MOHAWK: Run Myst in 8bpp

7 files changed, 205 insertions, 75 deletions

diff --git a/engines/mohawk/cursors.cpp b/engines/mohawk/cursors.cpp
index f1baac02e2..4b66829e6a 100644
--- a/engines/mohawk/cursors.cpp
+++ b/engines/mohawk/cursors.cpp
@@ -122,7 +122,11 @@ void MystCursorManager::setCursor(uint16 id) {
 	// Myst ME stores some cursors as 24bpp images instead of 8bpp
 	if (surface->format.bytesPerPixel == 1) {
 		CursorMan.replaceCursor(surface->getPixels(), surface->w, surface->h, hotspotX, hotspotY, 0);
-		CursorMan.replaceCursorPalette(mhkSurface->getPalette(), 0, 256);
+
+		// We're using the screen palette for the original game, but we need
+		// to use this for any 8bpp cursor in ME.
+		if (_vm->getFeatures() & GF_ME)
+			CursorMan.replaceCursorPalette(mhkSurface->getPalette(), 0, 256);
 	} else {
 		Graphics::PixelFormat pixelFormat = g_system->getScreenFormat();
 		CursorMan.replaceCursor(surface->getPixels(), surface->w, surface->h, hotspotX, hotspotY, pixelFormat.RGBToColor(255, 255, 255), false, &pixelFormat);
diff --git a/engines/mohawk/myst.cpp b/engines/mohawk/myst.cpp
index 7634e8d88a..b6a6c27329 100644
--- a/engines/mohawk/myst.cpp
+++ b/engines/mohawk/myst.cpp
@@ -413,7 +413,12 @@ void MohawkEngine_Myst::changeToStack(uint16 stack, uint16 card, uint16 linkSrcS
 
 	// Fill screen with black and empty cursor
 	_cursor->setCursor(0);
-	_system->fillScreen(_system->getScreenFormat().RGBToColor(0, 0, 0));
+
+	if (getFeatures() & GF_ME)
+		_system->fillScreen(_system->getScreenFormat().RGBToColor(0, 0, 0));
+	else
+		_gfx->clearScreenPalette();
+
 	_system->updateScreen();
 
 	_sound->stopSound();
@@ -495,9 +500,10 @@ void MohawkEngine_Myst::changeToStack(uint16 stack, uint16 card, uint16 linkSrcS
 	_cache.clear();
 	_gfx->clearCache();
 
-	// Play Flyby Entry Movie on Masterpiece Edition.
-	const char *flyby = 0;
 	if (getFeatures() & GF_ME) {
+		// Play Flyby Entry Movie on Masterpiece Edition.
+		const char *flyby = 0;
+
 		switch (_curStack) {
 		case kSeleniticStack:
 			flyby = "selenitic flyby";
diff --git a/engines/mohawk/myst_graphics.cpp b/engines/mohawk/myst_graphics.cpp
index 9ea9f15444..49f97cca63 100644
--- a/engines/mohawk/myst_graphics.cpp
+++ b/engines/mohawk/myst_graphics.cpp
@@ -28,6 +28,7 @@
 #include "common/system.h"
 #include "common/textconsole.h"
 #include "engines/util.h"
+#include "graphics/palette.h"
 #include "image/pict.h"
 
 namespace Mohawk {
@@ -37,16 +38,20 @@ MystGraphics::MystGraphics(MohawkEngine_Myst* vm) : GraphicsManager(), _vm(vm) {
 
 	_viewport = Common::Rect(544, 332);
 
-	// The original version of Myst could run in 8bpp color too.
-	// However, it dithered videos to 8bpp and they looked considerably
-	// worse (than they already did :P). So we're not even going to
-	// support 8bpp mode in Myst (Myst ME required >8bpp anyway).
-	initGraphics(_viewport.width(), _viewport.height(), true, NULL); // What an odd screen size!
+	if (_vm->getFeatures() & GF_ME) {
+		// High color
+		initGraphics(_viewport.width(), _viewport.height(), true, NULL);
 
