Fix a few DPI / retina draw issues:

* Color picker cursor was too small, and color cirle was not smooth enough.
* Border select gesture cross before first click did not reach to the border
  of the window.
* Buttons were not drawing emboss properly (also for non-retina actually).
  Note it doesn't draw entirely right for aligned buttons, but this was also
  the case before it got broken.

1 files changed, 3 insertions, 2 deletions

diff --git a/source/blender/editors/space_buttons/buttons_header.c b/source/blender/editors/space_buttons/buttons_header.c
index ebba7d92819..701048cd229 100644
--- a/source/blender/editors/space_buttons/buttons_header.c
+++ b/source/blender/editors/space_buttons/buttons_header.c
@@ -97,14 +97,15 @@ static void do_buttons_buttons(bContext *C, void *UNUSED(arg), int event)
 	sbuts->mainbuser = sbuts->mainb;
 }
 
-#define BUT_UNIT_X (UI_UNIT_X + 2)
+#define BUT_UNIT_X (UI_UNIT_X + 2*U.pixelsize)
 
 void buttons_header_buttons(const bContext *C, ARegion *ar)
 {
 	SpaceButs *sbuts = CTX_wm_space_buts(C);
 	uiBlock *block;
 	uiBut *but;
-	int xco, yco = 2;
+	int headery = ED_area_headersize();
+	int xco, yco = 0.5f*(headery - UI_UNIT_Y);
 
 	buttons_context_compute(C, sbuts);