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/* ScummVM - Scumm Interpreter
* Copyright (C) 2004 The ScummVM project
*
* The ReInherit Engine is (C)2000-2003 by Daniel Balsom.
*
* 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.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* $Header$
*
*/
#include <stdio.h>
#include "yslib.h"
namespace Saga {
void
ys_read_4cc(char *fourcc,
const unsigned char *data_p, const unsigned char **data_pp)
{
fourcc[0] = (char)data_p[0];
fourcc[1] = (char)data_p[1];
fourcc[2] = (char)data_p[2];
fourcc[3] = (char)data_p[3];
if (data_pp) {
*data_pp = data_p + 4;
}
return;
}
unsigned int
ys_read_u8(const unsigned char *data_p, const unsigned char **data_pp)
/*---------------------------------------------------------------------------*\
* Reads an unsigned 8 bit integer in from the array of bytes pointed to by
* 'data_p'. If 'data_pp' is not null, it will set '*data_pp' to point past
* the integer read.
\*---------------------------------------------------------------------------*/
{
unsigned int u8 = *data_p;
if (data_pp != NULL) {
*data_pp = data_p + 1;
}
return u8;
}
int ys_read_s8(const unsigned char *data_p, const unsigned char **data_pp)
/*---------------------------------------------------------------------------*\
* Reads a signed 8 bit integer in two's complement notation from the array
* of bytes pointed to by 'data_p'. If 'data_pp' is not null, it will set
* '*data_pp' to point past the integer read.
\*---------------------------------------------------------------------------*/
{
unsigned int u8 = *data_p;
int s8;
#ifndef YS_ASSUME_2S_COMP
if (u8 & 0x80U) {
s8 = (int)(u8 - 0x80U) - 0x7F - 1;
} else
#endif
s8 = u8;
if (data_pp != NULL) {
*data_pp = data_p + 1;
}
return s8;
}
unsigned int
ys_read_u16_be(const unsigned char *data_p, const unsigned char **data_pp)
/*---------------------------------------------------------------------------*\
* Reads an unsigned 16 bit integer in big-endian format from the array of
* bytes pointed to by 'data_p'. If 'data_pp' is not null, it will set
* '*data_pp' to point past the integer read.
\*---------------------------------------------------------------------------*/
{
unsigned int u16_be = ((unsigned int)data_p[0] << 8) | data_p[1];
if (data_pp != NULL) {
*data_pp = data_p + 2;
}
return u16_be;
}
unsigned int
ys_read_u16_le(const unsigned char *data_p, const unsigned char **data_pp)
/*---------------------------------------------------------------------------*\
* Reads an unsigned 16 bit integer in little-endian format from the array of
* bytes pointed to by 'data_p'. If 'data_pp' is not null, it will set
* '*data_pp' to point past the integer read.
\*---------------------------------------------------------------------------*/
{
unsigned int u16_le = ((unsigned int)data_p[1] << 8) | data_p[0];
if (data_pp != NULL) {
*data_pp = data_p + 2;
}
return u16_le;
}
int ys_read_s16_be(const unsigned char *data_p, const unsigned char **data_pp)
/*---------------------------------------------------------------------------*\
* Reads a signed 16 bit integer in big-endian, 2's complement format from
* the array of bytes pointed to by 'data_p'.
* If 'data_pp' is not null, it will set '*data_pp' to point past the integer
* read.
\*---------------------------------------------------------------------------*/
{
unsigned int u16_be = ((unsigned int)data_p[0] << 8) | data_p[1];
int s16_be;
#ifndef YS_ASSUME_2S_COMP
if (u16_be & 0x8000U) {
s16_be = (int)(u16_be - 0x8000U) - 0x7FFF - 1;
} else
#endif
s16_be = u16_be;
if (data_pp != NULL) {
*data_pp = data_p + 2;
}
return s16_be;
}
int ys_read_s16_le(const unsigned char *data_p, const unsigned char **data_pp)
/*---------------------------------------------------------------------------*\
* Reads a signed 16 bit integer in little-endian, 2's complement format from
* the array of bytes pointed to by 'data_p'.
* If 'data_pp' is not null, it will set '*data_pp' to point past the integer
* read.
\*---------------------------------------------------------------------------*/
{
unsigned int u16_le = ((unsigned int)data_p[1] << 8) | data_p[0];
int s16_le;
#ifndef YS_ASSUME_2S_COMP
if (u16_le & 0x8000U) {
s16_le = (int)(u16_le - 0x8000U) - 0x7FFF - 1;
} else
#endif
s16_le = u16_le;
if (data_pp != NULL) {
*data_pp = data_p + 2;
}
return s16_le;
}
unsigned long
ys_read_u24_le(const unsigned char *data_p, const unsigned char **data_pp)
/*---------------------------------------------------------------------------*\
* Reads an unsigned 24 bit integer in big-endian format from the array of
* bytes pointed to by 'data_p'. If 'data_pp' is not null, it will set
* '*data_pp' to point past the integer read.
\*---------------------------------------------------------------------------*/
{
unsigned long u24_le = ((unsigned long)data_p[3] << 16) |
((unsigned long)data_p[2] << 8) | data_p[0];
if (data_pp != NULL) {
*data_pp = data_p + 3;
}
return u24_le;
}
unsigned long
ys_read_u32_be(const unsigned char *data_p, const unsigned char **data_pp)
/*---------------------------------------------------------------------------*\
* Reads an unsigned 32 bit integer in big-endian format from the array of
* bytes pointed to by 'data_p'. If 'data_pp' is not null, it will set
* '*data_pp' to point past the integer read.
\*---------------------------------------------------------------------------*/
{
unsigned long u32_be = ((unsigned long)data_p[0] << 24) |
((unsigned long)data_p[1] << 16) |
((unsigned long)data_p[2] << 8) | data_p[3];
if (data_pp != NULL) {
*data_pp = data_p + 4;
}
return u32_be;
}
unsigned long
ys_read_u32_le(const unsigned char *data_p, const unsigned char **data_pp)
/*---------------------------------------------------------------------------*\
* Reads an unsigned 32 bit integer in little-endian format from the array of
* bytes pointed to by 'data_p'. If 'data_pp' is not null, it will set
* '*data_pp' to point past the integer read.
\*---------------------------------------------------------------------------*/
{
unsigned long u32_le = ((unsigned long)data_p[3] << 24) |
((unsigned long)data_p[2] << 16) |
((unsigned long)data_p[1] << 8) | data_p[0];
if (data_pp != NULL) {
*data_pp = data_p + 4;
}
return u32_le;
}
} // End of namespace Saga
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