-	_pixelFormat = _vm->_system->getScreenFormat();
+		if (_vm->_system->getScreenFormat().bytesPerPixel == 1)
+			error("Myst ME requires greater than 256 colors to run");
+	} else {
+		// Paletted
+		initGraphics(_viewport.width(), _viewport.height(), true);
+		setBasePalette();
+		setPaletteToScreen();
+	}
 
-	if (_pixelFormat.bytesPerPixel == 1)
-		error("Myst requires greater than 256 colors to run");
+	_pixelFormat = _vm->_system->getScreenFormat();
 
 	// Initialize our buffer
 	_backBuffer = new Graphics::Surface();
@@ -101,7 +106,9 @@ MohawkSurface *MystGraphics::decodeImage(uint16 id) {
 		mhkSurface = new MohawkSurface(pict.getSurface()->convertTo(_pixelFormat));
 	} else {
 		mhkSurface = _bmpDecoder->decodeImage(dataStream);
-		mhkSurface->convertToTrueColor();
+
+		if (_vm->getFeatures() & GF_ME)
+			mhkSurface->convertToTrueColor();
 	}
 
 	assert(mhkSurface);
@@ -151,7 +158,8 @@ void MystGraphics::copyImageSectionToScreen(uint16 image, Common::Rect src, Comm
 }
 
 void MystGraphics::copyImageSectionToBackBuffer(uint16 image, Common::Rect src, Common::Rect dest) {
-	Graphics::Surface *surface = findImage(image)->getSurface();
+	MohawkSurface *mhkSurface = findImage(image);
+	Graphics::Surface *surface = mhkSurface->getSurface();
 
 	// Make sure the image is bottom aligned in the dest rect
 	dest.top = dest.bottom - MIN<int>(surface->h, dest.height());
@@ -190,6 +198,13 @@ void MystGraphics::copyImageSectionToBackBuffer(uint16 image, Common::Rect src,
 
 	for (uint16 i = 0; i < height; i++)
 		memcpy(_backBuffer->getBasePtr(dest.left, i + dest.top), surface->getBasePtr(src.left, top + i), width * surface->format.bytesPerPixel);
+
+	if (!(_vm->getFeatures() & GF_ME)) {
+		// Make sure the palette is set
+		assert(mhkSurface->getPalette());
+		memcpy(_palette + 10 * 3, mhkSurface->getPalette() + 10 * 3, (256 - 10 * 2) * 3);
+		setPaletteToScreen();
+	}
 }
 
 void MystGraphics::copyImageToScreen(uint16 image, Common::Rect dest) {
@@ -419,12 +434,16 @@ void MystGraphics::transitionDissolve(Common::Rect rect, uint step) {
 
 		for (uint16 x = rect.left; x < rect.right; x++) {
 			if (linePattern[x % 4]) {
-				if (_pixelFormat.bytesPerPixel == 2) {
-					uint16 *dst = (uint16 *)screen->getBasePtr(x, y);
-					*dst = *(const uint16 *)_backBuffer->getBasePtr(x, y);
-				} else {
-					uint32 *dst = (uint32 *)screen->getBasePtr(x, y);
-					*dst = *(const uint32 *)_backBuffer->getBasePtr(x, y);
+				switch (_pixelFormat.bytesPerPixel) {
+				case 1:
+					*((byte *)screen->getBasePtr(x, y)) = *((const byte *)_backBuffer->getBasePtr(x, y));
+					break;
+				case 2:
+					*((uint16 *)screen->getBasePtr(x, y)) = *((const uint16 *)_backBuffer->getBasePtr(x, y));
+					break;
+				case 4:
+					*((uint32 *)screen->getBasePtr(x, y)) = *((const uint32 *)_backBuffer->getBasePtr(x, y));
+					break;
 				}
 			}
 		}
@@ -588,11 +607,11 @@ void MystGraphics::drawRect(Common::Rect rect, RectState state) {
 	Graphics::Surface *screen = _vm->_system->lockScreen();
 
