Move rwops functions into virtfsdir and virtfszip without optimisations.

11 files changed, 526 insertions, 167 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 85ae478d2..432da847a 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -896,10 +896,14 @@ SET(SRCS
     fs/virtfs/virtdirentry.h
     fs/virtfs/virtfsdir.cpp
     fs/virtfs/virtfsdir.h
+    fs/virtfs/virtfsdirrwops.cpp
+    fs/virtfs/virtfsdirrwops.h
     fs/virtfs/virtfsentry.cpp
     fs/virtfs/virtfsentry.h
     fs/virtfs/virtfszip.cpp
     fs/virtfs/virtfszip.h
+    fs/virtfs/virtfsziprwops.cpp
+    fs/virtfs/virtfsziprwops.h
     fs/virtfs/virtzipentry.cpp
     fs/virtfs/virtzipentry.h
     fs/virtfs/zip.cpp
@@ -1796,10 +1800,14 @@ SET(DYE_CMD_SRCS
     fs/virtfs/virtdirentry.h
     fs/virtfs/virtfsdir.cpp
     fs/virtfs/virtfsdir.h
+    fs/virtfs/virtfsdirrwops.cpp
+    fs/virtfs/virtfsdirrwops.h
     fs/virtfs/virtfsentry.cpp
     fs/virtfs/virtfsentry.h
     fs/virtfs/virtfszip.cpp
     fs/virtfs/virtfszip.h
+    fs/virtfs/virtfsziprwops.cpp
+    fs/virtfs/virtfsziprwops.h
     fs/virtfs/virtzipentry.cpp
     fs/virtfs/virtzipentry.h
     fs/virtfs/zip.cpp
diff --git a/src/Makefile.am b/src/Makefile.am
index c6b35a6df..193d5b8ca 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -843,10 +843,14 @@ BASE_SRC += events/actionevent.h \
 	      fs/virtfs/virtfs.h \
 	      fs/virtfs/virtfsdir.cpp \
 	      fs/virtfs/virtfsdir.h \
+	      fs/virtfs/virtfsdirrwops.cpp \
+	      fs/virtfs/virtfsdirrwops.h \
 	      fs/virtfs/virtfsentry.cpp \
 	      fs/virtfs/virtfsentry.h \
 	      fs/virtfs/virtfszip.cpp \
 	      fs/virtfs/virtfszip.h \
+	      fs/virtfs/virtfsziprwops.cpp \
+	      fs/virtfs/virtfsziprwops.h \
 	      fs/virtfs/virtzipentry.cpp \
 	      fs/virtfs/virtzipentry.h \
 	      fs/virtfs/zip.cpp \
diff --git a/src/fs/virtfs/virtfsdir.cpp b/src/fs/virtfs/virtfsdir.cpp
index b6f197ae3..c3c2cad73 100644
--- a/src/fs/virtfs/virtfsdir.cpp
+++ b/src/fs/virtfs/virtfsdir.cpp
@@ -26,6 +26,7 @@
 
 #include "fs/virtfs/virtdirentry.h"
 #include "fs/virtfs/virtfile.h"
+#include "fs/virtfs/virtfsdirrwops.h"
 #include "fs/virtfs/virtfsfuncs.h"
 #include "fs/virtfs/virtlist.h"
 
@@ -136,6 +137,13 @@ namespace VirtFsDir
         ptr->openWrite = &VirtFsDir::openWrite;
         ptr->openAppend = &VirtFsDir::openAppend;
         ptr->loadFile = &VirtFsDir::loadFile;
+        ptr->rwops_seek = &VirtFsDir::rwops_seek;
+        ptr->rwops_read = &VirtFsDir::rwops_read;
+        ptr->rwops_write = &VirtFsDir::rwops_write;
+        ptr->rwops_close = &VirtFsDir::rwops_close;
+#ifdef USE_SDL2
+        ptr->rwops_size = &VirtFsDir::rwops_size;
+#endif  // USE_SDL2
     }
 
