add initial language support using a simple MO parser

CMakeLists.txt

@@ -241,6 +241,7 @@ set(devilutionx_SRCS
   Source/inv.cpp
   Source/itemdat.cpp
   Source/items.cpp
+  Source/language.cpp
   Source/lighting.cpp
   Source/loadsave.cpp
   Source/main.cpp

Source/DiabloUI/mainmenu.cpp

@@ -1,5 +1,6 @@
 
 #include "control.h"
+#include "language.h"
 #include "DiabloUI/diabloui.h"
 #include "DiabloUI/selok.h"
 

Source/diablo.cpp

@@ -26,6 +26,7 @@
 #include "gmenu.h"
 #include "help.h"
 #include "init.h"
+#include "language.h"
 #include "lighting.h"
 #include "loadsave.h"
 #include "mainmenu.h"
@@ -188,6 +189,8 @@ static void diablo_parse_flags(int argc, char **argv)
 			SetPrefPath(argv[++i]);
 		} else if (strcasecmp("--config-dir", argv[i]) == 0) {
 			SetConfigPath(argv[++i]);
+		} else if (strcasecmp("--lang-dir", argv[i]) == 0) {
+			SetLangPath(argv[++i]);
 		} else if (strcasecmp("--ttf-dir", argv[i]) == 0) {
 			SetTtfPath(argv[++i]);
 		} else if (strcasecmp("--ttf-name", argv[i]) == 0) {
@@ -517,6 +520,8 @@ static void SaveOptions()
 	setIniInt("Controller", "Enable Rear Touchpad", sgOptions.Controller.bRearTouch);
 #endif
 
+	setIniValue("Language", "Code", sgOptions.Language.szCode);
+
 	SaveIni();
 }
 
@@ -591,6 +596,8 @@ static void LoadOptions()
 	sgOptions.Controller.bRearTouch = getIniBool("Controller", "Enable Rear Touchpad", true);
 #endif
 
+	getIniValue("Language", "Code", sgOptions.Language.szCode, sizeof(sgOptions.Language.szCode), "en");
+
 	sbWasOptionsLoaded = true;
 }
 
@@ -625,6 +632,7 @@ static void diablo_init()
 
 	gbIsHellfireSaveGame = gbIsHellfire;
 
+	LanguageInitialize();
 	UiInitialize();
 	UiSetSpawned(gbIsSpawn);
 	was_ui_init = true;

Source/language.cpp

@@ -0,0 +1,125 @@
+#include "options.h"
+#include "utils/paths.h"
+#include <map>
+
+
+using namespace devilution;
+#define MO_MAGIC 0x950412de
+
+
+namespace {
+
+  struct cstring_cmp {
+    bool operator()(const char *s1, const char *s2) const {
+      return strcmp(s1, s2) < 0;
+    }
+  };
+
+  std::map<const char*, const char*, cstring_cmp> map;
+
+
+  struct mo_head {
+    uint32_t magic;
+    struct {
+      uint16_t major;
+      uint16_t minor;
+    } revision;
+
+    uint32_t nb_mappings;
+    uint32_t src_offset;
+    uint32_t dst_offset;
+  };
+
+
+  struct mo_entry {
+    uint32_t length;
+    uint32_t offset;
+  };
+
+
+  void* read_entry(FILE *fp, mo_entry* e) {
+    void *data;
+
+    if(fseek(fp, e->offset, SEEK_SET)) {
+      return NULL;
+    }
+
+    if(!(data = calloc(e->length, sizeof(char)))) {
+      return NULL;
+    }
+
+    if(fread(data, sizeof(char), e->length, fp) != e->length) {
+      free(data);
+      return NULL;
+    }
+
+    return data;
+  }
+}
+
+
+const char* LanguageTranslate(const char* key) {
+  auto it = map.find(key);
+  if(it == map.end()) {
+    return key;
+  }
+
+  return it->second;
+}
+
+
+void LanguageInitialize() {
+  std::string path = GetLangPath() + "./" + sgOptions.Language.szCode + ".mo";
+  mo_head head;
+  FILE *fp;
+
+  if(!(fp = fopen(path.c_str(), "rb"))) {
+    perror(path.c_str());
+    return;
+  }
+  // Read header and do sanity checks
+  if(fread(&head, sizeof(mo_head), 1, fp) != 1) {
+    return;
+  }
+
+  if(head.magic != MO_MAGIC) {
+    return; // not a MO file
+  }
+
+  if(head.revision.major > 1 || head.revision.minor > 1) {
+    return; // unsupported revision
+  }
+
+  // Read entries of source strings
+  mo_entry src[head.nb_mappings];
+  if(fseek(fp, head.src_offset, SEEK_SET)) {
+    return;
+  }
+  if(fread(src, sizeof(mo_entry), head.nb_mappings, fp) != head.nb_mappings) {
+    return;
+  }
+
+  // Read entries of target strings
+  mo_entry dst[head.nb_mappings];
+  if(fseek(fp, head.dst_offset, SEEK_SET)) {
+    return;
+  }
+
+  if(fread(dst, sizeof(mo_entry), head.nb_mappings, fp) != head.nb_mappings) {
+    return;
+  }
+
+  // Read strings described by entries
+  for(uint32_t i=0; i<head.nb_mappings; i++) {
+    void *key, *val;
+    if((key = read_entry(fp, src+i))) {
+      if((val = read_entry(fp, dst+i))) {
+	map[static_cast<const char*>(key)] = static_cast<const char*>(val);
+      } else {
+	free(key);
+      }
+    }
+  }
+}	
+
+

