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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* 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 "glk/alan3/state_stack.h"
#include "glk/alan3/syserr.h"
#include "glk/alan3/memory.h"
#include "glk/alan3/state.h"
namespace Glk {
namespace Alan3 {
/* CONSTANTS: */
#define EXTENT 10
/* PRIVATE TYPES: */
struct StateStackStructure {
void **states;
char **commands;
int stackSize;
int stackPointer; /* Points above used stack, 0 initially */
int elementSize; /* Size of elements in the stack */
};
/*----------------------------------------------------------------------*/
static void *reallocate(void *from, int newSize) {
void *newArea = realloc(from, newSize * sizeof(void *));
if (newArea == NULL)
syserr("Out of memory in 'reallocateStack()'");
return newArea;
}
/*======================================================================*/
StateStackP createStateStack(int elementSize) {
StateStackP stack = NEW(StateStackStructure);
stack->stackSize = 0;
stack->stackPointer = 0;
stack->elementSize = elementSize;
return stack;
}
/*======================================================================*/
void deleteStateStack(StateStackP stateStack) {
if (stateStack != NULL) {
while (stateStack->stackPointer > 0) {
stateStack->stackPointer--;
deallocateGameState((GameState *)stateStack->states[stateStack->stackPointer]);
deallocate(stateStack->states[stateStack->stackPointer]);
deallocate(stateStack->commands[stateStack->stackPointer]);
}
if (stateStack->stackSize > 0) {
deallocate(stateStack->states);
deallocate(stateStack->commands);
}
deallocate(stateStack);
}
}
/*======================================================================*/
bool stateStackIsEmpty(StateStackP stateStack) {
return stateStack->stackPointer == 0;
}
/*----------------------------------------------------------------------*/
static void ensureSpaceForGameState(StateStackP stack) {
if (stack->stackPointer == stack->stackSize) {
stack->states = (void **)reallocate(stack->states, stack->stackSize + EXTENT);
stack->commands = (char **)reallocate(stack->commands, stack->stackSize + EXTENT);
stack->stackSize += EXTENT;
}
}
/*======================================================================*/
void pushGameState(StateStackP stateStack, void *gameState) {
void *element = allocate(stateStack->elementSize);
memcpy(element, gameState, stateStack->elementSize);
ensureSpaceForGameState(stateStack);
stateStack->commands[stateStack->stackPointer] = NULL;
stateStack->states[stateStack->stackPointer++] = element;
}
/*======================================================================*/
void attachPlayerCommandsToLastState(StateStackP stateStack, char *playerCommands) {
stateStack->commands[stateStack->stackPointer - 1] = strdup(playerCommands);
}
/*======================================================================*/
void popGameState(StateStackP stateStack, void *gameState, char **playerCommand) {
if (stateStack->stackPointer == 0)
syserr("Popping GameState from empty stack");
else {
stateStack->stackPointer--;
memcpy(gameState, stateStack->states[stateStack->stackPointer], stateStack->elementSize);
deallocate(stateStack->states[stateStack->stackPointer]);
*playerCommand = stateStack->commands[stateStack->stackPointer];
}
}
} // End of namespace Alan3
} // End of namespace Glk
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