MOHAWK: Myst: Update the screen only once per frame

Change all inner loops to call the same frame function.

Remove the draw delay code. Now that we have proper frame pacing it is
not necessary anymore to wait before drawing to make sure the previous
frame stayed on the screen long enough.

Fixes #9915, #9922, #9923.

1 files changed, 13 insertions, 104 deletions

diff --git a/engines/mohawk/myst_graphics.cpp b/engines/mohawk/myst_graphics.cpp
index 333da402fa..0aceb1de04 100644
--- a/engines/mohawk/myst_graphics.cpp
+++ b/engines/mohawk/myst_graphics.cpp
@@ -55,9 +55,6 @@ MystGraphics::MystGraphics(MohawkEngine_Myst* vm) : GraphicsManager(), _vm(vm) {
 	// Initialize our buffer
 	_backBuffer = new Graphics::Surface();
 	_backBuffer->create(_vm->_system->getWidth(), _vm->_system->getHeight(), _pixelFormat);
-
-	_nextAllowedDrawTime = _vm->_system->getMillis();
-	_enableDrawingTimeSimulation = 0;
 }
 
 MystGraphics::~MystGraphics() {
@@ -156,8 +153,6 @@ void MystGraphics::copyImageSectionToScreen(uint16 image, Common::Rect src, Comm
 	debug(3, "\twidth: %d", width);
 	debug(3, "\theight: %d", height);
 
-	simulatePreviousDrawDelay(dest);
-
 	_vm->_system->copyRectToScreen(surface->getBasePtr(src.left, top), surface->pitch, dest.left, dest.top, width, height);
 }
 
@@ -222,16 +217,11 @@ void MystGraphics::copyImageToBackBuffer(uint16 image, Common::Rect dest) {
 void MystGraphics::copyBackBufferToScreen(Common::Rect r) {
 	r.clip(_viewport);
 
-	simulatePreviousDrawDelay(r);
-
 	_vm->_system->copyRectToScreen(_backBuffer->getBasePtr(r.left, r.top), _backBuffer->pitch, r.left, r.top, r.width(), r.height());
 }
 
 void MystGraphics::runTransition(TransitionType type, Common::Rect rect, uint16 steps, uint16 delay) {
 
-	// Transitions are barely visible without adding delays between the draw calls
-	enableDrawingTimeSimulation(true);
-
 	switch (type) {
 	case kTransitionLeftToRight:	{
 			debugC(kDebugView, "Left to Right");
@@ -242,18 +232,14 @@ void MystGraphics::runTransition(TransitionType type, Common::Rect rect, uint16
 				area.left = rect.left + step * i;
 				area.right = area.left + step;
 
-				_vm->_system->delayMillis(delay);
-				_vm->pollAndDiscardEvents();
-
 				copyBackBufferToScreen(area);
-				_vm->_system->updateScreen();
+				_vm->wait(delay);
 			}
 			if (area.right < rect.right) {
 				area.left = area.right;
 				area.right = rect.right;
 
 				copyBackBufferToScreen(area);
-				_vm->_system->updateScreen();
 			}
 		}
 		break;
@@ -266,18 +252,14 @@ void MystGraphics::runTransition(TransitionType type, Common::Rect rect, uint16
 				area.right = rect.right - step * i;
 				area.left = area.right - step;
 
-				_vm->_system->delayMillis(delay);
-				_vm->pollAndDiscardEvents();
-
 				copyBackBufferToScreen(area);
-				_vm->_system->updateScreen();
+				_vm->wait(delay);
 			}
 			if (area.left > rect.left) {
 				area.right = area.left;
 				area.left = rect.left;
 
 				copyBackBufferToScreen(area);
-				_vm->_system->updateScreen();
 			}
 		}
 		break;
@@ -293,11 +275,8 @@ void MystGraphics::runTransition(TransitionType type, Common::Rect rect, uint16
 			debugC(kDebugView, "Dissolve");
 
 			for (int16 step = 0; step < 8; step++) {
-				// Only one eighth of the rect pixels are updated by a draw step,
-				// delay by one eighth of the regular time
-				simulatePreviousDrawDelay(Common::Rect(rect.width() / 8, rect.height()));
-
 				transitionDissolve(rect, step);
+				_vm->doFrame();
 			}
 		}
 		break;
@@ -310,18 +289,14 @@ void MystGraphics::runTransition(TransitionType type, Common::Rect rect, uint16
 				area.top = rect.top + step * i;
 				area.bottom = area.top + step;
 
