View: provide the transform between different coordinate spaces

There's currently no way for an application to convert between view and drawing coordinates with a drawing states stack without keeping track of all the transformations itself, which is not very convenient for helper or library functions. Handle other spaces too, for good measure. Change-Id: Ic8404a1c111e273fff1eebf2f9f59f58246b796c Reviewed-on: https://review.haiku-os.org/c/haiku/+/5775 Tested-by: Commit checker robot <[email protected]> Reviewed-by: waddlesplash <[email protected]>
2022-11-13 04:04:30 +00:00
parent 423e3645e1
commit 241f109ccb
7 changed files with 199 additions and 4 deletions
@@ -45,6 +45,7 @@ enum {
 	B_VIEW_WHICH_VIEW_COLOR_BIT	= 0x00100000,
 	B_VIEW_WHICH_LOW_COLOR_BIT	= 0x00200000,
 	B_VIEW_WHICH_HIGH_COLOR_BIT	= 0x00400000,
+	B_VIEW_PARENT_COMPOSITE_BIT	= 0x00800000,

 	B_VIEW_ALL_BITS				= 0x00ffffff,

@@ -131,6 +132,11 @@ class ViewState {
 		float				scale;
 		BAffineTransform	transform;

+		// composite transformation stack
+		BPoint				parent_composite_origin;
+		float				parent_composite_scale;
+		BAffineTransform	parent_composite_transform;
+
 		// line modes
 		join_mode			line_join;
 		cap_mode			line_cap;