imgui prototype

library/src/interactor_impl.cxx

@@ -30,6 +30,8 @@
 
 #include "camera.h"
 
+#include "imgui_impl_vtk.h"
+
 namespace f3d::detail
 {
 class interactor_impl::internals
@@ -51,6 +53,8 @@ class interactor_impl::internals
  // in order to be able to interact while animating
  this->VTKInteractor->RemoveObservers(vtkCommand::TimerEvent);
 
+ ImGui_ImplVTK_AddObservers(this->VTKInteractor);
+
  vtkNew<vtkCallbackCommand> keyPressCallback;
  keyPressCallback->SetClientData(this);
  keyPressCallback->SetCallback(OnKeyPress);

library/src/window_impl.cxx

@@ -10,13 +10,13 @@
 #include "vtkF3DGenericImporter.h"
 #include "vtkF3DNoRenderWindow.h"
 #include "vtkF3DRendererWithColoring.h"
+#include "vtkF3DUIRenderWindow.h"
 
 #include <vtkCamera.h>
 #include <vtkImageData.h>
 #include <vtkImageExport.h>
 #include <vtkPNGReader.h>
 #include <vtkPointGaussianMapper.h>
-#include <vtkRenderWindow.h>
 #include <vtkRendererCollection.h>
 #include <vtkVersion.h>
 #include <vtkWindowToImageFilter.h>
@@ -169,7 +169,7 @@ window_impl::window_impl(const options& options, Type type)
  }
  else
  {
- this->Internals->RenWin = vtkSmartPointer<vtkRenderWindow>::New();
+ this->Internals->RenWin = vtkSmartPointer<vtkF3DUIRenderWindow>::New();
  this->Internals->RenWin->SetOffScreenRendering(type == Type::NATIVE_OFFSCREEN);
  this->Internals->RenWin->SetMultiSamples(0); // Disable hardware antialiasing
 

vtkext/private/module/CMakeLists.txt

@@ -11,12 +11,19 @@ f3d_embed_file(
  NAME F3DDefaultHDRI
  BINARY)
 set(sources
+ ${CMAKE_CURRENT_SOURCE_DIR}/imgui_impl_opengl3.cpp
+ ${CMAKE_CURRENT_SOURCE_DIR}/imgui_impl_vtk.cpp
  ${CMAKE_CURRENT_BINARY_DIR}/F3DDefaultHDRI.cxx)
 set(private_headers
+ ${CMAKE_CURRENT_SOURCE_DIR}/imgui_impl_opengl3.h
+ ${CMAKE_CURRENT_SOURCE_DIR}/imgui_impl_opengl3_loader.h
+ ${CMAKE_CURRENT_SOURCE_DIR}/imgui_impl_vtk.h
  ${CMAKE_CURRENT_BINARY_DIR}/F3DDefaultHDRI.h)
 
 set(shader_files
- glsl/vtkF3DComputeDepthCS.glsl)
+ glsl/vtkF3DComputeDepthCS.glsl
+ glsl/vtkF3DImguiFS.glsl
+ glsl/vtkF3DImguiVS.glsl)
 
 foreach(file IN LISTS shader_files)
  vtk_encode_string(
@@ -49,6 +56,7 @@ set(classes
  vtkF3DRenderer
  vtkF3DRendererWithColoring
  vtkF3DUserRenderPass
+ vtkF3DUIRenderWindow
  )
 
 # Needs https://gitlab.kitware.com/vtk/vtk/-/merge_requests/10675
@@ -93,3 +101,6 @@ endif()
 if(F3D_MODULE_EXR)
  vtk_module_link(f3d::vtkextPrivate PRIVATE OpenEXR::OpenEXR)
 endif()
+
+find_package(imgui REQUIRED)
+vtk_module_link(f3d::vtkextPrivate PRIVATE imgui::imgui)

vtkext/private/module/glsl/vtkF3DImguiFS.glsl

@@ -0,0 +1,10 @@
+//VTK::System::Dec
+
+uniform sampler2D Texture;
+in vec2 Frag_UV;
+in vec4 Frag_Color;
+out vec4 Out_Color;
+void main()
+{
+ Out_Color = Frag_Color * texture(Texture, Frag_UV.st);
+}

