SCI32: Fix terrible rendering performance when vsync is enabled

More than one call to OSystem::updateScreen per frame on systems
with vsync ruins performance because the call is blocked until
the next vsync interval.

This also fixes bad rendering performance with the OpenGL backend.

5 files changed, 16 insertions, 12 deletions

diff --git a/engines/sci/graphics/cursor32.cpp b/engines/sci/graphics/cursor32.cpp
index 2f74873229..624714619e 100644
--- a/engines/sci/graphics/cursor32.cpp
+++ b/engines/sci/graphics/cursor32.cpp
@@ -122,7 +122,6 @@ void GfxCursor32::drawToHardware(const DrawRegion &source) {
 	byte *sourcePixel = source.data + (sourceYOffset * source.rect.width()) + sourceXOffset;
 
 	g_system->copyRectToScreen(sourcePixel, source.rect.width(), drawRect.left, drawRect.top, drawRect.width(), drawRect.height());
-	g_system->updateScreen();
 }
 
 void GfxCursor32::unhide() {
@@ -381,6 +380,10 @@ void GfxCursor32::deviceMoved(Common::Point &position) {
 		position.y = _restrictedArea.bottom - 1;
 	}
 
+	if (_position == position) {
+		return;
+	}
+
 	_position = position;
 
 	g_system->warpMouse(position.x, position.y);
diff --git a/engines/sci/graphics/frameout.cpp b/engines/sci/graphics/frameout.cpp
index e0506e67ac..b4c842dd4a 100644
--- a/engines/sci/graphics/frameout.cpp
+++ b/engines/sci/graphics/frameout.cpp
@@ -439,7 +439,7 @@ void GfxFrameout::frameOut(const bool shouldShowBits, const Common::Rect &eraseR
 		robotPlayer.frameAlmostVisible();
 	}
 
-	_palette->updateHardware(!shouldShowBits);
+	_palette->updateHardware();
 
 	if (shouldShowBits) {
 		showBits();
@@ -547,7 +547,7 @@ void GfxFrameout::palMorphFrameOut(const int8 *styleRanges, PlaneShowStyle *show
 
 	_palette->submit(nextPalette);
 	_palette->updateFFrame();
-	_palette->updateHardware(false);
+	_palette->updateHardware();
 	showBits();
 }
 
diff --git a/engines/sci/graphics/palette32.cpp b/engines/sci/graphics/palette32.cpp
index d13ae2c097..de85b71a2c 100644
--- a/engines/sci/graphics/palette32.cpp
+++ b/engines/sci/graphics/palette32.cpp
@@ -455,7 +455,7 @@ void GfxPalette32::updateFFrame() {
 	g_sci->_gfxRemap32->remapAllTables(_nextPalette != _currentPalette);
 }
 
-void GfxPalette32::updateHardware(const bool updateScreen) {
+void GfxPalette32::updateHardware() {
 	if (_currentPalette == _nextPalette && !_gammaChanged) {
 		return;
 	}
@@ -494,10 +494,6 @@ void GfxPalette32::updateHardware(const bool updateScreen) {
 	}
 
 	g_system->getPaletteManager()->setPalette(bpal, 0, 256);
-	if (updateScreen) {
-		g_system->updateScreen();
-	}
-
 	_gammaChanged = false;
 }
 
diff --git a/engines/sci/graphics/palette32.h b/engines/sci/graphics/palette32.h
index 267ec39d96..0fcd7e00ab 100644
--- a/engines/sci/graphics/palette32.h
+++ b/engines/sci/graphics/palette32.h
@@ -240,11 +240,8 @@ public:
 	/**
 	 * Copies all entries from `nextPalette` to `currentPalette` and updates the
 	 * backend's raw palette.
-	 *
-	 * @param updateScreen If true, this call will also tell the backend to draw
-	 * to the screen.
 	 */
-	void updateHardware(const bool updateScreen = true);
+	void updateHardware();
 
 private:
 	ResourceManager *_resMan;
diff --git a/engines/sci/sci.cpp b/engines/sci/sci.cpp
index 026c423d75..9d6e4e0451 100644
--- a/engines/sci/sci.cpp
+++ b/engines/sci/sci.cpp
@@ -816,6 +816,14 @@ void SciEngine::sleep(uint32 msecs) {
 	for (;;) {
 		// let backend process events and update the screen
 		_eventMan->getSciEvent(SCI_EVENT_PEEK);
+#ifdef ENABLE_SCI32
+		// If a game is in a wait loop, kFrameOut is not called, but mouse
+		// movement is still occurring and the screen needs to be updated to
+		// reflect it
+		if (getSciVersion() >= SCI_VERSION_2) {
+			g_system->updateScreen();
+		}
+#endif
 		time = g_system->getMillis();
 		if (time + 10 < wakeUpTime) {
 			g_system->delayMillis(10);