I am trying to install IMGUI but I get the following errors.

Severity Code Description Project File Line Suppression State

Error (active) E1097 unknown attribute "no_init_all" Project84 C:\Program Files (x86)\Windows Kits\10\Include\10.0.19041.0\um\winnt.h 7623

Error (active) E0011 unrecognized preprocessing directive Project84 C:\Users\Owner\Desktop\ocornut-imgui-f7eea63\examples\example_glut_opengl2\main.cpp 21

Error LNK2019 unresolved external symbol "struct ImGuiContext * __cdecl ImGui::CreateContext(struct ImFontAtlas *)" (?CreateContext@ImGui@@YAPAUImGuiContext@@PAUImFontAtlas@@@Z) referenced in function _main Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "void __cdecl ImGui::DestroyContext(struct ImGuiContext *)" (?DestroyContext@ImGui@@YAXPAUImGuiContext@@@Z) referenced in function _main Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "struct ImGuiIO & __cdecl ImGui::GetIO(void)" (?GetIO@ImGui@@YAAAUImGuiIO@@XZ) referenced in function "void __cdecl MainLoopStep(void)" (?MainLoopStep@@YAXXZ) Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "void __cdecl ImGui::NewFrame(void)" (?NewFrame@ImGui@@YAXXZ) referenced in function "void __cdecl MainLoopStep(void)" (?MainLoopStep@@YAXXZ) Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "void __cdecl ImGui::Render(void)" (?Render@ImGui@@YAXXZ) referenced in function "void __cdecl MainLoopStep(void)" (?MainLoopStep@@YAXXZ) Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "struct ImDrawData * __cdecl ImGui::GetDrawData(void)" (?GetDrawData@ImGui@@YAPAUImDrawData@@XZ) referenced in function "void __cdecl MainLoopStep(void)" (?MainLoopStep@@YAXXZ) Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "void __cdecl ImGui::ShowDemoWindow(bool *)" (?ShowDemoWindow@ImGui@@YAXPA_N@Z) referenced in function "void __cdecl MainLoopStep(void)" (?MainLoopStep@@YAXXZ) Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "void __cdecl ImGui::StyleColorsDark(struct ImGuiStyle *)" (?StyleColorsDark@ImGui@@YAXPAUImGuiStyle@@@Z) referenced in function _main Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "bool __cdecl ImGui::Begin(char const *,bool *,int)" (?Begin@ImGui@@YA_NPBDPA_NH@Z) referenced in function "void __cdecl MainLoopStep(void)" (?MainLoopStep@@YAXXZ) Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "void __cdecl ImGui::End(void)" (?End@ImGui@@YAXXZ) referenced in function "void __cdecl MainLoopStep(void)" (?MainLoopStep@@YAXXZ) Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "void __cdecl ImGui::SameLine(float,float)" (?SameLine@ImGui@@YAXMM@Z) referenced in function "void __cdecl MainLoopStep(void)" (?MainLoopStep@@YAXXZ) Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "void __cdecl ImGui::Text(char const *,...)" (?Text@ImGui@@YAXPBDZZ) referenced in function "void __cdecl MainLoopStep(void)" (?MainLoopStep@@YAXXZ) Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "bool __cdecl ImGui::Button(char const *,struct ImVec2 const &)" (?Button@ImGui@@YA_NPBDABUImVec2@@@Z) referenced in function "void __cdecl MainLoopStep(void)" (?MainLoopStep@@YAXXZ) Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "bool __cdecl ImGui::Checkbox(char const *,bool *)" (?Checkbox@ImGui@@YA_NPBDPA_N@Z) referenced in function "void __cdecl MainLoopStep(void)" (?MainLoopStep@@YAXXZ) Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "bool __cdecl ImGui::SliderFloat(char const *,float *,float,float,char const *,int)" (?SliderFloat@ImGui@@YA_NPBDPAMMM0H@Z) referenced in function "void __cdecl MainLoopStep(void)" (?MainLoopStep@@YAXXZ) Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "bool __cdecl ImGui::ColorEdit3(char const *,float * const,int)" (?ColorEdit3@ImGui@@YA_NPBDQAMH@Z) referenced in function "void __cdecl MainLoopStep(void)" (?MainLoopStep@@YAXXZ) Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "bool __cdecl ImGui::DebugCheckVersionAndDataLayout(char const *,unsigned int,unsigned int,unsigned int,unsigned int,unsigned int,unsigned int)" (?DebugCheckVersionAndDataLayout@ImGui@@YA_NPBDIIIIII@Z) referenced in function _main Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "bool __cdecl ImGui_ImplGLUT_Init(void)" (?ImGui_ImplGLUT_Init@@YA_NXZ) referenced in function _main Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "void __cdecl ImGui_ImplGLUT_InstallFuncs(void)" (?ImGui_ImplGLUT_InstallFuncs@@YAXXZ) referenced in function _main Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "void __cdecl ImGui_ImplGLUT_Shutdown(void)" (?ImGui_ImplGLUT_Shutdown@@YAXXZ) referenced in function _main Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "void __cdecl ImGui_ImplGLUT_NewFrame(void)" (?ImGui_ImplGLUT_NewFrame@@YAXXZ) referenced in function "void __cdecl MainLoopStep(void)" (?MainLoopStep@@YAXXZ) Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "bool __cdecl ImGui_ImplOpenGL2_Init(void)" (?ImGui_ImplOpenGL2_Init@@YA_NXZ) referenced in function _main Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "void __cdecl ImGui_ImplOpenGL2_Shutdown(void)" (?ImGui_ImplOpenGL2_Shutdown@@YAXXZ) referenced in function _main Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "void __cdecl ImGui_ImplOpenGL2_NewFrame(void)" (?ImGui_ImplOpenGL2_NewFrame@@YAXXZ) referenced in function "void __cdecl MainLoopStep(void)" (?MainLoopStep@@YAXXZ) Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK2019 unresolved external symbol "void __cdecl ImGui_ImplOpenGL2_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL2_RenderDrawData@@YAXPAUImDrawData@@@Z) referenced in function "void __cdecl MainLoopStep(void)" (?MainLoopStep@@YAXXZ) Project84 C:\Users\Owner\source\repos\Project84\Project84\main.obj 1

Error LNK1120 25 unresolved externals Project84 C:\Users\Owner\source\repos\Project84\Debug\Project84.exe 1

Your first step for any kind of compiler error, like your first error, should be google:

https://letmegooglethat.com/?q=unknown+attribute+%22no_init_all%22​

All of those linker errors would indicate that you're not linking the imgui libraries to your project (or not including the appropriate source).

Have you followed the directions for integrating imgui?

https://github.com/ocornut/imgui/wiki/Getting-Started

What compiler/development environment are you using? What are your linker input lib settings?

SBD said:
Your first step for any kind of compiler error, like your first error, should be google:

Amen.