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vcmi/client/renderSDL/SDLRWwrapper.cpp

98 lines
2.0 KiB
C++

/*
* SDLRWwrapper.cpp, part of VCMI engine
*
* Authors: listed in file AUTHORS in main folder
*
* License: GNU General Public License v2.0 or later
* Full text of license available in license.txt file, in main folder
*
*/
#include "StdInc.h"
#include "SDLRWwrapper.h"
#include "../../lib/filesystem/CInputStream.h"
#include <SDL_rwops.h>
static inline CInputStream* get_stream(SDL_RWops* context)
{
return static_cast<CInputStream*>(context->hidden.unknown.data1);
}
static Sint64 impl_size(SDL_RWops* context)
{
return get_stream(context)->getSize();
}
static Sint64 impl_seek(SDL_RWops* context, Sint64 offset, int whence)
{
auto stream = get_stream(context);
switch (whence)
{
case RW_SEEK_SET:
return stream->seek(offset);
break;
case RW_SEEK_CUR:
return stream->seek(stream->tell() + offset);
break;
case RW_SEEK_END:
return stream->seek(stream->getSize() + offset);
break;
default:
return -1;
}
}
static std::size_t impl_read(SDL_RWops* context, void *ptr, size_t size, size_t maxnum)
{
auto stream = get_stream(context);
auto oldpos = stream->tell();
auto count = stream->read(static_cast<ui8*>(ptr), size*maxnum);
if (count != 0 && count != size*maxnum)
{
// if not a whole amount of objects of size has been read, we need to seek
stream->seek(oldpos + size * (count / size));
}
return count / size;
}
static std::size_t impl_write(SDL_RWops* context, const void *ptr, size_t size, size_t num)
{
// writing is not supported
return 0;
}
static int impl_close(SDL_RWops* context)
{
if (context == nullptr)
return 0;
delete get_stream(context);
SDL_FreeRW(context);
return 0;
}
SDL_RWops* MakeSDLRWops(std::unique_ptr<CInputStream> in)
{
SDL_RWops* result = SDL_AllocRW();
if (!result)
return nullptr;
result->size = &impl_size;
result->seek = &impl_seek;
result->read = &impl_read;
result->write = &impl_write;
result->close = &impl_close;
result->type = SDL_RWOPS_UNKNOWN;
result->hidden.unknown.data1 = in.release();
return result;
}