Getting errors about including imgui.h when it should just work fine

[nathangur]

Hey all. First time diving into ImGUI and I'm getting a bunch of errors in my main access script (everything is in c++ by the way.)

Here is that script for reference:

`
// PhysicsTest.cpp

#include "simulation.h"
#include "imgui/imgui.h"
#include "SDL/include/SDL_events.h"
#include "SDL/include/SDL_opengl.h"
#include "SDL/include/SDL.h"
#include "SDL/include/SDL_syswm.h"

// Simulation and window variables
PhysicsSimulation simulation;
SDL_Window* window = nullptr;
SDL_GLContext gl_context = nullptr;

// Update function that is called every frame
void update() {
// Calculate the time elapsed between each frame
float deltaTime = ImGui::GetIO().DeltaTime;

  // Check if the simulation is paused
  if (!simulation.isPaused()) {
      // If the simulation is not paused, simulate different types of motion based on user input
      if (ImGui::RadioButton("Constant Velocity", simulation.getCurrentMotion() == 0)) {
          simulation.setCurrentMotion(0);
      }
      if (ImGui::RadioButton("Gravity", simulation.getCurrentMotion() == 1)) {
          simulation.setCurrentMotion(1);
      }
      if (ImGui::RadioButton("Elastic Collision", simulation.getCurrentMotion() == 2)) {
          simulation.setCurrentMotion(2);
      }

      switch (simulation.getCurrentMotion()) {
      case 0:
          simulation.constantVelocity(deltaTime); // Simulate constant velocity
          break;
      case 1:
          simulation.gravity(deltaTime); // Simulate gravity
          break;
      case 2:
          simulation.elasticCollision(deltaTime); // Simulate elastic collision
          break;
      }

      simulation.collisionDetection(); // Detect collisions between objects
      simulation.collisionResolution(); // Resolve all collisions
  }

  simulation.draw(); // Draw objects on the application window
  simulation.handleInput(); // Handle user input

}

int main() {
// Initialize SDL
if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0) {
printf("Error: %s\n", SDL_GetError());
return -1;
}

  // Set up SDL window
  SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
  SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
  SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 8);
  SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
  // Set up SDL window (cont.)
  SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);
  SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
  window = SDL_CreateWindow("Physics Simulation", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, window_flags);
  gl_context = SDL_GL_CreateContext(window);
  // Initialize objects
  std::vector<Object> objects = {
      {1, 0, 1, 0},
      {2, 1, 2, 0},
      {3, 2, 3, 0},
      {4, 3, 4, 0},
      {5, 4, 5, 0}
  };
  // Create a simulation object with the initialized objects
  simulation = PhysicsSimulation(objects);

  // Initialize imgui
  ImGui::CreateContext();
  ImGuiIO& io = ImGui::GetIO(); (void)io;
  ImGui::StyleColorsDark();

  // Set up imgui rendering
  ImGui_ImplOpenGL3_Init("#version 150");
  ImGui_ImplSDL2_InitForOpenGL(window, gl_context);

  // Main loop
  bool done = false;
  while (!done) {
      // Poll events from SDL
      SDL_Event event;
      while (SDL_PollEvent(&event)) {
          // Pass event data to imgui
          ImGui_ImplSDL2_ProcessEvent(&event);
          // Handle events
          if (event.type == SDL_QUIT) {
              done = true;
          }
      }

      // Start a new imgui frame
      ImGui_ImplOpenGL3_NewFrame();
      ImGui_ImplSDL2_NewFrame(window);
      ImGui::NewFrame();

      // Update the simulation and render the GUI
      update();
      ImGui::Render();
      SDL_GL_MakeCurrent(window, gl_context);
      SDL_GL_SwapWindow(window);
  }

  // Clean up
  ImGui_ImplOpenGL3_Shutdown();
  ImGui_ImplSDL2_Shutdown();
  ImGui::DestroyContext();
  SDL_GL_DeleteContext(gl_context);
  SDL_DestroyWindow(window);
  SDL_Quit();

  return 0;

}
`

From this script I get the following errors:

