Added WIP support for affine transformations to BViews.

Everything untested, but compiles, so it must work. The idea is to introduce
BAffineTransform additionally to the existing Origin and Scale properties of
BViews. One may use it in parallel or as an alternative. Painter in app_server
is not yet aware of the additional transformation. It is however already used
to transform drawing coordinates. It probably needs to work differently,
perhaps only in Painter and AGGTextRenderer.

headers/private/interface/ViewPrivate.h

@@ -39,8 +39,9 @@ enum {
 	B_VIEW_LOW_COLOR_BIT		= 0x00008000,
 	B_VIEW_VIEW_COLOR_BIT		= 0x00010000,
 	B_VIEW_PATTERN_BIT			= 0x00020000,
+	B_VIEW_TRANSFORM_BIT		= 0x00040000,
 
-	B_VIEW_ALL_BITS				= 0x0003ffff,
+	B_VIEW_ALL_BITS				= 0x0007ffff,
 
 	// these used for archiving only
 	B_VIEW_RESIZE_BIT			= 0x00001000,
@@ -111,7 +112,11 @@ class ViewState {
 		::drawing_mode		drawing_mode;
 		BRegion				clipping_region;
 		bool				clipping_region_used;
+
+		// transformation
 		BPoint				origin;
+		float				scale;
+		BAffineTransform	transform;
 
 		// line modes
 		join_mode			line_join;
@@ -122,8 +127,6 @@ class ViewState {
 		source_alpha		alpha_source_mode;
 		alpha_function		alpha_function_mode;
 
-		float				scale;
-
 		// fonts
 		BFont				font;
 		uint16				font_flags;