-				_vm->_system->delayMillis(delay);
-				_vm->pollAndDiscardEvents();
-
 				copyBackBufferToScreen(area);
-				_vm->_system->updateScreen();
+				_vm->wait(delay);
 			}
 			if (area.bottom < rect.bottom) {
 				area.top = area.bottom;
 				area.bottom = rect.bottom;
 
 				copyBackBufferToScreen(area);
-				_vm->_system->updateScreen();
 			}
 		}
 		break;
@@ -334,18 +309,14 @@ void MystGraphics::runTransition(TransitionType type, Common::Rect rect, uint16
 				area.bottom = rect.bottom - step * i;
 				area.top = area.bottom - step;
 
-				_vm->_system->delayMillis(delay);
-				_vm->pollAndDiscardEvents();
-
 				copyBackBufferToScreen(area);
-				_vm->_system->updateScreen();
+				_vm->wait(delay);
 			}
 			if (area.top > rect.top) {
 				area.bottom = area.top;
 				area.top = rect.top;
 
 				copyBackBufferToScreen(area);
-				_vm->_system->updateScreen();
 			}
 		}
 		break;
@@ -371,13 +342,10 @@ void MystGraphics::runTransition(TransitionType type, Common::Rect rect, uint16
 		break;
 	case kTransitionCopy:
 		copyBackBufferToScreen(rect);
-		_vm->_system->updateScreen();
 		break;
 	default:
 		error("Unknown transition %d", type);
 	}
-
-	enableDrawingTimeSimulation(false);
 }
 
 void MystGraphics::transitionDissolve(Common::Rect rect, uint step) {
@@ -460,8 +428,6 @@ void MystGraphics::transitionDissolve(Common::Rect rect, uint step) {
 	}
 
 	_vm->_system->unlockScreen();
-	_vm->pollAndDiscardEvents();
-	_vm->_system->updateScreen();
 }
 
 void MystGraphics::transitionSlideToLeft(Common::Rect rect, uint16 steps, uint16 delay) {
@@ -475,18 +441,13 @@ void MystGraphics::transitionSlideToLeft(Common::Rect rect, uint16 steps, uint16
 		dstRect.right = dstRect.left + step * stepWidth;
 		srcRect.left = srcRect.right - step * stepWidth;
 
-		_vm->_system->delayMillis(delay);
-
-		simulatePreviousDrawDelay(dstRect);
 		_vm->_system->copyRectToScreen(_backBuffer->getBasePtr(dstRect.left, dstRect.top),
 				_backBuffer->pitch, srcRect.left, srcRect.top, srcRect.width(), srcRect.height());
-		_vm->pollAndDiscardEvents();
-		_vm->_system->updateScreen();
+		_vm->wait(delay);
 	}
 
 	if (dstRect.right != rect.right) {
 		copyBackBufferToScreen(rect);
-		_vm->_system->updateScreen();
 	}
 }
 
@@ -501,18 +462,13 @@ void MystGraphics::transitionSlideToRight(Common::Rect rect, uint16 steps, uint1
 		dstRect.left = dstRect.right - step * stepWidth;
 		srcRect.right = srcRect.left + step * stepWidth;
 
-		_vm->_system->delayMillis(delay);
-
-		simulatePreviousDrawDelay(dstRect);
 		_vm->_system->copyRectToScreen(_backBuffer->getBasePtr(dstRect.left, dstRect.top),
 				_backBuffer->pitch, srcRect.left, srcRect.top, srcRect.width(), srcRect.height());
-		_vm->pollAndDiscardEvents();
-		_vm->_system->updateScreen();
+		_vm->wait(delay);
 	}
 
 	if (dstRect.left != rect.left) {
 		copyBackBufferToScreen(rect);
-		_vm->_system->updateScreen();
 	}
 }
 
@@ -527,19 +483,14 @@ void MystGraphics::transitionSlideToTop(Common::Rect rect, uint16 steps, uint16
 		dstRect.bottom = dstRect.top + step * stepWidth;
 		srcRect.top = srcRect.bottom - step * stepWidth;
 
-		_vm->_system->delayMillis(delay);
-
-		simulatePreviousDrawDelay(dstRect);
 		_vm->_system->copyRectToScreen(_backBuffer->getBasePtr(dstRect.left, dstRect.top),
 				_backBuffer->pitch, srcRect.left, srcRect.top, srcRect.width(), srcRect.height());
-		_vm->pollAndDiscardEvents();
-		_vm->_system->updateScreen();
+		_vm->wait(delay);
 	}
 
 
 	if (dstRect.bottom < rect.bottom) {
 		copyBackBufferToScreen(rect);
-		_vm->_system->updateScreen();
 	}
 }
 
@@ -554,19 +505,14 @@ void MystGraphics::transitionSlideToBottom(Common::Rect rect, uint16 steps, uint
 		dstRect.top = dstRect.bottom - step * stepWidth;
 		srcRect.bottom = srcRect.top + step * stepWidth;
 
