[Qt] Initial Imgui integration

This commit is contained in:
wheremyfoodat 2024-01-28 22:27:30 +02:00
parent 8ff2d7f9b2
commit 918645479a
211 changed files with 49460 additions and 21918 deletions

View file

@ -3,10 +3,15 @@
// Implemented features:
// [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID!
// [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
// You can copy and use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
// 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
// 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
// **DO NOT USE THIS CODE IF YOUR CODE/ENGINE IS USING MODERN OPENGL (SHADERS, VBO, VAO, etc.)**
// **Prefer using the code in imgui_impl_opengl3.cpp**
@ -18,6 +23,11 @@
// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
// 2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
// 2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
// 2021-12-08: OpenGL: Fixed mishandling of the the ImDrawCmd::IdxOffset field! This is an old bug but it never had an effect until some internal rendering changes in 1.86.
// 2021-06-29: Reorganized backend to pull data from a single structure to facilitate usage with multiple-contexts (all g_XXXX access changed to bd->XXXX).
// 2021-05-19: OpenGL: Replaced direct access to ImDrawCmd::TextureId with a call to ImDrawCmd::GetTexID(). (will become a requirement)
// 2021-01-03: OpenGL: Backup, setup and restore GL_SHADE_MODEL state, disable GL_STENCIL_TEST and disable GL_NORMAL_ARRAY client state to increase compatibility with legacy OpenGL applications.
// 2020-01-23: OpenGL: Backup, setup and restore GL_TEXTURE_ENV to increase compatibility with legacy OpenGL applications.
// 2019-04-30: OpenGL: Added support for special ImDrawCallback_ResetRenderState callback to reset render state.
@ -32,11 +42,15 @@
// 2016-09-05: OpenGL: Fixed save and restore of current scissor rectangle.
#include "imgui.h"
#ifndef IMGUI_DISABLE
#include "imgui_impl_opengl2.h"
#if defined(_MSC_VER) && _MSC_VER <= 1500 // MSVC 2008 or earlier
#include <stddef.h> // intptr_t
#else
#include <stdint.h> // intptr_t
// Clang/GCC warnings with -Weverything
#if defined(__clang__)
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wunused-macros" // warning: macro is not used
#pragma clang diagnostic ignored "-Wnonportable-system-include-path"
#endif
// Include OpenGL header (without an OpenGL loader) requires a bit of fiddling
@ -53,26 +67,62 @@
#include <GL/gl.h>
#endif
// OpenGL Data
static GLuint g_FontTexture = 0;
struct ImGui_ImplOpenGL2_Data
{
GLuint FontTexture;
ImGui_ImplOpenGL2_Data() { memset((void*)this, 0, sizeof(*this)); }
};
// 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_ImplOpenGL2_Data* ImGui_ImplOpenGL2_GetBackendData()
{
return ImGui::GetCurrentContext() ? (ImGui_ImplOpenGL2_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
}
// Forward Declarations
static void ImGui_ImplOpenGL2_InitPlatformInterface();
static void ImGui_ImplOpenGL2_ShutdownPlatformInterface();
// Functions
bool ImGui_ImplOpenGL2_Init()
{
// Setup backend capabilities flags
ImGuiIO& io = ImGui::GetIO();
IM_ASSERT(io.BackendRendererUserData == nullptr && "Already initialized a renderer backend!");
// Setup backend capabilities flags
ImGui_ImplOpenGL2_Data* bd = IM_NEW(ImGui_ImplOpenGL2_Data)();
io.BackendRendererUserData = (void*)bd;
io.BackendRendererName = "imgui_impl_opengl2";
io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports; // We can create multi-viewports on the Renderer side (optional)
if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
ImGui_ImplOpenGL2_InitPlatformInterface();
return true;
}
void ImGui_ImplOpenGL2_Shutdown()
{
ImGui_ImplOpenGL2_Data* bd = ImGui_ImplOpenGL2_GetBackendData();
IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
ImGuiIO& io = ImGui::GetIO();
ImGui_ImplOpenGL2_ShutdownPlatformInterface();
ImGui_ImplOpenGL2_DestroyDeviceObjects();
io.BackendRendererName = nullptr;
io.BackendRendererUserData = nullptr;
io.BackendFlags &= ~ImGuiBackendFlags_RendererHasViewports;
IM_DELETE(bd);
}
void ImGui_ImplOpenGL2_NewFrame()
{
if (!g_FontTexture)
ImGui_ImplOpenGL2_Data* bd = ImGui_ImplOpenGL2_GetBackendData();
IM_ASSERT(bd != nullptr && "Did you call ImGui_ImplOpenGL2_Init()?");
if (!bd->FontTexture)
ImGui_ImplOpenGL2_CreateDeviceObjects();
}
@ -153,9 +203,9 @@ void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data)
const ImDrawList* cmd_list = draw_data->CmdLists[n];
const ImDrawVert* vtx_buffer = cmd_list->VtxBuffer.Data;
const ImDrawIdx* idx_buffer = cmd_list->IdxBuffer.Data;
glVertexPointer(2, GL_FLOAT, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + IM_OFFSETOF(ImDrawVert, pos)));
