mirror of
https://github.com/bec-project/bec_widgets.git
synced 2025-12-31 19:11:18 +01:00
85 lines
2.6 KiB
Python
85 lines
2.6 KiB
Python
"""
|
|
This module provides a utility class for counting and reporting frames per second (FPS) in a PyQtGraph application.
|
|
|
|
Classes:
|
|
FPSCounter: A class that monitors the paint events of a `ViewBox` to calculate and emit FPS values.
|
|
|
|
Usage:
|
|
The `FPSCounter` class can be used to monitor the rendering performance of a `ViewBox` in a PyQtGraph application.
|
|
It connects to the `ViewBox`'s paint event and calculates the FPS over a specified interval, emitting the FPS value
|
|
at regular intervals.
|
|
|
|
Example:
|
|
from qtpy import QtWidgets, QtCore
|
|
import pyqtgraph as pg
|
|
from fps_counter import FPSCounter
|
|
|
|
app = pg.mkQApp("FPS Counter Example")
|
|
win = pg.GraphicsLayoutWidget()
|
|
win.show()
|
|
|
|
vb = pg.ViewBox()
|
|
plot_item = pg.PlotItem(viewBox=vb)
|
|
win.addItem(plot_item)
|
|
|
|
fps_counter = FPSCounter(vb)
|
|
fps_counter.sigFpsUpdate.connect(lambda fps: print(f"FPS: {fps:.2f}"))
|
|
|
|
sys.exit(app.exec_())
|
|
"""
|
|
|
|
from time import perf_counter
|
|
|
|
import pyqtgraph as pg
|
|
from qtpy import QtCore
|
|
|
|
|
|
class FPSCounter(QtCore.QObject):
|
|
"""
|
|
A utility class for counting and reporting frames per second (FPS).
|
|
|
|
This class connects to a `ViewBox`'s paint event to count the number of
|
|
frames rendered and calculates the FPS over a specified interval. It emits
|
|
a signal with the FPS value at regular intervals.
|
|
|
|
Attributes:
|
|
sigFpsUpdate (QtCore.Signal): Signal emitted with the FPS value.
|
|
view_box (pg.ViewBox): The `ViewBox` instance to monitor.
|
|
"""
|
|
|
|
sigFpsUpdate = QtCore.Signal(float)
|
|
|
|
def __init__(self, view_box):
|
|
super().__init__()
|
|
self.view_box = view_box
|
|
self.view_box.sigPaint.connect(self.increment_count)
|
|
self.count = 0
|
|
self.last_update = perf_counter()
|
|
self.timer = QtCore.QTimer()
|
|
self.timer.timeout.connect(self.calculate_fps)
|
|
self.timer.start(1000)
|
|
|
|
def increment_count(self):
|
|
"""
|
|
Increment the frame count when the `ViewBox` is painted.
|
|
"""
|
|
self.count += 1
|
|
|
|
def calculate_fps(self):
|
|
"""
|
|
Calculate the frames per second (FPS) based on the number of frames
|
|
"""
|
|
now = perf_counter()
|
|
elapsed = now - self.last_update
|
|
fps = self.count / elapsed if elapsed > 0 else 0.0
|
|
self.last_update = now
|
|
self.count = 0
|
|
self.sigFpsUpdate.emit(fps)
|
|
|
|
def cleanup(self):
|
|
"""
|
|
Clean up the FPS counter by stopping the timer and disconnecting the signal.
|
|
"""
|
|
self.timer.stop()
|
|
self.timer.timeout.disconnect(self.calculate_fps)
|