crawl-ref/source/l_colour.cc

   1 /*
   2  * File:     l_colour.cc
   3  * Summary:  Colour related functions
   4  */
   5
   6 #include "AppHdr.h"
   7
   8 #include "cluautil.h"
   9 #include "colour.h"
  10 #include "dlua.h"
  11
  12 typedef int (*lua_element_colour_calculator)(int, const coord_def&, lua_datum);
  13
  14 static int _lua_element_colour(int rand, const coord_def& loc,
  15                                lua_datum function);
  16
  17 struct lua_element_colour_calc : public element_colour_calc
  18 {
  19     lua_element_colour_calc(element_type _type, std::string _name,
  20                             lua_datum _function)
  21         : element_colour_calc(_type, _name, (element_colour_calculator)_lua_element_colour),
  22           function(_function)
  23         {};
  24
  25     virtual int get(const coord_def& loc = coord_def(),
  26                     bool non_random = false);
  27
  28 protected:
  29     lua_datum function;
  30 };
  31
  32 int lua_element_colour_calc::get(const coord_def& loc, bool non_random)
  33 {
  34     // casting function pointers from other function pointers is guaranteed
  35     // to be safe, but calling them on pointers not of their type isn't, so
  36     // assert here to be safe - add to this assert if something different is
  37     // needed
  38     ASSERT((lua_element_colour_calculator)calc == _lua_element_colour);
  39     lua_element_colour_calculator real_calc =
  40         (lua_element_colour_calculator)calc;
  41     return (*real_calc)(rand(non_random), loc, function);
  42 }
  43
  44 static int next_colour = ETC_FIRST_LUA;
  45
  46 static int _lua_element_colour(int rand, const coord_def& loc,
  47                                lua_datum function)
  48 {
  49     lua_State *ls = dlua.state();
  50
  51     function.push();
  52     lua_pushinteger(ls, rand);
  53     lua_pushinteger(ls, loc.x);
  54     lua_pushinteger(ls, loc.y);
  55     if (!dlua.callfn(NULL, 3, 1))
  56     {
  57         mpr(dlua.error.c_str(), MSGCH_WARN);
  58         return BLACK;
  59     }
  60
  61     std::string colour = luaL_checkstring(ls, -1);
  62     lua_pop(ls, 1);
  63
  64     return str_to_colour(colour);
  65 }
  66
  67 LUAFN(l_add_colour)
  68 {
  69     const std::string &name = luaL_checkstring(ls, 1);
  70     if (lua_gettop(ls) != 2 || !lua_isfunction(ls, 2))
  71         luaL_error(ls, "Expected colour generation function.");
  72
  73     CLua& vm(CLua::get_vm(ls));
  74     lua_datum function(vm, 2);
  75
  76     add_element_colour(
  77         new lua_element_colour_calc((element_type)(next_colour++),
  78                                     name, function)
  79   );
  80
  81     return 0;
  82 }
  83
  84 static const struct luaL_reg colour_lib[] =
  85 {
  86     { "add_colour", l_add_colour },
  87
  88     { NULL, NULL }
  89 };
  90
  91 void dluaopen_colour(lua_State *ls)
  92 {
  93     luaL_openlib(ls, "colour", colour_lib, 0);
  94 }