-		_vm->_system->delayMillis(delay);
-
-		simulatePreviousDrawDelay(dstRect);
 		_vm->_system->copyRectToScreen(_backBuffer->getBasePtr(dstRect.left, dstRect.top),
 				_backBuffer->pitch, srcRect.left, srcRect.top, srcRect.width(), srcRect.height());
-		_vm->pollAndDiscardEvents();
-		_vm->_system->updateScreen();
+		_vm->wait(delay);
 	}
 
 
 	if (dstRect.top > rect.top) {
 		copyBackBufferToScreen(rect);
-		_vm->_system->updateScreen();
 	}
 }
 
@@ -581,15 +527,12 @@ void MystGraphics::transitionPartialToRight(Common::Rect rect, uint32 width, uin
 		dstRect.right = dstRect.left + step * stepWidth;
 		srcRect.left = srcRect.right - step * stepWidth;
 
-		simulatePreviousDrawDelay(dstRect);
 		_vm->_system->copyRectToScreen(_backBuffer->getBasePtr(dstRect.left, dstRect.top),
 				_backBuffer->pitch, srcRect.left, srcRect.top, srcRect.width(), srcRect.height());
-		_vm->pollAndDiscardEvents();
-		_vm->_system->updateScreen();
+		_vm->doFrame();
 	}
 
 	copyBackBufferToScreen(rect);
-	_vm->_system->updateScreen();
 }
 
 void MystGraphics::transitionPartialToLeft(Common::Rect rect, uint32 width, uint32 steps) {
@@ -603,15 +546,12 @@ void MystGraphics::transitionPartialToLeft(Common::Rect rect, uint32 width, uint
 		dstRect.left = dstRect.right - step * stepWidth;
 		srcRect.right = srcRect.left + step * stepWidth;
 
-		simulatePreviousDrawDelay(dstRect);
 		_vm->_system->copyRectToScreen(_backBuffer->getBasePtr(dstRect.left, dstRect.top),
 				_backBuffer->pitch, srcRect.left, srcRect.top, srcRect.width(), srcRect.height());
-		_vm->pollAndDiscardEvents();
-		_vm->_system->updateScreen();
+		_vm->doFrame();
 	}
 
 	copyBackBufferToScreen(rect);
-	_vm->_system->updateScreen();
 }
 
 void MystGraphics::drawRect(Common::Rect rect, RectState state) {
@@ -637,36 +577,6 @@ void MystGraphics::drawLine(const Common::Point &p1, const Common::Point &p2, ui
 	_backBuffer->drawLine(p1.x, p1.y, p2.x, p2.y, color);
 }
 
-void MystGraphics::enableDrawingTimeSimulation(bool enable) {
-	if (enable)
-		_enableDrawingTimeSimulation++;
-	else
-		_enableDrawingTimeSimulation--;
-
-	if (_enableDrawingTimeSimulation < 0)
-		_enableDrawingTimeSimulation = 0;
-}
-
-void MystGraphics::simulatePreviousDrawDelay(const Common::Rect &dest) {
-	uint32 time = 0;
-
-	if (_enableDrawingTimeSimulation) {
-		time = _vm->_system->getMillis();
-
-		// Do not draw anything new too quickly after the previous draw call
-		// so that images stay at least a little while on screen
-		// This is enabled only for scripted draw calls
-		if (time < _nextAllowedDrawTime) {
-			debugC(kDebugView, "Delaying draw call by %d ms", _nextAllowedDrawTime - time);
-			_vm->_system->delayMillis(_nextAllowedDrawTime - time);
-		}
-	}
-
-	// Next draw call allowed at DELAY + AERA * COEFF milliseconds from now
-	time = _vm->_system->getMillis();
-	_nextAllowedDrawTime = time + _constantDrawDelay + dest.height() * dest.width() / _proportionalDrawDelay;
-}
-
 void MystGraphics::fadeToBlack() {
 	// This is only for the demo
 	assert(!(_vm->getFeatures() & GF_ME));
@@ -681,7 +591,7 @@ void MystGraphics::fadeToBlack() {
 			*dst++ = *src++ * i / 64;
 
 		_vm->_system->getPaletteManager()->setPalette(palette, 0, 256);
-		_vm->_system->updateScreen();
+		_vm->doFrame();
 	}
 }
 
@@ -701,12 +611,11 @@ void MystGraphics::fadeFromBlack() {
 			*dst++ = *src++ * i / 64;
 
 		_vm->_system->getPaletteManager()->setPalette(palette, 0, 256);
-		_vm->_system->updateScreen();
+		_vm->doFrame();
 	}
 
 	// Set the full palette
 	_vm->_system->getPaletteManager()->setPalette(_palette, 0, 256);
-	_vm->_system->updateScreen();
 }
 
 void MystGraphics::clearScreenPalette() {