Windows 上未链接的 OpenGL 扩展
OpenGL extensions not linking on Windows
我正在尝试 link OpenGL 到 Windows 的应用程序（基于 Windows）。
我使用 Conan 作为包管理器，使用 CMake 进行构建，使用 MSVC 作为编译器（使用 CLion 作为 IDE）。
程序可以编译，但我有 linker 错误，因为我认为是 OpenGL 中的扩展函数：
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glBlendEquation referenced in function "void __cdecl ImGui_ImplOpenGL3_SetupRenderState(struct ImDrawData *,int,int,unsigned int)" (?ImGui_ImplOpenGL3_SetupRenderState@@YAXPEAUImDrawData@@HHI@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glActiveTexture referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glBlendFuncSeparate referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glBindBuffer referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glDeleteBuffers referenced in function "void __cdecl ImGui_ImplOpenGL3_DestroyDeviceObjects(void)" (?ImGui_ImplOpenGL3_DestroyDeviceObjects@@YAXXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glGenBuffers referenced in function "bool __cdecl ImGui_ImplOpenGL3_CreateDeviceObjects(void)" (?ImGui_ImplOpenGL3_CreateDeviceObjects@@YA_NXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glBufferData referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glBlendEquationSeparate referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glAttachShader referenced in function "bool __cdecl ImGui_ImplOpenGL3_CreateDeviceObjects(void)" (?ImGui_ImplOpenGL3_CreateDeviceObjects@@YA_NXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glCompileShader referenced in function "bool __cdecl ImGui_ImplOpenGL3_CreateDeviceObjects(void)" (?ImGui_ImplOpenGL3_CreateDeviceObjects@@YA_NXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glCreateProgram referenced in function "bool __cdecl ImGui_ImplOpenGL3_CreateDeviceObjects(void)" (?ImGui_ImplOpenGL3_CreateDeviceObjects@@YA_NXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glCreateShader referenced in function "bool __cdecl ImGui_ImplOpenGL3_CreateDeviceObjects(void)" (?ImGui_ImplOpenGL3_CreateDeviceObjects@@YA_NXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glDeleteProgram referenced in function "void __cdecl ImGui_ImplOpenGL3_DestroyDeviceObjects(void)" (?ImGui_ImplOpenGL3_DestroyDeviceObjects@@YAXXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glDeleteShader referenced in function "void __cdecl ImGui_ImplOpenGL3_DestroyDeviceObjects(void)" (?ImGui_ImplOpenGL3_DestroyDeviceObjects@@YAXXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glDetachShader referenced in function "void __cdecl ImGui_ImplOpenGL3_DestroyDeviceObjects(void)" (?ImGui_ImplOpenGL3_DestroyDeviceObjects@@YAXXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glEnableVertexAttribArray referenced in function "void __cdecl ImGui_ImplOpenGL3_SetupRenderState(struct ImDrawData *,int,int,unsigned int)" (?ImGui_ImplOpenGL3_SetupRenderState@@YAXPEAUImDrawData@@HHI@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glGetAttribLocation referenced in function "bool __cdecl ImGui_ImplOpenGL3_CreateDeviceObjects(void)" (?ImGui_ImplOpenGL3_CreateDeviceObjects@@YA_NXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glGetProgramiv referenced in function "bool __cdecl CheckProgram(unsigned int,char const *)" (?CheckProgram@@YA_NIPEBD@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glGetProgramInfoLog referenced in function "bool __cdecl CheckProgram(unsigned int,char const *)" (?CheckProgram@@YA_NIPEBD@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glGetShaderiv referenced in function "bool __cdecl CheckShader(unsigned int,char const *)" (?CheckShader@@YA_NIPEBD@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glGetShaderInfoLog referenced in function "bool __cdecl CheckShader(unsigned int,char const *)" (?CheckShader@@YA_NIPEBD@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glGetUniformLocation referenced in function "bool __cdecl ImGui_ImplOpenGL3_CreateDeviceObjects(void)" (?ImGui_ImplOpenGL3_CreateDeviceObjects@@YA_NXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glLinkProgram referenced in function "bool __cdecl ImGui_ImplOpenGL3_CreateDeviceObjects(void)" (?ImGui_ImplOpenGL3_CreateDeviceObjects@@YA_NXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glShaderSource referenced in function "bool __cdecl ImGui_ImplOpenGL3_CreateDeviceObjects(void)" (?ImGui_ImplOpenGL3_CreateDeviceObjects@@YA_NXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glUseProgram referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glUniform1i referenced in function "void __cdecl ImGui_ImplOpenGL3_SetupRenderState(struct ImDrawData *,int,int,unsigned int)" (?ImGui_ImplOpenGL3_SetupRenderState@@YAXPEAUImDrawData@@HHI@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glUniformMatrix4fv referenced in function "void __cdecl ImGui_ImplOpenGL3_SetupRenderState(struct ImDrawData *,int,int,unsigned int)" (?ImGui_ImplOpenGL3_SetupRenderState@@YAXPEAUImDrawData@@HHI@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glVertexAttribPointer referenced in function "void __cdecl ImGui_ImplOpenGL3_SetupRenderState(struct ImDrawData *,int,int,unsigned int)" (?ImGui_ImplOpenGL3_SetupRenderState@@YAXPEAUImDrawData@@HHI@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glGetStringi referenced in function "bool __cdecl ImGui_ImplOpenGL3_Init(char const *)" (?ImGui_ImplOpenGL3_Init@@YA_NPEBD@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glBindVertexArray referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glDeleteVertexArrays referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glGenVertexArrays referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glDrawElementsBaseVertex referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glBindSampler referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
soundstate.exe : fatal error LNK1120: 34 unresolved externals
我想我已经在整个互联网上寻找解决方案，但我不明白缺少什么。我的直觉是，目前 OpenGL 扩展没有 linked（作为 OpenGL 菜鸟，我不是 100% 确定这甚至意味着什么）。
我正在使用 GL_GLEXT_PROTOTYPES=1 进行编译。
这是正在执行的 linker 命令：
C:\PROGRA~2\MIB055~119\COMMUN~1\VC\Tools\MSVC29~1.300\bin\Hostx86\x64\link.exe /nologo @CMakeFiles\soundstate.dir\objects1.rsp /out:soundstate.exe /implib:soundstate.lib /pdb:<project dir>\cmake-build-debug\soundstate.pdb /version:0.0 /machine:x64 /debug /INCREMENTAL /subsystem:console core.lib ..