SDLGLFB: Implement mouse coordinate scaling for the menus.

src/posix/sdl/sdlglvideo.cpp

@@ -555,3 +555,38 @@ int SDLGLFB::GetClientHeight()
 	SDL_GL_GetDrawableSize(Screen, nullptr, &height);
 	return height;
 }
+
+void SDLGLFB::ScaleCoordsFromWindow(int16_t &x, int16_t &y)
+{
+	int w, h;
+	SDL_GetWindowSize (Screen, &w, &h);
+
+	// Detect if we're doing scaling in the Window and adjust the mouse
+	// coordinates accordingly. This could be more efficent, but I
+	// don't think performance is an issue in the menus.
+	if(IsFullscreen())
+	{
+		int realw = w, realh = h;
+		ScaleWithAspect (realw, realh, SCREENWIDTH, SCREENHEIGHT);
+		if (realw != SCREENWIDTH || realh != SCREENHEIGHT)
+		{
+			double xratio = (double)SCREENWIDTH/realw;
+			double yratio = (double)SCREENHEIGHT/realh;
+			if (realw < w)
+			{
+				x = (x - (w - realw)/2)*xratio;
+				y *= yratio;
+			}
+			else
+			{
+				y = (y - (h - realh)/2)*yratio;
+				x *= xratio;
+			}
+		}
+	}
+	else
+	{
+		x = (int16_t)(x*Width/w);
+		y = (int16_t)(y*Height/h);
+	}
+}

src/posix/sdl/sdlglvideo.h

@@ -72,6 +72,8 @@ public:
 	int GetClientWidth();
 	int GetClientHeight();
 
+	virtual void ScaleCoordsFromWindow(int16_t &x, int16_t &y);
+
 	SDL_Window *GetSDLWindow() override { return Screen; }
 
 protected:

src/posix/sdl/sdlvideo.cpp

@@ -112,31 +112,6 @@ static cycle_t SDLFlipCycles;
 
 // CODE --------------------------------------------------------------------
 
-void ScaleWithAspect (int &w, int &h, int Width, int Height)
-{
-	int resRatio = CheckRatio (Width, Height);
-	int screenRatio;
-	CheckRatio (w, h, &screenRatio);
-	if (resRatio == screenRatio)
-		return;
-
-	double yratio;
-	switch(resRatio)
-	{
-		case 0: yratio = 4./3.; break;
-		case 1: yratio = 16./9.; break;
-		case 2: yratio = 16./10.; break;
-		case 3: yratio = 17./10.; break;
-		case 4: yratio = 5./4.; break;
-		default: return;
-	}
-	double y = w/yratio;
-	if (y > h)
-		w = h*yratio;
-	else
-		h = y;
-}
-
 // FrameBuffer implementation -----------------------------------------------
 
 SDLFB::SDLFB (int width, int height, bool bgra, bool fullscreen, SDL_Window *oldwin)

src/v_video.cpp

@@ -1747,6 +1747,32 @@ bool AspectTallerThanWide(float aspect)
 	return aspect < 1.333f;
 }
 
+void ScaleWithAspect (int &w, int &h, int Width, int Height)
+{
+	int resRatio = CheckRatio (Width, Height);
+	int screenRatio;
+	CheckRatio (w, h, &screenRatio);
+	if (resRatio == screenRatio)
+		return;
+
+	double yratio;
+	switch(resRatio)
+	{
+		case 0: yratio = 4./3.; break;
+		case 1: yratio = 16./9.; break;
+		case 2: yratio = 16./10.; break;
+		case 3: yratio = 17./10.; break;
+		case 4: yratio = 5./4.; break;
+		case 6: yratio = 21./9.; break;
+		default: return;
+	}
+	double y = w/yratio;
+	if (y > h)
+		w = h*yratio;
+	else
+		h = y;
+}
+
 void IVideo::DumpAdapters ()
 {
 	Printf("Multi-monitor support unavailable.\n");

src/v_video.h

@@ -565,6 +565,8 @@ int AspectBaseHeight(float aspect);
 double AspectPspriteOffset(float aspect);
 int AspectMultiplier(float aspect);
 bool AspectTallerThanWide(float aspect);
+void ScaleWithAspect(int &w, int &h, int Width, int Height);
+
 int GetUIScale(int altval);
 
 EXTERN_CVAR(Int, uiscale);