{
vertex_shader_info.format = SDL_GPU_SHADERFORMAT_SPIRV;
vertex_shader_info.code = spirv_vertex;
vertex_shader_info.code_size = sizeof(spirv_vertex);
fragment_shader_info.format = SDL_GPU_SHADERFORMAT_SPIRV;
fragment_shader_info.code = spirv_fragment;
fragment_shader_info.code_size = sizeof(spirv_fragment);
}
else if (strcmp(driver, "direct3d12") == 0)
{
vertex_shader_info.format = SDL_GPU_SHADERFORMAT_DXBC;
vertex_shader_info.code = dxbc_vertex;
vertex_shader_info.code_size = sizeof(dxbc_vertex);
fragment_shader_info.format = SDL_GPU_SHADERFORMAT_DXBC;
fragment_shader_info.code = dxbc_fragment;
fragment_shader_info.code_size = sizeof(dxbc_fragment);
}
#ifdef __APPLE__
else
{
vertex_shader_info.entrypoint = "main0";
vertex_shader_info.format = SDL_GPU_SHADERFORMAT_METALLIB;
vertex_shader_info.code = metallib_vertex;
vertex_shader_info.code_size = sizeof(metallib_vertex);
fragment_shader_info.entrypoint = "main0";
fragment_shader_info.format = SDL_GPU_SHADERFORMAT_METALLIB;
fragment_shader_info.code = metallib_fragment;
fragment_shader_info.code_size = sizeof(metallib_fragment);
}
#endif
bd->VertexShader = SDL_CreateGPUShader(v->GpuDevice, &vertex_shader_info);
bd->FragmentShader = SDL_CreateGPUShader(v->GpuDevice, &fragment_shader_info);
IM_ASSERT(bd->VertexShader != nullptr && "Failed to create vertex shader, call SDL_GetError() for more information");
IM_ASSERT(bd->FragmentShader != nullptr && "Failed to create fragment shader, call SDL_GetError() for more information");
}
static void ImGui_ImplSDLGPU3_CreateGraphicsPipeline()
{
ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
ImGui_ImplSDLGPU3_InitInfo* v = &bd->GPUInitInfo;
Imgui_ImplSDLGPU3_CreateShaders();
SDL_GPUVertexBufferDescription vertex_buffer_desc[1];
vertex_buffer_desc[0].slot = 0;
vertex_buffer_desc[0].input_rate = SDL_GPU_VERTEXINPUTRATE_VERTEX;
vertex_buffer_desc[0].instance_step_rate = 0;
vertex_buffer_desc[0].pitch = sizeof(ImDrawVert);
SDL_GPUVertexAttribute vertex_attributes[3];
vertex_attributes[0].buffer_slot = 0;
vertex_attributes[0].format = SDL_GPU_VERTEXELEMENTFORMAT_FLOAT2;
vertex_attributes[0].location = 0;
vertex_attributes[0].offset = offsetof(ImDrawVert,pos);
vertex_attributes[1].buffer_slot = 0;
vertex_attributes[1].format = SDL_GPU_VERTEXELEMENTFORMAT_FLOAT2;
vertex_attributes[1].location = 1;
vertex_attributes[1].offset = offsetof(ImDrawVert, uv);
vertex_attributes[2].buffer_slot = 0;
vertex_attributes[2].format = SDL_GPU_VERTEXELEMENTFORMAT_UBYTE4_NORM;
vertex_attributes[2].location = 2;
vertex_attributes[2].offset = offsetof(ImDrawVert, col);
SDL_GPUVertexInputState vertex_input_state = {};
vertex_input_state.num_vertex_attributes = 3;
