1 files changed, 199 insertions, 0 deletions
diff --git a/saga/sstack.cpp b/saga/sstack.cpp
new file mode 100644
index 0000000000..99741ac632
--- /dev/null
+++ b/saga/sstack.cpp
@@ -0,0 +1,199 @@
+/* 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.
+ *
+ * $Header$
+ *
+ */
+/*
+
+ Description:   
+ 
+    Scripting engine stack component
+
+ Notes: 
+*/
+
+#include "reinherit.h"
+
+#include "yslib.h"
+
+/*
+ * Uses the following modules:
+\*--------------------------------------------------------------------------*/
+#include "console_mod.h"
+#include "text_mod.h"
+
+/*
+ * Begin module component
+\*--------------------------------------------------------------------------*/
+#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
+