Externals: Add libepoxy submodule.

.gitmodules

@@ -7,3 +7,6 @@
 [submodule "externals/nihstro"]
 	path = externals/nihstro
 	url = https://github.com/neobrain/nihstro.git
+[submodule "externals/libepoxy/libepoxy"]
+	path = externals/libepoxy/libepoxy
+	url = https://github.com/anholt/libepoxy.git

CMakeLists.txt

@@ -34,6 +34,8 @@ else()
 endif()
 add_definitions(-DSINGLETHREADED)
 
+find_package(PkgConfig)
+
 find_package(PNG QUIET)
 if (PNG_FOUND)
     add_definitions(-DHAVE_PNG)
@@ -55,6 +57,16 @@ list(APPEND CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/externals/cmake-modules")
 find_package(OpenGL REQUIRED)
 include_directories(${OPENGL_INCLUDE_DIR})
 
+pkg_search_module(LIBEPOXY epoxy)
+if(LIBEPOXY_FOUND)
+    message("Using shared libepoxy")
+else()
+    message("Using static libepoxy from externals")
+    add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/externals/libepoxy)
+    include_directories(${CMAKE_CURRENT_BINARY_DIR}/externals/libepoxy/include
+                        ${CMAKE_CURRENT_SOURCE_DIR}/externals/libepoxy/libepoxy/include)
+endif()
+
 option(ENABLE_GLFW "Enable the GLFW frontend" ON)
 if (ENABLE_GLFW)
     if (WIN32)

externals/libepoxy/CMakeLists.txt

@@ -0,0 +1,36 @@
+cmake_minimum_required(VERSION 2.6)
+
+project(libepoxy)
+
+#set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c99")
+add_definitions(-std=c99)
+
+set(top_srcdir ${CMAKE_CURRENT_SOURCE_DIR}/libepoxy)
+set(top_builddir ${CMAKE_CURRENT_BINARY_DIR})
+set(srcdir ${top_srcdir}/src)
+set(builddir ${top_builddir}/src)
+
+make_directory(${top_builddir}/include/epoxy)
+make_directory(${top_builddir}/src)
+
+foreach(REGISTRY gl egl glx wgl)
+    execute_process(COMMAND python3 ${srcdir}/gen_dispatch.py --dir ${top_builddir} ${top_srcdir}/registry/${REGISTRY}.xml)
+endforeach()
+
+include_directories(${top_srcdir}/include)
+
+set(SRCS ${srcdir}/dispatch_common.c ${builddir}/gl_generated_dispatch.c)
+
+if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
+    if (WIN32)
+        set(SRCS ${SRCS} ${srcdir}/dispatch_wgl.c ${builddir}/wgl_generated_dispatch.c)
+    elseif (NOT APPLE)
+        find_package(X11)
+        if (NOT X11_FOUND)
+            set(SRCS ${SRCS} ${srcdir}/dispatch_glx.c ${builddir}/glx_generated_dispatch.c)
+        endif()
+        set(SRCS ${SRCS} ${srcdir}/dispatch_egl.c ${builddir}/egl_generated_dispatch.c)
+    endif()
+endif()
+
+add_library(epoxy STATIC ${SRCS})

externals/libepoxy/libepoxy

@@ -0,0 +1 @@
+Subproject commit 20062c25e7612cab023cdef44d3277ba1bd0b2de