essence-os/apps/doom/w_file_stdc.c

93 lines
2.1 KiB
C

//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// 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 (at your option) 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.
//
// DESCRIPTION:
// WAD I/O functions.
//
#include "essence/include.h"
#include "m_misc.h"
#include "w_file.h"
#include "z_zone.h"
typedef struct
{
wad_file_t wad;
ES_File *fstream;
} stdc_wad_file_t;
extern wad_file_class_t stdc_wad_file;
static wad_file_t *W_StdC_OpenFile(char *path)
{
stdc_wad_file_t *result;
ES_File *fstream;
fstream = ES_fopen(path, ES_READ_MODE | ES_BYTE_MODE);
if (fstream == NULL)
{
return NULL;
}
// Create a new stdc_wad_file_t to hold the file handle.
result = Z_Malloc(sizeof(stdc_wad_file_t), PU_STATIC, 0);
result->wad.file_class = &stdc_wad_file;
result->wad.mapped = NULL;
result->wad.length = M_FileLength(fstream);
result->fstream = fstream;
return &result->wad;
}
static void W_StdC_CloseFile(wad_file_t *wad)
{
stdc_wad_file_t *stdc_wad;
stdc_wad = (stdc_wad_file_t *) wad;
ES_fclose(stdc_wad->fstream);
Z_Free(stdc_wad);
}
// Read data from the specified position in the file into the
// provided buffer. Returns the number of bytes read.
size_t W_StdC_Read(wad_file_t *wad, unsigned int offset,
void *buffer, size_t buffer_len)
{
stdc_wad_file_t *stdc_wad;
size_t result;
stdc_wad = (stdc_wad_file_t *) wad;
// Jump to the specified position in the file.
ES_fseek(stdc_wad->fstream, offset, ES_SEEK_SET);
// Read into the buffer.
result = ES_fread(buffer, buffer_len, 1, stdc_wad->fstream);
return result;
}
wad_file_class_t stdc_wad_file =
{
W_StdC_OpenFile,
W_StdC_CloseFile,
W_StdC_Read,
};