     VirtFsFuncs *getFuncs()
diff --git a/src/fs/virtfs/virtfsdirrwops.cpp b/src/fs/virtfs/virtfsdirrwops.cpp
new file mode 100644
index 000000000..428e416b3
--- /dev/null
+++ b/src/fs/virtfs/virtfsdirrwops.cpp
@@ -0,0 +1,182 @@
+/*
+ *  The ManaPlus Client
+ *  Copyright (C) 2013-2017  The ManaPlus Developers
+ *
+ *  This file is part of The ManaPlus Client.
+ *
+ *  This program 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; either version 2 of the License, or
+ *  any later version.
+ *
+ *  This program 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.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "fs/virtfs/virtfsdirrwops.h"
+
+#include "logger.h"
+
+#include "fs/virtfs/virtfile.h"
+#include "fs/virtfs/virtfs.h"
+
+#include <SDL_rwops.h>
+
+#include "debug.h"
+
+namespace VirtFsDir
+{
+    RWOPSINT rwops_seek(SDL_RWops *const rw,
+                        const RWOPSINT offset,
+                        const int whence)
+    {
+        if (!rw)
+            return -1;
+        VirtFile *const handle = static_cast<VirtFile *const>(
+            rw->hidden.unknown.data1);
+        RWOPSINT pos = 0;
+
+        if (whence == SEEK_SET)
+        {
+            pos = offset;
+        }
+        else if (whence == SEEK_CUR)
+        {
+            const int64_t current = VirtFs::tell(handle);
+            if (current == -1)
+            {
+                logger->assertLog(
+                    "VirtFs::rwops_seek: Can't find position in file.");
+                return -1;
+            }
+
+            pos = CAST_S32(current);
+            if (static_cast<int64_t>(pos) != current)
+            {
+                logger->assertLog("VirtFs::rwops_seek: "
+                    "Can't fit current file position in an int!");
+                return -1;
+            }
+
+            if (offset == 0)  /* this is a "tell" call. We're done. */
+                return pos;
+
+            pos += offset;
+        }
+        else if (whence == SEEK_END)
+        {
+            const int64_t len = VirtFs::fileLength(handle);
+            if (len == -1)
+            {
+                logger->assertLog(
+                    "VirtFs::rwops_seek:Can't find end of file.");
+                return -1;
+            }
+
+            pos = static_cast<RWOPSINT>(len);
+            if (static_cast<int64_t>(pos) != len)
+            {
+                logger->assertLog("VirtFs::rwops_seek: "
+                    "Can't fit end-of-file position in an int!");
+                return -1;
+            }
+
+            pos += offset;
+        }
+        else
+        {
+            logger->assertLog(
+                "VirtFs::rwops_seek: Invalid 'whence' parameter.");
+            return -1;
+        }
+
+        if (pos < 0)
+        {
+            logger->assertLog("VirtFs::rwops_seek: "
+                "Attempt to seek past start of file.");
+            return -1;
+        }
+
+        if (!VirtFs::seek(handle, static_cast<uint64_t>(pos)))
+        {
+            logger->assertLog("VirtFs::rwops_seek: seek error.");
+            return -1;
+        }
+
+        return pos;
+    }
+
+    RWOPSSIZE rwops_read(SDL_RWops *const rw,
+                         void *const ptr,
+                         const RWOPSSIZE size,
+                         const RWOPSSIZE maxnum)
+    {
+        if (!rw)
+            return 0;
+        VirtFile *const handle = static_cast<VirtFile *const>(
+            rw->hidden.unknown.data1);
