[Add] First 2D vector support for lua.

src/llua.c

@@ -1,3 +1,15 @@
+/**
+ * @file llua.c
+ *
+ * @brief Contains some standard Lua binding libraries.
+ *
+ * Namely:
+ *    -- lephisto : General game stuff.
+ *    -- time     : For manipulating time.
+ *    -- rnd      : For access to the random number generator.
+ *    -- tk       : Access to the toolkit.
+ */
+
 #include "lauxlib.h"
 
 #include "log.h"

src/llua_space.c

@@ -10,6 +10,7 @@
 
 static int planetL_createmetatable(lua_State* L);
 static int systemL_createmetatable(lua_State* L);
+static int vectorL_createmetatable(lua_State* L);
 
 /* Space. */
 static int planetL_get(lua_State* L);
@@ -48,9 +49,22 @@ static const luaL_reg system_methods[] = {
   { 0, 0 }
 };
 
+/* Vector metatable methods. */
+static int vectorL_add(lua_State* L);
+static int vectorL_sub(lua_State* L);
+static int vectorL_mul(lua_State* L);
+static int vectorL_div(lua_State* L);
+static const luaL_reg vector_methods[] = {
+  { "__add", vectorL_add },
+  { "__sub", vectorL_sub },
+  { "__mul", vectorL_mul },
+  { "__div", vectorL_div },
+  { 0, 0 }
+}; /**< Vector metatable methods. */
+
 /* Load the space library. */
 int lua_loadSpace(lua_State* L, int readonly) {
-  (void)readonly;
+  (void)readonly; /* Only read only atm. */
 
   /* Register the functions. */
   luaL_register(L, "space", space_methods);
@@ -58,6 +72,20 @@ int lua_loadSpace(lua_State* L, int readonly) {
   /* Register the metatables. */
   planetL_createmetatable(L);
   systemL_createmetatable(L);
+  lua_loadVector(L);
+
+  return 0;
+}
+
+/**
+ * @fn int lua_loadVector(lua_State* L)
+ *
+ * @brief Loads the vector metatable.
+ *    @param L State to load the vector metatable into.
+ *    @return 0 on success.
+ */
+int lua_loadVector(lua_State* L) {
+  vectorL_createmetatable(L);
 
   return 0;
 }
@@ -94,6 +122,27 @@ static int systemL_createmetatable(lua_State* L) {
   return 0; /* No error. */
 }
 
+/**
+ * @fn static int vectorL_createmetatable(lua_State* L)
+ *
+ * @brief Registers the vector metatable.
+ *    @param L Lua state to register metatable in.
+ *    @return 0 on success.
+ */
+static int vectorL_createmetatable(lua_State* L) {
+  /* Create the metatable. */
+  luaL_newmetatable(L, VECTOR_METATABLE);
+
+  /* Create the access table. */
+  lua_pushvalue(L, -1);
+  lua_setfield(L, -2, "__index");
+
+  /* Register the values. */
+  luaL_register(L, NULL, vector_methods);
+
+  return 0; /* No error. */
+}
+
 /* -- PLANET -- */
 
 /* Get planet at index. */
@@ -380,3 +429,201 @@ static int systemL_jumpdistance(lua_State* L) {
   return 1;
 }
 
