app_server: Move AlphaMask management into DrawState.

* Give DrawState a real copy constructor, handle deriving in PushState().
   (Although clipping region and alpha mask are not cloned, which is on the
   other hand just what's needed for now.)
 * Combining alpha masks from previous states is not yet handled.
 * Remove SetAlphaMask() from DrawingEngine and Painter. It is now done in
   SetDrawState().

src/servers/app/AlphaMask.cpp

@@ -12,6 +12,7 @@
 #include "BitmapHWInterface.h"
 #include "BitmapManager.h"
 #include "DrawingEngine.h"
+#include "DrawState.h"
 #include "ServerBitmap.h"
 #include "View.h"
 
@@ -101,7 +102,9 @@ AlphaMask::_RenderPicture(ServerPicture* picture, bool inverse) const
 
 	// Copy the current state of the client view, so we draw with the right
 	// font, color and everything
-	engine->SetDrawState(fView->CurrentState());
+	DrawState drawState(*fView->CurrentState());
+	engine->SetDrawState(&drawState);
+
 	OffscreenContext context(engine);
 	if (engine->LockParallelAccess()) {
 		// FIXME ConstrainClippingRegion docs says passing NULL disables

src/servers/app/DrawState.cpp

@@ -19,6 +19,7 @@
 
 #include <Region.h>
 
+#include "AlphaMask.h"
 #include "LinkReceiver.h"
 #include "LinkSender.h"
 #include "ServerProtocolStructs.h"
@@ -28,11 +29,13 @@ using std::nothrow;
 
 
 DrawState::DrawState()
-	: fOrigin(0.0, 0.0),
+	:
+	fOrigin(0.0, 0.0),
 	fCombinedOrigin(0.0, 0.0),
 	fScale(1.0),
 	fCombinedScale(1.0),
 	fClippingRegion(NULL),
+	fAlphaMask(NULL),
 
 	fHighColor((rgb_color){ 0, 0, 0, 255 }),
 	fLowColor((rgb_color){ 255, 255, 255, 255 }),
@@ -56,38 +59,40 @@ DrawState::DrawState()
 }
 
 
-DrawState::DrawState(DrawState* from)
+DrawState::DrawState(const DrawState& other)
-	: fOrigin(0.0, 0.0),
+	:
-	  fCombinedOrigin(from->fCombinedOrigin),
+	fOrigin(other.fOrigin),
-	  fScale(1.0),
+	fCombinedOrigin(other.fCombinedOrigin),
-	  fCombinedScale(from->fCombinedScale),
+	fScale(other.fScale),
+	fCombinedScale(other.fCombinedScale),
 	fClippingRegion(NULL),
+	fAlphaMask(NULL),
 
-	  fHighColor(from->fHighColor),
+	fHighColor(other.fHighColor),
-	  fLowColor(from->fLowColor),
+	fLowColor(other.fLowColor),
-	  fPattern(from->fPattern),
+	fPattern(other.fPattern),
 
-	  fDrawingMode(from->fDrawingMode),
+	fDrawingMode(other.fDrawingMode),
-	  fAlphaSrcMode(from->fAlphaSrcMode),
+	fAlphaSrcMode(other.fAlphaSrcMode),
-	  fAlphaFncMode(from->fAlphaFncMode),
+	fAlphaFncMode(other.fAlphaFncMode),
 
-	  fPenLocation(from->fPenLocation),
+	fPenLocation(other.fPenLocation),
-	  fPenSize(from->fPenSize),
+	fPenSize(other.fPenSize),
 
-	  fFont(from->fFont),
+	fFont(other.fFont),
-	  fFontAliasing(from->fFontAliasing),
+	fFontAliasing(other.fFontAliasing),
 
-	  fSubPixelPrecise(from->fSubPixelPrecise),
+	fSubPixelPrecise(other.fSubPixelPrecise),
 
-	  fLineCapMode(from->fLineCapMode),
+	fLineCapMode(other.fLineCapMode),
-	  fLineJoinMode(from->fLineJoinMode),
+	fLineJoinMode(other.fLineJoinMode),
-	  fMiterLimit(from->fMiterLimit),
+	fMiterLimit(other.fMiterLimit),
 
 	// Since fScale is reset to 1.0, the unscaled
 	// font size is the current size of the font
 	// (which is from->fUnscaledFontSize * from->fCombinedScale)
-	  fUnscaledFontSize(from->fUnscaledFontSize),
+	fUnscaledFontSize(other.fUnscaledFontSize),
-	  fPreviousState(from)
+	fPreviousState(NULL)
 {
 }
 