+        const int64_t rc = VirtFs::read(handle, ptr,
+            CAST_U32(size),
+            CAST_U32(maxnum));
+        if (rc != static_cast<int64_t>(maxnum))
+        {
+            if (!VirtFs::eof(handle)) /* not EOF? Must be an error. */
+            {
+                logger->assertLog("VirtFs::rwops_seek: read error.");
+            }
+        }
+
+        return CAST_S32(rc);
+    }
+
+    RWOPSSIZE rwops_write(SDL_RWops *const rw,
+                          const void *const ptr,
+                          const RWOPSSIZE size,
+                          const RWOPSSIZE num)
+    {
+        if (!rw)
+            return 0;
+        VirtFile *const handle = static_cast<VirtFile *const>(
+            rw->hidden.unknown.data1);
+        const int64_t rc = VirtFs::write(handle, ptr,
+            CAST_U32(size),
+            CAST_U32(num));
+        if (rc != static_cast<int64_t>(num))
+        {
+            logger->assertLog("VirtFs::rwops_seek: write error.");
+        }
+
+        return CAST_S32(rc);
+    }
+
+    int rwops_close(SDL_RWops *const rw)
+    {
+        if (!rw)
+            return 0;
+        VirtFile *const handle = static_cast<VirtFile*>(
+            rw->hidden.unknown.data1);
+        if (!VirtFs::close(handle))
+        {
+            logger->assertLog("VirtFs::rwops_seek: close error.");
+            return -1;
+        }
+
+        SDL_FreeRW(rw);
+        return 0;
+    }
+
+#ifdef USE_SDL2
+    RWOPSINT rwops_size(SDL_RWops *const rw)
+    {
+        VirtFile *const handle = static_cast<VirtFile *const>(
+            rw->hidden.unknown.data1);
+        return VirtFs::fileLength(handle);
+    }
+#endif  // USE_SDL2
+
+}  // namespace VirtFsDir
diff --git a/src/fs/virtfs/virtfsdirrwops.h b/src/fs/virtfs/virtfsdirrwops.h
new file mode 100644
index 000000000..d8f5c7d15
--- /dev/null
+++ b/src/fs/virtfs/virtfsdirrwops.h
@@ -0,0 +1,50 @@
+/*
+ *  The ManaPlus Client
+ *  Copyright (C) 2013-2017  The ManaPlus Developers
+ *
+ *  This file is part of The ManaPlus Client.
+ *
+ *  This program 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; either version 2 of the License, or
+ *  any later version.
+ *
+ *  This program 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.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef UTILS_VIRTFS_VIRTFSDIRRWOPS_H
+#define UTILS_VIRTFS_VIRTFSDIRRWOPS_H
+
+#include "fs/virtfs/rwopstypes.h"
+
+struct SDL_RWops;
+
+#include "localconsts.h"
+
+namespace VirtFsDir
+{
+    RWOPSINT rwops_seek(SDL_RWops *const rw,
+                        const RWOPSINT offset,
+                        const int whence);
+    RWOPSSIZE rwops_read(SDL_RWops *const rw,
+                         void *const ptr,
+                         const RWOPSSIZE size,
+                         const RWOPSSIZE maxnum);
+    RWOPSSIZE rwops_write(SDL_RWops *const rw,
+                          const void *const ptr,
+                          const RWOPSSIZE size,
+                          const RWOPSSIZE num);
+    int rwops_close(SDL_RWops *const rw);
+#ifdef USE_SDL2
+    RWOPSINT rwops_size(SDL_RWops *const rw);
+#endif  // USE_SDL2
+
+}  // namespace VirtFsDir
+
+#endif  // UTILS_VIRTFS_VIRTFSDIRRWOPS_H
diff --git a/src/fs/virtfs/virtfsfuncs.h b/src/fs/virtfs/virtfsfuncs.h
index 21b7a3220..84345679b 100644
--- a/src/fs/virtfs/virtfsfuncs.h
+++ b/src/fs/virtfs/virtfsfuncs.h
@@ -21,12 +21,15 @@
 #ifndef UTILS_VIRTFSFUNCS_H
 #define UTILS_VIRTFSFUNCS_H
 
