From 978ab32a11e663b2571c9f72ec43114e2eabf2c5 Mon Sep 17 00:00:00 2001
From: cracyc <cracyc@users.noreply.github.com>
Date: Fri, 8 Apr 2016 11:59:32 -0500
Subject: [PATCH] plugins/cheatfind: start lua cheat finder library [Carl]

---
 plugins/cheatfind/init.lua    | 98 +++++++++++++++++++++++++++++++++++
 plugins/cheatfind/plugin.json | 10 ++++
 2 files changed, 108 insertions(+)
 create mode 100644 plugins/cheatfind/init.lua
 create mode 100644 plugins/cheatfind/plugin.json

diff --git a/plugins/cheatfind/init.lua b/plugins/cheatfind/init.lua
new file mode 100644
index 00000000000..a4334b67aba
--- /dev/null
+++ b/plugins/cheatfind/init.lua
@@ -0,0 +1,98 @@
+-- license:BSD-3-Clause
+-- copyright-holders:Carl
+-- This is a library of functions to be used at the Lua console as cf.getspaces() etc...
+local exports = {}
+exports.name = "cheatfind"
+exports.version = "0.0.1"
+exports.description = "Cheat finder helper library"
+exports.license = "The BSD 3-Clause License"
+exports.author = { name = "Carl" }
+
+local cheatfind = exports
+
+function cheatfind.startplugin()
+	local cheat = {}
+
+	-- return table of devices and spaces
+	function cheat.getspaces()
+		local spaces = {}
+		for tag, device in pairs(manager:machine().devices) do
+			if device.spaces then
+				spaces[tag] = {}
+				for name, space in pairs(device.spaces) do
+					spaces[tag][name] = space
+				end
+			end
+		end
+		return spaces
+	end
+
+	-- return table of ram devices
+	function cheat.getram()
+		local ram = {}
+		for tag, device in pairs(manager:machine().devices) do
+			if device:shortname() == "ram" then
+				ram[tag] = device
+			end
+		end
+	end
+
+	-- save data block
+	function cheat.save(space, start, size)
+		local data = { block = "", dev = space, start = start, size = size, space = space }
+		if space.shortname then
+			if space:shortname() == "ram" then
+				data.block = emu.item(device.items["0/m_pointer"]):read_block(start, size)
+				if not data.block then
+					return nil
+				end
+			end
+		else
+			local block = ""
+			for i = start, start + size do
+				block = block .. string.pack("B", space:read_u8(i))
+			end
+			data.block = block
+		end
+		return data
+	end
+
+	-- compare a data block to the current state
+	function cheat.comp(olddata, oper, val)
+		local newdata = cheat.save(olddata.dev, olddata.start, olddata.size, olddata.space)
+		local ret = {}
+		if not val then
+			val = 0
+		end
+		if oper == "+" or oper == "inc" then
+			for i = 1, olddata.size do
+				local old = string.unpack("B", olddata.block, i)
+				local new = string.unpack("B", newdata.block, i)
+				if old < new then
+					if (val > 0 and (old + val) == new) or val == 0 then
+						ret[#ret + 1] = { addr = olddata.start + i,
+								  oldval = old,
+								  newval = new}
+					end
+				end
+			end
+		elseif oper == "-" or oper == "dec" then
+			for i = 1, olddata.size do
+				local old = string.unpack("B", olddata.block, i)
+				local new = string.unpack("B", newdata.block, i)
+				if old > new then
+					if (val > 0 and (old - val) == new) or val == 0 then
+						ret[#ret + 1] = { addr = olddata.start + i,
+								  oldval = old,
+								  newval = new}
+					end
+				end
+			end
+		end
+		return ret
+	end
+
+	_G.cf = cheat
+end
+
+return exports
diff --git a/plugins/cheatfind/plugin.json b/plugins/cheatfind/plugin.json
new file mode 100644
index 00000000000..8316cb5f334
--- /dev/null
+++ b/plugins/cheatfind/plugin.json
@@ -0,0 +1,10 @@
+{
+  "plugin": {
+    "name": "cheatfind",
+	"description": "Cheat finder helper library",
+    "version": "0.0.1",
+    "author": "Carl",
+	"type": "plugin",
+	"start": "false"
+  }
+}