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DEFINITIONS
This source file includes following definitions.
- gdNewFileCtx
- gdFreeFileCtx
- filePutbuf
- fileGetbuf
- filePutchar
- fileGetchar
- fileSeek
- fileTell
/*
* io_file.c
*
* Implements the file interface.
*
* As will all I/O modules, most functions are for local use only (called
* via function pointers in the I/O context).
*
* Most functions are just 'wrappers' for standard file functions.
*
* Written/Modified 1999, Philip Warner.
*
*/
/* For platforms with incomplete ANSI defines. Fortunately,
SEEK_SET is defined to be zero by the standard. */
#ifndef SEEK_SET
#define SEEK_SET 0
#endif /* SEEK_SET */
#include <math.h>
#include <string.h>
#include <stdlib.h>
#include "gd.h"
#include "gdhelpers.h"
/* this is used for creating images in main memory */
typedef struct fileIOCtx
{
gdIOCtx ctx;
FILE *f;
} fileIOCtx;
gdIOCtx *newFileCtx (FILE * f);
static int fileGetbuf (gdIOCtx *, void *, int);
static int filePutbuf (gdIOCtx *, const void *, int);
static void filePutchar (gdIOCtx *, int);
static int fileGetchar (gdIOCtx * ctx);
static int fileSeek (struct gdIOCtx *, const int);
static long fileTell (struct gdIOCtx *);
static void gdFreeFileCtx (gdIOCtx * ctx);
/* return data as a dynamic pointer */
gdIOCtx * gdNewFileCtx (FILE * f)
{
fileIOCtx *ctx;
ctx = (fileIOCtx *) gdMalloc(sizeof (fileIOCtx));
ctx->f = f;
ctx->ctx.getC = fileGetchar;
ctx->ctx.putC = filePutchar;
ctx->ctx.getBuf = fileGetbuf;
ctx->ctx.putBuf = filePutbuf;
ctx->ctx.tell = fileTell;
ctx->ctx.seek = fileSeek;
ctx->ctx.gd_free = gdFreeFileCtx;
return (gdIOCtx *) ctx;
}
static void gdFreeFileCtx (gdIOCtx * ctx)
{
gdFree(ctx);
}
static int filePutbuf (gdIOCtx * ctx, const void *buf, int size)
{
fileIOCtx *fctx;
fctx = (fileIOCtx *) ctx;
return fwrite(buf, 1, size, fctx->f);
}
static int fileGetbuf (gdIOCtx * ctx, void *buf, int size)
{
fileIOCtx *fctx;
fctx = (fileIOCtx *) ctx;
return fread(buf, 1, size, fctx->f);
}
static void filePutchar (gdIOCtx * ctx, int a)
{
unsigned char b;
fileIOCtx *fctx;
fctx = (fileIOCtx *) ctx;
b = a;
putc (b, fctx->f);
}
static int fileGetchar (gdIOCtx * ctx)
{
fileIOCtx *fctx;
fctx = (fileIOCtx *) ctx;
return getc (fctx->f);
}
static int fileSeek (struct gdIOCtx *ctx, const int pos)
{
fileIOCtx *fctx;
fctx = (fileIOCtx *) ctx;
return (fseek (fctx->f, pos, SEEK_SET) == 0);
}
static long fileTell (struct gdIOCtx *ctx)
{
fileIOCtx *fctx;
fctx = (fileIOCtx *) ctx;
return ftell (fctx->f);
}