@@ -96,13 +101,22 @@ DrawState::~DrawState()
 {
 	delete fClippingRegion;
 	delete fPreviousState;
+	delete fAlphaMask;
 }
 
 
 DrawState*
 DrawState::PushState()
 {
-	DrawState* next = new (nothrow) DrawState(this);
+	DrawState* next = new (nothrow) DrawState(*this);
+
+	if (next != NULL) {
+		// Prepare state as derived from this state
+		next->fOrigin = BPoint(0.0, 0.0);
+		next->fScale = 1.0;
+		next->fPreviousState = this;
+	}
+
 	return next;
 }
 
@@ -373,6 +387,28 @@ DrawState::GetCombinedClippingRegion(BRegion* region) const
 }
 
 
+void
+DrawState::SetAlphaMask(AlphaMask* mask)
+{
+	// BeOS compatibility: they implemented ClipToPicture by converting the
+	// picture to a complex BRegion and used that as a clipping region. As a
+	// result, youcan't have a picture and a region clipping at the same level
+	// (but you can either using PushState/PopState, or using
+	// ConstrainClippingRegion after ClipToPicture...)
+	// SetClippingRegion(NULL);
+
+	delete fAlphaMask;
+	fAlphaMask = mask;
+}
+
+
+AlphaMask*
+DrawState::GetAlphaMask() const
+{
+	return fAlphaMask;
+}
+
+
 // #pragma mark -
 
 

src/servers/app/DrawState.h

@@ -20,6 +20,7 @@
 #include "ServerFont.h"
 #include "PatternHandler.h"
 
+class AlphaMask;
 class BRegion;
 
 namespace BPrivate {
@@ -31,8 +32,7 @@ namespace BPrivate {
 class DrawState {
 public:
 							DrawState();
-private:
+							DrawState(const DrawState& other);
-							DrawState(DrawState* from);
 public:
 		virtual				~DrawState();
 
@@ -67,6 +67,9 @@ public:
 		bool				HasAdditionalClipping() const;
 		bool				GetCombinedClippingRegion(BRegion* region) const;
 
+			void			SetAlphaMask(AlphaMask* mask);
+			AlphaMask*		GetAlphaMask() const;
+
 							// coordinate transformations
 				void		Transform(float* x, float* y) const;
 				void		InverseTransform(float* x, float* y) const;
@@ -149,6 +152,8 @@ protected:
 
 		BRegion*			fClippingRegion;
 
+		AlphaMask*			fAlphaMask;
+
 		rgb_color			fHighColor;
 		rgb_color			fLowColor;
 		Pattern				fPattern;

src/servers/app/DrawingContext.cpp

@@ -33,6 +33,10 @@ DrawingContext::DrawingContext()
 }
 
 
+DrawingContext::~DrawingContext()
+{
+}
+
 
 status_t
 DrawingContext::InitCheck() const
@@ -108,7 +112,7 @@ DrawingContext::SetScale(float scale)
 float
 DrawingContext::Scale() const
 {
-	return CurrentState()->Scale();
+	return fDrawState->Scale();
 }
 
 
@@ -117,11 +121,25 @@ DrawingContext::SetUserClipping(const BRegion* region)
 {
 	fDrawState->SetClippingRegion(region);
 
-	// rebuild clipping (for just this view)
+	// rebuild clipping (for just this context)
 	RebuildClipping(false);
 }
 
 
+void
+DrawingContext::SetAlphaMask(AlphaMask* mask)
+{
+	fDrawState->SetAlphaMask(mask);
+}
+
+
+AlphaMask*
+DrawingContext::GetAlphaMask() const
+{
+	return fDrawState->GetAlphaMask();
+}
+
+
 //! converts a point from local *drawing* to screen coordinate system
 void
 DrawingContext::ConvertToScreenForDrawing(BPoint* point) const

src/servers/app/DrawingContext.h

@@ -17,6 +17,7 @@
 #include <Point.h>
 
 
+class AlphaMask;
 class BGradient;
 class BRegion;
 class DrawingEngine;
@@ -27,8 +28,10 @@ class ServerPicture;
 
 
 class DrawingContext {
-	public:
+public:
 							DrawingContext();
+	virtual					~DrawingContext();
+
 			status_t		InitCheck() const;
 
 	virtual	void			PushState();
@@ -44,6 +47,9 @@ class DrawingContext {
 			void			SetUserClipping(const BRegion* region);
 				// region is expected in view coordinates
 	