\vendor\fmod\windows\lib\x64\fmodL_vc.lib <user dir>\.conan\data\imgui-docking.83\trololo\stable\package6e49ae2c2d7b4448ca2380ea2b4c7a382d695b\lib\imgui.lib <user dir>\.conan\data\sdl2.0.14\bincrafters\stable\package\a5e24820448cb570d848a2e59f317dd7edebe889\lib\SDL2maind.lib <user dir>\.conan\data\sdl2.0.14\bincrafters\stable\package\a5e24820448cb570d848a2e59f317dd7edebe889\lib\SDL2d.lib user32.lib gdi32.lib winmm.lib imm32.lib ole32.lib oleaut32.lib version.lib uuid.lib advapi32.lib setupapi.lib shell32.lib <user dir>\.conan\data\libiconv.16\_\_\package\d057732059ea44a47760900cb5e4855d2bea8714\lib\iconv.lib C:\Users\simon\.conan\data\libiconv.16\_\_\package\d057732059ea44a47760900cb5e4855d2bea8714\lib\charset.lib <user dir>\.conan\data\glew.2.0\_\_\packagecd10aa7b17419a389740c9a9a85afec1178e5cf\lib\libglew32d.lib opengl32.lib Glu32.lib kernel32.lib user32.lib gdi32.lib winspool.lib shell32.lib ole32.lib oleaut32.lib uuid.lib comdlg32.lib advapi32.lib /MANIFEST /MANIFESTFILE:CMakeFiles\soundstate.dir/intermediate.manifest CMakeFiles\soundstate.dir/manifest.res
我试过：
- 使用 mingw（导致相同的 linker 错误）
- 添加 GLEW
- 使用共享的 SDL2 库
- 正在查找 glext.lib x64 版本（不确定是否存在或需要）
这是我的CMakeLists.txt
cmake_minimum_required(VERSION 3.16)
project(soundstate C CXX)
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_PREFIX_PATH ${CMAKE_BINARY_DIR})
set(CMAKE_MODULE_PATH ${CMAKE_BINARY_DIR})
find_package(imgui REQUIRED CONFIG)
find_package(SDL2 REQUIRED CONFIG)
find_package(immer REQUIRED CONFIG)
find_package(cereal REQUIRED CONFIG)
find_package(Boost REQUIRED CONFIG)
find_package(rxcpp REQUIRED CONFIG)
find_package(range-v3 REQUIRED CONFIG)
find_package(opengl_system REQUIRED CONFIG)
find_package(glew REQUIRED CONFIG)
#
# FMOD
#
set(CMAKE_VERBOSE_MAKEFILE ON)
if (WIN32)
add_library(fmod STATIC IMPORTED)
set_target_properties(fmod PROPERTIES
LINKER_LANGUAGE C
INTERFACE_INCLUDE_DIRECTORIES ${CMAKE_CURRENT_SOURCE_DIR}/vendor/fmod/linux/inc
IMPORTED_LOCATION ${CMAKE_CURRENT_SOURCE_DIR}/vendor/fmod/windows/lib/x64/fmodL_vc.lib
)
else ()
file(COPY vendor/fmod/linux/lib/x86_64/libfmodL.so.12.9 DESTINATION ${CMAKE_BINARY_DIR}/resources/lib)
set_target_properties(fmod PROPERTIES IMPORTED_LOCATION ${CMAKE_BINARY_DIR}/resources/lib/libfmodL.so)
endif ()
#
# Core
#
set(CORE_SOURCES
core/model.h
core/actions.h
core/reducers.h
core/utils.h core/utils.cpp
core/reducers.cpp
core/cursors.h core/cursors.cpp
core/io.cpp core/io.h
core/serialization.h
core/audio/audio_engine.cpp core/audio/audio_engine.h
core/audio/audio_context.cpp core/audio/audio_context.h)
add_library(core STATIC ${CORE_SOURCES})
target_include_directories(core PUBLIC include)
target_include_directories(core PUBLIC ${CONAN_INCLUDE_DIRS})
set(CORE_LIBS
immer::immer
cereal::cereal
Boost::Boost
rxcpp::rxcpp
range-v3::range-v3
)
set(ALL_LIBS
imgui::imgui
SDL2::SDL2
immer::immer
cereal::cereal
Boost::Boost
rxcpp::rxcpp
range-v3::range-v3
opengl::opengl
GLEW::GLEW
)
target_link_libraries(core fmod ${CORE_LIBS})
#
# Main
#
set(SOURCES
ui/imgui/main.cpp
ui/imgui/panels/panel.cpp ui/imgui/panels/panel.h
ui/imgui/panels/playables_tree_panel.cpp ui/imgui/panels/playables_tree_panel.h
ui/imgui/gui_manager.cpp ui/imgui/gui_manager.h
ui/imgui/panels/playable_editor_panel.cpp ui/imgui/panels/playable_editor_panel.h
ui/imgui/editors/editor.cpp ui/imgui/editors/editor.h
ui/imgui/editors/file_playable_editor.cpp ui/imgui/editors/file_playable_editor.h
ui/imgui/editors/list_playable_editor.cpp ui/imgui/editors/list_playable_editor.h
