MYST3: Implement script driven camera movement

engines/myst3/myst3.cpp

@@ -809,4 +809,61 @@ Common::Error Myst3Engine::loadGameState(int slot) {
 	return Common::kUnknownError;
 }
 
+void Myst3Engine::animateDirectionChange(float targetPitch, float targetHeading, uint16 scriptFrames) {
+	float startPitch = _state->getLookAtPitch();
+	float startHeading = _state->getLookAtHeading();
+
+	if (startPitch == targetPitch && startHeading == targetHeading)
+		return; // Fast path
+
+	float pitchDistance = targetPitch - startPitch;
+	float headingDistance = targetHeading - startHeading;
+
+	// Compute animation duration in frames
+	float numFrames;
+	if (scriptFrames) {
+		numFrames = scriptFrames;
+	} else {
+		numFrames = sqrt(pitchDistance * pitchDistance + headingDistance * headingDistance)
+				* 30.0f / _state->getCameraMoveSpeed();
+
+		if (numFrames > 0.0f)
+			numFrames += 10.0f;
+	}
+
+	uint startFrame = _state->getFrameCount();
+
+	// Draw animation
+	if (numFrames != 0.0f) {
+		while (1) {
+			uint elapsedFrames = _state->getFrameCount() - startFrame;
+			if (elapsedFrames >= numFrames)
+				break;
+
+			float step;
+			if (numFrames >= 15) {
+				// Fast then slow movement
+				if (elapsedFrames > numFrames / 2.0f)
+					step = 1.0f - (numFrames - elapsedFrames) * (numFrames - elapsedFrames)
+								/ (numFrames / 2.0f * numFrames / 2.0f) / 2.0f;
+				else
+					step = elapsedFrames * elapsedFrames / (numFrames / 2.0f * numFrames / 2.0f) / 2.0f;
+
+			} else {
+				// Constant speed movement
+				step = elapsedFrames / numFrames;
+			}
+
+			float nextPitch = startPitch + pitchDistance * step;
+			float nextHeading = startHeading + headingDistance * step;
+
+			_state->lookAt(nextPitch, nextHeading);
+			drawFrame();
+		}
+	}
+
+	_state->lookAt(targetPitch, targetHeading);
+	drawFrame();
+}
+
 } // end of namespace Myst3

engines/myst3/myst3.h

@@ -117,6 +117,8 @@ public:
 	void setMenuAction(uint16 action) { _menuAction = action; }
 	void setShouldQuit() { _shouldQuit = true; }
 
+	void animateDirectionChange(float pitch, float heading, uint16 speed);
+
 	void processInput(bool lookOnly);
 	void drawFrame();
 private:

engines/myst3/script.cpp

@@ -174,6 +174,8 @@ Script::Script(Myst3Engine *vm):
 	OP_2(141, zipToRoomNode,				kValue,		kValue											);
 	OP_1(147, moviePlay, 					kEvalValue													);
 	OP_1(148, moviePlaySynchronized,		kEvalValue													);
+	OP_2(153, lootAt,						kValue, 	kValue											);
+	OP_3(154, lootAtInXFrames,				kValue, 	kValue, 	kValue								);
 	OP_4(157, cameraLimitMovement,			kValue,		kValue,		kValue,		kValue					);
 	OP_0(158, cameraFreeMovement																		);
 	OP_2(159, cameraLookAt,					kValue,		kValue											);
@@ -1889,6 +1891,18 @@ void Script::runScriptWhileCondEachXFrames(Context &c, const Opcode &cmd) {
 	_vm->drawFrame();
 }
 
+void Script::lootAt(Context &c, const Opcode &cmd) {
+	debugC(kDebugScript, "Opcode %d: Look at %d, %d", cmd.op, cmd.args[0], cmd.args[1]);
+
+	_vm->animateDirectionChange(cmd.args[0], cmd.args[1], 0);
+}
+
+void Script::lootAtInXFrames(Context &c, const Opcode &cmd) {
+	debugC(kDebugScript, "Opcode %d: Look at %d, %d in %d frames", cmd.op, cmd.args[0], cmd.args[1], cmd.args[2]);
+
+	_vm->animateDirectionChange(cmd.args[0], cmd.args[1], cmd.args[2]);
+}
+
 void Script::runScriptForVarDrawFramesHelper(uint16 var, int32 startValue, int32 endValue, uint16 script, int32 numFrames) {
 	if (numFrames < 0) {
 		numFrames = -numFrames;

engines/myst3/script.h

@@ -224,6 +224,8 @@ private:
 	DECLARE_OPCODE(zipToRoomNode);
 	DECLARE_OPCODE(moviePlay);
 	DECLARE_OPCODE(moviePlaySynchronized);
+	DECLARE_OPCODE(lootAt);
+	DECLARE_OPCODE(lootAtInXFrames);
 	DECLARE_OPCODE(cameraLimitMovement);
 	DECLARE_OPCODE(cameraFreeMovement);
 	DECLARE_OPCODE(cameraLookAt);

engines/myst3/state.cpp

@@ -97,6 +97,8 @@ GameState::GameState(Myst3Engine *vm):
 
 	VAR(178, MovieUseBackground, false)
 
+	VAR(185, CameraMoveSpeed, false)
+
 	VAR(189, LocationNextNode, false)
 	VAR(190, LocationNextRoom, false)
 	VAR(191, LocationNextAge, false)

engines/myst3/state.h

@@ -111,6 +111,8 @@ public:
 
 	DECLARE_VAR(178, MovieUseBackground)
 
+	DECLARE_VAR(185, CameraMoveSpeed)
+
 	DECLARE_VAR(189, LocationNextNode)
 	DECLARE_VAR(190, LocationNextRoom)
 	DECLARE_VAR(191, LocationNextAge)