added step-based engine snapshots to undo/redo game steps

[rocksndiamonds.git] / src / libgame / snapshot.c

diff --git a/src/libgame/snapshot.c b/src/libgame/snapshot.c
index 51171d43738d657c6c819f9291e7dcb19939daf6..f57cb5fa6dd757f8de167541aecaaf77006d54be 100644 (file)
--- a/src/libgame/snapshot.c
+++ b/src/libgame/snapshot.c
@@ -12,12 +12,26 @@
 #include "snapshot.h"
 
 
-static ListNode *engine_snapshot_list = NULL;
+static ListNode *snapshot_single = NULL;
+static ListNode *snapshot_list = NULL;
+static ListNode *snapshot_current = NULL;
 
-void SaveEngineSnapshotBuffer(void *buffer, int size)
+static int num_snapshots_in_list = 0;
+
+
+#ifdef DEBUG
+#define DEBUG_SNAPSHOTS                        0
+#endif
+
+
+// -----------------------------------------------------------------------------
+// functions for handling buffers for a single snapshot
+// -----------------------------------------------------------------------------
+
+void SaveSnapshotBuffer(ListNode **snapshot_buffers, void *buffer, int size)
 {
-  struct EngineSnapshotNodeInfo *bi =
-    checked_calloc(sizeof(struct EngineSnapshotNodeInfo));
+  struct SnapshotNodeInfo *bi =
+    checked_calloc(sizeof(struct SnapshotNodeInfo));
 
   bi->buffer_orig = buffer;
   bi->buffer_copy = checked_malloc(size);
@@ -25,29 +39,132 @@ void SaveEngineSnapshotBuffer(void *buffer, int size)
 
   memcpy(bi->buffer_copy, buffer, size);
 
-  addNodeToList(&engine_snapshot_list, NULL, bi);
+  addNodeToList(snapshot_buffers, NULL, bi);
 }
 
-static void LoadEngineSnapshotBuffer(struct EngineSnapshotNodeInfo *bi)
+static void LoadSnapshotBuffer(struct SnapshotNodeInfo *bi)
 {
   memcpy(bi->buffer_orig, bi->buffer_copy, bi->size);
 }
 
-void LoadEngineSnapshotBuffers()
+void LoadSnapshotBuffers(ListNode *snapshot_buffers)
+{
+  while (snapshot_buffers != NULL)
+  {
+    LoadSnapshotBuffer((struct SnapshotNodeInfo *)snapshot_buffers->content);
+
+    snapshot_buffers = snapshot_buffers->next;
+  }
+}
+
+void FreeSnapshotBuffers(ListNode *snapshot_buffers)
+{
+  while (snapshot_buffers != NULL)
+    deleteNodeFromList(&snapshot_buffers, snapshot_buffers->key, checked_free);
+}
+
+// -----------------------------------------------------------------------------
+// functions for handling one of several snapshots
+// -----------------------------------------------------------------------------
+
+static void FreeSnapshotExt(void *snapshot_buffers_ptr)
+{
+  FreeSnapshotBuffers(snapshot_buffers_ptr);
+}
+
+void FreeSnapshotSingle()
+{
+  FreeSnapshotBuffers(snapshot_single);
+
+  snapshot_single = NULL;
+}
+
+void FreeSnapshotList_UpToNode(ListNode *node)
+{
+  while (snapshot_list != node)
+  {
+    deleteNodeFromList(&snapshot_list, snapshot_list->key, FreeSnapshotExt);
+
+    num_snapshots_in_list--;
+  }
+}
+
+void FreeSnapshotList()
+{
+  FreeSnapshotList_UpToNode(NULL);
+
+  snapshot_current = NULL;
+}
+
+void SaveSnapshotSingle(ListNode *snapshot_buffers)
+{
+  if (snapshot_single)
+    FreeSnapshotSingle();
+
+  snapshot_single = snapshot_buffers;
+}
+
+void SaveSnapshotToList(ListNode *snapshot_buffers)
 {
-  ListNode *node = engine_snapshot_list;
+  if (snapshot_current != snapshot_list)
+    FreeSnapshotList_UpToNode(snapshot_current);
+
+  addNodeToList(&snapshot_list, i_to_a(num_snapshots_in_list),
+               snapshot_buffers);
 
-  while (node != NULL)
+  snapshot_current = snapshot_list;
+
+  num_snapshots_in_list++;
+
+#if DEBUG_SNAPSHOTS
+  printf("::: SaveSnapshotToList() [%s]\n", snapshot_current->key);
+#endif
+}
+
+boolean LoadSnapshotSingle()
+{
+  if (snapshot_single)
   {
-    LoadEngineSnapshotBuffer((struct EngineSnapshotNodeInfo *)node->content);
+    LoadSnapshotBuffers(snapshot_single);
 
-    node = node->next;
+    return TRUE;
   }
+
+  return FALSE;
 }
 
-void FreeEngineSnapshotBuffers()
+boolean LoadSnapshotFromList_Older()
 {
-  while (engine_snapshot_list != NULL)
-    deleteNodeFromList(&engine_snapshot_list, engine_snapshot_list->key,
-                      checked_free);
+  if (snapshot_current->next)
+  {
+    snapshot_current = snapshot_current->next;
+
+    LoadSnapshotBuffers(snapshot_current->content);
+
+#if DEBUG_SNAPSHOTS
+    printf("::: LoadSnapshotFromList_Older() [%s]\n", snapshot_current->key);
+#endif
+
+    return TRUE;
+  }
+
+  return FALSE;
+}
+
+boolean LoadSnapshotFromList_Newer()
+{
+  if (snapshot_current->prev)
+  {
+    snapshot_current = snapshot_current->prev;
+
+    LoadSnapshotBuffers(snapshot_current->content);
+
+#if DEBUG_SNAPSHOTS
+    printf("::: LoadSnapshotFromList_Newer() [%s]\n", snapshot_current->key);
+#endif
+
+    return TRUE;
+  }
+
+  return FALSE;
 }