/*

 * 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.

 *

 */

#ifdef HAVE_CONFIG_H

#	include "config.h"

#endif

/* 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);

/*

	Function: gdNewFileCtx

	Return data as a dynamic pointer.

*/

BGD_DECLARE(gdIOCtx *) gdNewFileCtx(FILE *f)

{

	fileIOCtx *ctx;

	if (f == NULL) return NULL;

	ctx = (fileIOCtx *)gdMalloc(sizeof(fileIOCtx));

	if(ctx == NULL) {

		return NULL;

	}

	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);

}