ui/imgui/editors/state_editor.cpp ui/imgui/editors/state_editor.h
ui/imgui/editors/state_option_editor.cpp ui/imgui/editors/state_option_editor.h
ui/imgui/imgui_extras.h
ui/imgui/icons_fa5.h
include/ImGuiFileDialog/ImGuiFileDialog.cpp
ui/imgui/panels/state_list_panel.cpp
ui/imgui/panels/state_list_panel.h
ui/imgui/panels/debug_panel.cpp
ui/imgui/panels/debug_panel.h
ui/imgui/panels/controls_panel.cpp
ui/imgui/panels/controls_panel.h
bindings/imgui_impl_opengl3.h
bindings/imgui_impl_opengl3.cpp
bindings/imgui_impl_sdl.h
bindings/imgui_impl_sdl.cpp
bindings/imgui_stdlib.h
bindings/imgui_stdlib.cpp
)
add_executable(soundstate ${SOURCES})
target_include_directories(soundstate PUBLIC vendor)
# Configure Imgui to use OpengGL through SDL2
target_compile_definitions(soundstate PUBLIC IMGUI_IMPL_OPENGL_LOADER_CUSTOM=<SDL_opengl.h> GL_GLEXT_PROTOTYPES=1)
target_link_libraries(soundstate core ${ALL_LIBS})
# Copy resources
file(COPY resources/fonts/Roboto-Regular.ttf DESTINATION ${CMAKE_BINARY_DIR}/resources/fonts)
file(COPY resources/fonts/fa-regular-400.ttf DESTINATION ${CMAKE_BINARY_DIR}/resources/fonts)
file(GLOB AUDIO_FILES resources/audio/*)
file(COPY ${AUDIO_FILES} DESTINATION ${CMAKE_BINARY_DIR}/resources/audio)
file(COPY vendor/fmod/windows/lib/x64/fmodL.dll DESTINATION ${CMAKE_BINARY_DIR}/resources/lib)
file(COPY vendor/fmod/windows/lib/x64/fmodL_vc.lib DESTINATION ${CMAKE_BINARY_DIR}/resources/lib)
I'm compiling with GL_GLEXT_PROTOTYPES=1.
好吧，别那样做。这永远不会以便携的方式工作。在 windows 上，opengl32.dll 始终 仅导出 OpenGL 1.1 中的函数，对于除此之外的所有内容，您必须依赖 OpenGL extension loading mechanism 运行时.
I have tried:
- [...]
- Adding GLEW
这是朝着正确方向迈出的一步。但这并不能使事情神奇地起作用。像 GLEW 这样的 GL 加载器通常将其 own header 作为 GL.h 和 glext.h 等的 replacement ., 而典型的 GL 加载器（如 GLEW）只是 re-define 每个 GL 都作为一个宏运行，如下所示：
#define glFooFunc() __myloader_FooFunc
其中 __myloader_FooFunc 只是一个 函数指针 必须使用加载程序提供的某些函数进行初始化（如 glewInit）。
现在这有一些影响：如果在某些源文件中包含 GL 加载器的 header，预处理器将已经替换所有 glSomething 函数名称，链接器将永远看不到它们。但这只在那个特定的源文件中是正确的。如果您有另一个没有加载程序的源文件 header，将使用实际的 GL 函数名称，链接器将找不到它们。
从您的错误消息中，例如：
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glBlendEquation referenced in function "void __cdecl ImGui_ImplOpenGL3_SetupRenderState(struct ImDrawData *,int,int,unsigned int)" (?ImGui_ImplOpenGL3_SetupRenderState@@YAXPEAUImDrawData@@HHI@Z)
很容易看出函数ImGui_ImplOpenGL3_SetupRenderState没有用GL加载器编译，而是直接使用了GL函数名。
由于ImGui支持OpenGL后端，所以已经有办法处理，看官方examples:
// About Desktop OpenGL function loaders:
// Modern desktop OpenGL doesn't have a standard portable header file to load OpenGL function pointers.
// Helper libraries are often used for this purpose! Here we are supporting a few common ones (gl3w, glew, glad).
// You may use another loader/header of your choice (glext, glLoadGen, etc.), or chose to manually implement your own.
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)
#include <GL/gl3w.h> // Initialize with gl3wInit()
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)
#include <GL/glew.h> // Initialize with glewInit()
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
#include <glad/glad.h> // Initialize with gladLoadGL()
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD2)
#include <glad/gl.h> // Initialize with gladLoadGL(...) or gladLoaderLoadGL()
[...]