vertex_input_state.vertex_attributes = vertex_attributes;
vertex_input_state.num_vertex_buffers = 1;
vertex_input_state.vertex_buffer_descriptions = vertex_buffer_desc;
SDL_GPURasterizerState rasterizer_state = {};
rasterizer_state.fill_mode = SDL_GPU_FILLMODE_FILL;
rasterizer_state.cull_mode = SDL_GPU_CULLMODE_NONE;
rasterizer_state.front_face = SDL_GPU_FRONTFACE_COUNTER_CLOCKWISE;
rasterizer_state.enable_depth_bias = false;
rasterizer_state.enable_depth_clip = false;
SDL_GPUMultisampleState multisample_state = {};
multisample_state.sample_count = v->MSAASamples;
multisample_state.enable_mask = false;
SDL_GPUDepthStencilState depth_stencil_state = {};
depth_stencil_state.enable_depth_test = false;
depth_stencil_state.enable_depth_write = false;
depth_stencil_state.enable_stencil_test = false;
SDL_GPUColorTargetBlendState blend_state = {};
blend_state.enable_blend = true;
blend_state.src_color_blendfactor = SDL_GPU_BLENDFACTOR_SRC_ALPHA;
blend_state.dst_color_blendfactor = SDL_GPU_BLENDFACTOR_ONE_MINUS_SRC_ALPHA;
blend_state.color_blend_op = SDL_GPU_BLENDOP_ADD;
blend_state.src_alpha_blendfactor = SDL_GPU_BLENDFACTOR_ONE;
blend_state.dst_alpha_blendfactor = SDL_GPU_BLENDFACTOR_ONE_MINUS_SRC_ALPHA;
blend_state.alpha_blend_op = SDL_GPU_BLENDOP_ADD;
blend_state.color_write_mask = SDL_GPU_COLORCOMPONENT_R | SDL_GPU_COLORCOMPONENT_G | SDL_GPU_COLORCOMPONENT_B | SDL_GPU_COLORCOMPONENT_A;
SDL_GPUColorTargetDescription color_target_desc[1];
color_target_desc[0].format = v->ColorTargetFormat;
color_target_desc[0].blend_state = blend_state;
SDL_GPUGraphicsPipelineTargetInfo target_info = {};
target_info.num_color_targets = 1;
target_info.color_target_descriptions = color_target_desc;
target_info.has_depth_stencil_target = false;
SDL_GPUGraphicsPipelineCreateInfo pipeline_info = {};
pipeline_info.vertex_shader = bd->VertexShader;
pipeline_info.fragment_shader = bd->FragmentShader;
pipeline_info.vertex_input_state = vertex_input_state;
pipeline_info.primitive_type = SDL_GPU_PRIMITIVETYPE_TRIANGLELIST;
pipeline_info.rasterizer_state = rasterizer_state;
pipeline_info.multisample_state = multisample_state;
pipeline_info.depth_stencil_state = depth_stencil_state;
pipeline_info.target_info = target_info;
bd->Pipeline = SDL_CreateGPUGraphicsPipeline(v->GpuDevice, &pipeline_info);
IM_ASSERT(bd->Pipeline != nullptr && "Failed to create graphics pipeline, call SDL_GetError() for more information");
}
bool ImGui_ImplSDLGPU3_CreateDeviceObjects()
{
ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
ImGui_ImplSDLGPU3_InitInfo* v = &bd->GPUInitInfo;
if (!bd->FontSampler)
{
// Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling.
