Qt: Make rewind speed adjustable (#2902)

include/mgba/core/config.h

@@ -33,6 +33,7 @@ struct mCoreOptions {
 	int frameskip;
 	bool rewindEnable;
 	int rewindBufferCapacity;
+	int rewindBufferInterval;
 	float fpsTarget;
 	size_t audioBuffers;
 	unsigned sampleRate;

include/mgba/core/rewind.h

@@ -24,6 +24,7 @@ struct mCoreRewindContext {
 	size_t size;
 	struct VFile* previousState;
 	struct VFile* currentState;
+	int rewindFrameCounter;
 
 #ifndef DISABLE_THREADING
 	bool onThread;

src/core/config.c

@@ -406,6 +406,7 @@ void mCoreConfigMap(const struct mCoreConfig* config, struct mCoreOptions* opts)
 	_lookupIntValue(config, "frameskip", &opts->frameskip);
 	_lookupIntValue(config, "volume", &opts->volume);
 	_lookupIntValue(config, "rewindBufferCapacity", &opts->rewindBufferCapacity);
+	_lookupIntValue(config, "rewindBufferInterval", &opts->rewindBufferInterval);
 	_lookupFloatValue(config, "fpsTarget", &opts->fpsTarget);
 	unsigned audioBuffers;
 	if (_lookupUIntValue(config, "audioBuffers", &audioBuffers)) {
@@ -448,6 +449,7 @@ void mCoreConfigLoadDefaults(struct mCoreConfig* config, const struct mCoreOptio
 	ConfigurationSetIntValue(&config->defaultsTable, 0, "frameskip", opts->frameskip);
 	ConfigurationSetIntValue(&config->defaultsTable, 0, "rewindEnable", opts->rewindEnable);
 	ConfigurationSetIntValue(&config->defaultsTable, 0, "rewindBufferCapacity", opts->rewindBufferCapacity);
+	ConfigurationSetIntValue(&config->defaultsTable, 0, "rewindBufferInterval", opts->rewindBufferInterval);
 	ConfigurationSetFloatValue(&config->defaultsTable, 0, "fpsTarget", opts->fpsTarget);
 	ConfigurationSetUIntValue(&config->defaultsTable, 0, "audioBuffers", opts->audioBuffers);
 	ConfigurationSetUIntValue(&config->defaultsTable, 0, "sampleRate", opts->sampleRate);

src/core/rewind.c

@@ -30,6 +30,7 @@ void mCoreRewindContextInit(struct mCoreRewindContext* context, size_t entries,
 	context->previousState = VFileMemChunk(0, 0);
 	context->currentState = VFileMemChunk(0, 0);
 	context->size = 0;
+	context->rewindFrameCounter = 0;
 #ifndef DISABLE_THREADING
 	context->onThread = onThread;
 	context->ready = false;

src/core/thread.c

@@ -157,7 +157,11 @@ void _frameStarted(void* context) {
 	}
 	if (thread->core->opts.rewindEnable && thread->core->opts.rewindBufferCapacity > 0) {
 		if (!thread->impl->rewinding || !mCoreRewindRestore(&thread->impl->rewind, thread->core)) {
-			mCoreRewindAppend(&thread->impl->rewind, thread->core);
+			if (thread->impl->rewind.rewindFrameCounter == 0) {
+				mCoreRewindAppend(&thread->impl->rewind, thread->core);
+				thread->impl->rewind.rewindFrameCounter = thread->core->opts.rewindBufferInterval;
+			}
+			thread->impl->rewind.rewindFrameCounter--;
 		}
 	}
 }

src/platform/qt/ConfigController.cpp

@@ -125,6 +125,7 @@ ConfigController::ConfigController(QObject* parent)
 	m_opts.logLevel = mLOG_WARN | mLOG_ERROR | mLOG_FATAL;
 	m_opts.rewindEnable = false;
 	m_opts.rewindBufferCapacity = 300;
+	m_opts.rewindBufferInterval = 1;
 	m_opts.useBios = true;
 	m_opts.suspendScreensaver = true;
 	m_opts.lockAspectRatio = true;

