ALL: Replace cursorTargetScale in OSystem API with a simple "do not scale" logic.

All uses of the old target scale API actually wanted to disallow scaling of
the mouse cursor. This commit adapts our API to this and thus simplifies
backend implementations.

Some backends, most notable the Wii and Android, did some implementation of
the cursor target scale, which I didn't adapt yet. I added a TODO for the
porters there.

2 files changed, 26 insertions, 32 deletions

diff --git a/backends/graphics/opengl/opengl-graphics.cpp b/backends/graphics/opengl/opengl-graphics.cpp
index cd820ae3b2..8449048997 100644
--- a/backends/graphics/opengl/opengl-graphics.cpp
+++ b/backends/graphics/opengl/opengl-graphics.cpp
@@ -49,7 +49,7 @@ OpenGLGraphicsManager::OpenGLGraphicsManager()
 	_transactionMode(kTransactionNone),
 	_cursorNeedsRedraw(false), _cursorPaletteDisabled(true),
 	_cursorVisible(false), _cursorKeyColor(0),
-	_cursorTargetScale(1),
+	_cursorDontScale(false),
 	_formatBGR(false),
 	_displayX(0), _displayY(0), _displayWidth(0), _displayHeight(0) {
 
@@ -591,7 +591,7 @@ void OpenGLGraphicsManager::warpMouse(int x, int y) {
 	setInternalMousePosition(scaledX, scaledY);
 }
 
-void OpenGLGraphicsManager::setMouseCursor(const byte *buf, uint w, uint h, int hotspotX, int hotspotY, uint32 keycolor, int cursorTargetScale, const Graphics::PixelFormat *format) {
+void OpenGLGraphicsManager::setMouseCursor(const byte *buf, uint w, uint h, int hotspotX, int hotspotY, uint32 keycolor, bool dontScale, const Graphics::PixelFormat *format) {
 #ifdef USE_RGB_COLOR
 	if (format)
 		_cursorFormat = *format;
@@ -616,7 +616,7 @@ void OpenGLGraphicsManager::setMouseCursor(const byte *buf, uint w, uint h, int
 	_cursorState.hotX = hotspotX;
 	_cursorState.hotY = hotspotY;
 	_cursorKeyColor = keycolor;
-	_cursorTargetScale = cursorTargetScale;
+	_cursorDontScale = dontScale;
 	_cursorNeedsRedraw = true;
 
 	refreshCursorScale();
@@ -829,28 +829,19 @@ void OpenGLGraphicsManager::refreshCursor() {
 }
 
 void OpenGLGraphicsManager::refreshCursorScale() {
-	// Calculate the scale factors of the screen. We limit ourselves to 3 at
-	// most here to avoid really big (and ugly) cursors for big resolutions.
-	// It might be noteworthy that 3 is the (current) target scale for the
-	// modern theme and thus assures the cursor is *never* scaled.
+	// Calculate the scale factors of the screen.
 	// We also totally ignore the aspect of the overlay cursor, since aspect
 	// ratio correction only applies to the game screen.
-	uint screenScaleFactorX = MIN(30000, _videoMode.hardwareWidth * 10000 / _videoMode.screenWidth);
-	uint screenScaleFactorY = MIN(30000, _videoMode.hardwareHeight * 10000 / _videoMode.screenHeight);
-
-	// Apply the target scale factor to the cursor.
-	// It might be noteworthy we only apply any scaling to the cursor in case
-	// the current scale factor is bigger than the target scale to match
-	// SurfaceSdlGraphicsManager's behavior. Otherwise we would downscale the
-	// GUI cursor of the modern theme for example.
-	if (screenScaleFactorX > uint(_cursorTargetScale * 10000))
-		screenScaleFactorX /= _cursorTargetScale;
-	else
+	// TODO: It might make sense to always ignore scaling of the mouse cursor
+	// when the overlay is visible.
+	uint screenScaleFactorX = _videoMode.hardwareWidth * 10000 / _videoMode.screenWidth;
+	uint screenScaleFactorY = _videoMode.hardwareHeight * 10000 / _videoMode.screenHeight;
+
+	// Ignore scaling when the cursor should not be scaled.
+	if (_cursorDontScale) {
 		screenScaleFactorX = 10000;
-	if (screenScaleFactorY > uint(_cursorTargetScale * 10000))
-		screenScaleFactorY /= _cursorTargetScale;
-	else
 		screenScaleFactorY = 10000;
+	}
 
 	// Apply them (without any possible) aspect ratio correction to the
 	// overlay.
@@ -859,16 +850,19 @@ void OpenGLGraphicsManager::refreshCursorScale() {
 	_cursorState.rHotX = (int16)(_cursorState.hotX * screenScaleFactorX / 10000);
 	_cursorState.rHotY = (int16)(_cursorState.hotY * screenScaleFactorY / 10000);
 
-	// Make sure we properly scale the cursor according to the desired aspect.
-	// It might be noteworthy that, unlike with the overlay, we do not limit
-	// the scale factor here to avoid odd looks if the game uses items as
-	// mouse cursor, which would otherwise suddenly be smaller.
-	int width, height;
-	calculateDisplaySize(width, height);
-	screenScaleFactorX = (width * 10000 / _videoMode.screenWidth) / _cursorTargetScale;
-	screenScaleFactorY = (height * 10000 / _videoMode.screenHeight) / _cursorTargetScale;
+	// Only apply scaling when it's desired.
+	if (_cursorDontScale) {
+		screenScaleFactorX = 10000;
+		screenScaleFactorY = 10000;
+	} else {
+		// Make sure we properly scale the cursor according to the desired aspect.
+		int width, height;
+		calculateDisplaySize(width, height);
+		screenScaleFactorX = (width * 10000 / _videoMode.screenWidth);
+		screenScaleFactorY = (height * 10000 / _videoMode.screenHeight);
+	}
 
-	// Always scale the cursor for the game.
+	// Apply the scale cursor scaling for the game screen.
 	_cursorState.vW = (int16)(_cursorState.w * screenScaleFactorX / 10000);
 	_cursorState.vH = (int16)(_cursorState.h * screenScaleFactorY / 10000);
 	_cursorState.vHotX = (int16)(_cursorState.hotX * screenScaleFactorX / 10000);
diff --git a/backends/graphics/opengl/opengl-graphics.h b/backends/graphics/opengl/opengl-graphics.h
index ad8765bab1..956722c08f 100644
--- a/backends/graphics/opengl/opengl-graphics.h
+++ b/backends/graphics/opengl/opengl-graphics.h
@@ -104,7 +104,7 @@ public:
 
 	virtual bool showMouse(bool visible);
 	virtual void warpMouse(int x, int y);
-	virtual void setMouseCursor(const byte *buf, uint w, uint h, int hotspotX, int hotspotY, uint32 keycolor, int cursorTargetScale = 1, const Graphics::PixelFormat *format = NULL);
+	virtual void setMouseCursor(const byte *buf, uint w, uint h, int hotspotX, int hotspotY, uint32 keycolor, bool dontScale = false, const Graphics::PixelFormat *format = NULL);
 	virtual void setCursorPalette(const byte *colors, uint start, uint num);
 
 	virtual void displayMessageOnOSD(const char *msg);
@@ -283,7 +283,7 @@ protected:
 	MousePos _cursorState;
 	bool _cursorVisible;
 	uint32 _cursorKeyColor;
-	int _cursorTargetScale;
+	bool _cursorDontScale;
 	bool _cursorNeedsRedraw;
 
 	/**