Add initial Craft API example

modules/water.lua

@@ -0,0 +1,18 @@
+-- water.lua
+-- adding a water block via lua module
+
+water_block_id = 0;
+
+function startup()
+	io.write("adding a 'water' block\n");
+
+	water_block_id = api.add_block_type('water');
+end
+
+function shutdown()
+	io.write("water module shutting down\n");
+end
+
+function after_terrain_generated()
+	io.write("fires after a block of terrain is generated");
+end

src/api.c

@@ -0,0 +1,169 @@
+#include "api.h"
+#include <string.h>
+#include <stdlib.h>
+
+#ifdef _WIN32
+#include <windows.h>
+#else
+#include <dirent.h>
+#endif
+
+#define MAX_FILENAME_LENGTH 1024
+#define MAX_ERROR_SIZE 255
+
+#define MODULE_DIR "modules/"
+
+// API functions
+int api_add_block_type(lua_State *l)
+{
+    // add the given 'block type' to our engine and return the generated block ID
+    const char *block_name = lua_tostring(l, 1);
+    int block_id = 37;  // random id. we should have a real dynamic way to add block types in the engine
+    lua_pushnumber(l, block_id);
+    return 1;
+}
+
+luaL_Reg clua_regs[] =
+{
+    { "add_block_type", api_add_block_type },
+    { NULL, NULL }
+};
+
+
+// structs
+struct module_name_list {
+    char *filename;
+    struct module_name_list *next_ptr;
+};
+
+struct loaded_module_list {
+    char *filename;
+    lua_State *L;
+    struct loaded_module_list *next_ptr;
+};
+
+struct loaded_module_list *loaded_mods;
+
+
+// lua init/shutdown
+int clua_init()
+{
+    struct module_name_list *mod, *mod_names;
+    mod_names = NULL;
+    loaded_mods = NULL;
+
+    // get list of modules
+#ifdef _WIN32
+    WIN32_FIND_DATA fdFile;
+    HANDLE hFind = NULL;
+
+    char sPath[2048];
+
+    sprintf(sPath, "%s\\*.lua", MODULE_DIR);
+
+    if((hFind = FindFirstFile(sPath, &fdFile)) == INVALID_HANDLE_VALUE) {
+        dprintf(stderr, "Module folder not found: [%s]\n", sDir);
+        return 1;
+    }
+
+    do {
+        if(strcmp(fdFile.cFileName, ".") != 0
+           && strcmp(fdFile.cFileName, "..") != 0)
+        {
+            sprintf(sPath, "%s\\%s", sDir, fdFile.cFileName);
+
+            mod = malloc(sizeof(struct module_name_list));
+            mod->filename = sPath;
+
+            SGLIB_LIST_ADD(struct module_name_list, mod_names, mod, next_ptr);
+        }
+    } while (FindNextFile(hFind, &fdFile));
+
+    FindClose(hFind);
+#else
+    DIR *d;
+    struct dirent *dir;
+    d = opendir(MODULE_DIR);
+
+    if (d) {
+        char *ext = ".lua";
+        int ext_len = strlen(ext);
+
+        while ((dir = readdir(d)) != NULL) {
+            int name_len = strlen(dir->d_name);
+
+            if ((name_len > ext_len) && (0 == strncmp(dir->d_name + (name_len - ext_len), ext, ext_len))) {
+                char module_filename[MAX_FILENAME_LENGTH] = {0};
+
+                if (MAX_FILENAME_LENGTH <= (strlen(MODULE_DIR) + strlen(dir->d_name))) {
+                    fprintf(stderr, "Module name is too large: %s\n", dir->d_name);
+                    continue;
+                }
+
+                strncpy(module_filename, MODULE_DIR, strlen(MODULE_DIR));
+                strncat(module_filename, dir->d_name, MAX_FILENAME_LENGTH - strlen(MODULE_DIR) - 1);
+
+                mod = malloc(sizeof(struct module_name_list));
+                mod->filename = module_filename;
+
+                SGLIB_LIST_ADD(struct module_name_list, mod_names, mod, next_ptr);
+            }
+        }
+
+        closedir(d);
+    }
+#endif
+
+    // load lua modules
+    SGLIB_LIST_MAP_ON_ELEMENTS(struct module_name_list, mod_names, mod_name, next_ptr, {
+        printf("Loading module %s\n", mod_name->filename);
+
+        struct loaded_module_list *mod;
+        mod = malloc(sizeof(struct loaded_module_list));
+
+        // we have a separate lua state for every single module we load
+        mod->L = luaL_newstate();
+        luaL_openlibs(mod->L);
+
+        // init our API
+        lua_newtable(mod->L);
+        luaL_setfuncs(mod->L, clua_regs, 0);
+        lua_setglobal(mod->L, "api");
+
+        if (luaL_loadfile(mod->L, mod_name->filename)) {
+            fprintf(stderr, "Lua module %s failed to load\n", mod_name->filename);
+            free(mod);
+        }
+        else {
+            if (lua_pcall(mod->L, 0, 0, 0)) {
+                fprintf(stderr, "Lua module %s failed to run\n", mod_name->filename);
+                free(mod);
+            }
+            else {
+                lua_getglobal(mod->L, "startup");
+
+                if (lua_pcall(mod->L, 0, 0, 0)) {
+                    fprintf(stderr, "Startup in %s failed\n", mod_name->filename);
+                    free(mod);
+                }
+                else {
+                    SGLIB_LIST_ADD(struct loaded_module_list, loaded_mods, mod, next_ptr)
+                }
+            }
+        }
+    });
+
+    return 0;
+}
+
+
+int clua_close()
+{
+    // close lua on every loaded module
+    SGLIB_LIST_MAP_ON_ELEMENTS(struct loaded_module_list, loaded_mods, mod, next_ptr, {
+        lua_close(mod->L);
+        free(mod);
+    });
+
+    return 0;
+}

src/api.h

@@ -0,0 +1,13 @@
+#ifndef _api_h_
+#define _api_h_
+
+#include "lua.h"
+#include "lauxlib.h"
+#include "lualib.h"
+#include <sglib.h>
+
+int clua_init();
+int clua_load_modules();
+int clua_close();
+
+#endif

src/main.c

@@ -6,6 +6,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
+#include "api.h"
 #include "auth.h"
 #include "client.h"
 #include "config.h"
@@ -2771,6 +2772,9 @@ int main(int argc, char **argv) {
             s->y = highest_block(s->x, s->z) + 2;
         }
 
+        // INITIALIZE LUA //
+        clua_init();
+
         // BEGIN MAIN LOOP //
         double previous = glfwGetTime();
         while (1) {
@@ -2947,6 +2951,7 @@ int main(int argc, char **argv) {
         }
 
         // SHUTDOWN //
+        clua_close();
         db_save_state(s->x, s->y, s->z, s->rx, s->ry);
         db_close();
         db_disable();