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, 40 insertions, 58 deletions

diff --git a/backends/graphics/surfacesdl/surfacesdl-graphics.cpp b/backends/graphics/surfacesdl/surfacesdl-graphics.cpp
index e841ecb834..652c08dc45 100644
--- a/backends/graphics/surfacesdl/surfacesdl-graphics.cpp
+++ b/backends/graphics/surfacesdl/surfacesdl-graphics.cpp
@@ -63,17 +63,12 @@ static const OSystem::GraphicsMode s_supportedGraphicsModes[] = {
 
 DECLARE_TRANSLATION_ADDITIONAL_CONTEXT("Normal (no scaling)", "lowres")
 
-// Table of relative scalers magnitudes
-// [definedScale - 1][scaleFactor - 1]
-static ScalerProc *scalersMagn[3][3] = {
+// Table of the cursor scalers [scaleFactor - 1]
+static ScalerProc *scalersMagn[3] = {
 #ifdef USE_SCALERS
-	{ Normal1x, AdvMame2x, AdvMame3x },
-	{ Normal1x, Normal1x, Normal1o5x },
-	{ Normal1x, Normal1x, Normal1x }
+	Normal1x, AdvMame2x, AdvMame3x
 #else // remove dependencies on other scalers
-	{ Normal1x, Normal1x, Normal1x },
-	{ Normal1x, Normal1x, Normal1x },
-	{ Normal1x, Normal1x, Normal1x }
+	Normal1x, Normal1x, Normal1x
 #endif
 };
 
@@ -135,7 +130,7 @@ SurfaceSdlGraphicsManager::SurfaceSdlGraphicsManager(SdlEventSource *sdlEventSou
 	_overlayscreen(0), _tmpscreen2(0),
 	_scalerProc(0), _screenChangeCount(0),
 	_mouseVisible(false), _mouseNeedsRedraw(false), _mouseData(0), _mouseSurface(0),
-	_mouseOrigSurface(0), _cursorTargetScale(1), _cursorPaletteDisabled(true),
+	_mouseOrigSurface(0), _cursorDontScale(false), _cursorPaletteDisabled(true),
 	_currentShakePos(0), _newShakePos(0),
 	_paletteDirtyStart(0), _paletteDirtyEnd(0),
 	_screenIsLocked(false),
@@ -1718,7 +1713,7 @@ void SurfaceSdlGraphicsManager::warpMouse(int x, int y) {
 	}
 }
 
-void SurfaceSdlGraphicsManager::setMouseCursor(const byte *buf, uint w, uint h, int hotspot_x, int hotspot_y, uint32 keycolor, int cursorTargetScale, const Graphics::PixelFormat *format) {
+void SurfaceSdlGraphicsManager::setMouseCursor(const byte *buf, uint w, uint h, int hotspot_x, int hotspot_y, uint32 keycolor, bool dontScale, const Graphics::PixelFormat *format) {
 #ifdef USE_RGB_COLOR
 	if (!format)
 		_cursorFormat = Graphics::PixelFormat::createFormatCLUT8();
@@ -1739,7 +1734,7 @@ void SurfaceSdlGraphicsManager::setMouseCursor(const byte *buf, uint w, uint h,
 
 	_mouseKeyColor = keycolor;
 
-	_cursorTargetScale = cursorTargetScale;
+	_cursorDontScale = dontScale;
 
 	if (_mouseCurState.w != (int)w || _mouseCurState.h != (int)h) {
 		_mouseCurState.w = w;
@@ -1847,51 +1842,34 @@ void SurfaceSdlGraphicsManager::blitCursor() {
 	}
 
 	int rW, rH;
+	int cursorScale;
 
-	if (_cursorTargetScale >= _videoMode.scaleFactor) {
-		// The cursor target scale is greater or equal to the scale at
-		// which the rest of the screen is drawn. We do not downscale
-		// the cursor image, we draw it at its original size. It will
-		// appear too large on screen.
-
-		rW = w;
-		rH = h;
-		_mouseCurState.rHotX = _mouseCurState.hotX;
-		_mouseCurState.rHotY = _mouseCurState.hotY;
-
-		// The virtual dimensions may be larger than the original.
-
-		_mouseCurState.vW = w * _cursorTargetScale / _videoMode.scaleFactor;
-		_mouseCurState.vH = h * _cursorTargetScale / _videoMode.scaleFactor;
-		_mouseCurState.vHotX = _mouseCurState.hotX * _cursorTargetScale /
-			_videoMode.scaleFactor;
-		_mouseCurState.vHotY = _mouseCurState.hotY * _cursorTargetScale /
-			_videoMode.scaleFactor;
+	if (_cursorDontScale) {
+		// Don't scale the cursor at all if the user requests this behavior.
+		cursorScale = 1;
 	} else {
-		// The cursor target scale is smaller than the scale at which
-		// the rest of the screen is drawn. We scale up the cursor
-		// image to make it appear correct.
+		// Scale the cursor with the game screen scale factor.
+		cursorScale = _videoMode.scaleFactor;
+	}
 