src/platform/qt/SettingsView.cpp

@@ -480,6 +480,7 @@ void SettingsView::updateConfig() {
 	saveSetting("fastForwardMute", m_ui.muteFf);
 	saveSetting("rewindEnable", m_ui.rewind);
 	saveSetting("rewindBufferCapacity", m_ui.rewindCapacity);
+	saveSetting("rewindBufferInterval", m_ui.rewindBufferInterval);
 	saveSetting("resampleVideo", m_ui.resampleVideo);
 	saveSetting("allowOpposingDirections", m_ui.allowOpposingDirections);
 	saveSetting("suspendScreensaver", m_ui.suspendScreensaver);
@@ -708,6 +709,7 @@ void SettingsView::reloadConfig() {
 	loadSetting("fastForwardMute", m_ui.muteFf, m_ui.mute->isChecked());
 	loadSetting("rewindEnable", m_ui.rewind);
 	loadSetting("rewindBufferCapacity", m_ui.rewindCapacity);
+	loadSetting("rewindBufferInterval", m_ui.rewindBufferInterval);
 	loadSetting("resampleVideo", m_ui.resampleVideo);
 	loadSetting("allowOpposingDirections", m_ui.allowOpposingDirections);
 	loadSetting("suspendScreensaver", m_ui.suspendScreensaver);

src/platform/qt/SettingsView.ui

@@ -1195,21 +1195,51 @@
          </item>
         </layout>
        </item>
-       <item row="6" column="0" colspan="2">
+       <item row="6" column="0">
+        <widget class="QLabel" name="label_54">
+         <property name="text">
+          <string>Rewind speed:</string>
+         </property>
+        </widget>
+       </item>
+       <item row="6" column="1">
+        <layout class="QHBoxLayout" name="horizontalLayout_23">
+         <item>
+          <widget class="QSpinBox" name="rewindBufferInterval">
+           <property name="suffix">
+            <string notr="true">×</string>
+           </property>
+           <property name="minimum">
+            <number>1</number>
+           </property>
+           <property name="maximum">
+            <number>10</number>
+           </property>
+           <property name="singleStep">
+            <number>1</number>
+           </property>
+           <property name="value">
+            <number>1</number>
+           </property>
+          </widget>
+         </item>
+        </layout>
+       </item>
+       <item row="7" column="0" colspan="2">
         <widget class="Line" name="line_3">
          <property name="orientation">
           <enum>Qt::Horizontal</enum>
          </property>
         </widget>
        </item>
-       <item row="7" column="0">
+       <item row="8" column="0">
         <widget class="QLabel" name="label_15">
          <property name="text">
           <string>Idle loops:</string>
          </property>
         </widget>
        </item>
-       <item row="7" column="1">
+       <item row="8" column="1">
         <widget class="QComboBox" name="idleOptimization">
          <item>
           <property name="text">
@@ -1228,21 +1258,21 @@
          </item>
         </widget>
        </item>
-       <item row="8" column="1">
+       <item row="9" column="1">
         <widget class="QCheckBox" name="preload">
          <property name="text">
           <string>Preload entire ROM into memory</string>
          </property>
         </widget>
        </item>
-       <item row="9" column="1">
+       <item row="10" column="1">
         <widget class="QCheckBox" name="forceGbp">
          <property name="text">
           <string>Enable Game Boy Player features by default</string>
          </property>
         </widget>
        </item>
-       <item row="10" column="1">
+       <item row="11" column="1">
         <widget class="QCheckBox" name="vbaBugCompat">
          <property name="text">
           <string>Enable VBA bug compatibility in ROM hacks</string>

src/platform/qt/Window.cpp

@@ -1827,6 +1827,11 @@ void Window::setupOptions() {
 		reloadConfig();
 	}, this);
 
+	ConfigOption* rewindBufferInterval = m_config->addOption("rewindBufferInterval");
+	rewindBufferInterval->connect([this](const QVariant&) {
+		reloadConfig();
+	}, this);
+
 	ConfigOption* allowOpposingDirections = m_config->addOption("allowOpposingDirections");
 	allowOpposingDirections->connect([this](const QVariant&) {
 		reloadConfig();

src/platform/sdl/main.c

@@ -61,6 +61,7 @@ int main(int argc, char** argv) {
 		.useBios = true,
 		.rewindEnable = true,
 		.rewindBufferCapacity = 600,
+		.rewindBufferInterval = 1,
 		.audioBuffers = 1024,
 		.videoSync = false,
 		.audioSync = true,