Re: git: 2769cf2656ae - main - x11-toolkits/imgui: New port: Bloat-free Graphical User interface for C++ with minimal dependencies

Yuri Victorovich <yuri@FreeBSD.org> writes:

> +OPTIONS_DEFAULT=		GLFW OPENGL2 OPENGL3

Can you enable Vulkan by default? vulkan-loader is more likely to
be already installed (pulled by another port) than glfw. In glfw package
Vulkan is used via dlopen(3), so not visible via *_DEPENDS in the port.

I did confirm VULKAN=on works fine on FreeBSD with Intel iGPU using the
following which also helped to uncover a bug in imgui itself (missing
dependency in shared library).

--- examples/example_glfw_vulkan/CMakeLists.txt.orig	2023-01-05 14:49:29 UTC
+++ examples/example_glfw_vulkan/CMakeLists.txt
@@ -14,32 +14,20 @@ set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DVK_PROTOTYP
 set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DVK_PROTOTYPES")
 set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DVK_PROTOTYPES")
 
-# GLFW
-set(GLFW_DIR ../../../glfw) # Set this to point to an up-to-date GLFW repo
-option(GLFW_BUILD_EXAMPLES "Build the GLFW example programs" OFF)
-option(GLFW_BUILD_TESTS "Build the GLFW test programs" OFF)
-option(GLFW_BUILD_DOCS "Build the GLFW documentation" OFF)
-option(GLFW_INSTALL "Generate installation target" OFF)
-option(GLFW_DOCUMENT_INTERNALS "Include internals in documentation" OFF)
-add_subdirectory(${GLFW_DIR} binary_dir EXCLUDE_FROM_ALL)
-include_directories(${GLFW_DIR}/include)
-
-# Dear ImGui
-set(IMGUI_DIR ../../)
-include_directories(${IMGUI_DIR} ${IMGUI_DIR}/backends ..)
-
 # Libraries
+find_package(VulkanHeaders REQUIRED)
 find_package(Vulkan REQUIRED)
-#find_library(VULKAN_LIBRARY
-  #NAMES vulkan vulkan-1)
-#set(LIBRARIES "glfw;${VULKAN_LIBRARY}")
-set(LIBRARIES "glfw;Vulkan::Vulkan")
+find_package(glfw3)
+find_package(imgui)
+set(LIBRARIES "Vulkan::Vulkan;glfw;imgui::imgui")
 
-# Use vulkan headers from glfw:
-include_directories(${GLFW_DIR}/deps)
+# Work around underlinking in imgui package e.g.,
+# ld: error: undefined reference due to --no-allow-shlib-undefined: glDeleteTextures
+find_package(OpenGL)
+list(APPEND LIBRARIES OpenGL::OpenGL)
 
 file(GLOB sources *.cpp)
 
-add_executable(example_glfw_vulkan ${sources} ${IMGUI_DIR}/backends/imgui_impl_glfw.cpp ${IMGUI_DIR}/backends/imgui_impl_vulkan.cpp ${IMGUI_DIR}/imgui.cpp ${IMGUI_DIR}/imgui_draw.cpp ${IMGUI_DIR}/imgui_demo.cpp ${IMGUI_DIR}/imgui_tables.cpp ${IMGUI_DIR}/imgui_widgets.cpp)
+add_executable(example_glfw_vulkan ${sources})
 target_link_libraries(example_glfw_vulkan ${LIBRARIES})
 target_compile_definitions(example_glfw_vulkan PUBLIC -DImTextureID=ImU64)