/*

SDL - Simple DirectMedia Layer

This library is free software; you can redistribute it and/or

This library 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

You should have received a copy of the GNU Lesser General Public

License along with this library; if not, write to the Free Software

Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

Sam Lantinga

/* This file provides a general interface for SDL to read and write

data sources. It can easily be extended to files, memory, etc.

*/

#define WINDOWS_LEAN_AND_MEAN

#include <windows.h>

static int win32_file_open(SDL_RWops *context, const char *filename, const char *mode) {

UINT old_error_mode;

HANDLE h;

DWORD r_right, w_right;

DWORD must_exist, truncate;

int a_mode;

if (!context || !filename || !mode)

return -1;

context->hidden.win32io.h = INVALID_HANDLE_VALUE; /* mark this as unusable */

/* "r" = reading, file must exist */

/* "w" = writing, truncate existing, file may not exist */

/* "r+"= reading or writing, file must exist */

/* "a" = writing, append file may not exist */

/* "a+"= append + read, file may not exist */

/* "w+" = read, write, truncate. file may not exist */

must_exist = ( SDL_strchr(mode,'r') != NULL ) ? OPEN_EXISTING : 0;

truncate = ( SDL_strchr(mode,'w') != NULL ) ? CREATE_ALWAYS : 0;

r_right = ( SDL_strchr(mode,'+') != NULL || must_exist ) ? GENERIC_READ : 0;

a_mode = ( SDL_strchr(mode,'a') != NULL );

w_right = ( a_mode || SDL_strchr(mode,'w') || truncate ) ? GENERIC_WRITE : 0;

if (!r_right && !w_right) /* inconsistent mode */

return -1; /* failed (invalid call)*/

/* Do not open a dialog box if failure */

old_error_mode = SetErrorMode(SEM_NOOPENFILEERRORBOX|SEM_FAILCRITICALERRORS);

h = CreateFile(filename, (w_right|r_right), (w_right)? 0 : FILE_SHARE_READ,

NULL, (must_exist|truncate), FILE_ATTRIBUTE_NORMAL,NULL);

/* restore old behaviour */

SetErrorMode(old_error_mode);

if (h==INVALID_HANDLE_VALUE) {

SDL_SetError("Couldn't open %s",filename);

return -2; /* failed (CreateFile) */

}

context->hidden.win32io.h = h;

context->hidden.win32io.append = a_mode;

return 0; /* ok */

}

static int win32_file_seek(SDL_RWops *context, int offset, int whence) {

DWORD win32whence;

int file_pos;

if (!context || context->hidden.win32io.h == INVALID_HANDLE_VALUE) {

SDL_SetError("win32_file_seek: invalid context/file not opened");

return -1;

}

switch (whence) {

case RW_SEEK_SET:

win32whence = FILE_BEGIN; break;

case RW_SEEK_CUR:

win32whence = FILE_CURRENT; break;

case RW_SEEK_END:

win32whence = FILE_END; break;

default:

SDL_SetError("win32_file_seek: Unknown value for 'whence'");

return -1;

}

file_pos = SetFilePointer(context->hidden.win32io.h,offset,NULL,win32whence);

if ( file_pos != INVALID_SET_FILE_POINTER )

return file_pos; /* success */

SDL_Error(SDL_EFSEEK);

return -1; /* error */

}

static int win32_file_read(SDL_RWops *context, void *ptr, int size, int maxnum) {

int total_bytes;

DWORD byte_read,nread;

total_bytes = size*maxnum;

if (!context || context->hidden.win32io.h == INVALID_HANDLE_VALUE || total_bytes<=0 || !size)

return 0;

if (!ReadFile(context->hidden.win32io.h,ptr,total_bytes,&byte_read,NULL)) {

SDL_Error(SDL_EFREAD);

return 0;

}

nread = byte_read/size;

return nread;

}

static int win32_file_write(SDL_RWops *context, const void *ptr, int size, int num) {

int total_bytes;

DWORD byte_written,nwritten;

total_bytes = size*num;

if (!context || context->hidden.win32io.h==INVALID_HANDLE_VALUE || total_bytes<=0 || !size)

return 0;

/* if in append mode, we must go to the EOF before write */

if (context->hidden.win32io.append) {

if ( SetFilePointer(context->hidden.win32io.h,0L,NULL,FILE_END) == INVALID_SET_FILE_POINTER ) {

SDL_Error(SDL_EFWRITE);

return 0;

}

}

if (!WriteFile(context->hidden.win32io.h,ptr,total_bytes,&byte_written,NULL)) {

SDL_Error(SDL_EFWRITE);

return 0;

}

nwritten = byte_written/size;

return nwritten;