 	if (state == kRectEnabled)
-		screen->frameRect(rect, _pixelFormat.RGBToColor(0, 255, 0));
+		screen->frameRect(rect, (_vm->getFeatures() & GF_ME) ? _pixelFormat.RGBToColor(0, 255, 0) : 250);
 	else if (state == kRectUnreachable)
-		screen->frameRect(rect, _pixelFormat.RGBToColor(0, 0, 255));
+		screen->frameRect(rect, (_vm->getFeatures() & GF_ME) ? _pixelFormat.RGBToColor(0, 0, 255) : 252);
 	else
-		screen->frameRect(rect, _pixelFormat.RGBToColor(255, 0, 0));
+		screen->frameRect(rect, (_vm->getFeatures() & GF_ME) ? _pixelFormat.RGBToColor(255, 0, 0) : 249);
 
 	_vm->_system->unlockScreen();
 }
@@ -629,50 +648,94 @@ void MystGraphics::simulatePreviousDrawDelay(const Common::Rect &dest) {
 	_nextAllowedDrawTime = time + _constantDrawDelay + dest.height() * dest.width() / _proportionalDrawDelay;
 }
 
-void MystGraphics::copyBackBufferToScreenWithSaturation(int16 saturation) {
-	Graphics::Surface *screen = _vm->_system->lockScreen();
+void MystGraphics::fadeToBlack() {
+	// This is only for the demo
+	assert(!(_vm->getFeatures() & GF_ME));
 
-	for (uint16 y = 0; y < _viewport.height(); y++)
-		for (uint16 x = 0; x < _viewport.width(); x++) {
-			uint32 color;
-			uint8 r, g, b;
+	// Linear fade in 64 steps
+	for (int i = 63; i >= 0; i--) {
+		byte palette[256 * 3];
+		byte *src = _palette;
+		byte *dst = palette;
 
-			if (_pixelFormat.bytesPerPixel == 2)
-				color = *(const uint16 *)_backBuffer->getBasePtr(x, y);
-			else
-				color = *(const uint32 *)_backBuffer->getBasePtr(x, y);
+		for (uint j = 0; j < sizeof(palette); j++)
+			*dst++ = *src++ * i / 64;
 
-			_pixelFormat.colorToRGB(color, r, g, b);
+		_vm->_system->getPaletteManager()->setPalette(palette, 0, 256);
+		_vm->_system->updateScreen();
+	}
+}
 
-			r = CLIP<int16>((int16)r - saturation, 0, 255);
-			g = CLIP<int16>((int16)g - saturation, 0, 255);
-			b = CLIP<int16>((int16)b - saturation, 0, 255);
+void MystGraphics::fadeFromBlack() {
+	// This is only for the demo
+	assert(!(_vm->getFeatures() & GF_ME));
 
-			color = _pixelFormat.RGBToColor(r, g, b);
+	copyBackBufferToScreen(_viewport);
 
-			if (_pixelFormat.bytesPerPixel == 2) {
-				uint16 *dst = (uint16 *)screen->getBasePtr(x, y);
-				*dst = color;
-			} else {
-				uint32 *dst = (uint32 *)screen->getBasePtr(x, y);
-				*dst = color;
-			}
-		}
+	// Linear fade in 64 steps
+	for (int i = 0; i < 64; i++) {
+		byte palette[256 * 3];
+		byte *src = _palette;
+		byte *dst = palette;
 
-	_vm->_system->unlockScreen();
+		for (uint j = 0; j < sizeof(palette); j++)
+			*dst++ = *src++ * i / 64;
+
+		_vm->_system->getPaletteManager()->setPalette(palette, 0, 256);
+		_vm->_system->updateScreen();
+	}
+
+	// Set the full palette
+	_vm->_system->getPaletteManager()->setPalette(_palette, 0, 256);
 	_vm->_system->updateScreen();
 }
 
