ZVISION: Add support for doubleFPS feature

3 files changed, 12 insertions, 0 deletions

diff --git a/engines/zvision/detection.cpp b/engines/zvision/detection.cpp
index 5ad2e7d977..1492ade639 100644
--- a/engines/zvision/detection.cpp
+++ b/engines/zvision/detection.cpp
@@ -106,6 +106,13 @@ static const ExtraGuiOption ZVisionExtraGuiOption = {
 	false
 };
 
+static const ExtraGuiOption ZVisionExtraGuiOption2 = {
+	_s("Double FPS"),
+	_s("Halve the update delay"),
+	"doublefps",
+	false
+};
+
 class ZVisionMetaEngine : public AdvancedMetaEngine {
 public:
 	ZVisionMetaEngine() : AdvancedMetaEngine(ZVision::gameDescriptions, sizeof(ZVision::ZVisionGameDescription), zVisionGames) {
@@ -162,6 +169,7 @@ bool ZVisionMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADG
 const ExtraGuiOptions ZVisionMetaEngine::getExtraGuiOptions(const Common::String &target) const {
 	ExtraGuiOptions options;
 	options.push_back(ZVisionExtraGuiOption);
+	options.push_back(ZVisionExtraGuiOption2);
 	return options;
 }
 
diff --git a/engines/zvision/zvision.cpp b/engines/zvision/zvision.cpp
index a78d68dc8c..0bc5fef39a 100644
--- a/engines/zvision/zvision.cpp
+++ b/engines/zvision/zvision.cpp
@@ -173,6 +173,7 @@ void ZVision::initialize() {
 
 	// Create debugger console. It requires GFX to be initialized
 	_console = new Console(this);
+	_halveDelay = ConfMan.getBool("doublefps");
 }
 
 Common::Error ZVision::run() {
@@ -210,6 +211,8 @@ Common::Error ZVision::run() {
 		int delay = _desiredFrameTime - int32(_system->getMillis() - currentTime);
 		// Ensure non-negative
 		delay = delay < 0 ? 0 : delay;
+		if (_halveDelay)
+			delay >>= 1;
 		_system->delayMillis(delay);
 	}
 
diff --git a/engines/zvision/zvision.h b/engines/zvision/zvision.h
index cbd10da0d5..8a305f5d37 100644
--- a/engines/zvision/zvision.h
+++ b/engines/zvision/zvision.h
@@ -121,6 +121,7 @@ private:
 
 	int _rendDelay;
 	int16 _velocity;
+	bool _halveDelay;
 public:
 	uint32 getFeatures() const;
 	Common::Language getLanguage() const;