Source/language.h

@@ -0,0 +1,7 @@
+#pragma once
+
+#define _(x) LanguageTranslate(x)
+
+void LanguageInitialize();
+const char* LanguageTranslate(const char* key);
+

Source/options.h

@@ -124,6 +124,11 @@ struct ChatOptions {
 	char szHotKeyMsgs[4][MAX_SEND_STR_LEN];
 };
 
+struct LanguageOptions {
+	/** @brief Language code (ISO 639-1) for text. */
+	char szCode[2];
+};
+
 struct Options {
 	DiabloOptions Diablo;
 	HellfireOptions Hellfire;
@@ -133,6 +138,7 @@ struct Options {
 	ControllerOptions Controller;
 	NetworkOptions Network;
 	ChatOptions Chat;
+	LanguageOptions Language;
 };
 
 extern Options sgOptions;

Source/utils/paths.cpp

@@ -14,13 +14,18 @@
 #define TTF_FONT_NAME "CharisSILB.ttf"
 #endif
 
+#ifndef MO_LANG_DIR
+#define MO_LANG_DIR ""
+#endif
+
 namespace devilution {
 
 namespace {
 
 std::string *basePath = NULL;
 std::string *prefPath = NULL;
 std::string *configPath = NULL;
+std::string *langPath = NULL;
 std::string *ttfPath = NULL;
 std::string *ttfName = NULL;
 
@@ -82,6 +87,13 @@ const std::string &GetTtfPath()
 	return *ttfPath;
 }
 
+const std::string &GetLangPath()
+{
+	if (langPath == NULL)
+		langPath = new std::string(MO_LANG_DIR);
+	return *langPath;
+}
+
 const std::string &GetTtfName()
 {
 	if (ttfName == NULL)
@@ -113,6 +125,14 @@ void SetConfigPath(const char *path)
 	AddTrailingSlash(configPath);
 }
 
+void SetLangPath(const char *path)
+{
+	if (langPath == NULL)
+		langPath = new std::string;
+	*langPath = path;
+	AddTrailingSlash(langPath);
+}
+
 void SetTtfPath(const char *path)
 {
 	if (ttfPath == NULL)

Source/utils/paths.h

@@ -7,12 +7,14 @@ namespace devilution {
 const std::string &GetBasePath();
 const std::string &GetPrefPath();
 const std::string &GetConfigPath();
+const std::string &GetLangPath();
 const std::string &GetTtfPath();
 const std::string &GetTtfName();
-
+  
 void SetBasePath(const char *path);
 void SetPrefPath(const char *path);
 void SetConfigPath(const char *path);
+void SetLangPath(const char *path);
 void SetTtfPath(const char *path);
 void SetTtfName(const char *path);