-void MystGraphics::fadeToBlack() {
-	for (int16 i = 0; i < 256; i += 32) {
-		copyBackBufferToScreenWithSaturation(i);
-	}
+void MystGraphics::clearScreenPalette() {
+	// Set the palette to all black
+	byte palette[256 * 3];
+	memset(palette, 0, sizeof(palette));
+	_vm->_system->getPaletteManager()->setPalette(palette, 0, 256);
 }
 
-void MystGraphics::fadeFromBlack() {
-	for (int16 i = 256; i >= 0; i -= 32) {
-		copyBackBufferToScreenWithSaturation(i);
-	}
+void MystGraphics::setBasePalette() {
+	// Entries [0, 9] of the palette
+	static const byte lowPalette[] = {
+		0xFF, 0xFF, 0xFF,
+		0x80, 0x00, 0x00,
+		0x00, 0x80, 0x00,
+		0x80, 0x80, 0x00,
+		0x00, 0x00, 0x80,
+		0x80, 0x00, 0x80,
+		0x00, 0x80, 0x80,
+		0xC0, 0xC0, 0xC0,
+		0xC0, 0xDC, 0xC0,
+		0xA6, 0xCA, 0xF0
+	};
+
+	// Entries [246, 255] of the palette
+	static const byte highPalette[] = {
+		0xFF, 0xFB, 0xF0,
+		0xA0, 0xA0, 0xA4,
+		0x80, 0x80, 0x80,
+		0xFF, 0x00, 0x00,
+		0x00, 0xFF, 0x00,
+		0xFF, 0xFF, 0x00,
+		0x00, 0x00, 0xFF,
+		0xFF, 0x00, 0xFF,
+		0x00, 0xFF, 0xFF,
+		0x00, 0x00, 0x00
+	};
+
+	// Note that 0 and 255 are different from normal Windows.
+	// Myst seems to hack that to white, resp. black (probably for Mac compat).
+
+	memcpy(_palette, lowPalette, sizeof(lowPalette));
+	memset(_palette + sizeof(lowPalette), 0, sizeof(_palette) - sizeof(lowPalette) - sizeof(highPalette));
+	memcpy(_palette + sizeof(_palette) - sizeof(highPalette), highPalette, sizeof(highPalette));
+}
+
+void MystGraphics::setPaletteToScreen() {
+	_vm->_system->getPaletteManager()->setPalette(_palette, 0, 256);
 }
 
 } // End of namespace Mohawk
diff --git a/engines/mohawk/myst_graphics.h b/engines/mohawk/myst_graphics.h
index 1f70320bf6..6281c94cc8 100644
--- a/engines/mohawk/myst_graphics.h
+++ b/engines/mohawk/myst_graphics.h
@@ -40,7 +40,7 @@ enum RectState {
 
 class MystGraphics : public GraphicsManager {
 public:
-	MystGraphics(MohawkEngine_Myst*);
+	MystGraphics(MohawkEngine_Myst *vm);
 	~MystGraphics();
 
 	void copyImageSectionToScreen(uint16 image, Common::Rect src, Common::Rect dest);
@@ -55,18 +55,15 @@ public:
 	void fadeToBlack();
 	void fadeFromBlack();
 