vtkext/private/module/glsl/vtkF3DImguiVS.glsl

@@ -0,0 +1,14 @@
+//VTK::System::Dec
+
+uniform mat4 ProjMtx;
+in vec2 Position;
+in vec2 UV;
+in vec4 Color;
+out vec2 Frag_UV;
+out vec4 Frag_Color;
+void main()
+{
+ Frag_UV = UV;
+ Frag_Color = Color;
+ gl_Position = ProjMtx * vec4(Position.xy,0,1);
+}

vtkext/private/module/imgui_impl_opengl3.h

@@ -0,0 +1,63 @@
+// dear imgui: Renderer Backend for modern OpenGL with shaders / programmatic pipeline
+// - Desktop GL: 2.x 3.x 4.x
+// - Embedded GL: ES 2.0 (WebGL 1.0), ES 3.0 (WebGL 2.0)
+// This needs to be used along with a Platform Backend (e.g. GLFW, SDL, Win32, custom..)
+
+// Implemented features:
+// [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID!
+// [x] Renderer: Large meshes support (64k+ vertices) with 16-bit indices (Desktop OpenGL only).
+
+// About WebGL/ES:
+// - You need to '#define IMGUI_IMPL_OPENGL_ES2' or '#define IMGUI_IMPL_OPENGL_ES3' to use WebGL or OpenGL ES.
+// - This is done automatically on iOS, Android and Emscripten targets.
+// - For other targets, the define needs to be visible from the imgui_impl_opengl3.cpp compilation unit. If unsure, define globally or in imconfig.h.
+
+// 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
+
+// About GLSL version:
+// The 'glsl_version' initialization parameter should be nullptr (default) or a "#version XXX" string.
+// On computer platform the GLSL version default to "#version 130". On OpenGL ES 3 platform it defaults to "#version 300 es"
+// Only override if your GL version doesn't handle this GLSL version. See GLSL version table at the top of imgui_impl_opengl3.cpp.
+
+#pragma once
+#include "imgui.h" // IMGUI_IMPL_API
+#ifndef IMGUI_DISABLE
+
+// Backend API
+IMGUI_IMPL_API bool ImGui_ImplOpenGL3_Init(const char* glsl_version = nullptr);
+IMGUI_IMPL_API void ImGui_ImplOpenGL3_Shutdown();
+IMGUI_IMPL_API void ImGui_ImplOpenGL3_NewFrame();
+IMGUI_IMPL_API void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data);
+
+// (Optional) Called by Init/NewFrame/Shutdown
+IMGUI_IMPL_API bool ImGui_ImplOpenGL3_CreateFontsTexture();
+IMGUI_IMPL_API void ImGui_ImplOpenGL3_DestroyFontsTexture();
+IMGUI_IMPL_API bool ImGui_ImplOpenGL3_CreateDeviceObjects();
+IMGUI_IMPL_API void ImGui_ImplOpenGL3_DestroyDeviceObjects();
+
+// Specific OpenGL ES versions
+//#define IMGUI_IMPL_OPENGL_ES2 // Auto-detected on Emscripten
+//#define IMGUI_IMPL_OPENGL_ES3 // Auto-detected on iOS/Android
+
+// You can explicitly select GLES2 or GLES3 API by using one of the '#define IMGUI_IMPL_OPENGL_LOADER_XXX' in imconfig.h or compiler command-line.
+#if !defined(IMGUI_IMPL_OPENGL_ES2) \
+ && !defined(IMGUI_IMPL_OPENGL_ES3)
+
+// Try to detect GLES on matching platforms
+#if defined(__APPLE__)
+#include <TargetConditionals.h>
+#endif
+#if (defined(__APPLE__) && (TARGET_OS_IOS || TARGET_OS_TV)) || (defined(__ANDROID__))
+#define IMGUI_IMPL_OPENGL_ES3 // iOS, Android -> GL ES 3, "#version 300 es"
+#elif defined(__EMSCRIPTEN__) || defined(__amigaos4__)
+#define IMGUI_IMPL_OPENGL_ES2 // Emscripten -> GL ES 2, "#version 100"
+#else
+// Otherwise imgui_impl_opengl3_loader.h will be used.
+#endif
+
+#endif
+
+#endif // #ifndef IMGUI_DISABLE