From 899ab6ae7564cbce89a9e44269b0241897f03a41 Mon Sep 17 00:00:00 2001
From: Serge Bazanski <q3k@q3k.org>
Date: Mon, 12 Jun 2023 13:02:28 +0200
Subject: [PATCH] py/demo_worms: hack around double buffering
---
python_payload/apps/demo_worms.py | 48 +++++++++++++++----------------
1 file changed, 24 insertions(+), 24 deletions(-)
diff --git a/python_payload/apps/demo_worms.py b/python_payload/apps/demo_worms.py
index 0f7193f77d..1fc6eafd8f 100644
--- a/python_payload/apps/demo_worms.py
+++ b/python_payload/apps/demo_worms.py
@@ -12,12 +12,20 @@ class AppWorms(application.Application):
def on_init(self):
print("on init")
- # TODO(q3k): factor out frame limiter
- self.last_render = None
- self.target_fps = 30
- self.target_delta = 1000 / self.target_fps
- self.frame_slack = None
- self.last_report = None
+ # HACK: we work against double buffering by keeping note of how many
+ # times on_draw got called.
+ #
+ # We know there's two buffers, so if we render the same state twice in a
+ # row we'll be effectively able to keep a persistent framebuffer, like
+ # with the old API.
+ #
+ # When bufn is in [0, 1] we render the background image.
+ # When bufn is in [2, ...) we render the worms.
+ # When bufn is > 3, we enable updating the worm state.
+ #
+ # TODO(q3k): allow apps to request single-buffered graphics for
+ # persistent framebuffers.
+ self.bufn = 0
self.add_event(
event.Event(
@@ -40,36 +48,28 @@ class AppWorms(application.Application):
self.just_shown = True
def on_draw(self, ctx):
- if self.just_shown:
+ if self.bufn == 0 or self.bufn == 1:
ctx.rgb(*ui.BLUE).rectangle(
-ui.WIDTH / 2, -ui.HEIGHT / 2, ui.WIDTH, ui.HEIGHT
).fill()
+ ctx.text_align = ctx.CENTER
+ ctx.text_baseline = ctx.MIDDLE
ctx.move_to(0, 0).rgb(*ui.WHITE).text("touch me :)")
- self.just_shown = False
+ self.bufn += 1
+ return
- ctx.text_align = ctx.CENTER
- ctx.text_baseline = ctx.MIDDLE
for w in self.worms:
w.draw(ctx)
+ self.bufn += 1
def main_foreground(self):
now = time.ticks_ms()
- if self.last_render is not None:
- delta = now - self.last_render
- if self.frame_slack is None:
- self.frame_slack = self.target_delta - delta
- if delta < self.target_delta:
- return
-
- if self.last_report is None or (now - self.last_report) > 1000:
- fps = 1000 / delta
- print(f"fps: {fps:.3}, frame budget slack: {self.frame_slack:.3}ms")
- self.last_report = now
-
# Simulation is currently locked to FPS.
- for w in self.worms:
- w.move()
+ if self.bufn > 3:
+ for w in self.worms:
+ w.move()
+ self.bufn = 2
self.last_render = now
--
GitLab