MYST3: Add the rotation effect used by ENPP 11

engines/myst3/effects.cpp

@@ -570,4 +570,40 @@ bool ShakeEffect::update() {
 void ShakeEffect::applyForFace(uint face, Graphics::Surface* src, Graphics::Surface* dst) {
 }
 
+RotationEffect::RotationEffect(Myst3Engine *vm) :
+		Effect(vm),
+		_lastUpdate(0),
+		_headingOffset(0) {
+}
+
+RotationEffect::~RotationEffect() {
+}
+
+RotationEffect *RotationEffect::create(Myst3Engine *vm) {
+	if (vm->_state->getRotationEffectSpeed() == 0) {
+		return nullptr;
+	}
+
+	return new RotationEffect(vm);
+}
+
+bool RotationEffect::update() {
+	// Check if the effect is active
+	int32 speed = _vm->_state->getRotationEffectSpeed();
+	if (speed == 0) {
+		return false;
+	}
+
+	if (_lastUpdate != 0) {
+		_headingOffset = speed * (g_system->getMillis() - _lastUpdate) / 1000.0;
+	}
+
+	_lastUpdate = g_system->getMillis();
+
+	return true;
+}
+
+void RotationEffect::applyForFace(uint face, Graphics::Surface* src, Graphics::Surface* dst) {
+}
+
 } // End of namespace Myst3

engines/myst3/effects.h

@@ -147,6 +147,24 @@ protected:
 
 };
 
+class RotationEffect : public Effect {
+public:
+	static RotationEffect *create(Myst3Engine *vm);
+	virtual ~RotationEffect();
+
+	bool update();
+	void applyForFace(uint face, Graphics::Surface *src, Graphics::Surface *dst);
+
+	float getHeadingOffset() { return _headingOffset; }
+
+protected:
+	RotationEffect(Myst3Engine *vm);
+
+	uint32 _lastUpdate;
+	float _headingOffset;
+
+};
+
 } // End of namespace Myst3
 
 #endif // EFFECTS_H_

engines/myst3/myst3.cpp

@@ -77,7 +77,7 @@ Myst3Engine::Myst3Engine(OSystem *syst, const Myst3GameDescription *version) :
 		_inputSpacePressed(false), _inputEnterPressed(false),
 		_inputEscapePressed(false), _inputTildePressed(false),
 		_menuAction(0), _projectorBackground(0),
-		_shakeEffect(0) {
+		_shakeEffect(0), _rotationEffect(0) {
 	DebugMan.addDebugChannel(kDebugVariable, "Variable", "Track Variable Accesses");
 	DebugMan.addDebugChannel(kDebugSaveLoad, "SaveLoad", "Track Save/Load Function");
 	DebugMan.addDebugChannel(kDebugScript, "Script", "Track Script Execution");
@@ -526,6 +526,14 @@ void Myst3Engine::drawFrame(bool noSwap) {
 		float heading = _state->getLookAtHeading();
 		float fov = _state->getLookAtFOV();
 
+		// Apply the rotation effect
+		if (_rotationEffect) {
+			_rotationEffect->update();
+
+			heading += _rotationEffect->getHeadingOffset();
+			_state->lookAt(pitch, heading);
+		}
+
 		// Apply the shake effect
 		if (_shakeEffect) {
 			_shakeEffect->update();
@@ -677,8 +685,9 @@ void Myst3Engine::loadNode(uint16 nodeID, uint32 roomID, uint32 ageID) {
 
 	runNodeInitScripts();
 
-	// The shake effect can only be created after running the scripts
+	// These effects can only be created after running the node init scripts
 	_shakeEffect = ShakeEffect::create(this);
+	_rotationEffect = RotationEffect::create(this);
 
 	// WORKAROUND: In Narayan, the scripts in node NACH 9 test on var 39
 	// without first reinitializing it leading to Saavedro not always giving
@@ -700,12 +709,15 @@ void Myst3Engine::unloadNode() {
 
 	_sunspots.clear();
 
-	// Clean up the shake effect
+	// Clean up the effects
 	delete _shakeEffect;
+	_shakeEffect = nullptr;
 	_state->setShakeEffectAmpl(0);
+	delete _rotationEffect;
+	_rotationEffect = nullptr;
 
 	delete _node;
-	_node = 0;
+	_node = nullptr;
 }
 
 void Myst3Engine::runNodeInitScripts() {

engines/myst3/myst3.h

@@ -87,6 +87,7 @@ class Menu;
 class Sound;
 class Ambient;
 class ShakeEffect;
+class RotationEffect;
 struct NodeData;
 struct Myst3GameDescription;
 
@@ -197,8 +198,10 @@ private:
 
 	uint16 _menuAction;
 
-	// Used Amateria's magnetic rings
+	// Used by Amateria's magnetic rings
 	ShakeEffect *_shakeEffect;
+	// Used by Voltaic's spinning gears
+	RotationEffect *_rotationEffect;
 
 	bool _inputSpacePressed;
 	bool _inputEnterPressed;

engines/myst3/state.cpp

@@ -142,7 +142,7 @@ GameState::GameState(Myst3Engine *vm):
 
 	VAR(112, ShakeEffectAmpl, false)
 	VAR(113, ShakeEffectFramePeriod, false)
-
+	VAR(114, RotationEffectSpeed, false)
 	VAR(115, SunspotIntensity, false)
 	VAR(116, SunspotColor, false)
 	VAR(117, SunspotRadius, false)

engines/myst3/state.h

@@ -122,7 +122,7 @@ public:
 
 	DECLARE_VAR(112, ShakeEffectAmpl)
 	DECLARE_VAR(113, ShakeEffectFramePeriod)
-
+	DECLARE_VAR(114, RotationEffectSpeed)
 	DECLARE_VAR(115, SunspotIntensity)
 	DECLARE_VAR(116, SunspotColor)
 	DECLARE_VAR(117, SunspotRadius)