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