WIP for SAGA engine.

 o text formatting is not consistent with rules, just indent utility is too
   dumb for that
 o it does not use OSystem, i.e. it runs on direct SDL calls
 o it may not even compile on your box
 o if you enable it, expect zillions of warnings
 o no sound

Now it runs ITE intro as reinherit did

svn-id: r13564

1 files changed, 180 insertions, 0 deletions

diff --git a/saga/stack.cpp b/saga/stack.cpp
new file mode 100644
index 0000000000..ef5552d4a1
--- /dev/null
+++ b/saga/stack.cpp
@@ -0,0 +1,180 @@
+/* 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:	
+ 
+	Simple integer stack module
+
+ Notes: 
+*/
+
+#include "reinherit.h"
+
+#include "stack.h"
+#include "stack_mod.h"
+
+namespace Saga {
+
+int ISTACK_Create(R_ISTACK * stack, int stack_len, int flags)
+{
+
+	R_ISTACK new_stack;
+	int *new_stack_data;
+
+	*stack = NULL;
+
+	new_stack = (R_ISTACK_tag *)malloc(sizeof(struct R_ISTACK_tag));
+
+	if (new_stack == NULL) {
+		return STACK_MEM;
+	}
+
+	new_stack_data = (int *)calloc(stack_len, sizeof(int));
+
+	if (new_stack_data == NULL) {
+
+		free(new_stack);
+		return STACK_MEM;
+	}
+
+	new_stack->flags = flags;
+	new_stack->len = stack_len;
+	new_stack->top = -1;
+
+	return STACK_SUCCESS;
+}
+
+int ISTACK_Destroy(R_ISTACK * stack)
+{
+
+	if (stack != NULL) {
+		free((*stack)->data);
+	}
+
+	free(stack);
+
+	*stack = NULL;
+
+	return STACK_SUCCESS;
+}
+
+int ISTACK_Clear(R_ISTACK stack)
+{
+
+	stack->top = -1;
+	return STACK_SUCCESS;
+}
+
+int ISTACK_PushNull(R_ISTACK stack)
+{
+
+	if (stack->top >= (stack->len - 1)) {
+
+		if (stack->flags & STACK_FIXED) {
+
+			return STACK_OVERFLOW;
+		} else if (ISTACK_Grow(stack) != STACK_SUCCESS) {
+
+			return STACK_MEM;
+		}
+	}
+
+	stack->top++;
+
+}
+
+int ISTACK_Push(R_ISTACK stack, int value)
+{
+
+	if (stack->top >= (stack->len - 1)) {
+
+		if (stack->flags & STACK_FIXED) {
+
+			return STACK_OVERFLOW;
+		} else if (ISTACK_Grow(stack) != STACK_SUCCESS) {
+
+			return STACK_MEM;
+		}
+	}
+
+	stack->top++;
+	stack->data[stack->top] = value;
+
+	return STACK_SUCCESS;
+}
+
+int ISTACK_Pop(R_ISTACK stack, int *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 ISTACK_Top(R_ISTACK stack, int *value)
+{
+	*value = 0;
+
+	if (stack->top <= -1) {
+
+		return STACK_UNDERFLOW;
+	}
+
+	*value = stack->data[stack->top];
+
+	return STACK_SUCCESS;
+
+}
+
+int ISTACK_Grow(R_ISTACK stack)
+{
+
+	int *new_data;
+
+	new_data = (int *)realloc(stack->data, (stack->len * 2) * sizeof(int));
+
+	if (new_data == NULL) {
+
+		return STACK_MEM;
+	};
+
+	stack->data = new_data;
+	stack->len *= 2;
+
+	return STACK_SUCCESS;
+}
+
+} // End of namespace Saga
+