aboutsummaryrefslogtreecommitdiff
path: root/saga/sstack.cpp
blob: 8d899b8101eafb4e29d38164a34c8eee4fdcbb64 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
/* 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 "yslib.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