mirror of
https://github.com/libretro/scummvm.git
synced 2024-12-24 18:56:33 +00:00
3e6414a55f
target was commented out until existence of the demo is confirmed. svn-id: r24697
219 lines
6.1 KiB
C
219 lines
6.1 KiB
C
/* ScummVM - Scumm Interpreter
|
|
* Copyright (C) 2001 Ludvig Strigeus
|
|
* Copyright (C) 2001-2006 The ScummVM project
|
|
*
|
|
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
*
|
|
* $URL$
|
|
* $Id$
|
|
*
|
|
*/
|
|
|
|
#ifndef COMMON_ENDIAN_H
|
|
#define COMMON_ENDIAN_H
|
|
|
|
#include "common/scummsys.h"
|
|
|
|
//
|
|
// Endian conversion functions, macros etc., follow from here!
|
|
//
|
|
|
|
/**
|
|
* Swap the bytes in a 32 bit word in order to convert LE encoded data to BE
|
|
* and vice versa.
|
|
*/
|
|
FORCEINLINE uint32 SWAP_BYTES_32(uint32 a) {
|
|
return ((a >> 24) & 0x000000FF) |
|
|
((a >> 8) & 0x0000FF00) |
|
|
((a << 8) & 0x00FF0000) |
|
|
((a << 24) & 0xFF000000);
|
|
}
|
|
|
|
/**
|
|
* Swap the bytes in a 16 bit word in order to convert LE encoded data to BE
|
|
* and vice versa.
|
|
*/
|
|
FORCEINLINE uint16 SWAP_BYTES_16(uint16 a) {
|
|
return ((a >> 8) & 0x00FF) + ((a << 8) & 0xFF00);
|
|
}
|
|
|
|
|
|
/**
|
|
* A wrapper macro used around four character constants, like 'DATA', to
|
|
* ensure portability. Typical usage: MKID_BE('DATA').
|
|
*
|
|
* Why is this necessary? The C/C++ standard does not define the endianess to
|
|
* be used for character constants. Hence if one uses multi-byte character
|
|
* constants, a potential portability problem opens up.
|
|
*
|
|
* Fortunately, a semi-standard has been established: On almost all systems
|
|
* and compilers, multi-byte character constants are encoded using the big
|
|
* endian convention (probably in analogy to the encoding of string constants).
|
|
* Still some systems differ. This is why we provide the MKID_BE macro. If
|
|
* you wrap your four character constants with it, the result will always be
|
|
* BE encoded, even on systems which differ from the default BE encoding.
|
|
*
|
|
* For the latter systems we provide the INVERSE_MKID override.
|
|
*/
|
|
#if defined(INVERSE_MKID)
|
|
#define MKID_BE(a) ((uint32) \
|
|
(((a) >> 24) & 0x000000FF) | \
|
|
(((a) >> 8) & 0x0000FF00) | \
|
|
(((a) << 8) & 0x00FF0000) | \
|
|
(((a) << 24) & 0xFF000000))
|
|
|
|
#else
|
|
# define MKID_BE(a) ((uint32)(a))
|
|
#endif
|
|
|
|
|
|
|
|
#if defined(SCUMM_LITTLE_ENDIAN)
|
|
|
|
#define READ_UINT16(a) READ_LE_UINT16(a)
|
|
#define READ_UINT32(a) READ_LE_UINT32(a)
|
|
|
|
#define WRITE_UINT16(a, v) WRITE_LE_UINT16(a, v)
|
|
#define WRITE_UINT32(a, v) WRITE_LE_UINT32(a, v)
|
|
|
|
#define FROM_LE_32(a) ((uint32)(a))
|
|
#define FROM_LE_16(a) ((uint16)(a))
|
|
|
|
#define FROM_BE_32(a) SWAP_BYTES_32(a)
|
|
#define FROM_BE_16(a) SWAP_BYTES_16(a)
|
|
|
|
#define TO_LE_32(a) ((uint32)(a))
|
|
#define TO_LE_16(a) ((uint16)(a))
|
|
|
|
#define TO_BE_32(a) SWAP_BYTES_32(a)
|
|
#define TO_BE_16(a) SWAP_BYTES_16(a)
|
|
|
|
#elif defined(SCUMM_BIG_ENDIAN)
|
|
|
|
#define MKID(a) ((uint32)(a))
|
|
#define MKID_BE(a) ((uint32)(a))
|
|
|
|
#define READ_UINT16(a) READ_BE_UINT16(a)
|
|
#define READ_UINT32(a) READ_BE_UINT32(a)
|
|
|
|