因此，如果您想将 ImGui 与 GLEW 一起使用，则必须使用 IMGUI_IMPL_OPENGL_LOADER_GLEW
我正在尝试 link OpenGL 到 Windows 的应用程序（基于 Windows）。
我使用 Conan 作为包管理器，使用 CMake 进行构建，使用 MSVC 作为编译器（使用 CLion 作为 IDE）。
程序可以编译，但我有 linker 错误，因为我认为是 OpenGL 中的扩展函数：
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glBlendEquation referenced in function "void __cdecl ImGui_ImplOpenGL3_SetupRenderState(struct ImDrawData *,int,int,unsigned int)" (?ImGui_ImplOpenGL3_SetupRenderState@@YAXPEAUImDrawData@@HHI@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glActiveTexture referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glBlendFuncSeparate referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glBindBuffer referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glDeleteBuffers referenced in function "void __cdecl ImGui_ImplOpenGL3_DestroyDeviceObjects(void)" (?ImGui_ImplOpenGL3_DestroyDeviceObjects@@YAXXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glGenBuffers referenced in function "bool __cdecl ImGui_ImplOpenGL3_CreateDeviceObjects(void)" (?ImGui_ImplOpenGL3_CreateDeviceObjects@@YA_NXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glBufferData referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glBlendEquationSeparate referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glAttachShader referenced in function "bool __cdecl ImGui_ImplOpenGL3_CreateDeviceObjects(void)" (?ImGui_ImplOpenGL3_CreateDeviceObjects@@YA_NXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glCompileShader referenced in function "bool __cdecl ImGui_ImplOpenGL3_CreateDeviceObjects(void)" (?ImGui_ImplOpenGL3_CreateDeviceObjects@@YA_NXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glCreateProgram referenced in function "bool __cdecl ImGui_ImplOpenGL3_CreateDeviceObjects(void)" (?ImGui_ImplOpenGL3_CreateDeviceObjects@@YA_NXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glCreateShader referenced in function "bool __cdecl ImGui_ImplOpenGL3_CreateDeviceObjects(void)" (?ImGui_ImplOpenGL3_CreateDeviceObjects@@YA_NXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glDeleteProgram referenced in function "void __cdecl ImGui_ImplOpenGL3_DestroyDeviceObjects(void)" (?ImGui_ImplOpenGL3_DestroyDeviceObjects@@YAXXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glDeleteShader referenced in function "void __cdecl ImGui_ImplOpenGL3_DestroyDeviceObjects(void)" (?ImGui_ImplOpenGL3_DestroyDeviceObjects@@YAXXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glDetachShader referenced in function "void __cdecl ImGui_ImplOpenGL3_DestroyDeviceObjects(void)" (?ImGui_ImplOpenGL3_DestroyDeviceObjects@@YAXXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glEnableVertexAttribArray referenced in function "void __cdecl ImGui_ImplOpenGL3_SetupRenderState(struct ImDrawData *,int,int,unsigned int)" (?ImGui_ImplOpenGL3_SetupRenderState@@YAXPEAUImDrawData@@HHI@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glGetAttribLocation referenced in function "bool __cdecl ImGui_ImplOpenGL3_CreateDeviceObjects(void)" (?ImGui_ImplOpenGL3_CreateDeviceObjects@@YA_NXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glGetProgramiv referenced in function "bool __cdecl CheckProgram(unsigned int,char const *)" (?CheckProgram@@YA_NIPEBD@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glGetProgramInfoLog