src/script/script_info_dummy.cpp

   1 /* $Id$ */
   2
   3 /*
   4  * This file is part of OpenTTD.
   5  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
   6  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   7  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   8  */
   9
  10 /** @file script_info_dummy.cpp Implementation of a dummy Script. */
  11
  12 #include "../stdafx.h"
  13 #include <squirrel.h>
  14
  15 #include "../string_func.h"
  16 #include "../strings_func.h"
  17
  18 #include "../safeguards.h"
  19
  20 /* The reason this exists in C++, is that a user can trash his ai/ or game/ dir,
  21  *  leaving no Scripts available. The complexity to solve this is insane, and
  22  *  therefore the alternative is used, and make sure there is always a Script
  23  *  available, no matter what the situation is. By defining it in C++, there
  24  *  is simply no way a user can delete it, and therefore safe to use. It has
  25  *  to be noted that this Script is complete invisible for the user, and impossible
  26  *  to select manual. It is a fail-over in case no Scripts are available.
  27  */
  28
  29 /** Run the dummy info.nut. */
  30 void Script_CreateDummyInfo(HSQUIRRELVM vm, const char *type, const char *dir)
  31 {
  32         char dummy_script[4096];
  33         char *dp = dummy_script;
  34         dp += seprintf(dp, lastof(dummy_script), "class Dummy%s extends %sInfo {\n", type, type);
  35         dp += seprintf(dp, lastof(dummy_script), "function GetAuthor()      { return \"OpenTTD Developers Team\"; }\n");
  36         dp += seprintf(dp, lastof(dummy_script), "function GetName()        { return \"Dummy%s\"; }\n", type);
  37         dp += seprintf(dp, lastof(dummy_script), "function GetShortName()   { return \"DUMM\"; }\n");
  38         dp += seprintf(dp, lastof(dummy_script), "function GetDescription() { return \"A Dummy %s that is loaded when your %s/ dir is empty\"; }\n", type, dir);
  39         dp += seprintf(dp, lastof(dummy_script), "function GetVersion()     { return 1; }\n");
  40         dp += seprintf(dp, lastof(dummy_script), "function GetDate()        { return \"2008-07-26\"; }\n");
  41         dp += seprintf(dp, lastof(dummy_script), "function CreateInstance() { return \"Dummy%s\"; }\n", type);
  42         dp += seprintf(dp, lastof(dummy_script), "} RegisterDummy%s(Dummy%s());\n", type, type);
  43
  44         const SQChar *sq_dummy_script = dummy_script;
  45
  46         sq_pushroottable(vm);
  47
  48         /* Load and run the script */
  49         if (SQ_SUCCEEDED(sq_compilebuffer(vm, sq_dummy_script, strlen(sq_dummy_script), "dummy", SQTrue))) {
  50                 sq_push(vm, -2);
  51                 if (SQ_SUCCEEDED(sq_call(vm, 1, SQFalse, SQTrue))) {
  52                         sq_pop(vm, 1);
  53                         return;
  54                 }
  55         }
  56         NOT_REACHED();
  57 }
  58
  59 /** Run the dummy AI and let it generate an error message. */
  60 void Script_CreateDummy(HSQUIRRELVM vm, StringID string, const char *type)
  61 {
  62         /* We want to translate the error message.
  63          * We do this in three steps:
  64          * 1) We get the error message
  65          */
  66         char error_message[1024];
  67         GetString(error_message, string, lastof(error_message));
  68
  69         /* Make escapes for all quotes and slashes. */
  70         char safe_error_message[1024];
  71         char *q = safe_error_message;
  72         for (const char *p = error_message; *p != '\0' && q < lastof(safe_error_message) - 2; p++, q++) {
  73                 if (*p == '"' || *p == '\\') *q++ = '\\';
  74                 *q = *p;
  75         }
  76         *q = '\0';
  77
  78         /* 2) We construct the AI's code. This is done by merging a header, body and footer */
  79         char dummy_script[4096];
  80         char *dp = dummy_script;
  81         dp += seprintf(dp, lastof(dummy_script), "class Dummy%s extends %sController {\n  function Start()\n  {\n", type, type);
  82
  83         /* As special trick we need to split the error message on newlines and
  84          * emit each newline as a separate error printing string. */
  85         char *newline;
  86         char *p = safe_error_message;
  87         do {
  88                 newline = strchr(p, '\n');
  89                 if (newline != NULL) *newline = '\0';
  90
  91                 dp += seprintf(dp, lastof(dummy_script), "    %sLog.Error(\"%s\");\n", type, p);
  92                 p = newline + 1;
  93         } while (newline != NULL);
  94
  95         dp = strecpy(dp, "  }\n}\n", lastof(dummy_script));
  96
  97         /* 3) We translate the error message in the character format that Squirrel wants.
  98          *    We can use the fact that the wchar string printing also uses %s to print
  99          *    old style char strings, which is what was generated during the script generation. */
 100         const SQChar *sq_dummy_script = dummy_script;
 101
 102         /* And finally we load and run the script */
 103         sq_pushroottable(vm);
 104         if (SQ_SUCCEEDED(sq_compilebuffer(vm, sq_dummy_script, strlen(sq_dummy_script), "dummy", SQTrue))) {
 105                 sq_push(vm, -2);
 106                 if (SQ_SUCCEEDED(sq_call(vm, 1, SQFalse, SQTrue))) {
 107                         sq_pop(vm, 1);
 108                         return;
 109                 }
 110         }
 111         NOT_REACHED();
 112 }