}

static int win32_file_close(SDL_RWops *context) {

if ( context ) {

if (context->hidden.win32io.h != INVALID_HANDLE_VALUE) {

CloseHandle(context->hidden.win32io.h);

context->hidden.win32io.h = INVALID_HANDLE_VALUE; /* to be sure */

}

SDL_FreeRW(context);

}

return(0);

}

static int stdio_seek(SDL_RWops *context, int offset, int whence)

{

if ( fseek(context->hidden.stdio.fp, offset, whence) == 0 ) {

return(ftell(context->hidden.stdio.fp));

} else {

SDL_Error(SDL_EFSEEK);

return(-1);

}

}

static int stdio_read(SDL_RWops *context, void *ptr, int size, int maxnum)

{

size_t nread;

nread = fread(ptr, size, maxnum, context->hidden.stdio.fp);

if ( nread == 0 && ferror(context->hidden.stdio.fp) ) {

SDL_Error(SDL_EFREAD);

}

return(nread);

}

static int stdio_write(SDL_RWops *context, const void *ptr, int size, int num)

{

size_t nwrote;

nwrote = fwrite(ptr, size, num, context->hidden.stdio.fp);

if ( nwrote == 0 && ferror(context->hidden.stdio.fp) ) {

SDL_Error(SDL_EFWRITE);

}

return(nwrote);

}

static int stdio_close(SDL_RWops *context)

{

if ( context ) {

if ( context->hidden.stdio.autoclose ) {

/* WARNING: Check the return value here! */

fclose(context->hidden.stdio.fp);

}

SDL_FreeRW(context);

}

return(0);

}

/* Functions to read/write memory pointers */

static int mem_seek(SDL_RWops *context, int offset, int whence)

{

Uint8 *newpos;

switch (whence) {

newpos = context->hidden.mem.base+offset;

break;

newpos = context->hidden.mem.here+offset;

break;

newpos = context->hidden.mem.stop+offset;

break;

default:

SDL_SetError("Unknown value for 'whence'");

return(-1);

}

if ( newpos < context->hidden.mem.base ) {

newpos = context->hidden.mem.base;

}

if ( newpos > context->hidden.mem.stop ) {

newpos = context->hidden.mem.stop;

}

context->hidden.mem.here = newpos;

return(context->hidden.mem.here-context->hidden.mem.base);

}

static int mem_read(SDL_RWops *context, void *ptr, int size, int maxnum)

{

int total_bytes;

int mem_available;

total_bytes = (maxnum * size);

if ( (maxnum <= 0) || (size <= 0) || ((total_bytes / maxnum) != size) ) {

return 0;

mem_available = (context->hidden.mem.stop - context->hidden.mem.here);

if (total_bytes > mem_available) {

total_bytes = mem_available;

}

context->hidden.mem.here += total_bytes;

return (total_bytes / size);

}

static int mem_write(SDL_RWops *context, const void *ptr, int size, int num)

{

if ( (context->hidden.mem.here + (num*size)) > context->hidden.mem.stop ) {

num = (context->hidden.mem.stop-context->hidden.mem.here)/size;

}

context->hidden.mem.here += num*size;

return(num);

}

static int mem_writeconst(SDL_RWops *context, const void *ptr, int size, int num)

{

SDL_SetError("Can't write to read-only memory");

return(-1);

}

static int mem_close(SDL_RWops *context)

{

if ( context ) {

}

return(0);

}

/* Functions to create SDL_RWops structures from various data sources */

/*

* translate unix-style slash-separated filename to mac-style colon-separated

* name; return malloced string

*/

static char *unix_to_mac(const char *file)

{

int flen = SDL_strlen(file);

char *path = SDL_malloc(flen + 2);

const char *src = file;

char *dst = path;

if(*src == '/') {

/* really depends on filesystem layout, hope for the best */

src++;

} else {

/* Check if this is a MacOS path to begin with */

if(*src != ':')

*dst++ = ':'; /* relative paths begin with ':' */

}

while(src < file + flen) {

int len;

if(!end)

end = file + flen; /* last component */

len = end - src;

if(len == 0 || (len == 1 && src[0] == '.')) {

/* remove repeated slashes and . */

} else {

if(len == 2 && src[0] == '.' && src[1] == '.') {

/* replace .. with the empty string */

} else {

dst += len;

}

if(end < file + flen)

*dst++ = ':';

}

src = end + 1;

}

*dst++ = '\0';

return path;

}

SDL_RWops *SDL_RWFromFile(const char *file, const char *mode)

{

#ifdef __WIN32__

rwops = SDL_AllocRW();

rwops->hidden.win32io.h = INVALID_HANDLE_VALUE;

if (win32_file_open(rwops,file,mode)) {

SDL_FreeRW(rwops);

return NULL;

}

rwops->seek = win32_file_seek;

rwops->read = win32_file_read;

rwops->write = win32_file_write;

rwops->close = win32_file_close;