referenced in function "bool __cdecl CheckProgram(unsigned int,char const *)" (?CheckProgram@@YA_NIPEBD@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glGetShaderiv referenced in function "bool __cdecl CheckShader(unsigned int,char const *)" (?CheckShader@@YA_NIPEBD@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glGetShaderInfoLog referenced in function "bool __cdecl CheckShader(unsigned int,char const *)" (?CheckShader@@YA_NIPEBD@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glGetUniformLocation referenced in function "bool __cdecl ImGui_ImplOpenGL3_CreateDeviceObjects(void)" (?ImGui_ImplOpenGL3_CreateDeviceObjects@@YA_NXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glLinkProgram referenced in function "bool __cdecl ImGui_ImplOpenGL3_CreateDeviceObjects(void)" (?ImGui_ImplOpenGL3_CreateDeviceObjects@@YA_NXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glShaderSource referenced in function "bool __cdecl ImGui_ImplOpenGL3_CreateDeviceObjects(void)" (?ImGui_ImplOpenGL3_CreateDeviceObjects@@YA_NXZ)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glUseProgram referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glUniform1i referenced in function "void __cdecl ImGui_ImplOpenGL3_SetupRenderState(struct ImDrawData *,int,int,unsigned int)" (?ImGui_ImplOpenGL3_SetupRenderState@@YAXPEAUImDrawData@@HHI@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glUniformMatrix4fv referenced in function "void __cdecl ImGui_ImplOpenGL3_SetupRenderState(struct ImDrawData *,int,int,unsigned int)" (?ImGui_ImplOpenGL3_SetupRenderState@@YAXPEAUImDrawData@@HHI@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glVertexAttribPointer referenced in function "void __cdecl ImGui_ImplOpenGL3_SetupRenderState(struct ImDrawData *,int,int,unsigned int)" (?ImGui_ImplOpenGL3_SetupRenderState@@YAXPEAUImDrawData@@HHI@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glGetStringi referenced in function "bool __cdecl ImGui_ImplOpenGL3_Init(char const *)" (?ImGui_ImplOpenGL3_Init@@YA_NPEBD@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glBindVertexArray referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glDeleteVertexArrays referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glGenVertexArrays referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glDrawElementsBaseVertex referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glBindSampler referenced in function "void __cdecl ImGui_ImplOpenGL3_RenderDrawData(struct ImDrawData *)" (?ImGui_ImplOpenGL3_RenderDrawData@@YAXPEAUImDrawData@@@Z)
soundstate.exe : fatal error LNK1120: 34 unresolved externals
我想我已经在整个互联网上寻找解决方案，但我不明白缺少什么。我的直觉是，目前 OpenGL 扩展没有 linked（作为 OpenGL 菜鸟，我不是 100% 确定这甚至意味着什么）。
我正在使用 GL_GLEXT_PROTOTYPES=1 进行编译。
这是正在执行的 linker 命令：
C:\PROGRA~2\MIB055~119\COMMUN~1\VC\Tools\MSVC29~1.300\bin\Hostx86\x64\link.exe /nologo @CMakeFiles\soundstate.dir\objects1.rsp /out:soundstate.exe /implib:soundstate.lib /pdb:<project dir>\cmake-build-debug\soundstate.pdb /version:0.0 /machine:x64 /debug /INCREMENTAL /subsystem:console core.lib ..