+	void clearScreenPalette();
+	void setBasePalette();
+	void setPaletteToScreen();
+	const byte *getPalette() const { return _palette; }
+
 protected:
 	MohawkSurface *decodeImage(uint16 id);
 	MohawkEngine *getVM() { return (MohawkEngine *)_vm; }
-	void simulatePreviousDrawDelay(const Common::Rect &dest);
-	void copyBackBufferToScreenWithSaturation(int16 saturation);
-	void transitionDissolve(Common::Rect rect, uint step);
-	void transitionSlideToLeft(Common::Rect rect, uint16 steps, uint16 delay);
-	void transitionSlideToRight(Common::Rect rect, uint16 steps, uint16 delay);
-	void transitionSlideToTop(Common::Rect rect, uint16 steps, uint16 delay);
-	void transitionSlideToBottom(Common::Rect rect, uint16 steps, uint16 delay);
-	void transitionPartialToRight(Common::Rect rect, uint32 width, uint32 steps);
-	void transitionPartialToLeft(Common::Rect rect, uint32 width, uint32 steps);
+
 private:
 	MohawkEngine_Myst *_vm;
 	MystBitmap *_bmpDecoder;
@@ -74,11 +71,21 @@ private:
 	Graphics::Surface *_backBuffer;
 	Graphics::PixelFormat _pixelFormat;
 	Common::Rect _viewport;
+	byte _palette[256 * 3];
 
 	int _enableDrawingTimeSimulation;
 	uint32 _nextAllowedDrawTime;
 	static const uint _constantDrawDelay = 10; // ms
 	static const uint _proportionalDrawDelay = 500; // pixels per ms
+
+	void simulatePreviousDrawDelay(const Common::Rect &dest);
+	void transitionDissolve(Common::Rect rect, uint step);
+	void transitionSlideToLeft(Common::Rect rect, uint16 steps, uint16 delay);
+	void transitionSlideToRight(Common::Rect rect, uint16 steps, uint16 delay);
+	void transitionSlideToTop(Common::Rect rect, uint16 steps, uint16 delay);
+	void transitionSlideToBottom(Common::Rect rect, uint16 steps, uint16 delay);
+	void transitionPartialToRight(Common::Rect rect, uint32 width, uint32 steps);
+	void transitionPartialToLeft(Common::Rect rect, uint32 width, uint32 steps);
 };
 
 } // End of namespace Mohawk
diff --git a/engines/mohawk/myst_stacks/myst.cpp b/engines/mohawk/myst_stacks/myst.cpp
index c500df5ad3..ca6e7c0ee5 100644
--- a/engines/mohawk/myst_stacks/myst.cpp
+++ b/engines/mohawk/myst_stacks/myst.cpp
@@ -3201,13 +3201,21 @@ Common::Point Myst::towerRotationMapComputeCoords(const Common::Point &center, u
 }
 
 void Myst::towerRotationMapDrawLine(const Common::Point &center, const Common::Point &end) {
-	Graphics::PixelFormat pf = _vm->_system->getScreenFormat();
-	uint32 color = 0;
+	uint32 color;
 
-	if (!_towerRotationOverSpot)
-		color = pf.RGBToColor(0xFF, 0xFF, 0xFF); // White
-	else
-		color = pf.RGBToColor(0xFF, 0, 0); // Red
+	if (_vm->getFeatures() & GF_ME) {
+		Graphics::PixelFormat pf = _vm->_system->getScreenFormat();
+
+		if (!_towerRotationOverSpot)
+			color = pf.RGBToColor(0xFF, 0xFF, 0xFF); // White
+		else
+			color = pf.RGBToColor(0xFF, 0, 0); // Red
+	} else {
+		if (!_towerRotationOverSpot)
+			color = 0x00; // White
+		else
+			color = 0xF9; // Red
+	}
 
 	const Common::Rect rect = Common::Rect(106, 42, 459, 273);
 
diff --git a/engines/mohawk/video.cpp b/engines/mohawk/video.cpp
index cebb72e24f..ca38f22b7a 100644
--- a/engines/mohawk/video.cpp
+++ b/engines/mohawk/video.cpp
@@ -53,6 +53,8 @@ bool VideoEntry::endOfVideo() {
 }
 
 VideoManager::VideoManager(MohawkEngine* vm) : _vm(vm) {
+	// Set dithering enabled, if required
+	_enableDither = _vm->getGameType() == GType_MYST && !(_vm->getFeatures() & GF_ME);
 }
 
