allow defining colour patterns in lua

1 files changed, 108 insertions, 0 deletions

diff --git a/crawl-ref/source/l_colour.cc b/crawl-ref/source/l_colour.cc
new file mode 100644
index 0000000000..7727691233
--- /dev/null
+++ b/crawl-ref/source/l_colour.cc
@@ -0,0 +1,108 @@
+/*
+ * File:     l_colour.cc
+ * Summary:  Colour related functions
+ */
+
+#include "AppHdr.h"
+
+#include "clua.h"
+#include "cluautil.h"
+#include "colour.h"
+#include "message.h"
+
+typedef int (*lua_element_colour_calculator)(int, const coord_def&,
+                                             std::string);
+
+static int _lua_element_colour(int rand, const coord_def& loc,
+                               std::string function);
+
+struct lua_element_colour_calc : public element_colour_calc
+{
+    lua_element_colour_calc(element_type _type, std::string _name,
+                            std::string _function)
+        : element_colour_calc(_type, _name, (element_colour_calculator)_lua_element_colour),
+          function(_function)
+        {};
+
+    virtual int get(const coord_def& loc = coord_def(),
+                    bool non_random = false);
+
+protected:
+    std::string function;
+};
+
+int lua_element_colour_calc::get(const coord_def& loc, bool non_random)
+{
+    // casting function pointers from other function pointers is guaranteed
+    // to be safe, but calling them on pointers not of their type isn't, so
+    // assert here to be safe - add to this assert if something different is
+    // needed
+    ASSERT((lua_element_colour_calculator)calc == _lua_element_colour);
+    lua_element_colour_calculator real_calc =
+        (lua_element_colour_calculator)calc;
+    return (*real_calc)(rand(non_random), loc, function);
+}
+
+static int next_colour = ETC_FIRST_LUA;
+
+static int _lua_element_colour(int rand, const coord_def& loc,
+                               std::string function)
+{
+    lua_State *ls = clua.state();
+
+    if (clua.loadbuffer(function.data(), function.length(),
+                        "lua colour definition"))
+    {
+        mpr(clua.error.c_str(), MSGCH_WARN);
+        return BLACK;
+    }
+    lua_pushinteger(ls, rand);
+    lua_pushinteger(ls, loc.x);
+    lua_pushinteger(ls, loc.y);
+    if (!clua.callfn(NULL, 3, 1))
+    {
+        mpr(clua.error.c_str(), MSGCH_WARN);
+        return BLACK;
+    }
+
+    std::string colour = luaL_checkstring(ls, -1);
+    lua_pop(ls, 1);
+
+    return str_to_colour(colour);
+}
+
+static int _string_dumper(lua_State *ls, const void *p, size_t sz, void *ud)
+{
+    std::string *function = (std::string*)ud;
+    *function += std::string((const char *)p, sz);
+    return 0;
+}
+
+LUAFN(l_add_colour)
+{
+    const std::string &name = luaL_checkstring(ls, 1);
+    if (lua_gettop(ls) != 2 || !lua_isfunction(ls, 2))
+        luaL_error(ls, "Expected colour generation function.");
+
+    std::string function;
+    lua_dump(ls, _string_dumper, &function);
+
+    add_element_colour(
+        new lua_element_colour_calc((element_type)(next_colour++),
+                                    name, function)
+    );
+
+    return 0;
+}
+
+static const struct luaL_reg colour_lib[] =
+{
+    { "add_colour", l_add_colour },
+
+    { NULL, NULL }
+};
+
+void dluaopen_colour(lua_State *ls)
+{
+    luaL_openlib(ls, "colour", colour_lib, 0);
+}