+#include "fs/virtfs/rwopstypes.h"
+
 #include "utils/stringvector.h"
 
 #include "localconsts.h"
 
 struct VirtFile;
 struct VirtFsEntry;
+struct SDL_RWops;
 
 struct VirtFsFuncs final
 {
@@ -45,7 +48,14 @@ struct VirtFsFuncs final
         openWrite(nullptr),
         openAppend(nullptr),
         eof(nullptr),
-        loadFile(nullptr)
+        loadFile(nullptr),
+        rwops_seek(nullptr),
+        rwops_read(nullptr),
+        rwops_write(nullptr),
+#ifdef USE_SDL2
+        rwops_size(nullptr),
+#endif  // USE_SDL2
+        rwops_close(nullptr)
     {
     }
 
@@ -87,6 +97,22 @@ struct VirtFsFuncs final
     const char *(*loadFile) (VirtFsEntry *restrict const entry,
                              const std::string &restrict fileName,
                              int &restrict fileSize);
+
+    RWOPSINT (*rwops_seek) (SDL_RWops *const rw,
+                            const RWOPSINT offset,
+                            const int whence);
+    RWOPSSIZE (*rwops_read) (SDL_RWops *const rw,
+                             void *const ptr,
+                             const RWOPSSIZE size,
+                             const RWOPSSIZE maxnum);
+    RWOPSSIZE (*rwops_write) (SDL_RWops *const rw,
+                              const void *const ptr,
+                              const RWOPSSIZE size,
+                              const RWOPSSIZE num);
+#ifdef USE_SDL2
+    RWOPSINT (*rwops_size) (SDL_RWops *const rw);
+#endif  // USE_SDL2
+    int (*rwops_close) (SDL_RWops *const rw);
 };
 
 #endif  // UTILS_VIRTFSFUNCS_H
diff --git a/src/fs/virtfs/virtfsrwops.cpp b/src/fs/virtfs/virtfsrwops.cpp
index c354b2e14..8b5dc57b0 100644
--- a/src/fs/virtfs/virtfsrwops.cpp
+++ b/src/fs/virtfs/virtfsrwops.cpp
@@ -46,158 +46,14 @@
 
 #include "logger.h"
 
+#include "fs/virtfs/virtfile.h"
 #include "fs/virtfs/virtfs.h"
+#include "fs/virtfs/virtfsfuncs.h"
 
 #include "utils/fuzzer.h"
 
 #include "debug.h"
 
-RWOPSINT VirtFs::rwops_seek(SDL_RWops *const rw,
-                            const RWOPSINT offset,
-                            const int whence)
-{
-    if (!rw)
-        return -1;
-    VirtFile *const handle = static_cast<VirtFile *const>(
-        rw->hidden.unknown.data1);
-    RWOPSINT pos = 0;
-
-    if (whence == SEEK_SET)
-    {
-        pos = offset;
-    } /* if */
-    else if (whence == SEEK_CUR)
-    {
-        const int64_t current = VirtFs::tell(handle);
-        if (current == -1)
-        {
-            logger->assertLog(
-                "VirtFs::rwops_seek: Can't find position in file.");
-            return -1;
-        } /* if */
-
-        pos = CAST_S32(current);
-        if (static_cast<int64_t>(pos) != current)
-        {
-            logger->assertLog("VirtFs::rwops_seek: "
-                "Can't fit current file position in an int!");
-            return -1;
-        } /* if */
-
-        if (offset == 0)  /* this is a "tell" call. We're done. */
-            return pos;
-
-        pos += offset;
-    } /* else if */
-    else if (whence == SEEK_END)
-    {
-        const int64_t len = VirtFs::fileLength(handle);
-        if (len == -1)
-        {
-            logger->assertLog("VirtFs::rwops_seek:Can't find end of file.");
-            return -1;
-        } /* if */
-
-        pos = static_cast<RWOPSINT>(len);
-        if (static_cast<int64_t>(pos) != len)
-        {
-            logger->assertLog("VirtFs::rwops_seek: "
-                "Can't fit end-of-file position in an int!");
-            return -1;
-        } /* if */
-
-        pos += offset;
-    } /* else if */
-    else
-    {
-        logger->assertLog("VirtFs::rwops_seek: Invalid 'whence' parameter.");
-        return -1;
-    } /* else */
-
-    if (pos < 0)
-    {
-        logger->assertLog("VirtFs::rwops_seek: "
-            "Attempt to seek past start of file.");
-        return -1;
-    } /* if */
-
-    if (!VirtFs::seek(handle, static_cast<uint64_t>(pos)))
-    {
-        logger->assertLog("VirtFs::rwops_seek: seek error.");
-        return -1;
-    } /* if */
-
-    return pos;
-} /* VirtFs::rwops_seek */
-
-RWOPSSIZE VirtFs::rwops_read(SDL_RWops *const rw,
-                             void *const ptr,
-                             const RWOPSSIZE size,
-                             const RWOPSSIZE maxnum)
-{
-    if (!rw)
-        return 0;
-    VirtFile *const handle = static_cast<VirtFile *const>(
-        rw->hidden.unknown.data1);
-    const int64_t rc = VirtFs::read(handle, ptr,
-        CAST_U32(size),
-        CAST_U32(maxnum));
-    if (rc != static_cast<int64_t>(maxnum))
-    {
-        if (!VirtFs::eof(handle)) /* not EOF? Must be an error. */
-        {
-            logger->assertLog("VirtFs::rwops_seek: read error.");
-        }
-    } /* if */
-
-    return CAST_S32(rc);
-} /* VirtFs::rwops_read */
-
-RWOPSSIZE VirtFs::rwops_write(SDL_RWops *const rw,
-                              const void *const ptr,
-                              const RWOPSSIZE size,
-                              const RWOPSSIZE num)
-{
-    if (!rw)
-        return 0;
-    VirtFile *const handle = static_cast<VirtFile *const>(
-        rw->hidden.unknown.data1);
-    const int64_t rc = VirtFs::write(handle, ptr,
-        CAST_U32(size),
-        CAST_U32(num));
-    if (rc != static_cast<int64_t>(num))
-    {
-        logger->assertLog("VirtFs::rwops_seek: write error.");
-    }
-
-    return CAST_S32(rc);
-} /* VirtFs::rwops_write */
-
-int VirtFs::rwops_close(SDL_RWops *const rw)
-{
-    if (!rw)
-        return 0;
-    VirtFile *const handle = static_cast<VirtFile*>(
-        rw->hidden.unknown.data1);
-    if (!VirtFs::close(handle))
-    {
-        logger->assertLog("VirtFs::rwops_seek: close error.");
-        return -1;
-    } /* if */
-
-    SDL_FreeRW(rw);
-    return 0;
-} /* VirtFs::rwops_close */
-
-#ifdef USE_SDL2
-RWOPSINT VirtFs::rwops_size(SDL_RWops *const rw)
-{
-    VirtFile *const handle = static_cast<VirtFile *const>(
-        rw->hidden.unknown.data1);
-    return VirtFs::fileLength(handle);
-} /* VirtFs::rwops_size */
-#endif  // USE_SDL2
-
 SDL_RWops *VirtFs::create_rwops(VirtFile *const file)
 {
     SDL_RWops *retval = nullptr;
@@ -212,13 +68,13 @@ SDL_RWops *VirtFs::create_rwops(VirtFile *const file)
         if (retval)
         {
 #ifdef USE_SDL2
-            retval->size  = &VirtFs::rwops_size;
+            retval->size  = file->funcs->rwops_size;
 #endif  // USE_SDL2
 
