Cache relief colors on Haiku since their computation is expensive

* src/haikufns.c (haiku_create_frame, haiku_create_tip_frame):
Clear `relief_background'.
* src/haikuterm.c (haiku_calculate_relief_colors): Cache relief
colors for each frame.
* src/haikuterm.h (struct haiku_output): New fields for caching
the last relief color.

1 files changed, 11 insertions, 0 deletions

diff --git a/src/haikuterm.h b/src/haikuterm.h
index d20d491838f..30b474b1e1d 100644
--- a/src/haikuterm.h
+++ b/src/haikuterm.h
@@ -181,6 +181,17 @@ struct haiku_output
 
   /* The type of any event that's being waited for.  */
   int wait_for_event_type;
+
+  /* The "dark" color of the current relief.  */
+  uint32_t black_relief_pixel;
+
+  /* The "light" color of the current relief.  */
+  uint32_t white_relief_pixel;
+
+  /* The background for which the relief colors above were computed.
+     They are changed only when a different background is involved.
+     -1 means no color has been computed.  */
+  long relief_background;
 };
 
 struct x_output