+			void			SetAlphaMask(AlphaMask* mask);
+			AlphaMask*		GetAlphaMask() const;
+	
 			void			ConvertToScreenForDrawing(BPoint* point) const;
 			void			ConvertToScreenForDrawing(BRect* rect) const;
 			void			ConvertToScreenForDrawing(BRegion* region) const;
@@ -70,13 +76,13 @@ class DrawingContext {
 	virtual void			ResyncDrawState() {};
 	virtual void			UpdateCurrentDrawingRegion() {};
 
-	protected:
+protected:
 			DrawState*		fDrawState;
 };
 
 
 class OffscreenContext: public DrawingContext {
-	public:
+public:
 							OffscreenContext(DrawingEngine* engine)
 								: fDrawingEngine(engine)
 							{};
@@ -96,7 +102,7 @@ class OffscreenContext: public DrawingContext {
 			void			RebuildClipping(bool deep) { /* TODO */ }
 			ServerPicture*	GetPicture(int32 token) const
 								{ /* TODO */ return NULL; }
-	private:
+private:
 			DrawingEngine*	fDrawingEngine;
 };
 

src/servers/app/ServerWindow.cpp

@@ -51,6 +51,7 @@
 #include "clipping.h"
 #include "utf8_functions.h"
 
+#include "AlphaMask.h"
 #include "AppServer.h"
 #include "AutoDeleter.h"
 #include "BBitmapBuffer.h"
@@ -1869,7 +1870,8 @@ fDesktop->LockSingleWindow();
 
 			link.Read<int32>(&pictureToken);
 			if (pictureToken < 0) {
-				fCurrentView->SetAlphaMask(NULL, false, B_ORIGIN);
+				fCurrentView->SetAlphaMask(NULL);
+				_UpdateDrawState(fCurrentView);
 				break;
 			}
 
@@ -1881,7 +1883,10 @@ fDesktop->LockSingleWindow();
 			if (picture == NULL)
 				break;
 
-			fCurrentView->SetAlphaMask(picture, inverse, where);
+			fCurrentView->SetAlphaMask(new(std::nothrow) AlphaMask(
+				fCurrentView, picture, inverse, where));
+			_UpdateDrawState(fCurrentView);
+
 			picture->ReleaseReference();
 			break;
 		}
@@ -2174,7 +2179,6 @@ ServerWindow::_DispatchViewDrawingMessage(int32 code,
 	// that's why you need to use the clipping only for as long
 	// as you have it locked
 	drawingEngine->ConstrainClippingRegion(&fCurrentDrawingRegion);
-	drawingEngine->SetAlphaMask(fCurrentView->GetAlphaMask());
 
 	switch (code) {
 		case AS_STROKE_LINE:
@@ -2840,7 +2844,6 @@ ServerWindow::_DispatchViewDrawingMessage(int32 code,
 			break;
 	}
 
-	drawingEngine->SetAlphaMask(NULL);
 	drawingEngine->UnlockParallelAccess();
 }
 

src/servers/app/View.cpp

@@ -113,7 +113,6 @@ View::View(IntRect frame, IntPoint scrollingOffset, const char* name,
 
 	fCursor(NULL),
 	fPicture(NULL),
-	fAlphaMask(NULL),
 
 	fLocalClipping((BRect)Bounds()),
 	fScreenClipping(),
@@ -134,7 +133,6 @@ View::~View()
 	delete fScreenAndUserClipping;
 	delete fUserClipping;
 	delete fDrawState;
-	delete fAlphaMask;
 
 //	if (fWindow && this == fWindow->TopView())
 //		fWindow->SetTopView(NULL);
@@ -1575,32 +1573,6 @@ View::InvalidateScreenClipping()
 }
 