SDL_GPUSamplerCreateInfo sampler_info = {};
sampler_info.min_filter = SDL_GPU_FILTER_LINEAR;
sampler_info.mag_filter = SDL_GPU_FILTER_LINEAR;
sampler_info.mipmap_mode = SDL_GPU_SAMPLERMIPMAPMODE_LINEAR;
sampler_info.address_mode_u = SDL_GPU_SAMPLERADDRESSMODE_CLAMP_TO_EDGE;
sampler_info.address_mode_v = SDL_GPU_SAMPLERADDRESSMODE_CLAMP_TO_EDGE;
sampler_info.address_mode_w = SDL_GPU_SAMPLERADDRESSMODE_CLAMP_TO_EDGE;
sampler_info.mip_lod_bias = 0.0f;
sampler_info.min_lod = -1000.0f;
sampler_info.max_lod = 1000.0f;
sampler_info.enable_anisotropy = true;
sampler_info.max_anisotropy = 1.0f;
sampler_info.enable_compare = false;
bd->FontSampler = SDL_CreateGPUSampler(v->GpuDevice, &sampler_info);
bd->FontBinding.sampler = bd->FontSampler;
IM_ASSERT(bd->FontSampler != nullptr && "Failed to create font sampler, call SDL_GetError() for more information");
}
ImGui_ImplSDLGPU3_CreateGraphicsPipeline();
return true;
}
void ImGui_ImplSDLGPU3_DestroyFrameData()
{
ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
ImGui_ImplSDLGPU3_InitInfo* v = &bd->GPUInitInfo;
SDL_ReleaseGPUBuffer(v->GpuDevice, bd->MainWindowFrameData.VertexBuffer);
SDL_ReleaseGPUBuffer(v->GpuDevice, bd->MainWindowFrameData.IndexBuffer);
bd->MainWindowFrameData.VertexBuffer = nullptr;
bd->MainWindowFrameData.IndexBuffer = nullptr;
bd->MainWindowFrameData.VertexBufferSize = 0;
bd->MainWindowFrameData.IndexBufferSize = 0;
}
void ImGui_ImplSDLGPU3_DestroyDeviceObjects()
{
ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
ImGui_ImplSDLGPU3_InitInfo* v = &bd->GPUInitInfo;
ImGui_ImplSDLGPU3_DestroyFrameData();
ImGui_ImplSDLGPU3_DestroyFontsTexture();
if (bd->VertexShader) { SDL_ReleaseGPUShader(v->GpuDevice, bd->VertexShader); bd->VertexShader = nullptr;}
if (bd->FragmentShader) { SDL_ReleaseGPUShader(v->GpuDevice, bd->FragmentShader); bd->FragmentShader = nullptr;}
if (bd->FontSampler) { SDL_ReleaseGPUSampler(v->GpuDevice, bd->FontSampler); bd->FontSampler = nullptr;}
if (bd->Pipeline) { SDL_ReleaseGPUGraphicsPipeline(v->GpuDevice, bd->Pipeline); bd->Pipeline = nullptr;}
}
bool ImGui_ImplSDLGPU3_Init(ImGui_ImplSDLGPU3_InitInfo* info)
{
ImGuiIO& io = ImGui::GetIO();
IMGUI_CHECKVERSION();
IM_ASSERT(io.BackendRendererUserData == nullptr && "Already initialized a renderer backend!");
// Setup backend capabilities flags
ImGui_ImplSDLGPU3_Data* bd = IM_NEW(ImGui_ImplSDLGPU3_Data)();
io.BackendRendererUserData = (void*)bd;
io.BackendRendererName = "imgui_impl_sdlgpu3";
io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset; // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
IM_ASSERT(info->GpuDevice != nullptr);
IM_ASSERT(info->ColorTargetFormat != SDL_GPU_TEXTUREFORMAT_INVALID);
bd->GPUInitInfo = *info;
ImGui_ImplSDLGPU3_CreateDeviceObjects();
return true;
}
void ImGui_ImplSDLGPU3_Shutdown()
{
ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
ImGuiIO& io = ImGui::GetIO();
ImGui_ImplSDLGPU3_DestroyDeviceObjects();
io.BackendRendererName = nullptr;
io.BackendRendererUserData = nullptr;
io.BackendFlags &= ~ImGuiBackendFlags_RendererHasVtxOffset;
IM_DELETE(bd);
}
void ImGui_ImplSDLGPU3_NewFrame()
{
ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
IM_ASSERT(bd != nullptr && "Context or backend not initialized! Did you call ImGui_ImplSDLGPU3_Init()?");
if (!bd->FontTexture)
ImGui_ImplSDLGPU3_CreateFontsTexture();
}
#endif // #ifndef IMGUI_DISABLE