libgd/src/gd_io.c

/*
 * io.c
 *
 * Implements the simple I/O 'helper' routines.
 *
 * Not really essential, but these routines were used extensively in GD,
 * so they were moved here. They also make IOCtx calls look better...
 *
 * Written (or, at least, moved) 1999, Philip Warner.
 */

#ifdef HAVE_CONFIG_H
#	include "config.h"
#endif

#include <math.h>
#include <string.h>
#include <stdlib.h>
#include "gd.h"

/* Use this for commenting out debug-print statements. */
/* Just use the first '#define' to allow all the prints... */
/*#define IO_DBG(s) (s) */
#define IO_DBG(s)

#define GD_IO_EOF_CHK(r) \
	if(r == EOF) { \
		return 0; \
	}

void gdPutC(const unsigned char c, gdIOCtx *ctx)
{
	(ctx->putC)(ctx, c);
}

void gdPutWord (int w, gdIOCtx *ctx)
{
	IO_DBG(printf("Putting word...\n"));
	(ctx->putC)(ctx, (unsigned char)(w >> 8));
	(ctx->putC)(ctx, (unsigned char)(w & 0xFF));
	IO_DBG(printf("put.\n"));
}

void gdPutInt (int w, gdIOCtx *ctx)
{
	IO_DBG(printf("Putting int...\n"));
	(ctx->putC)(ctx, (unsigned char) (w >> 24));
	(ctx->putC)(ctx, (unsigned char) ((w >> 16) & 0xFF));
	(ctx->putC)(ctx, (unsigned char) ((w >> 8) & 0xFF));
	(ctx->putC)(ctx, (unsigned char) (w & 0xFF));
	IO_DBG(printf("put.\n"));
}

int gdGetC(gdIOCtx *ctx)
{
	return ((ctx->getC)(ctx));
}

int gdGetByte(int *result, gdIOCtx *ctx)
{
	int r;

	r = (ctx->getC)(ctx);
	if(r == EOF) {
		return 0;
	}

	*result = r;

	return 1;
}

int gdGetWord(int *result, gdIOCtx *ctx)
{
	int r;

	r = (ctx->getC)(ctx);
	if(r == EOF) {
		return 0;
	}

	*result = r << 8;

	r = (ctx->getC)(ctx);
	if(r == EOF) {
		return 0;
	}

	*result += r;

	return 1;
}

int gdGetWordLSB(signed short int *result, gdIOCtx *ctx)
{
	int high = 0, low = 0;
	low = (ctx->getC) (ctx);
	if (low == EOF) {
		return 0;
	}

	high = (ctx->getC) (ctx);
	if (high == EOF) {
		return 0;
	}

	if (result) {
		*result = (high << 8) | low;
	}

	return 1;
}

int gdGetInt(int *result, gdIOCtx *ctx)
{
	unsigned int r;

	r = (ctx->getC)(ctx);
	if(r == EOF) {
		return 0;
	}

	*result = r << 24;

	r = (ctx->getC)(ctx);
	if(r == EOF) {
		return 0;
	}

	*result += r << 16;

	r = (ctx->getC)(ctx);
	if(r == EOF) {
		return 0;
	}

	*result += r << 8;

	r = (ctx->getC)(ctx);
	if(r == EOF) {
		return 0;
	}

	*result += r;

	return 1;
}

int gdGetIntLSB(signed int *result, gdIOCtx *ctx)
{
	unsigned int c;
	unsigned int r = 0;

	c = (ctx->getC) (ctx);
	if (c == EOF) {
		return 0;
	}
	r |= (c << 24);
	r >>= 8;

	c = (ctx->getC) (ctx);
	if (c == EOF) {
		return 0;
	}
	r |= (c << 24);
	r >>= 8;

	c = (ctx->getC) (ctx);
	if (c == EOF) {
		return 0;
	}
	r |= (c << 24);
	r >>= 8;

	c = (ctx->getC) (ctx);
	if (c == EOF) {
		return 0;
	}
	r |= (c << 24);

	if (result) {
		*result = (signed int)r;
	}

	return 1;
}

int gdPutBuf(const void *buf, int size, gdIOCtx *ctx)
{
	IO_DBG(printf("Putting buf...\n"));
	return (ctx->putBuf)(ctx, buf, size);
	IO_DBG(printf("put.\n"));
}

int gdGetBuf(void *buf, int size, gdIOCtx *ctx)
{
	return (ctx->getBuf)(ctx, buf, size);
}

int gdSeek(gdIOCtx *ctx, const int pos)
{
	IO_DBG(printf("Seeking...\n"));
	return ((ctx->seek)(ctx, pos));
	IO_DBG(printf("Done.\n"));
}

long gdTell(gdIOCtx *ctx)
{
	IO_DBG(printf("Telling...\n"));
	return ((ctx->tell)(ctx));
	IO_DBG(printf("told.\n"));
}