added premake

premake5.lua

@@ -0,0 +1,63 @@
+function platform_defines()
+    defines{"PLATFORM_DESKTOP"}
+
+    filter {"options:graphics=opengl43"}
+        defines{"GRAPHICS_API_OPENGL_43"}
+
+    filter {"options:graphics=opengl33"}
+        defines{"GRAPHICS_API_OPENGL_33"}
+
+    filter {"options:graphics=opengl21"}
+        defines{"GRAPHICS_API_OPENGL_21"}
+
+    filter {"options:graphics=opengl11"}
+        defines{"GRAPHICS_API_OPENGL_11"}
+
+    filter {"system:macosx"}
+        disablewarnings {"deprecated-declarations"}
+
+    filter {"system:linux"}
+        defines {"_GLFW_X11"}
+        defines {"_GNU_SOURCE"}
+-- This is necessary, otherwise compilation will fail since
+-- there is no CLOCK_MONOTOMIC. raylib claims to have a workaround
+-- to compile under c99 without -D_GNU_SOURCE, but it didn't seem
+-- to work. raylib's Makefile also adds this flag, probably why it went
+-- unnoticed for so long.
+-- It compiles under c11 without -D_GNU_SOURCE, because c11 requires
+-- to have CLOCK_MONOTOMIC
+-- See: https://github.com/raysan5/raylib/issues/2729
+
+    filter{}
+end
+
+project "raylib"
+    kind "StaticLib"
+    raylib_dir = "."
+
+    platform_defines()
+
+    language "C"
+    targetdir ("%{wks.location}/bin/" .. outputdir .. "/%{prj.name}")
+    objdir ("%{wks.location}/bin-int/" .. outputdir .. "/%{prj.name}")
+
+    filter "action:vs*"
+        defines{"_WINSOCK_DEPRECATED_NO_WARNINGS", "_CRT_SECURE_NO_WARNINGS"}
+        characterset ("MBCS")
+        buildoptions { "/Zc:__cplusplus" }
+    filter{}
+
+    includedirs {raylib_dir .. "/src", raylib_dir .. "/src/external/glfw/include" }
+    vpaths
+    {
+        ["Header Files"] = { raylib_dir .. "/src/**.h"},
+        ["Source Files/*"] = { raylib_dir .. "/src/**.c"},
+    }
+    files {raylib_dir .. "/src/*.h", raylib_dir .. "/src/*.c"}
+
+    removefiles {raylib_dir .. "/src/rcore_*.c"}
+
+    filter { "system:macosx", "files:" .. raylib_dir .. "/src/rglfw.c" }
+        compileas "Objective-C"
+
+    filter{}