+/**
+ * @defgroup META_VECTOR Vector Metatable
+ *
+ * @brief Represents a 2d vector in Lua.
+ *
+ * To call members of the metatable always use:
+ * @code
+ * vector:function(param)
+ * @endcode
+ */
+
+/**
+ * @fn LuaVector* lua_tovector(lua_State* L, int ind)
+ * 
+ * @brief Gets vector at index.
+ *    @param L Lua state to get vector from.
+ *    @param ind Index position of vector.
+ *    @return The LuaVector at ind.
+ */
+LuaVector* lua_tovector(lua_State* L, int ind) {
+  if(lua_isuserdata(L, ind)) {
+    return (LuaVector*)lua_touserdata(L, ind);
+  }
+
+  luaL_typerror(L, ind, VECTOR_METATABLE);
+  return NULL;
+}
+
+/**
+ * @fn LuaVector* lua_pushvector(lua_State* L, LuaVector vec)
+ *
+ * @brief Pushes a vector on the stack.
+ *    @param L Lua state to push vector onto.
+ *    @param sys Vector to push.
+ *    @return Vector just pushed.
+ */
+LuaVector* lua_pushvector(lua_State* L, LuaVector vec) {
+  LuaVector* v;
+  v = (LuaVector*) lua_newuserdata(L, sizeof(LuaVector));
+  *v = vec;
+  luaL_getmetatable(L, VECTOR_METATABLE);
+  lua_setmetatable(L, -2);
+  return v;
+}
+
+/**
+ * @fn int lua_isvector(lua_State* L, int ind)
+ *
+ * @brief Check to see if ind is a vector.
+ *    @param L lua state to check.
+ *    @param ind Index position to check.
+ *    @return 1 if there is a vector at index position.
+ */
+int lua_isvector(lua_State* L, int ind) {
+  int ret;
+
+  if(lua_getmetatable(L, ind)==0)
+    return 0;
+  lua_getfield(L, LUA_REGISTRYINDEX, VECTOR_METATABLE);
+  
+  ret = 0;
+  if(lua_rawequal(L, -1, -2)) /* Does it have the correct mt? */
+    ret = 1;
+
+  lua_pop(L, 2); /* Remove both metatables. */
+  return ret;
+}
+
+/**
+ * @fn static int vectorL_add(lua_State* L)
+ * @ingroup META_VECTOR
+ *
+ * @brief __add(Vec2 vector)
+ *
+ * __add(number x, number y)
+ *
+ * Adds two vectors or a vector and some cartesian coords.
+ */
+static int vectorL_add(lua_State* L) {
+  LLUA_MIN_ARGS(2);
+  LuaVector* v1, *v2;
+  double x, y;
+
+  /* Get self. */
+  if(lua_isvector(L, 1))
+    v1 = lua_tovector(L, 1);
+  else LLUA_INVALID_PARAMETER();
+
+  /* Get rest of parameters. */
+  v2 = NULL;
+  if(lua_isvector(L, 2)) {
+    v2 = lua_tovector(L, 2);
+    x = v2->vec.x;
+    y = v2->vec.y;
+  }
+  else LLUA_INVALID_PARAMETER();
+
+  /* Actually add it. */
+  vect_cadd(&v1->vec, x, y);
+  return 0;
+}
+
+/**
+ * @fn static int vectorL_sub(lua_State* L)
+ * @ingroup META_VECTOR
+ *
+ * @brief __sub(Vec2 vector)
+ *
+ * __sub(number x, number y)
+ *
+ * Subtracts two vectors or a vector and some cartesian coords.
+ */
+static int vectorL_sub(lua_State* L) {
+  LLUA_MIN_ARGS(2);
+  LuaVector* v1, *v2;
+  double x, y;
+
+  /* Get self. */
+  if(lua_isvector(L, 1))
+    v1 = lua_tovector(L, 1);
+  else LLUA_INVALID_PARAMETER();
+
+  /* Get rest of parameters. */
+  v2 = NULL;
+  if(lua_isvector(L, 2)) {
+    v2 = lua_tovector(L, 2);
+    x = v2->vec.x;
+    y = v2->vec.y;
+  }
+  else if((lua_gettop(L) > 2) && lua_isnumber(L, 2) && lua_isnumber(L, 3)) {
+    x = lua_tonumber(L, 2);
+    y = lua_tonumber(L, 3);
+  }
+  else LLUA_INVALID_PARAMETER();
+
+  /* Actually add it. */
+  vect_cadd(&v1->vec, -x, -y);
+  return 0;
+}
+
+/**
+ * @fn static int vectorL_mul(lua_State* L)
+ * @ingroup META_VECTOR
+ *
+ * @brief __mul(number mod)
+ *
+ * Multiplies by a number.
+ *    @param mod Amount to multiply by.
+ */
+static int vectorL_mul(lua_State* L) {
+  LLUA_MIN_ARGS(2);
+  LuaVector* v1;
+  double mod;
+  
+  /* Get self. */
+  if(lua_isvector(L, 1))
+    v1 = lua_tovector(L, 1);
+  else LLUA_INVALID_PARAMETER();
+
+  /* Get rest of parameters. */
+  if(lua_isnumber(L, 2))
+    mod = lua_tonumber(L, 2);
+  else LLUA_INVALID_PARAMETER();
+
+  /* Actually add it. */
+  vect_cadd(&v1->vec, v1->vec.x * mod, v1->vec.x * mod);
+  return 0;
+}
+
+/**
+ * @fn static int vectorL_div(lua_State* L)
+ * @ingroup META_VECTOR
+ *
+ * @brief __div(number mod)
+ *
+ * Divides a vector by a number.
+ *    @param mod Amount to divide by.
+ */
+static int vectorL_div(lua_State* L) {
+  LLUA_MIN_ARGS(2);
+  LuaVector* v1;
+  double mod;
+
+  /* Get self. */
+  if(lua_isvector(L, 1))
+    v1 = lua_tovector(L, 1);
+  else LLUA_INVALID_PARAMETER();
+
+  /* Get rest of parameters. */
+  if(lua_isnumber(L, 2))
+    mod = lua_tonumber(L, 2);
+  else LLUA_INVALID_PARAMETER();
+
+  /* Actually add it. */
+  vect_cadd(&v1->vec, v1->vec.x / mod, v1->vec.x / mod);
+  return 0;
+}
+

src/llua_space.h

@@ -4,17 +4,22 @@
 
 #define PLANET_METATABLE    "Planet"
 #define SYSTEM_METATABLE    "System"
+#define VECTOR_METATABLE    "Vec2"
 
 /* Lua wrappers. */
-typedef struct LuaPlanet_ {
+typedef struct LuaPlanet_s {
   Planet* p;
 } LuaPlanet;
-typedef struct LuaSystem_ {
+typedef struct LuaSystem_s {
   StarSystem* s;
 } LuaSystem;
+typedef struct LuaVector_s {
+  Vec2 vec;
+} LuaVector;
 
 /* Load the space library. */
 int lua_loadSpace(lua_State* L, int readonly);
+int lua_loadVector(lua_State* L);
 
 /* Planet operations. */
 LuaPlanet* lua_toplanet(lua_State* L, int ind);
@@ -26,3 +31,8 @@ LuaSystem* lua_tosystem(lua_State* L, int ind);
 LuaSystem* lua_pushsystem(lua_State* L, LuaSystem sys);
 int lua_issystem(lua_State* L, int ind);
 
+/* Vector operations. */
+LuaVector* lua_tovector(lua_State* L, int ind);
+LuaVector* lua_pushvector(lua_State* L, LuaVector vec);
+int lua_isvector(lua_State* L, int ind);
+