-            retval->seek  = &VirtFs::rwops_seek;
-            retval->read  = &VirtFs::rwops_read;
-            retval->write = &VirtFs::rwops_write;
-            retval->close = &VirtFs::rwops_close;
+            retval->seek  = file->funcs->rwops_seek;
+            retval->read  = file->funcs->rwops_read;
+            retval->write = file->funcs->rwops_write;
+            retval->close = file->funcs->rwops_close;
             retval->hidden.unknown.data1 = file;
         } /* if */
     } /* else */
diff --git a/src/fs/virtfs/virtfsrwops.h b/src/fs/virtfs/virtfsrwops.h
index cc3fe55cf..28990706e 100644
--- a/src/fs/virtfs/virtfsrwops.h
+++ b/src/fs/virtfs/virtfsrwops.h
@@ -57,21 +57,6 @@ struct VirtFile;
 namespace VirtFs
 {
     SDL_RWops *create_rwops(VirtFile *const file);
-    RWOPSINT rwops_seek(SDL_RWops *const rw,
-                        const RWOPSINT offset,
-                        const int whence);
-    RWOPSSIZE rwops_read(SDL_RWops *const rw,
-                         void *const ptr,
-                         const RWOPSSIZE size,
-                         const RWOPSSIZE maxnum);
-    RWOPSSIZE rwops_write(SDL_RWops *const rw,
-                          const void *const ptr,
-                          const RWOPSSIZE size,
-                          const RWOPSSIZE num);
-    int rwops_close(SDL_RWops *const rw);
-#ifdef USE_SDL2
-    RWOPSINT rwops_size(SDL_RWops *const rw);
-#endif  // USE_SDL2
 
     SDL_RWops *rwopsOpenRead(const std::string &restrict fname);
     SDL_RWops *rwopsOpenWrite(const std::string &restrict fname) A_WARN_UNUSED;
diff --git a/src/fs/virtfs/virtfszip.cpp b/src/fs/virtfs/virtfszip.cpp
index d344a4c64..8999cb54c 100644
--- a/src/fs/virtfs/virtfszip.cpp
+++ b/src/fs/virtfs/virtfszip.cpp
@@ -22,6 +22,7 @@
 