\vendor\fmod\windows\lib\x64\fmodL_vc.lib <user dir>\.conan\data\imgui-docking.83\trololo\stable\package6e49ae2c2d7b4448ca2380ea2b4c7a382d695b\lib\imgui.lib <user dir>\.conan\data\sdl2.0.14\bincrafters\stable\package\a5e24820448cb570d848a2e59f317dd7edebe889\lib\SDL2maind.lib <user dir>\.conan\data\sdl2.0.14\bincrafters\stable\package\a5e24820448cb570d848a2e59f317dd7edebe889\lib\SDL2d.lib user32.lib gdi32.lib winmm.lib imm32.lib ole32.lib oleaut32.lib version.lib uuid.lib advapi32.lib setupapi.lib shell32.lib <user dir>\.conan\data\libiconv.16\_\_\package\d057732059ea44a47760900cb5e4855d2bea8714\lib\iconv.lib C:\Users\simon\.conan\data\libiconv.16\_\_\package\d057732059ea44a47760900cb5e4855d2bea8714\lib\charset.lib <user dir>\.conan\data\glew.2.0\_\_\packagecd10aa7b17419a389740c9a9a85afec1178e5cf\lib\libglew32d.lib opengl32.lib Glu32.lib kernel32.lib user32.lib gdi32.lib winspool.lib shell32.lib ole32.lib oleaut32.lib uuid.lib comdlg32.lib advapi32.lib /MANIFEST /MANIFESTFILE:CMakeFiles\soundstate.dir/intermediate.manifest CMakeFiles\soundstate.dir/manifest.res
我试过：
- 使用 mingw（导致相同的 linker 错误）
- 添加 GLEW
- 使用共享的 SDL2 库
- 正在查找 glext.lib x64 版本（不确定是否存在或需要）
这是我的CMakeLists.txt
cmake_minimum_required(VERSION 3.16)
project(soundstate C CXX)
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_PREFIX_PATH ${CMAKE_BINARY_DIR})
set(CMAKE_MODULE_PATH ${CMAKE_BINARY_DIR})
find_package(imgui REQUIRED CONFIG)
find_package(SDL2 REQUIRED CONFIG)
find_package(immer REQUIRED CONFIG)
find_package(cereal REQUIRED CONFIG)
find_package(Boost REQUIRED CONFIG)
find_package(rxcpp REQUIRED CONFIG)
find_package(range-v3 REQUIRED CONFIG)
find_package(opengl_system REQUIRED CONFIG)
find_package(glew REQUIRED CONFIG)
#
# FMOD
#
set(CMAKE_VERBOSE_MAKEFILE ON)
if (WIN32)
add_library(fmod STATIC IMPORTED)
set_target_properties(fmod PROPERTIES
LINKER_LANGUAGE C
INTERFACE_INCLUDE_DIRECTORIES ${CMAKE_CURRENT_SOURCE_DIR}/vendor/fmod/linux/inc
IMPORTED_LOCATION ${CMAKE_CURRENT_SOURCE_DIR}/vendor/fmod/windows/lib/x64/fmodL_vc.lib
)
else ()
file(COPY vendor/fmod/linux/lib/x86_64/libfmodL.so.12.9 DESTINATION ${CMAKE_BINARY_DIR}/resources/lib)
set_target_properties(fmod PROPERTIES IMPORTED_LOCATION ${CMAKE_BINARY_DIR}/resources/lib/libfmodL.so)
endif ()
#
# Core
#
set(CORE_SOURCES
core/model.h
core/actions.h
core/reducers.h
core/utils.h core/utils.cpp
core/reducers.cpp
core/cursors.h core/cursors.cpp
core/io.cpp core/io.h
core/serialization.h
core/audio/audio_engine.cpp core/audio/audio_engine.h
core/audio/audio_context.cpp core/audio/audio_context.h)
add_library(core STATIC ${CORE_SOURCES})
target_include_directories(core PUBLIC include)
target_include_directories(core PUBLIC ${CONAN_INCLUDE_DIRS})
set(CORE_LIBS
immer::immer
cereal::cereal
Boost::Boost
rxcpp::rxcpp
range-v3::range-v3
)
set(ALL_LIBS
imgui::imgui
SDL2::SDL2
immer::immer
cereal::cereal
Boost::Boost
rxcpp::rxcpp
range-v3::range-v3
opengl::opengl
GLEW::GLEW
)
target_link_libraries(core fmod ${CORE_LIBS})
#
# Main
#
set(SOURCES
ui/imgui/main.cpp
ui/imgui/panels/panel.cpp ui/imgui/panels/panel.h
ui/imgui/panels/playables_tree_panel.cpp ui/imgui/panels/playables_tree_panel.h
ui/imgui/gui_manager.cpp ui/imgui/gui_manager.h
ui/imgui/panels/playable_editor_panel.cpp ui/imgui/panels/playable_editor_panel.h
ui/imgui/editors/editor.cpp ui/imgui/editors/editor.h
ui/imgui/editors/file_playable_editor.cpp ui/imgui/editors/file_playable_editor.h
ui/imgui/editors/list_playable_editor.cpp ui/imgui/editors/list_playable_editor.h
