Declare callback types with stdcall in Windows, fixing segfaults when…

… trying to use them. (Not generated in non-windows builds, yet)

gen/cdef.py

@@ -62,17 +62,21 @@
 		# Otherwise just include it in the cdef
 		elif in_gl:
 			# Windows likes to add __stdcall__ to everything, but it isn't needed and is actually harmful when using under linux.
-			line = line.replace('__attribute__((__stdcall__)) ', '')
+			# However, it is needed for callbacks in windows.
+			if line.find("typedef") >= 0 and line.find(" PFNGL") < 0:
+				line = line.replace('__attribute__((__stdcall__)) ', 'WINDOWS_STDCALL ')
+			else:
+				line = line.replace('__attribute__((__stdcall__)) ', '')
 			# While linux likes to add __attribute__((visibility("default"))) 
 			line = line.replace('__attribute__((visibility("default"))) ', '')
 			cdefs.append(line.replace('__attribute__((__stdcall__)) ', ''))
 
 	# Output the file
 	print("--[[ BEGIN AUTOGENERATED SEGMENT ]]")
-	print("local glc; do require('ffi').cdef [[")
+	print("local glc; do local cdecl = [[")
 	for line in cdefs:
 		print("\t", line, sep="")
-	print("\t]]; glc = {")
+	print("\t]]; if require('ffi').os == 'Windows' then cdecl = cdecl:gsub('WINDOWS_STDCALL', '__attribute__((__stdcall__))') else cdecl = cdecl:gsub('WINDOWS_STDCALL', '') end; require('ffi').cdef(cdecl); glc = {")
 
 	for k in sorted(defines.keys()):
 		print("\t%s = %s," % ("['"+k+"']", defines[k]))

readme.md

@@ -10,10 +10,10 @@ Building
 --------
 
 LuaJIT-GLFW builds bindings from the systems OpenGL and GLFW headers, as well as an included `glext.h` file.
-To build the bindings, you need to have `gcc`, headers for OpenGL and GLFW 3, and Python 3 installed, though the resulting
+To build the bindings, you need to have a C preprocessor (only GCC is supported at the moment), headers for OpenGL and GLFW 3, and Python 3 installed, though the resulting
 file should be cross-platform compatible.
 
-To build, just run `build.sh` in the repository directory. This will create a `glfw.lua` file, which is the only file
+To build with GCC, just run `build.sh` in the repository directory. This will create a `glfw.lua` file, which is the only file
 you need to install.
 
 Usage