Implemented LuaJIT FFI versions of love.math.random and RandomGenerator:random.

src/modules/math/wrap_RandomGenerator.lua

@@ -0,0 +1,80 @@
+R"luastring"--(
+-- DO NOT REMOVE THE ABOVE LINE. It is used to load this file as a C++ string.
+-- There is a matching delimiter at the bottom of the file.
+
+--[[
+Copyright (c) 2006-2015 LOVE Development Team
+
+This software is provided 'as-is', without any express or implied
+warranty.  In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not
+claim that you wrote the original software. If you use this software
+in a product, an acknowledgment in the product documentation would be
+appreciated but is not required.
+2. Altered source versions must be plainly marked as such, and must not be
+misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+--]]
+
+local RandomGenerator_mt, ffifuncspointer = ...
+local RandomGenerator = RandomGenerator_mt.__index
+
+local type, tonumber, error = type, tonumber, error
+local floor = math.floor
+
+local _random = RandomGenerator._random
+
+local function getrandom(r, l, u)
+	if u ~= nil then
+		if type(r) ~= "number" then error("bad argument #1 to 'random' (number expected)", 2) end
+		if type(l) ~= "number" then error("bad argument #2 to 'random' (number expected)", 2) end
+		return floor(r * (u - l + 1)) + l
+	elseif l ~= nil then
+		if type(l) ~= "number" then error("bad argument #1 to 'random' (number expected)", 2) end
+		return floor(r * l) + 1
+	else
+		return r
+	end
+end
+
+function RandomGenerator:random(l, u)
+	local r = _random(self)
+	return getrandom(r, l, u)
+end
+
+if type(jit) ~= "table" or not jit.status() then
+	-- LuaJIT's FFI is *much* slower than LOVE's regular methods when the JIT
+	-- compiler is disabled.
+	return
+end
+
+local status, ffi = pcall(require, "ffi")
+if not status then return end
+
+pcall(ffi.cdef, [[
+typedef struct Proxy Proxy;
+
+typedef struct FFI_RandomGenerator
+{
+	double (*random)(Proxy *p);
+} FFI_RandomGenerator;
+]])
+
+local ffifuncs = ffi.cast("FFI_RandomGenerator *", ffifuncspointer)
+
+
+-- Overwrite some regular love.math functions with FFI implementations.
+
+function RandomGenerator:random(l, u)
+	local r = tonumber(ffifuncs.random(self))
+	return getrandom(r, l, u)
+end
+
+-- DO NOT REMOVE THE NEXT LINE. It is used to load this file as a C++ string.
+--)luastring"--"