From 807edd4c6669028eb0be5b2acbae7bd27ee88241 Mon Sep 17 00:00:00 2001
From: Scott Shawcroft <scott@tannewt.org>
Date: Fri, 29 Sep 2023 14:53:13 -0700
Subject: [PATCH] Improve framebufferdisplay.refresh()

Now the defaults make it easy to refresh when you want. It matches
the displayio.Display().refresh() behavior.
---
 .../framebufferio/FramebufferDisplay.c        | 36 +++++++++++++------
 .../framebufferio/FramebufferDisplay.c        |  2 +-
 2 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/shared-bindings/framebufferio/FramebufferDisplay.c b/shared-bindings/framebufferio/FramebufferDisplay.c
index 45eedcaa95..1aff2df73f 100644
--- a/shared-bindings/framebufferio/FramebufferDisplay.c
+++ b/shared-bindings/framebufferio/FramebufferDisplay.c
@@ -100,29 +100,38 @@ static framebufferio_framebufferdisplay_obj_t *native_display(mp_obj_t display_o
 }
 
 //|     def refresh(
-//|         self, *, target_frames_per_second: int = 60, minimum_frames_per_second: int = 1
+//|         self,
+//|         *,
+//|         target_frames_per_second: Optional[int] = None,
+//|         minimum_frames_per_second: int = 0
 //|     ) -> bool:
-//|         """When auto refresh is off, waits for the target frame rate and then refreshes the display,
-//|         returning True. If the call has taken too long since the last refresh call for the given
-//|         target frame rate, then the refresh returns False immediately without updating the screen to
+//|         """When auto_refresh is off, and :py:attr:`target_frames_per_second` is not `None` this waits
+//|         for the target frame rate and then refreshes the display,
+//|         returning `True`. If the call has taken too long since the last refresh call for the given
+//|         target frame rate, then the refresh returns `False` immediately without updating the screen to
 //|         hopefully help getting caught up.
 //|
 //|         If the time since the last successful refresh is below the minimum frame rate, then an
-//|         exception will be raised. Set minimum_frames_per_second to 0 to disable.
+//|         exception will be raised. The default :py:attr:`minimum_frames_per_second` of 0 disables this behavior.
 //|
-//|         When auto refresh is on, updates the display immediately. (The display will also update
+//|         When auto_refresh is off, and :py:attr:`target_frames_per_second` is `None` this
+//|         will update the display immediately.
+//|
+//|         When auto_refresh is on, updates the display immediately. (The display will also update
 //|         without calls to this.)
 //|
-//|         :param int target_frames_per_second: How many times a second `refresh` should be called and the screen updated.
+//|         :param Optional[int] target_frames_per_second: The target frame rate that :py:func:`refresh` should try to
+//|             achieve. Set to `None` for immediate refresh.
 //|         :param int minimum_frames_per_second: The minimum number of times the screen should be updated per second.
 //|         """
 //|         ...
 STATIC mp_obj_t framebufferio_framebufferdisplay_obj_refresh(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
     enum { ARG_target_frames_per_second, ARG_minimum_frames_per_second };
     static const mp_arg_t allowed_args[] = {
-        { MP_QSTR_target_frames_per_second, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 60} },
-        { MP_QSTR_minimum_frames_per_second, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 1} },
+        { MP_QSTR_target_frames_per_second, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = mp_const_none} },
+        { MP_QSTR_minimum_frames_per_second, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
     };
+
     mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
     mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
 
@@ -132,7 +141,14 @@ STATIC mp_obj_t framebufferio_framebufferdisplay_obj_refresh(size_t n_args, cons
     if (minimum_frames_per_second > 0) {
         maximum_ms_per_real_frame = 1000 / minimum_frames_per_second;
     }
-    return mp_obj_new_bool(common_hal_framebufferio_framebufferdisplay_refresh(self, 1000 / args[ARG_target_frames_per_second].u_int, maximum_ms_per_real_frame));
+
+    uint32_t target_ms_per_frame;
+    if (args[ARG_target_frames_per_second].u_obj == mp_const_none) {
+        target_ms_per_frame = 0xffffffff;
+    } else {
+        target_ms_per_frame = 1000 / mp_obj_get_int(args[ARG_target_frames_per_second].u_obj);
+    }
+    return mp_obj_new_bool(common_hal_framebufferio_framebufferdisplay_refresh(self, target_ms_per_frame, maximum_ms_per_real_frame));
 }
 MP_DEFINE_CONST_FUN_OBJ_KW(framebufferio_framebufferdisplay_refresh_obj, 1, framebufferio_framebufferdisplay_obj_refresh);
 
diff --git a/shared-module/framebufferio/FramebufferDisplay.c b/shared-module/framebufferio/FramebufferDisplay.c
index ec59efef4a..417422afd0 100644
--- a/shared-module/framebufferio/FramebufferDisplay.c
+++ b/shared-module/framebufferio/FramebufferDisplay.c
@@ -283,7 +283,7 @@ uint16_t common_hal_framebufferio_framebufferdisplay_get_rotation(framebufferio_
 
 
 bool common_hal_framebufferio_framebufferdisplay_refresh(framebufferio_framebufferdisplay_obj_t *self, uint32_t target_ms_per_frame, uint32_t maximum_ms_per_real_frame) {
-    if (!self->auto_refresh && !self->first_manual_refresh) {
+    if (!self->auto_refresh && !self->first_manual_refresh && (target_ms_per_frame != 0xffffffff)) {
         uint64_t current_time = supervisor_ticks_ms64();
         uint32_t current_ms_since_real_refresh = current_time - self->core.last_refresh;
         // Test to see if the real frame time is below our minimum.