GLK: ALAN3: Initial files commit

1 files changed, 128 insertions, 0 deletions

diff --git a/engines/glk/alan3/state_stack.cpp b/engines/glk/alan3/state_stack.cpp
new file mode 100644
index 0000000000..38e8bb66ec
--- /dev/null
+++ b/engines/glk/alan3/state_stack.cpp
@@ -0,0 +1,128 @@
+/* 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