glTexCoordPointer(2, GL_FLOAT, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + IM_OFFSETOF(ImDrawVert, uv)));
glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + IM_OFFSETOF(ImDrawVert, col)));
glVertexPointer(2, GL_FLOAT, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + offsetof(ImDrawVert, pos)));
glTexCoordPointer(2, GL_FLOAT, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + offsetof(ImDrawVert, uv)));
glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + offsetof(ImDrawVert, col)));
for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
{
@ -172,23 +222,18 @@ void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data)
else
{
// Project scissor/clipping rectangles into framebuffer space
ImVec4 clip_rect;
clip_rect.x = (pcmd->ClipRect.x - clip_off.x) * clip_scale.x;
clip_rect.y = (pcmd->ClipRect.y - clip_off.y) * clip_scale.y;
clip_rect.z = (pcmd->ClipRect.z - clip_off.x) * clip_scale.x;
clip_rect.w = (pcmd->ClipRect.w - clip_off.y) * clip_scale.y;
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;
if (clip_rect.x < fb_width && clip_rect.y < fb_height && clip_rect.z >= 0.0f && clip_rect.w >= 0.0f)
{
// Apply scissor/clipping rectangle
glScissor((int)clip_rect.x, (int)(fb_height - clip_rect.w), (int)(clip_rect.z - clip_rect.x), (int)(clip_rect.w - clip_rect.y));
// Apply scissor/clipping rectangle (Y is inverted in OpenGL)
glScissor((int)clip_min.x, (int)((float)fb_height - clip_max.y), (int)(clip_max.x - clip_min.x), (int)(clip_max.y - clip_min.y));
// Bind texture, Draw
glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId);
glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, idx_buffer);
}
// Bind texture, Draw
glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->GetTexID());
glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, idx_buffer + pcmd->IdxOffset);
}
idx_buffer += pcmd->ElemCount;
}
}
@ -213,22 +258,24 @@ bool ImGui_ImplOpenGL2_CreateFontsTexture()
{
// Build texture atlas
ImGuiIO& io = ImGui::GetIO();
ImGui_ImplOpenGL2_Data* bd = ImGui_ImplOpenGL2_GetBackendData();
unsigned char* pixels;
int width, height;
io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height); // Load as RGBA 32-bit (75% of the memory is wasted, but default font is so small) because it is more likely to be compatible with user's existing shaders. If your ImTextureId represent a higher-level concept than just a GL texture id, consider calling GetTexDataAsAlpha8() instead to save on GPU memory.
// Upload texture to graphics system
// (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling)
GLint last_texture;
glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
glGenTextures(1, &g_FontTexture);
glBindTexture(GL_TEXTURE_2D, g_FontTexture);
glGenTextures(1, &bd->FontTexture);
glBindTexture(GL_TEXTURE_2D, bd->FontTexture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
// Store our identifier
io.Fonts->SetTexID((ImTextureID)(intptr_t)g_FontTexture);
io.Fonts->SetTexID((ImTextureID)(intptr_t)bd->FontTexture);
// Restore state
glBindTexture(GL_TEXTURE_2D, last_texture);
@ -238,12 +285,13 @@ bool ImGui_ImplOpenGL2_CreateFontsTexture()
void ImGui_ImplOpenGL2_DestroyFontsTexture()
{
if (g_FontTexture)
ImGuiIO& io = ImGui::GetIO();
ImGui_ImplOpenGL2_Data* bd = ImGui_ImplOpenGL2_GetBackendData();
if (bd->FontTexture)
{
ImGuiIO& io = ImGui::GetIO();
glDeleteTextures(1, &g_FontTexture);
glDeleteTextures(1, &bd->FontTexture);
io.Fonts->SetTexID(0);
g_FontTexture = 0;
bd->FontTexture = 0;
}
}
@ -256,3 +304,40 @@ void ImGui_ImplOpenGL2_DestroyDeviceObjects()
{
ImGui_ImplOpenGL2_DestroyFontsTexture();
}
//--------------------------------------------------------------------------------------------------------
// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
//--------------------------------------------------------------------------------------------------------
static void ImGui_ImplOpenGL2_RenderWindow(ImGuiViewport* viewport, void*)
{
if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear))
{
ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
glClear(GL_COLOR_BUFFER_BIT);
}
ImGui_ImplOpenGL2_RenderDrawData(viewport->DrawData);
}
static void ImGui_ImplOpenGL2_InitPlatformInterface()
{
ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
platform_io.Renderer_RenderWindow = ImGui_ImplOpenGL2_RenderWindow;
}
static void ImGui_ImplOpenGL2_ShutdownPlatformInterface()
{
ImGui::DestroyPlatformWindows();
}
//-----------------------------------------------------------------------------
#if defined(__clang__)
#pragma clang diagnostic pop
#endif
#endif // #ifndef IMGUI_DISABLE