ui/imgui/editors/state_editor.cpp ui/imgui/editors/state_editor.h
ui/imgui/editors/state_option_editor.cpp ui/imgui/editors/state_option_editor.h
ui/imgui/imgui_extras.h
ui/imgui/icons_fa5.h
include/ImGuiFileDialog/ImGuiFileDialog.cpp
ui/imgui/panels/state_list_panel.cpp
ui/imgui/panels/state_list_panel.h
ui/imgui/panels/debug_panel.cpp
ui/imgui/panels/debug_panel.h
ui/imgui/panels/controls_panel.cpp
ui/imgui/panels/controls_panel.h
bindings/imgui_impl_opengl3.h
bindings/imgui_impl_opengl3.cpp
bindings/imgui_impl_sdl.h
bindings/imgui_impl_sdl.cpp
bindings/imgui_stdlib.h
bindings/imgui_stdlib.cpp
)
add_executable(soundstate ${SOURCES})
target_include_directories(soundstate PUBLIC vendor)
# Configure Imgui to use OpengGL through SDL2
target_compile_definitions(soundstate PUBLIC IMGUI_IMPL_OPENGL_LOADER_CUSTOM=<SDL_opengl.h> GL_GLEXT_PROTOTYPES=1)
target_link_libraries(soundstate core ${ALL_LIBS})
# Copy resources
file(COPY resources/fonts/Roboto-Regular.ttf DESTINATION ${CMAKE_BINARY_DIR}/resources/fonts)
file(COPY resources/fonts/fa-regular-400.ttf DESTINATION ${CMAKE_BINARY_DIR}/resources/fonts)
file(GLOB AUDIO_FILES resources/audio/*)
file(COPY ${AUDIO_FILES} DESTINATION ${CMAKE_BINARY_DIR}/resources/audio)
file(COPY vendor/fmod/windows/lib/x64/fmodL.dll DESTINATION ${CMAKE_BINARY_DIR}/resources/lib)
file(COPY vendor/fmod/windows/lib/x64/fmodL_vc.lib DESTINATION ${CMAKE_BINARY_DIR}/resources/lib)
I'm compiling with
GL_GLEXT_PROTOTYPES=1.
好吧，别那样做。这永远不会以便携的方式工作。在 windows 上，opengl32.dll 始终 仅导出 OpenGL 1.1 中的函数，对于除此之外的所有内容，您必须依赖 OpenGL extension loading mechanism 运行时.
I have tried:
- [...]
- Adding GLEW
这是朝着正确方向迈出的一步。但这并不能使事情神奇地起作用。像 GLEW 这样的 GL 加载器通常将其 own header 作为 GL.h 和 glext.h 等的 replacement ., 而典型的 GL 加载器（如 GLEW）只是 re-define 每个 GL 都作为一个宏运行，如下所示：
#define glFooFunc() __myloader_FooFunc
其中 __myloader_FooFunc 只是一个 函数指针 必须使用加载程序提供的某些函数进行初始化（如 glewInit）。
现在这有一些影响：如果在某些源文件中包含 GL 加载器的 header，预处理器将已经替换所有 glSomething 函数名称，链接器将永远看不到它们。但这只在那个特定的源文件中是正确的。如果您有另一个没有加载程序的源文件 header，将使用实际的 GL 函数名称，链接器将找不到它们。
从您的错误消息中，例如：
imgui_impl_opengl3.cpp.obj : error LNK2019: unresolved external symbol __imp_glBlendEquation referenced in function "void __cdecl ImGui_ImplOpenGL3_SetupRenderState(struct ImDrawData *,int,int,unsigned int)" (?ImGui_ImplOpenGL3_SetupRenderState@@YAXPEAUImDrawData@@HHI@Z)
很容易看出函数ImGui_ImplOpenGL3_SetupRenderState没有用GL加载器编译，而是直接使用了GL函数名。
由于ImGui支持OpenGL后端，所以已经有办法处理，看官方examples:
// About Desktop OpenGL function loaders: // Modern desktop OpenGL doesn't have a standard portable header file to load OpenGL function pointers. // Helper libraries are often used for this purpose! Here we are supporting a few common ones (gl3w, glew, glad). // You may use another loader/header of your choice (glext, glLoadGen, etc.), or chose to manually implement your own. #elif defined(IMGUI_IMPL_OPENGL_LOADER_GL3W) #include <GL/gl3w.h> // Initialize with gl3wInit() #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW) #include <GL/glew.h> // Initialize with glewInit() #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD) #include <glad/glad.h> // Initialize with gladLoadGL() #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD2) #include <glad/gl.h> // Initialize with gladLoadGL(...) or gladLoaderLoadGL() [...]
因此，如果您想将 ImGui 与 GLEW 一起使用，则必须使用 IMGUI_IMPL_OPENGL_LOADER_GLEW