#define WRITE_UINT16(a, v) WRITE_BE_UINT16(a, v)
|
|
#define WRITE_UINT32(a, v) WRITE_BE_UINT32(a, v)
|
|
|
|
#define FROM_LE_32(a) SWAP_BYTES_32(a)
|
|
#define FROM_LE_16(a) SWAP_BYTES_16(a)
|
|
|
|
#define FROM_BE_32(a) ((uint32)(a))
|
|
#define FROM_BE_16(a) ((uint16)(a))
|
|
|
|
#define TO_LE_32(a) SWAP_BYTES_32(a)
|
|
#define TO_LE_16(a) SWAP_BYTES_16(a)
|
|
|
|
#define TO_BE_32(a) ((uint32)(a))
|
|
#define TO_BE_16(a) ((uint16)(a))
|
|
|
|
#else
|
|
|
|
#error No endianness defined
|
|
|
|
|
|
#endif
|
|
|
|
|
|
#if defined(SCUMM_NEED_ALIGNMENT) || defined(SCUMM_BIG_ENDIAN)
|
|
FORCEINLINE uint16 READ_LE_UINT16(const void *ptr) {
|
|
const byte *b = (const byte *)ptr;
|
|
return (b[1] << 8) + b[0];
|
|
}
|
|
FORCEINLINE uint32 READ_LE_UINT32(const void *ptr) {
|
|
const byte *b = (const byte *)ptr;
|
|
return (b[3] << 24) + (b[2] << 16) + (b[1] << 8) + (b[0]);
|
|
}
|
|
FORCEINLINE void WRITE_LE_UINT16(void *ptr, uint16 value) {
|
|
byte *b = (byte *)ptr;
|
|
b[0] = (byte)(value >> 0);
|
|
b[1] = (byte)(value >> 8);
|
|
}
|
|
FORCEINLINE void WRITE_LE_UINT32(void *ptr, uint32 value) {
|
|
byte *b = (byte *)ptr;
|
|
b[0] = (byte)(value >> 0);
|
|
b[1] = (byte)(value >> 8);
|
|
b[2] = (byte)(value >> 16);
|
|
b[3] = (byte)(value >> 24);
|
|
}
|
|
#else
|
|
FORCEINLINE uint16 READ_LE_UINT16(const void *ptr) {
|
|
return *(const uint16 *)(ptr);
|
|
}
|
|
FORCEINLINE uint32 READ_LE_UINT32(const void *ptr) {
|
|
return *(const uint32 *)(ptr);
|
|
}
|
|
FORCEINLINE void WRITE_LE_UINT16(void *ptr, uint16 value) {
|
|
*(uint16 *)(ptr) = value;
|
|
}
|
|
FORCEINLINE void WRITE_LE_UINT32(void *ptr, uint32 value) {
|
|
*(uint32 *)(ptr) = value;
|
|
}
|
|
#endif
|
|
|
|
|
|
#if defined(SCUMM_NEED_ALIGNMENT) || defined(SCUMM_LITTLE_ENDIAN)
|
|
FORCEINLINE uint16 READ_BE_UINT16(const void *ptr) {
|
|
const byte *b = (const byte *)ptr;
|
|
return (b[0] << 8) + b[1];
|
|
}
|
|
FORCEINLINE uint32 READ_BE_UINT32(const void *ptr) {
|
|
const byte *b = (const byte*)ptr;
|
|
return (b[0] << 24) + (b[1] << 16) + (b[2] << 8) + (b[3]);
|
|
}
|
|
FORCEINLINE void WRITE_BE_UINT16(void *ptr, uint16 value) {
|
|
byte *b = (byte *)ptr;
|
|
b[0] = (byte)(value >> 8);
|
|
b[1] = (byte)(value >> 0);
|
|
}
|
|
FORCEINLINE void WRITE_BE_UINT32(void *ptr, uint32 value) {
|
|
byte *b = (byte *)ptr;
|
|
b[0] = (byte)(value >> 24);
|
|
b[1] = (byte)(value >> 16);
|
|
b[2] = (byte)(value >> 8);
|
|
b[3] = (byte)(value >> 0);
|
|
}
|
|
#else
|
|
FORCEINLINE uint16 READ_BE_UINT16(const void *ptr) {
|
|
return *(const uint16 *)(ptr);
|
|
}
|
|
FORCEINLINE uint32 READ_BE_UINT32(const void *ptr) {
|
|
return *(const uint32 *)(ptr);
|
|
}
|
|
FORCEINLINE void WRITE_BE_UINT16(void *ptr, uint16 value) {
|
|
*(uint16 *)(ptr) = value;
|
|
}
|
|
FORCEINLINE void WRITE_BE_UINT32(void *ptr, uint32 value) {
|
|
*(uint32 *)(ptr) = value;
|
|
}
|
|
#endif
|
|
|
|
FORCEINLINE uint32 READ_LE_UINT24(const void *ptr) {
|
|
const byte *b = (const byte *)ptr;
|
|
return (b[2] << 16) + (b[1] << 8) + (b[0]);
|
|
}
|
|
|
|
FORCEINLINE uint32 READ_BE_UINT24(const void *ptr) {
|
|
const byte *b = (const byte*)ptr;
|
|
return (b[0] << 16) + (b[1] << 8) + (b[2]);
|
|
}
|
|
|
|
|
|
#endif
|