 
-// TODO we should be storing the ServerPicture here, so we can recompute the
-// bitmap mask when the view is scaled, resized or the origin is changed.
-// This would allow us to keep a bitmap mask matching exactly the view size.
-// Moreover, we should clip that bitmap mask using the region-based clipping,
-// so it can mask out all the clipped regions, and we don't have to worry about
-// them whendoing further drawing. Essentially, switch from region-based to
-// bitmap based clipping for all ourdrawing.
-void
-View::SetAlphaMask(ServerPicture* picture, bool inverse, BPoint origin)
-{
-	// BeOS compatibility: they implemented ClipToPicture by converting the
-	// picture to a complex BRegion and used that as a clipping region. As a
-	// result, youcan't have a picture and a region clipping at the same level
-	// (but you can either using PushState/PopState, or using
-	// ConstrainClippingRegion after ClipToPicture...)
-	// SetUserClipping(NULL);
-
-	delete fAlphaMask;
-	if (picture != NULL) {
-		fAlphaMask = new(std::nothrow) AlphaMask(this, picture, inverse,
-			origin);
-	} else
-		fAlphaMask = NULL;
-}
-
-
 BRegion&
 View::_ScreenClipping(BRegion* windowContentClipping, bool force) const
 {

src/servers/app/View.h

@@ -29,7 +29,6 @@ namespace BPrivate {
 	class PortLink;
 };
 
-class AlphaMask;
 class DrawingEngine;
 class Overlay;
 class Window;
@@ -221,10 +220,6 @@ public:
 										&& fScreenAndUserClipping != NULL));
 								}
 
-			void			SetAlphaMask(ServerPicture* picture, bool inverse,
-								BPoint where);
-			AlphaMask*		GetAlphaMask() { return fAlphaMask; }
-
 			// debugging
 			void			PrintToStream() const;
 #if 0
@@ -274,7 +269,6 @@ protected:
 
 			ServerCursor*	fCursor;
 			ServerPicture*	fPicture;
-			AlphaMask*		fAlphaMask;
 
 			// clipping
 			BRegion			fLocalClipping;

src/servers/app/drawing/DrawingEngine.cpp

@@ -17,7 +17,6 @@
 #include <algorithm>
 #include <stack>
 
-#include "AlphaMask.h"
 #include "DrawState.h"
 #include "GlyphLayoutEngine.h"
 #include "Painter.h"
@@ -235,16 +234,6 @@ DrawingEngine::ConstrainClippingRegion(const BRegion* region)
 }
 
 
-void
-DrawingEngine::SetAlphaMask(AlphaMask* mask)
-{
-	scanline_unpacked_masked_type* scanline = NULL;
-	if (mask != NULL)
-		scanline = mask->Generate();
-	fPainter->SetAlphaMask(scanline);
-}
-
-
 void
 DrawingEngine::SetDrawState(const DrawState* state, int32 xOffset,
 	int32 yOffset)

src/servers/app/drawing/DrawingEngine.h

@@ -25,7 +25,6 @@ class BPoint;
 class BRect;
 class BRegion;
 
-class AlphaMask;
 class DrawState;
 class Painter;
 class ServerBitmap;
@@ -68,7 +67,6 @@ public:
 	// clipping for all drawing functions, passing a NULL region
 	// will remove any clipping (drawing allowed everywhere)
 	virtual	void			ConstrainClippingRegion(const BRegion* region);
-			void			SetAlphaMask(AlphaMask* mask);
 
 	virtual	void			SetDrawState(const DrawState* state,
 								int32 xOffset = 0, int32 yOffset = 0);

src/servers/app/drawing/Painter/Painter.cpp

@@ -289,6 +289,11 @@ Painter::SetDrawState(const DrawState* data, int32 xOffset, int32 yOffset)
 
 	fSubpixelPrecise = data->SubPixelPrecise();
 
+	if (data->GetAlphaMask() != NULL)
+		fMaskedUnpackedScanline = data->GetAlphaMask()->Generate();
+	else
+		fMaskedUnpackedScanline = NULL;
+
 	// any of these conditions means we need to use a different drawing
 	// mode instance
 	bool updateDrawingMode
@@ -336,13 +341,6 @@ Painter::ConstrainClipping(const BRegion* region)
 }
 
 
-void
-Painter::SetAlphaMask(scanline_unpacked_masked_type* mask)
-{
-	fMaskedUnpackedScanline = mask;
-}
-
-
 // SetHighColor
 void
 Painter::SetHighColor(const rgb_color& color)

src/servers/app/drawing/Painter/Painter.h

@@ -54,8 +54,6 @@ public:
 			void				ConstrainClipping(const BRegion* region);
 			const BRegion*		ClippingRegion() const
 									{ return fClippingRegion; }
-			void				SetAlphaMask(
-									scanline_unpacked_masked_type* mask);
 
 			void				SetDrawState(const DrawState* data,
 									int32 xOffset = 0,