Implement ClipToPicture inside a BPicture. Not working yet.

BView::ClipToPicture doesn't work anymore, when nested inside a BPicture,
This happened when its implementation was moved server-side.

headers/private/interface/PictureDataWriter.h

@@ -40,6 +40,8 @@ public:
 			status_t			WriteSetScale(const float& scale);
 			status_t			WriteSetTransform(BAffineTransform transform);
 			status_t			WriteSetPattern(const ::pattern& pattern);
+			status_t			WriteClipToPicture(int32 pictureToken,
+									const BPoint& origin, bool inverse);
 			status_t			WriteSetClipping(const BRegion& region);
 			status_t			WriteClearClipping();
 

headers/private/interface/PicturePlayer.h

@@ -51,7 +51,7 @@ struct picture_player_callbacks {
 	void (*draw_picture)(void* userData, const BPoint& where, int32 token);
 	void (*set_clipping_rects)(void* userData, size_t numRects,
 		const BRect rects[]);
-	void (*clip_to_picture)(void* userData, const BPicture& picture,
+	void (*clip_to_picture)(void* userData, int32 token,
 		const BPoint& where, bool clipToInverse);
 	void (*push_state)(void* userData);
 	void (*pop_state)(void* userData);

src/kits/interface/PictureDataWriter.cpp

@@ -197,6 +197,25 @@ PictureDataWriter::WriteSetPattern(const ::pattern& pattern)
 }
 
 
+status_t
+PictureDataWriter::WriteClipToPicture(int32 pictureToken,
+						const BPoint& origin, bool inverse)
+{
+	// TODO: I don't know if it's compatible with R5's BPicture version
+	try {
+		BeginOp(B_PIC_CLIP_TO_PICTURE);
+		Write<int32>(pictureToken);
+		Write<BPoint>(origin);
+		Write<bool>(inverse);
+		EndOp();
+	} catch (status_t& status) {
+		return status;
+	}
+
+	return B_OK;
+}
+
+
 status_t
 PictureDataWriter::WriteSetClipping(const BRegion& region)
 {

src/kits/interface/PicturePlayer.cpp

@@ -215,9 +215,12 @@ set_clipping_rects(void* _context, size_t numRects, const BRect _rects[])
 
 
 static void
-clip_to_picture(void* context, const BPicture& picture, const BPoint& origin,
+clip_to_picture(void* _context, int32 token, const BPoint& origin,
 	bool clipToInverse)
 {
+	adapter_context* context = reinterpret_cast<adapter_context*>(_context);
+	((void (*)(void*, int32, BPoint, bool))context->function_table[21])(
+			context->user_data, token, origin, clipToInverse);
 }
 
 
@@ -930,7 +933,14 @@ PicturePlayer::_Play(const picture_player_callbacks& callbacks, void* userData,
 
 			case B_PIC_CLIP_TO_PICTURE:
 			{
-				// TODO: Implement
+				const int32* token;
+				const BPoint* where;
+				const bool* inverse;
+				if (callbacks.clip_to_picture == NULL || !reader.Get(token)
+					|| !reader.Get(where) || !reader.Get(inverse))
+					break;
+
+				callbacks.clip_to_picture(userData, *token, *where, *inverse);
 				break;
 			}
 

src/servers/app/ServerPicture.cpp

@@ -14,6 +14,7 @@
 #include <stdio.h>
 #include <stack>
 
+#include "AlphaMask.h"
 #include "DrawingEngine.h"
 #include "DrawState.h"
 #include "FontManager.h"
@@ -466,11 +467,23 @@ set_clipping_rects(void* _context, size_t numRects, const BRect rects[])
 
 
 static void
-clip_to_picture(void* context, const BPicture& picture, const BPoint& pt,
+clip_to_picture(void* _context, int32 pictureToken, const BPoint& where,
 	bool clipToInverse)
 {
-	printf("ClipToPicture(picture, BPoint(%.2f, %.2f), %s)\n",
-		pt.x, pt.y, clipToInverse ? "inverse" : "");
+	DrawingContext* context = reinterpret_cast<DrawingContext *>(_context);
+
+	ServerPicture* picture = context->GetPicture(pictureToken);
+	if (picture == NULL)
+		return;
+
+	AlphaMask* mask = new(std::nothrow) AlphaMask(
+		picture, clipToInverse, where, *context->CurrentState());
+	context->SetAlphaMask(mask);
+	context->UpdateCurrentDrawingRegion();
+	if (mask != NULL)
+		mask->ReleaseReference();
+
+	picture->ReleaseReference();
 }
 
 

src/servers/app/ServerWindow.cpp

@@ -3346,6 +3346,30 @@ ServerWindow::_DispatchPictureMessage(int32 code, BPrivate::LinkReceiver& link)
 			break;
 		}
 
+		case AS_VIEW_CLIP_TO_PICTURE:
+		{
+			int32 pictureToken;
+			BPoint where;
+			bool inverse = false;
+
+			link.Read<int32>(&pictureToken);
+			if (pictureToken < 0)
+				break;
+
+			link.Read<BPoint>(&where);
+			if (link.Read<bool>(&inverse) != B_OK)
+				break;
+
+			ServerPicture* picture = fServerApp->GetPicture(pictureToken);
+			if (picture == NULL)
+				break;
+
+			picture->WriteClipToPicture(picture->Token(), where, inverse);
+
+			picture->ReleaseReference();
+			break;
+		}
+
 		case AS_VIEW_BEGIN_PICTURE:
 		{
 			ServerPicture* newPicture = App()->CreatePicture();