lua_obj.c

#include "lua_obj.h"
#include "lua_script.h"
#include "lua_udata.h"
#include "obj.h"

#define OBJ_FIELDS(X) \
    X(type), \
    X(fuse), \
    X(x), X(y), X(z), \
    X(radius), \
    X(momx), X(momy), X(momz), \
    X(groundz), \
    X(onground), \
    X(scale), \
    X(gravity), \
    X(angle), \
    X(angleoffset), \
    X(sprite), X(frame), X(color), \
    X(overlaysprite), X(overlayframe), X(overlaycolor), \
    X(dropshadow), \
    X(interactive), \
    X(kartdata), \
    X(valid), \

UDATA_DECL(obj_t, OBJ_FIELDS);

static int luaobj_get(lua_State *L)
{
    obj_t *o = UDATA_GET(L, 1, obj_t);

    int field = udata_getfield(L, UDATA_FIELDS_REF(obj_t));

    if (!(o && o->valid))
    {
        if (field == UDATA_FIELD_NUM(valid))
        {
            lua_pushboolean(gL, false);
            return 1;
        }
        else
            return luaL_error(L, "accessed " UDATA_TYPENAME(obj_t) " does not exist anymore, please check .valid field first");
    }

#define INTFIELD_GET(name) \
    case UDATA_FIELD_NUM(name): \
        lua_pushinteger(L, o->name); \
    break;

#define FLOATFIELD_GET(name) \
    case UDATA_FIELD_NUM(name): \
        lua_pushnumber(L, o->name); \
    break;

#define BOOLFIELD_GET(name) \
    case UDATA_FIELD_NUM(name): \
        lua_pushboolean(L, o->name); \
    break;


    switch (field)
    {
        INTFIELD_GET(type);

        INTFIELD_GET(fuse);

        FLOATFIELD_GET(x);
        FLOATFIELD_GET(y);
        FLOATFIELD_GET(z);

        FLOATFIELD_GET(radius);

        FLOATFIELD_GET(momx);
        FLOATFIELD_GET(momy);
        FLOATFIELD_GET(momz);

        FLOATFIELD_GET(groundz);
        BOOLFIELD_GET(onground);

        FLOATFIELD_GET(scale);

        FLOATFIELD_GET(gravity);

        FLOATFIELD_GET(angle);
        FLOATFIELD_GET(angleoffset);

        INTFIELD_GET(sprite);
        INTFIELD_GET(frame);
        INTFIELD_GET(color);

        INTFIELD_GET(overlaysprite);
        INTFIELD_GET(overlayframe);
        INTFIELD_GET(overlaycolor);

        BOOLFIELD_GET(dropshadow);

        BOOLFIELD_GET(interactive);

        case UDATA_FIELD_NUM(kartdata):
            if (o->type == OBJ_KART)
                udata_push(L, o->extradata, UDATA_TYPENAME(kartdata_t), false);
            else
                lua_pushnil(L);
        break;

        BOOLFIELD_GET(valid);

        default:
            udata_custom_get(L);
        break;
    }

    return 1;
}

static int luaobj_set(lua_State *L)
{
    obj_t *o = UDATA_GET(L, 1, obj_t);
    int field = udata_getfield(L, UDATA_FIELDS_REF(obj_t));

    if (!(o && o->valid))
    {
        return luaL_error(L, "accessed " UDATA_TYPENAME(obj_t) " does not exist anymore, please check .valid field first");
    }

#define READONLY(name) \
    case UDATA_FIELD_NUM(name): \
        return luaL_error(L, "Field " #name " is read only"); \
    break;

#define INTFIELD_SET(name) \
    case UDATA_FIELD_NUM(name): \
        o->name = luaL_checkinteger(L, 3); \
    break;

#define INTFIELD_SET_RANGE(name, rangemin, rangemax) \
    case UDATA_FIELD_NUM(name): \
    { \
        int val = luaL_checkinteger(L, 3); \
        if (val < rangemin || val >= rangemax) \
            return luaL_error(L, "Field " #name " value is out of range [%d, %d)", rangemin, rangemax); \
        o->name = val; \
    } \
    break;

#define FLOATFIELD_SET(name) \
    case UDATA_FIELD_NUM(name): \
        o->name = luaL_checknumber(L, 3); \
    break;

#define BOOLFIELD_SET(name) \
    case UDATA_FIELD_NUM(name): \
        o->name = lua_toboolean(L, 3); \
    break;


    switch (field)
    {
        READONLY(type);

        INTFIELD_SET(fuse);

        FLOATFIELD_SET(x);
        FLOATFIELD_SET(y);
        FLOATFIELD_SET(z);

        FLOATFIELD_SET(radius);

        FLOATFIELD_SET(momx);
        FLOATFIELD_SET(momy);
        FLOATFIELD_SET(momz);

        READONLY(groundz);
        READONLY(onground);

        FLOATFIELD_SET(scale);

        FLOATFIELD_SET(gravity);

        FLOATFIELD_SET(angle);
        FLOATFIELD_SET(angleoffset);

        INTFIELD_SET_RANGE(sprite, 0, NUMSPRITES);
        INTFIELD_SET(frame);
        INTFIELD_SET_RANGE(color, 0, NUMSKINCOLORS);

        INTFIELD_SET_RANGE(overlaysprite, 0, NUMSPRITES);
        INTFIELD_SET(overlayframe);
        INTFIELD_SET_RANGE(overlaycolor, 0, NUMSKINCOLORS);

        BOOLFIELD_SET(dropshadow);

        BOOLFIELD_SET(interactive);

        READONLY(valid);

        default:
            udata_custom_set(L);
        break;
    }

    return 0;
}

static int luaobj_create(lua_State *L)
{
    float x = luaL_checknumber(L, 1);
    float y = luaL_checknumber(L, 2);
    objtype_t type = luaL_checkinteger(L, 3);

    if (type < 0 || type >= NUMOBJTYPES)
        return luaL_error(L, "object type is out of range [0, %d]", NUMOBJTYPES);

    obj_t *o = obj_create(x, y, type);

    udata_push(L, o, UDATA_TYPENAME(obj_t), true);

    return 1;
}

static int luaobj_remove(lua_State *L)
{
    obj_t *o = UDATA_GET(L, 1, obj_t);

    /* Passing nil or invalid objects is safe */
    if (!(o && o->valid))
        return 0;

    o->valid = false;

    return 0;
}

static const luaL_Reg obj_lib[] = {
    {"create", luaobj_create},
    {"remove", luaobj_remove},
    {NULL, NULL},
};

void luaobj_init(void)
{
    UDATA_REGISTER(gL, obj_t);
        lua_pushcfunction(gL, luaobj_get);
        lua_setfield(gL, -2, "__index");

        lua_pushcfunction(gL, luaobj_set);
        lua_setfield(gL, -2, "__newindex");
    lua_pop(gL, 1);

    lua_newtable(gL);
    luaL_setfuncs(gL, obj_lib, 0);
    lua_setglobal(gL, "obj");

    /* TODO - adding new object types, for now just adding constants for existing ones */
#define ADDCONST(name) lua_pushinteger(gL, name); lua_setglobal(gL, #name);
    ADDCONST(OBJ_KART);
    ADDCONST(OBJ_PARTICLE);
    ADDCONST(OBJ_EXPLOSION);
}