#elif HAVE_STDIO_H

FILE *fp;

{

char *mpath = unix_to_mac(file);

fp = fopen(mpath, mode);

}

#else

fp = fopen(file, mode);

#endif

if ( fp == NULL ) {

SDL_SetError("Couldn't open %s", file);

} else {

rwops = SDL_RWFromFP(fp, 1);

}

#else

SDL_SetError("SDL not compiled with stdio support");

return(rwops);

}

SDL_RWops *SDL_RWFromFP(FILE *fp, int autoclose)

{

rwops = SDL_AllocRW();

if ( rwops != NULL ) {

rwops->seek = stdio_seek;

rwops->read = stdio_read;

rwops->write = stdio_write;

rwops->close = stdio_close;

rwops->hidden.stdio.fp = fp;

rwops->hidden.stdio.autoclose = autoclose;

}

return(rwops);

}

SDL_RWops *SDL_RWFromMem(void *mem, int size)

{

SDL_RWops *rwops;

rwops = SDL_AllocRW();

if ( rwops != NULL ) {

rwops->seek = mem_seek;

rwops->read = mem_read;

rwops->write = mem_write;

rwops->close = mem_close;

rwops->hidden.mem.base = (Uint8 *)mem;

rwops->hidden.mem.here = rwops->hidden.mem.base;

rwops->hidden.mem.stop = rwops->hidden.mem.base+size;

}

return(rwops);

}

SDL_RWops *SDL_RWFromConstMem(const void *mem, int size)

{

SDL_RWops *rwops;

rwops = SDL_AllocRW();

if ( rwops != NULL ) {

rwops->seek = mem_seek;

rwops->read = mem_read;

rwops->write = mem_writeconst;

rwops->close = mem_close;

rwops->hidden.mem.base = (Uint8 *)mem;

rwops->hidden.mem.here = rwops->hidden.mem.base;

rwops->hidden.mem.stop = rwops->hidden.mem.base+size;

}

return(rwops);

}

SDL_RWops *SDL_AllocRW(void)

{

SDL_RWops *area;

if ( area == NULL ) {

SDL_OutOfMemory();

}

return(area);

}

void SDL_FreeRW(SDL_RWops *area)

{

/* Functions for dynamically reading and writing endian-specific values */

Uint16 SDL_ReadLE16 (SDL_RWops *src)

{

Uint16 value;

SDL_RWread(src, &value, (sizeof value), 1);

return(SDL_SwapLE16(value));

}

Uint16 SDL_ReadBE16 (SDL_RWops *src)

{

Uint16 value;

SDL_RWread(src, &value, (sizeof value), 1);

return(SDL_SwapBE16(value));

}

Uint32 SDL_ReadLE32 (SDL_RWops *src)

{

Uint32 value;

SDL_RWread(src, &value, (sizeof value), 1);

return(SDL_SwapLE32(value));

}

Uint32 SDL_ReadBE32 (SDL_RWops *src)

{

Uint32 value;

SDL_RWread(src, &value, (sizeof value), 1);

return(SDL_SwapBE32(value));

}

Uint64 SDL_ReadLE64 (SDL_RWops *src)

{

Uint64 value;

SDL_RWread(src, &value, (sizeof value), 1);

return(SDL_SwapLE64(value));

}

Uint64 SDL_ReadBE64 (SDL_RWops *src)

{

Uint64 value;

SDL_RWread(src, &value, (sizeof value), 1);

return(SDL_SwapBE64(value));

}

int SDL_WriteLE16 (SDL_RWops *dst, Uint16 value)

{

value = SDL_SwapLE16(value);

return(SDL_RWwrite(dst, &value, (sizeof value), 1));

}

int SDL_WriteBE16 (SDL_RWops *dst, Uint16 value)

{

value = SDL_SwapBE16(value);

return(SDL_RWwrite(dst, &value, (sizeof value), 1));

}

int SDL_WriteLE32 (SDL_RWops *dst, Uint32 value)

{

value = SDL_SwapLE32(value);

return(SDL_RWwrite(dst, &value, (sizeof value), 1));

}

int SDL_WriteBE32 (SDL_RWops *dst, Uint32 value)

{

value = SDL_SwapBE32(value);

return(SDL_RWwrite(dst, &value, (sizeof value), 1));

}

int SDL_WriteLE64 (SDL_RWops *dst, Uint64 value)

{

value = SDL_SwapLE64(value);

return(SDL_RWwrite(dst, &value, (sizeof value), 1));

}

int SDL_WriteBE64 (SDL_RWops *dst, Uint64 value)

{

value = SDL_SwapBE64(value);

return(SDL_RWwrite(dst, &value, (sizeof value), 1));

}