SCI32: Fix bad text rendering in RAMA

In SCI3, Sierra removed the ability of the main renderer to
automatically scale CelObjs with different source resolutions.
Instead, in SCI3, all CelObjs are treated as having the same
resolution as the screen (i.e. 640x480).

In all SCI3 games other than RAMA, keeping the code paths for
resolution-dependent scaling is not a problem because all the
assets and game code are correctly designed to use the same
640x480 resolution throughout. RAMA, on the other hand, was
written with the text subsystem set to a resolution of 630x450
(Phant1's screen resolution), and in SSCI, resolution-dependent
scaling code was not removed from the *text* subsystem. As a
result, RAMA's game scripts rely on the slightly larger scaled
dimensions coming out of the text system when determining the size
of screen items for rendering, and then also rely on the main
renderer ignoring the 630x450 resolution baked into the bitmaps
generated by the text subsystem when drawing them to the screen.

4 files changed, 41 insertions, 36 deletions

diff --git a/engines/sci/engine/kgraphics32.cpp b/engines/sci/engine/kgraphics32.cpp
index c07282f53e..e75f563efb 100644
--- a/engines/sci/engine/kgraphics32.cpp
+++ b/engines/sci/engine/kgraphics32.cpp
@@ -75,8 +75,11 @@ reg_t kBaseSetter32(EngineState *s, int argc, reg_t *argv) {
 
 	CelObjView celObj(viewId, loopNo, celNo);
 
-	const int16 scriptWidth = g_sci->_gfxFrameout->getCurrentBuffer().scriptWidth;
-	const Ratio scaleX(scriptWidth, celObj._xResolution);
+	Ratio scaleX;
+	if (getSciVersion() < SCI_VERSION_3) {
+		const int16 scriptWidth = g_sci->_gfxFrameout->getCurrentBuffer().scriptWidth;
+		scaleX = Ratio(scriptWidth, celObj._xResolution);
+	}
 
 	int16 brLeft;
 
@@ -414,7 +417,11 @@ reg_t kCelHigh32(EngineState *s, int argc, reg_t *argv) {
 	int16 loopNo = argv[1].toSint16();
 	int16 celNo = argv[2].toSint16();
 	CelObjView celObj(resourceId, loopNo, celNo);
-	return make_reg(0, mulru(celObj._height, Ratio(g_sci->_gfxFrameout->getCurrentBuffer().scriptHeight, celObj._yResolution)));
+	int16 height = celObj._height;
+	if (getSciVersion() < SCI_VERSION_3) {
+		height = mulru(height, Ratio(g_sci->_gfxFrameout->getCurrentBuffer().scriptHeight, celObj._yResolution));
+	}
+	return make_reg(0, height);
 }
 
 reg_t kCelWide32(EngineState *s, int argc, reg_t *argv) {
@@ -422,7 +429,11 @@ reg_t kCelWide32(EngineState *s, int argc, reg_t *argv) {
 	int16 loopNo = argv[1].toSint16();
 	int16 celNo = argv[2].toSint16();
 	CelObjView celObj(resourceId, loopNo, celNo);
-	return make_reg(0, mulru(celObj._width, Ratio(g_sci->_gfxFrameout->getCurrentBuffer().scriptWidth, celObj._xResolution)));
+	int16 width = celObj._width;
+	if (getSciVersion() < SCI_VERSION_3) {
+		width = mulru(width, Ratio(g_sci->_gfxFrameout->getCurrentBuffer().scriptWidth, celObj._xResolution));
+	}
+	return make_reg(0, width);
 }
 
 // Used by Shivers 1, room 23601 to determine what blocks on the red door
diff --git a/engines/sci/engine/script_patches.cpp b/engines/sci/engine/script_patches.cpp
index 8bfd1d1732..a8be13edd9 100644
--- a/engines/sci/engine/script_patches.cpp
+++ b/engines/sci/engine/script_patches.cpp
@@ -6382,25 +6382,6 @@ static const uint16 ramaBenchmarkPatch[] = {
 	PATCH_END
 };
 
-// RAMA initialises the font system with an incorrect text resolution (it uses
-// the resolution from Phant1) which causes text to be scaled incorrectly.
-static const uint16 ramaTextResolutionSignature[] = {
-	0x39, 0x03,                   // pushi 3
-	0x78,                         // push1
-	SIG_MAGICDWORD,
-	0x38, SIG_UINT16(0x276),      // pushi 630
-	0x38, SIG_UINT16(0x1c2),      // pushi 450
-	0x43, 0x49, SIG_UINT16(0x06), // callk Font, 6
-	SIG_END
-};
-
-static const uint16 ramaTextResolutionPatch[] = {
-	PATCH_ADDTOOFFSET(+3),     // pushi 3, push1
-	0x38, PATCH_UINT16(0x280), // pushi 640
-	0x38, PATCH_UINT16(0x1e0), // pushi 480
-	PATCH_END
-};
-
 // RAMA uses a custom save game format that game scripts read and write
 // manually. The save game format serialises object references, which in the
 // original engine could be done just by writing int16s (since object references
@@ -6474,7 +6455,6 @@ static const uint16 ramaChangeDirPatch[] = {
 };
 
