win32: savestate rewinding

desmume/src/saves.cpp

@@ -964,3 +964,60 @@ bool savestate_load(const char *file_name)
 
 	return savestate_load(&f);
 }
+
+static std::vector<std::vector <char>> rewindbuffer;
+
+int rewindstates = 16;
+int rewindinterval = 4;
+
+void rewindsave () {
+
+	if(currFrameCounter % rewindinterval)
+		return;
+
+	printf("rewindsave"); printf("%d%s", currFrameCounter, "\n");
+
+	memorystream ms;
+
+	if(!savestate_save(&ms, 0))
+		return;
+
+	ms.flush();
+
+	std::vector<char> v(ms.buf(), ms.buf() + ms.size());
+
+	//clip the header
+	v.erase(v.begin(),v.begin()+32);
+
+	rewindbuffer.push_back(v);
+	
+	if(rewindbuffer.size() > rewindstates) rewindbuffer.erase(rewindbuffer.begin());
+}
+
+void dorewind()
+{
+
+	if(currFrameCounter % rewindinterval)
+		return;
+
+	printf("rewind\n");
+
+	nds.debugConsole = FALSE;
+
+	int size = rewindbuffer.size();
+
+	if(size < 1) {
+		printf("rewind buffer empty\n");
+		return;
+	}
+
+	printf("%d", size);
+
+	memorystream mstemp(&rewindbuffer.at(size-1));
+
+	ReadStateChunks(&mstemp,(s32)mstemp.size());
+	loadstate();
+
+	rewindbuffer.pop_back();
+
+}

desmume/src/windows/hotkey.cpp

@@ -222,6 +222,12 @@ void HK_PlayMovie(int)
 	}
 }
 
+bool rewinding = false;
+
+void HK_RewindKeyDown(int) {rewinding = true;}
+
+void HK_RewindKeyUp(int){rewinding = false;}
+
 void HK_RecordMovie(int) 
 {
 	if (romloaded)
@@ -568,6 +574,13 @@ void InitCustomKeys (SCustomKeys *keys)
 	keys->TurboStart.page = HOTKEY_PAGE_TURBO;
 	keys->TurboStart.key = NULL;
 
+	keys->Rewind.handleKeyDown = HK_RewindKeyDown;
+	keys->Rewind.handleKeyUp = HK_RewindKeyUp;
+	keys->Rewind.code = "Rewind";
+	keys->Rewind.name = L"Rewind";
+	keys->Rewind.page = HOTKEY_PAGE_MOVIE;
+	keys->Rewind.key = NULL;
+
 	keys->NextSaveSlot.handleKeyDown = HK_NextSaveSlot;
 	keys->NextSaveSlot.code = "NextSaveSlot";
 	keys->NextSaveSlot.name = L"Next Save Slot";

desmume/src/windows/hotkey.h

@@ -80,6 +80,8 @@ struct SCustomKeys
 
 	SCustomKey RecordWAV, RecordAVI;
 
+	SCustomKey Rewind;
+
 	SCustomKey ToggleFrameCounter;
 	SCustomKey ToggleFPS;
 	SCustomKey ToggleInput;

desmume/src/windows/main.cpp

@@ -262,6 +262,7 @@ int autoframeskipenab=0;
 int frameskiprate=0;
 int emu_paused = 0;
 bool frameAdvance = false;
+bool staterewindingenabled = false;
 
 bool HudEditorMode = false;
 bool UseMicSample = false;
@@ -969,6 +970,18 @@ DWORD WINAPI run()
 			}
 			DRV_AviVideoUpdate((u16*)GPU_screen);
 
+			extern void rewindsave();
+			extern bool rewinding;
+			extern void dorewind();
+
+			if (staterewindingenabled) {
+
+				if(rewinding)
+					dorewind();
+				else
+					rewindsave();
+			}
+
 			CallRegisteredLuaFunctions(LUACALL_AFTEREMULATION);
 
 			static int fps3d = 0;
@@ -2570,6 +2583,8 @@ LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM
 			MainWindow->checkMenu(IDM_RENDER_SCANLINE, MF_BYCOMMAND | video.currentfilter == video.SCANLINE ? MF_CHECKED:MF_UNCHECKED);
 			MainWindow->checkMenu(IDM_RENDER_BILINEAR, MF_BYCOMMAND | video.currentfilter == video.BILINEAR ? MF_CHECKED:MF_UNCHECKED);
 
+			MainWindow->checkMenu(IDC_STATEREWINDING, MF_BYCOMMAND | staterewindingenabled == 1 ? MF_CHECKED:MF_UNCHECKED);
+
 			//Language selection
 
 			MainWindow->checkMenu(IDC_BACKGROUNDPAUSE, MF_BYCOMMAND | ((lostFocusPause)?MF_CHECKED:MF_UNCHECKED));
@@ -2896,6 +2911,9 @@ LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM
 			else
 				WavRecordTo();
 			break;
+		case IDC_STATEREWINDING:
+			if(staterewindingenabled) staterewindingenabled = false;
+			else staterewindingenabled = true;
 		case IDM_RENDER_NORMAL:
 			video.setfilter(video.NONE);
 			FilterUpdate(hwnd);

desmume/src/windows/resource.h

@@ -137,6 +137,7 @@
 #define IDC_LUAPATHEDIT                 364
 #define IDC_BROWSELUA                   365
 #define IDD_PATHSETTINGS                366
+#define IDC_STATEREWINDING              367
 #define IDC_DES_BOX                     402
 #define IDC_R0                          403
 #define IDC_R1                          404