 #include "fs/virtfs/virtfile.h"
 #include "fs/virtfs/virtfsfuncs.h"
+#include "fs/virtfs/virtfsziprwops.h"
 #include "fs/virtfs/virtlist.h"
 #include "fs/virtfs/virtzipentry.h"
 #include "fs/virtfs/zip.h"
@@ -72,6 +73,13 @@ namespace VirtFsZip
         ptr->openWrite = &VirtFsZip::openWrite;
         ptr->openAppend = &VirtFsZip::openAppend;
         ptr->loadFile = &VirtFsZip::loadFile;
+        ptr->rwops_seek = &VirtFsZip::rwops_seek;
+        ptr->rwops_read = &VirtFsZip::rwops_read;
+        ptr->rwops_write = &VirtFsZip::rwops_write;
+        ptr->rwops_close = &VirtFsZip::rwops_close;
+#ifdef USE_SDL2
+        ptr->rwops_size = &VirtFsZip::rwops_size;
+#endif  // USE_SDL2
     }
 
     bool getRealDir(VirtFsEntry *restrict const entry,
diff --git a/src/fs/virtfs/virtfsziprwops.cpp b/src/fs/virtfs/virtfsziprwops.cpp
new file mode 100644
index 000000000..094d0c4b0
--- /dev/null
+++ b/src/fs/virtfs/virtfsziprwops.cpp
@@ -0,0 +1,182 @@
+/*
+ *  The ManaPlus Client
+ *  Copyright (C) 2013-2017  The ManaPlus Developers
+ *
+ *  This file is part of The ManaPlus Client.
+ *
+ *  This program 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; either version 2 of the License, or
+ *  any later version.
+ *
+ *  This program 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.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "fs/virtfs/virtfsziprwops.h"
+
+#include "logger.h"
+
+#include "fs/virtfs/virtfile.h"
+#include "fs/virtfs/virtfs.h"
+
+#include <SDL_rwops.h>
+
+#include "debug.h"
+
+namespace VirtFsZip
+{
+    RWOPSINT rwops_seek(SDL_RWops *const rw,
+                        const RWOPSINT offset,
+                        const int whence)
+    {
+        if (!rw)
+            return -1;
+        VirtFile *const handle = static_cast<VirtFile *const>(
+            rw->hidden.unknown.data1);
+        RWOPSINT pos = 0;
+
+        if (whence == SEEK_SET)
+        {
+            pos = offset;
+        }
+        else if (whence == SEEK_CUR)
+        {
+            const int64_t current = VirtFs::tell(handle);
+            if (current == -1)
+            {
+                logger->assertLog(
+                    "VirtFs::rwops_seek: Can't find position in file.");
+                return -1;
+            }
+
+            pos = CAST_S32(current);
+            if (static_cast<int64_t>(pos) != current)
+            {
+                logger->assertLog("VirtFs::rwops_seek: "
+                    "Can't fit current file position in an int!");
+                return -1;
+            }
+
+            if (offset == 0)  /* this is a "tell" call. We're done. */
+                return pos;
+
+            pos += offset;
+        }
+        else if (whence == SEEK_END)
+        {
+            const int64_t len = VirtFs::fileLength(handle);
+            if (len == -1)
+            {
+                logger->assertLog(
+                    "VirtFs::rwops_seek:Can't find end of file.");
+                return -1;
+            }
+
+            pos = static_cast<RWOPSINT>(len);
+            if (static_cast<int64_t>(pos) != len)
+            {
+                logger->assertLog("VirtFs::rwops_seek: "
+                    "Can't fit end-of-file position in an int!");
+                return -1;
+            }
+
+            pos += offset;
+        }
+        else
+        {
+            logger->assertLog(
+                "VirtFs::rwops_seek: Invalid 'whence' parameter.");
+            return -1;
+        }
+
+        if (pos < 0)
+        {
+            logger->assertLog("VirtFs::rwops_seek: "
+                "Attempt to seek past start of file.");
+            return -1;
+        }
+
+        if (!VirtFs::seek(handle, static_cast<uint64_t>(pos)))
