128 lines
3.1 KiB
C++
128 lines
3.1 KiB
C++
/** @addtogroup Extensions
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*
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* @brief Various extensions including integration of libostd with other libs.
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*
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* @{
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*/
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/** @file sdl_rwops.hh
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*
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* @brief Integration of libostd streams with SDL RWops.
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*
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* This provides integration of libostd streams with SDL RWops so that
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* various APIs that provide a generic RWops interface to deal with
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* files can use libostd streams.
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*
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* Supports both SDL1 and SDL2, with SDL2 being default. If you want to
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* use SDL1 compatibility, define `OSTD_EXT_SDL_USE_SDL1` at build time
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* or before including this header.
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*
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* @copyright See COPYING.md in the project tree for further information.
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*/
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#ifndef OSTD_EXT_SDL_RWOPS_HH
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#define OSTD_EXT_SDL_RWOPS_HH
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#ifdef OSTD_EXT_SDL_USE_SDL1
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#include <SDL/SDL.h>
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#else
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#include <SDL2/SDL.h>
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#endif
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#include "ostd/stream.hh"
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namespace ostd {
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namespace sdl {
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/** @addtogroup Extensions
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* @{
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*/
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/** @brief Create an `SDL_RWops` using an libostd stream.
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*
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* The resulting RWops object is created using `SDL_AllocRW()`.
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*
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* The `size`, `seek`, `read`, `write` and `close` callbacks are set up,
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* but `close` will not actually close the stream, as the RWops object
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* does not take ownership.
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*
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* @returns The RWops object or `nullptr` on failure.
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*/
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inline SDL_RWops *stream_to_rwops(stream &s) noexcept {
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#ifdef OSTD_EXT_SDL_USE_SDL1
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using sdl_rwops_off_t = int;
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#else
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using sdl_rwops_off_t = int64_t;
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#endif
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SDL_RWops *rwr = SDL_AllocRW();
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if (!rwr) {
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return nullptr;
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}
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rwr->hidden.unknown.data1 = &s;
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rwr->size = [](SDL_RWops *rw) -> sdl_rwops_off_t {
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auto &is = *static_cast<stream *>(rw->hidden.unknown.data1);
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try {
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return static_cast<sdl_rwops_off_t>(is.size());
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} catch (stream_error const &) {
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return -1;
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}
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};
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rwr->seek = [](SDL_RWops *rw, sdl_rwops_off_t pos, int whence) ->
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sdl_rwops_off_t
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{
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auto &is = *static_cast<stream *>(rw->hidden.unknown.data1);
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try {
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if (!pos && whence == SEEK_CUR) {
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return static_cast<sdl_rwops_off_t>(is.tell());
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}
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if (is->seek((stream_off_t(pos), stream_seek(whence)))) {
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return static_cast<sdl_rwops_off_t>(is.tell());
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}
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} catch (stream_error const &) {
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return -1;
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}
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return -1;
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};
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rwr->read = [](SDL_RWops *rw, void *buf, size_t size, size_t nb) ->
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size_t
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{
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auto &is = *static_cast<stream *>(rw->hidden.unknown.data1);
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try {
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return is.read_bytes(buf, size * nb) / size;
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} catch (stream_error const &) {
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return 0;
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}
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};
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rwr->write = [](SDL_RWops *rw, void const *buf, size_t size, size_t nb) ->
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size_t
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{
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stream &is = *static_cast<stream *>(rw->hidden.unknown.data1);
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try {
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return is->write_bytes(buf, size * nb) / size;
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} catch (stream_error const &) {
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return 0;
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}
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};
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rwr->close = [](SDL_RWops *) -> int {
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return 0;
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};
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return rwr;
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}
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}
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}
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/** @} */
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#endif
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/** @} */
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