-		rW = w * _videoMode.scaleFactor / _cursorTargetScale;
-		rH = h * _videoMode.scaleFactor / _cursorTargetScale;
-		_mouseCurState.rHotX = _mouseCurState.hotX * _videoMode.scaleFactor /
-			_cursorTargetScale;
-		_mouseCurState.rHotY = _mouseCurState.hotY * _videoMode.scaleFactor /
-			_cursorTargetScale;
+	// Adapt the real hotspot according to the scale factor.
+	rW = w * cursorScale;
+	rH = h * cursorScale;
+	_mouseCurState.rHotX = _mouseCurState.hotX * cursorScale;
+	_mouseCurState.rHotY = _mouseCurState.hotY * cursorScale;
 
-		// The virtual dimensions will be the same as the original.
+	// The virtual dimensions will be the same as the original.
 
-		_mouseCurState.vW = w;
-		_mouseCurState.vH = h;
-		_mouseCurState.vHotX = _mouseCurState.hotX;
-		_mouseCurState.vHotY = _mouseCurState.hotY;
-	}
+	_mouseCurState.vW = w;
+	_mouseCurState.vH = h;
+	_mouseCurState.vHotX = _mouseCurState.hotX;
+	_mouseCurState.vHotY = _mouseCurState.hotY;
 
 #ifdef USE_SCALERS
 	int rH1 = rH; // store original to pass to aspect-correction function later
 #endif
 
-	if (_videoMode.aspectRatioCorrection && _cursorTargetScale == 1) {
+	if (!_cursorDontScale && _videoMode.aspectRatioCorrection) {
 		rH = real2Aspect(rH - 1) + 1;
 		_mouseCurState.rHotY = real2Aspect(_mouseCurState.rHotY);
 	}
@@ -1922,21 +1900,25 @@ void SurfaceSdlGraphicsManager::blitCursor() {
 
 	ScalerProc *scalerProc;
 
-	// If possible, use the same scaler for the cursor as for the rest of
-	// the game. This only works well with the non-blurring scalers so we
-	// actually only use the 1x, 1.5x, 2x and AdvMame scalers.
-
-	if (_cursorTargetScale == 1 && (_videoMode.mode == GFX_DOUBLESIZE || _videoMode.mode == GFX_TRIPLESIZE))
-		scalerProc = _scalerProc;
-	else
-		scalerProc = scalersMagn[_cursorTargetScale - 1][_videoMode.scaleFactor - 1];
+	// Only apply scaling, when the user allows it.
+	if (!_cursorDontScale) {
+		// If possible, use the same scaler for the cursor as for the rest of
+		// the game. This only works well with the non-blurring scalers so we
+		// actually only use the 1x, 2x and AdvMame scalers.
+		if (_videoMode.mode == GFX_DOUBLESIZE || _videoMode.mode == GFX_TRIPLESIZE)
+			scalerProc = _scalerProc;
+		else
+			scalerProc = scalersMagn[_videoMode.scaleFactor - 1];
+	} else {
+		scalerProc = Normal1x;
+	}
 
 	scalerProc((byte *)_mouseOrigSurface->pixels + _mouseOrigSurface->pitch + 2,
 		_mouseOrigSurface->pitch, (byte *)_mouseSurface->pixels, _mouseSurface->pitch,
 		_mouseCurState.w, _mouseCurState.h);
 
 #ifdef USE_SCALERS
-	if (_videoMode.aspectRatioCorrection && _cursorTargetScale == 1)
+	if (!_cursorDontScale && _videoMode.aspectRatioCorrection)
 		cursorStretch200To240((uint8 *)_mouseSurface->pixels, _mouseSurface->pitch, rW, rH1, 0, 0, 0);
 #endif
 
diff --git a/backends/graphics/surfacesdl/surfacesdl-graphics.h b/backends/graphics/surfacesdl/surfacesdl-graphics.h
index f71096d43e..32fb219bcd 100644
--- a/backends/graphics/surfacesdl/surfacesdl-graphics.h
+++ b/backends/graphics/surfacesdl/surfacesdl-graphics.h
@@ -131,7 +131,7 @@ 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);
 
 #ifdef USE_OSD
@@ -281,7 +281,7 @@ protected:
 #else
 	byte _mouseKeyColor;
 #endif
-	int _cursorTargetScale;
+	bool _cursorDontScale;
 	bool _cursorPaletteDisabled;
 	SDL_Surface *_mouseOrigSurface;
 	SDL_Surface *_mouseSurface;