 static const SciScriptPatcherEntry ramaSignatures[] = {
-	{  true,     0, "fix bad text resolution",                      1, ramaTextResolutionSignature,     ramaTextResolutionPatch },
 	{  true,    55, "fix bad DocReader::init priority calculation", 1, ramaDocReaderInitSignature,      ramaDocReaderInitPatch },
 	{  true,    85, "fix SaveManager to use normal readWord calls", 1, ramaSerializeRegTSignature1,     ramaSerializeRegTPatch1 },
 	{  true, 64908, "disable video benchmarking",                   1, ramaBenchmarkSignature,          ramaBenchmarkPatch },
diff --git a/engines/sci/graphics/frameout.cpp b/engines/sci/graphics/frameout.cpp
index d3e08bf1c1..6ea4975ea8 100644
--- a/engines/sci/graphics/frameout.cpp
+++ b/engines/sci/graphics/frameout.cpp
@@ -1228,7 +1228,9 @@ bool GfxFrameout::isOnMe(const ScreenItem &screenItem, const Plane &plane, const
 		scaledPosition.x -= screenItem._scaledPosition.x;
 		scaledPosition.y -= screenItem._scaledPosition.y;
 
-		mulru(scaledPosition, Ratio(celObj._xResolution, _currentBuffer.screenWidth), Ratio(celObj._yResolution, _currentBuffer.screenHeight));
+		if (getSciVersion() < SCI_VERSION_3) {
+			mulru(scaledPosition, Ratio(celObj._xResolution, _currentBuffer.screenWidth), Ratio(celObj._yResolution, _currentBuffer.screenHeight));
+		}
 
 		if (screenItem._scale.signal != kScaleSignalNone && screenItem._scale.x && screenItem._scale.y) {
 			scaledPosition.x = scaledPosition.x * 128 / screenItem._scale.x;
diff --git a/engines/sci/graphics/screen_item32.cpp b/engines/sci/graphics/screen_item32.cpp
index 8e4f713eb6..5a35d30c54 100644
--- a/engines/sci/graphics/screen_item32.cpp
+++ b/engines/sci/graphics/screen_item32.cpp
@@ -297,8 +297,12 @@ void ScreenItem::calcRects(const Plane &plane) {
 	if (scaleX.getNumerator() && scaleY.getNumerator()) {
 		_screenItemRect = _insetRect;
 
-		const Ratio celToScreenX(screenWidth, celObj._xResolution);
-		const Ratio celToScreenY(screenHeight, celObj._yResolution);
+		Ratio celToScreenX;
+		Ratio celToScreenY;
+		if (getSciVersion() < SCI_VERSION_3) {
+			celToScreenX = Ratio(screenWidth, celObj._xResolution);
+			celToScreenY = Ratio(screenHeight, celObj._yResolution);
+		}
 
 		// Cel may use a coordinate system that is not the same size as the
 		// script coordinate system (usually this means high-resolution
@@ -307,9 +311,11 @@ void ScreenItem::calcRects(const Plane &plane) {
 			// high resolution coordinates
 
 			if (_useInsetRect) {
-				const Ratio scriptToCelX(celObj._xResolution, scriptWidth);
-				const Ratio scriptToCelY(celObj._yResolution, scriptHeight);
-				mulru(_screenItemRect, scriptToCelX, scriptToCelY, 0);
+				if (getSciVersion() < SCI_VERSION_3) {
+					const Ratio scriptToCelX(celObj._xResolution, scriptWidth);
+					const Ratio scriptToCelY(celObj._yResolution, scriptHeight);
+					mulru(_screenItemRect, scriptToCelX, scriptToCelY, 0);
+				}
 
 				if (_screenItemRect.intersects(celRect)) {
 					_screenItemRect.clip(celRect);
@@ -445,7 +451,7 @@ void ScreenItem::calcRects(const Plane &plane) {
 			_scaledPosition.y += plane._gameRect.top;
 			_screenItemRect.translate(plane._gameRect.left, plane._gameRect.top);
 
-			if (celObj._xResolution != screenWidth || celObj._yResolution != screenHeight) {
+			if (!celToScreenX.isOne() || !celToScreenY.isOne()) {
 				mulru(_scaledPosition, celToScreenX, celToScreenY);
 				mulru(_screenItemRect, celToScreenX, celToScreenY, 1);
 			}
@@ -626,9 +632,11 @@ Common::Rect ScreenItem::getNowSeenRect(const Plane &plane) const {
 		// high resolution coordinates
 
 		if (_useInsetRect) {
-			Ratio scriptToCelX(celObj._xResolution, scriptWidth);
-			Ratio scriptToCelY(celObj._yResolution, scriptHeight);
-			mulru(nsRect, scriptToCelX, scriptToCelY, 0);
+			if (getSciVersion() < SCI_VERSION_3) {
+				const Ratio scriptToCelX(celObj._xResolution, scriptWidth);
+				const Ratio scriptToCelY(celObj._yResolution, scriptHeight);
+				mulru(nsRect, scriptToCelX, scriptToCelY, 0);
+			}
 
 			if (nsRect.intersects(celObjRect)) {
 				nsRect.clip(celObjRect);
@@ -668,8 +676,12 @@ Common::Rect ScreenItem::getNowSeenRect(const Plane &plane) const {
 			}
 		}
 
-		Ratio celToScriptX(scriptWidth, celObj._xResolution);
-		Ratio celToScriptY(scriptHeight, celObj._yResolution);
+		Ratio celToScriptX;
+		Ratio celToScriptY;
+		if (getSciVersion() < SCI_VERSION_3) {
+			celToScriptX = Ratio(scriptWidth, celObj._xResolution);
+			celToScriptY = Ratio(scriptHeight, celObj._yResolution);
+		}
 
 		originX = (originX * scaleX * celToScriptX).toInt();
 		originY = (originY * scaleY * celToScriptY).toInt();