 VideoManager::~VideoManager() {
@@ -230,16 +232,23 @@ bool VideoManager::updateMovies() {
 				Graphics::PixelFormat pixelFormat = _vm->_system->getScreenFormat();
 
 				if (frame->format != pixelFormat) {
-					// We don't support downconverting to 8bpp
-					if (pixelFormat.bytesPerPixel == 1)
-						error("Cannot convert high color video frame to 8bpp");
+					// We don't support downconverting to 8bpp without having
+					// support in the codec. Set _enableDither if shows up.
+					if (pixelFormat.bytesPerPixel == 1) {
+						warning("Cannot convert high color video frame to 8bpp");
+						delete _videoStreams[i].video;
+						_videoStreams[i].clear();
+						continue;
+					}
 
 					// Convert to the current screen format
 					convertedFrame = frame->convertTo(pixelFormat, _videoStreams[i]->getPalette());
 					frame = convertedFrame;
 				} else if (pixelFormat.bytesPerPixel == 1 && _videoStreams[i]->hasDirtyPalette()) {
 					// Set the palette when running in 8bpp mode only
-					_vm->_system->getPaletteManager()->setPalette(_videoStreams[i]->getPalette(), 0, 256);
+					// Don't do this for Myst, which has its own per-stack handling
+					if (_vm->getGameType() != GType_MYST)
+						_vm->_system->getPaletteManager()->setPalette(_videoStreams[i]->getPalette(), 0, 256);
 				}
 
 				// Clip the width/height to make sure we stay on the screen (Myst does this a few times)
@@ -394,6 +403,9 @@ VideoHandle VideoManager::createVideoHandle(uint16 id, uint16 x, uint16 y, bool
 	entry.loop = loop;
 	entry.enabled = true;
 
+	// Enable dither if necessary
+	checkEnableDither(entry);
+
 	entry->start();
 
 	// Search for any deleted videos so we can take a formerly used slot
@@ -431,6 +443,10 @@ VideoHandle VideoManager::createVideoHandle(const Common::String &filename, uint
 	}
 
 	entry->loadStream(file);
+
+	// Enable dither if necessary
+	checkEnableDither(entry);
+
 	entry->setVolume(volume);
 	entry->start();
 
@@ -551,4 +567,26 @@ void VideoManager::pauseMovie(VideoHandle handle, bool pause) {
 	_videoStreams[handle]->pauseVideo(pause);
 }
 
+void VideoManager::checkEnableDither(VideoEntry &entry) {
+	// If we're not dithering, bail out
+	if (!_enableDither)
+		return;
+
+	// Ignore any video which is already 8bpp
+	if (entry->getPixelFormat().bytesPerPixel == 1)
+		return;
+
+	// Set the palette
+	byte palette[256 * 3];
+	g_system->getPaletteManager()->grabPalette(palette, 0, 256);
+	entry->setDitheringPalette(palette);
+
+	if (entry->getPixelFormat().bytesPerPixel != 1) {
+		if (entry.filename.empty())
+			error("Failed to set dither for video %d", entry.id);
+		else
+			error("Failed to set dither for video %s", entry.filename.c_str());
+	}
+}
+
 } // End of namespace Mohawk
diff --git a/engines/mohawk/video.h b/engines/mohawk/video.h
index 43181e3e6c..deb09afe6b 100644
--- a/engines/mohawk/video.h
+++ b/engines/mohawk/video.h
@@ -124,6 +124,10 @@ private:
 
 	VideoHandle createVideoHandle(uint16 id, uint16 x, uint16 y, bool loop, uint16 volume = 0xff);
 	VideoHandle createVideoHandle(const Common::String &filename, uint16 x, uint16 y, bool loop, byte volume = 0xff);
+
+	// Dithering control
+	bool _enableDither;
+	void checkEnableDither(VideoEntry &entry);
 };
 
 } // End of namespace Mohawk