• Severity Code Description Project File Line Suppression State
  Error C2661 'ImGui::RadioButton': no overloaded function takes 1 arguments 23
  Error (active) E0140 too many arguments in function call 35
  Error (active) E0140 too many arguments in function call 38
  Error (active) E0140 too many arguments in function call 41
  Error (active) E0020 identifier "ImGui_ImplSDL2_Shutdown" is undefined 118
  Error (active) E0020 identifier "ImGui_ImplSDL2_ProcessEvent" is undefined 97
  Error (active) E0020 identifier "ImGui_ImplSDL2_NewFrame" is undefined 106
  Error (active) E0020 identifier "ImGui_ImplSDL2_InitForOpenGL" is undefined 88
  Error (active) E0020 identifier "ImGui_ImplOpenGL3_Shutdown" is undefined 117
  Error (active) E0020 identifier "ImGui_ImplOpenGL3_NewFrame" is undefined 105
  Error (active) E0020 identifier "ImGui_ImplOpenGL3_Init" is undefined Physics Test C87
  Error (active) E0135 class "PhysicsSimulation" has no member "setCurrentMotion" 24
  Error (active) E0135 class "PhysicsSimulation" has no member "setCurrentMotion" 27
  Error (active) E0135 class "PhysicsSimulation" has no member "setCurrentMotion" 30
  Error (active) E0135 class "PhysicsSimulation" has no member "getCurrentMotion" 23
  Error (active) E0135 class "PhysicsSimulation" has no member "getCurrentMotion" P26
  Error (active) E0135 class "PhysicsSimulation" has no member "getCurrentMotion" 29
  Error (active) E0135 class "PhysicsSimulation" has no member "getCurrentMotion" 33
  Error C2039 'setCurrentMotion': is not a member of 'PhysicsSimulation' Physics Test 24
  Error C2039 'setCurrentMotion': is not a member of 'PhysicsSimulation' Physics Test 27
  Error C2039 'setCurrentMotion': is not a member of 'PhysicsSimulation' Physics Test 30
  Error C2660 'PhysicsSimulation::gravity': function does not take 1 arguments 38
  Error C2660 'PhysicsSimulation::elasticCollision': function does not take 1 arguments 41
  Error C2660 'PhysicsSimulation::constantVelocity': function does not take 1 arguments 35
  Error C2512 'PhysicsSimulation': no appropriate default constructor available 11
  Error C3861 'ImGui_ImplSDL2_Shutdown': identifier not found 118
  Error C3861 'ImGui_ImplSDL2_ProcessEvent': identifier not found 97
  Error C3861 'ImGui_ImplSDL2_NewFrame': identifier not found 106
  Error C3861 'ImGui_ImplSDL2_InitForOpenGL': identifier not found 88
  Error C3861 'ImGui_ImplOpenGL3_Shutdown': identifier not found 117
  Error C3861 'ImGui_ImplOpenGL3_NewFrame': identifier not found 105
  Error C3861 'ImGui_ImplOpenGL3_Init': identifier not found 87
  Error C2661 'ImGui::RadioButton': no overloaded function takes 1 arguments 26
  Error C2661 'ImGui::RadioButton': no overloaded function takes 1 arguments 29
  Error C2039 'getCurrentMotion': is not a member of 'PhysicsSimulation' 23
  Error C2039 'getCurrentMotion': is not a member of 'PhysicsSimulation' 26
  Error C2039 'getCurrentMotion': is not a member of 'PhysicsSimulation' 29
  Error C2039 'getCurrentMotion': is not a member of 'PhysicsSimulation' 33

From all of this there is a bunch of not found identifiers. If I add includes for each of them another issue springs up as it now complains about imgui.h no being found but only on 3 files. Changing it to this: #include "imgui/imgui.h" it fixes itself but then I get an extra 60 errors of random things going haywire. Could anyone assist me in debugging this?

-Thanks

[PathogenDavid]

Hi, please make sure your posts are well-formatted. You need to use three backticks for multi-line codeblocks, IE:

```cpp
int main()
{
    printf("Hello, world!");
}
```

becomes

int main()
{
    printf("Hello, world!");
}

Also the error list shown in the Output tab will have much better formatting for copy+pasting.

---

You need to include the headers for the backends too. IE: imgui_impl_sdl.h and imgui_impl_opengl3.h.

You should not need to use the imgui/ or imgui/backends/ (or SDL/include/) prefixes on your includes. The fact that you do means your project is not set up correctly. Those directories should be added to the include paths of your project at the build system level.

I get an extra 60 errors of random things going haywire. Could anyone assist me in debugging this?

We can't assist you without knowing what the errors are.

[LuZixuan2022]

When I use it, it says:

It went wrong C2059 in line 2999 at imgui_internal.h.

Line 2991~3013 in imgui_internal.h is like these:

namespace ImGui
{
    // Windows
    // We should always have a CurrentWindow in the stack (there is an implicit "Debug" window)
    // If this ever crash because g.CurrentWindow is NULL it means that either
    // - ImGui::NewFrame() has never been called, which is illegal.
    // - You are calling ImGui functions after ImGui::EndFrame()/ImGui::Render() and before the next ImGui::NewFrame(), which is also illegal.
    inline    ImGuiWindow*  GetCurrentWindowRead()      { ImGuiContext& g = *GImGui; return g.CurrentWindow; }
    inline    ImGuiWindow*  GetCurrentWindow()          { ImGuiContext& g = *GImGui; g.CurrentWindow->WriteAccessed = true; return g.CurrentWindow; }
    IMGUI_API ImGuiWindow*  FindWindowByID(ImGuiID id);
    IMGUI_API ImGuiWindow*  FindWindowByName(const char* name);
    IMGUI_API void          UpdateWindowParentAndRootLinks(ImGuiWindow* window, ImGuiWindowFlags flags, ImGuiWindow* parent_window);
    IMGUI_API void          UpdateWindowSkipRefresh(ImGuiWindow* window);
    IMGUI_API ImVec2        CalcWindowNextAutoFitSize(ImGuiWindow* window);
    IMGUI_API bool          IsWindowChildOf(ImGuiWindow* window, ImGuiWindow* potential_parent, bool popup_hierarchy);
    IMGUI_API bool          IsWindowWithinBeginStackOf(ImGuiWindow* window, ImGuiWindow* potential_parent);
    IMGUI_API bool          IsWindowAbove(ImGuiWindow* potential_above, ImGuiWindow* potential_below);
    IMGUI_API bool          IsWindowNavFocusable(ImGuiWindow* window);
    IMGUI_API void          SetWindowPos(ImGuiWindow* window, const ImVec2& pos, ImGuiCond cond = 0);
    IMGUI_API void          SetWindowSize(ImGuiWindow* window, const ImVec2& size, ImGuiCond cond = 0);
    IMGUI_API void          SetWindowCollapsed(ImGuiWindow* window, bool collapsed, ImGuiCond cond = 0);
    IMGUI_API void          SetWindowHitTestHole(ImGuiWindow* window, const ImVec2& pos, const ImVec2& size);
    IMGUI_API void          SetWindowHiddenAndSkipItemsForCurrentFrame(ImGuiWindow* window);