scummvm/engines/icb/keyboard.cpp
2020-10-06 09:51:20 +02:00

77 lines
2.1 KiB
C++

/* ResidualVM - A 3D game interpreter
*
* ResidualVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the AUTHORS
* file distributed with this source distribution.
*
* Additional copyright for this file:
* Copyright (C) 1999-2000 Revolution Software Ltd.
* This code is based on source code created by Revolution Software,
* used with permission.
*
* 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.
*
*/
#include "engines/icb/common/px_common.h"
#include "engines/icb/keyboard.h"
namespace ICB {
#define MAX_KEY_BUFFER 32
uint8 keyBacklog = 0; // The number of key presses waiting to be processed.
uint8 keyPointer = 0; // Index of the next key to read from the buffer.
char keyBuffer[MAX_KEY_BUFFER]; // The keyboard buffer
void WriteKey(char key) {
if (keyBacklog < MAX_KEY_BUFFER) {
keyBuffer[(keyPointer + keyBacklog) % MAX_KEY_BUFFER] = key;
keyBacklog += 1;
}
}
void Clear_key_buffer() {
// clear all the backlog - we need this when we start using other methods (direct input) for reading keys
keyBacklog = 0;
keyPointer = 0;
}
bool KeyWaiting() {
if (keyBacklog)
return (true);
else
return (false);
}
int32 ReadKey(char *key) {
if (!keyBacklog)
return (0);
if (key == NULL)
return 0;
*key = keyBuffer[keyPointer++];
if (keyPointer == MAX_KEY_BUFFER)
keyPointer = 0;
keyBacklog -= 1;
return (1);
}
} // End of namespace ICB