+        {
+            logger->assertLog("VirtFs::rwops_seek: seek error.");
+            return -1;
+        }
+
+        return pos;
+    }
+
+    RWOPSSIZE rwops_read(SDL_RWops *const rw,
+                         void *const ptr,
+                         const RWOPSSIZE size,
+                         const RWOPSSIZE maxnum)
+    {
+        if (!rw)
+            return 0;
+        VirtFile *const handle = static_cast<VirtFile *const>(
+            rw->hidden.unknown.data1);
+        const int64_t rc = VirtFs::read(handle, ptr,
+            CAST_U32(size),
+            CAST_U32(maxnum));
+        if (rc != static_cast<int64_t>(maxnum))
+        {
+            if (!VirtFs::eof(handle)) /* not EOF? Must be an error. */
+            {
+                logger->assertLog("VirtFs::rwops_seek: read error.");
+            }
+        }
+
+        return CAST_S32(rc);
+    }
+
+    RWOPSSIZE rwops_write(SDL_RWops *const rw,
+                          const void *const ptr,
+                          const RWOPSSIZE size,
+                          const RWOPSSIZE num)
+    {
+        if (!rw)
+            return 0;
+        VirtFile *const handle = static_cast<VirtFile *const>(
+            rw->hidden.unknown.data1);
+        const int64_t rc = VirtFs::write(handle, ptr,
+            CAST_U32(size),
+            CAST_U32(num));
+        if (rc != static_cast<int64_t>(num))
+        {
+            logger->assertLog("VirtFs::rwops_seek: write error.");
+        }
+
+        return CAST_S32(rc);
+    }
+
+    int rwops_close(SDL_RWops *const rw)
+    {
+        if (!rw)
+            return 0;
+        VirtFile *const handle = static_cast<VirtFile*>(
+            rw->hidden.unknown.data1);
+        if (!VirtFs::close(handle))
+        {
+            logger->assertLog("VirtFs::rwops_seek: close error.");
+            return -1;
+        }
+
+        SDL_FreeRW(rw);
+        return 0;
+    }
+
+#ifdef USE_SDL2
+    RWOPSINT rwops_size(SDL_RWops *const rw)
+    {
+        VirtFile *const handle = static_cast<VirtFile *const>(
+            rw->hidden.unknown.data1);
+        return VirtFs::fileLength(handle);
+    }
+#endif  // USE_SDL2
+
+}  // namespace VirtFsZip
diff --git a/src/fs/virtfs/virtfsziprwops.h b/src/fs/virtfs/virtfsziprwops.h
new file mode 100644
index 000000000..4748cc875
--- /dev/null
+++ b/src/fs/virtfs/virtfsziprwops.h
@@ -0,0 +1,50 @@
+/*
+ *  The ManaPlus Client
+ *  Copyright (C) 2013-2017  The ManaPlus Developers
+ *
+ *  This file is part of The ManaPlus Client.
+ *
+ *  This program 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; either version 2 of the License, or
+ *  any later version.
+ *
+ *  This program 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.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef UTILS_VIRTFS_VIRTFSZIPRWOPS_H
+#define UTILS_VIRTFS_VIRTFSZIPRWOPS_H
+
+#include "fs/virtfs/rwopstypes.h"
+
+#include "localconsts.h"
+
+struct SDL_RWops;
+
+namespace VirtFsZip
+{
+    RWOPSINT rwops_seek(SDL_RWops *const rw,
+                        const RWOPSINT offset,
+                        const int whence);
+    RWOPSSIZE rwops_read(SDL_RWops *const rw,
+                         void *const ptr,
+                         const RWOPSSIZE size,
+                         const RWOPSSIZE maxnum);
+    RWOPSSIZE rwops_write(SDL_RWops *const rw,
+                          const void *const ptr,
+                          const RWOPSSIZE size,
+                          const RWOPSSIZE num);
+    int rwops_close(SDL_RWops *const rw);
+#ifdef USE_SDL2
+    RWOPSINT rwops_size(SDL_RWops *const rw);
+#endif  // USE_SDL2
+
+}  // namespace VirtFsZip
+
+#endif  // UTILS_VIRTFS_VIRTFSZIPRWOPS_H