SCI32: Stop throttling of kFrameOut during interactive VMD playback

Refs Trac#9974, Trac#9975.

3 files changed, 18 insertions, 1 deletions

diff --git a/engines/sci/graphics/frameout.cpp b/engines/sci/graphics/frameout.cpp
index b49332dcb3..4e28f80817 100644
--- a/engines/sci/graphics/frameout.cpp
+++ b/engines/sci/graphics/frameout.cpp
@@ -69,6 +69,7 @@ GfxFrameout::GfxFrameout(SegManager *segMan, GfxPalette32 *palette, GfxTransitio
 	_throttleState(0),
 	_remapOccurred(false),
 	_overdrawThreshold(0),
+	_throttleKernelFrameOut(true),
 	_palMorphIsOn(false),
 	_lastScreenUpdateTick(0) {
 
@@ -1136,7 +1137,9 @@ void GfxFrameout::kernelFrameOut(const bool shouldShowBits) {
 		frameOut(shouldShowBits);
 	}
 
-	throttle();
+	if (_throttleKernelFrameOut) {
+		throttle();
+	}
 }
 
 void GfxFrameout::throttle() {
diff --git a/engines/sci/graphics/frameout.h b/engines/sci/graphics/frameout.h
index 93dc35e632..d94689be5b 100644
--- a/engines/sci/graphics/frameout.h
+++ b/engines/sci/graphics/frameout.h
@@ -310,6 +310,11 @@ public:
 	}
 
 	/**
+	 * Whether or not to throttle kFrameOut calls.
+	 */
+	bool _throttleKernelFrameOut;
+
+	/**
 	 * Whether palMorphFrameOut should be used instead of
 	 * frameOut for rendering. Used by kMorphOn to
 	 * explicitly enable palMorphFrameOut for one frame.
diff --git a/engines/sci/graphics/video32.cpp b/engines/sci/graphics/video32.cpp
index d92f9a1893..da34a734e8 100644
--- a/engines/sci/graphics/video32.cpp
+++ b/engines/sci/graphics/video32.cpp
@@ -890,6 +890,13 @@ void VMDPlayer::initComposited() {
 	// here, but none of the game scripts seem to use this functionality.
 
 	g_sci->_gfxFrameout->addScreenItem(*_screenItem);
+
+	// Composited VMDs periodically yield to game scripts which will often call
+	// kFrameOut to make changes to other parts of the screen. Since VMDPlayer
+	// is responsible for throttling output during these times, GfxFrameout
+	// needs to stop throttling kFrameOut calls or else we will drop frames when
+	// kFrameOut sleeps right through the next frame
+	g_sci->_gfxFrameout->_throttleKernelFrameOut = false;
 }
 
 void VMDPlayer::renderComposited() const {
@@ -915,6 +922,8 @@ void VMDPlayer::closeComposited() {
 		// This call *actually* deletes the plane/screen item
 		g_sci->_gfxFrameout->frameOut(true);
 	}
+
+	g_sci->_gfxFrameout->_throttleKernelFrameOut = true;
 }
 
 #pragma mark -