scummvm/saga/sstack.cpp
2004-07-31 12:37:36 +00:00

156 lines
3.1 KiB
C++

/* 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.
*
* $Header$
*
*/
// Scripting engine stack component
#include "reinherit.h"
#include "console_mod.h"
#include "text_mod.h"
#include "script.h"
#include "sstack.h"
namespace Saga {
int SSTACK_Create(SSTACK *stack, int stack_len, int flags) {
SSTACK new_stack;
SDataWord_T *new_stack_data;
*stack = NULL;
new_stack = (SSTACK_tag *)malloc(sizeof(struct SSTACK_tag));
if (new_stack == NULL) {
return STACK_MEM;
}
new_stack_data = (SDataWord_T *)calloc(stack_len, sizeof *new_stack_data);
if (new_stack_data == NULL) {
free(new_stack);
return STACK_MEM;
}
new_stack->data = new_stack_data;
new_stack->flags = flags;
new_stack->len = stack_len;
new_stack->top = -1;
*stack = new_stack;
return STACK_SUCCESS;
}
int SSTACK_Destroy(SSTACK stack) {
if (stack != NULL) {
free(stack->data);
}
free(stack);
return STACK_SUCCESS;
}
int SSTACK_Clear(SSTACK stack) {
stack->top = -1;
return STACK_SUCCESS;
}
int SSTACK_PushNull(SSTACK stack) {
if (stack->top >= (stack->len - 1)) {
if (stack->flags & STACK_FIXED) {
return STACK_OVERFLOW;
} else if (SSTACK_Grow(stack) != STACK_SUCCESS) {
return STACK_MEM;
}
}
stack->top++;
return STACK_SUCCESS;
}
int SSTACK_Push(SSTACK stack, SDataWord_T value) {
if (stack->top >= (stack->len - 1)) {
if (stack->flags & STACK_FIXED) {
return STACK_OVERFLOW;
} else if (SSTACK_Grow(stack) != STACK_SUCCESS) {
return STACK_MEM;
}
}
stack->top++;
stack->data[stack->top] = value;
return STACK_SUCCESS;
}
int SSTACK_Pop(SSTACK stack, SDataWord_T *value) {
if (stack->top <= -1) {
return STACK_UNDERFLOW;
}
if (value == NULL) {
stack->top--;
return STACK_SUCCESS;
}
*value = stack->data[stack->top];
stack->top--;
return STACK_SUCCESS;
}
int SSTACK_Top(SSTACK stack, SDataWord_T *value) {
*value = 0;
if (stack->top <= -1) {
return STACK_UNDERFLOW;
}
*value = stack->data[stack->top];
return STACK_SUCCESS;
}
int SSTACK_Grow(SSTACK stack) {
SDataWord_T *new_data;
if ((stack->len * 2) > R_STACK_SIZE_LIMIT) {
CON_Print(S_ERROR_PREFIX "Stack fault: growing beyond limit.");
return STACK_OVERFLOW;
}
new_data = (SDataWord_T *)realloc(stack->data, (stack->len * 2) * sizeof *new_data);
if (new_data == NULL) {
return STACK_MEM;
}
stack->data = new_data;
stack->len *= 2;
return STACK_SUCCESS;
}
} // End of namespace Saga