1 files changed, 41 insertions, 0 deletions
diff --git a/frame_counter.py b/frame_counter.py
new file mode 100644
index 0000000..a71f915
--- /dev/null
+++ b/frame_counter.py
@@ -0,0 +1,41 @@
+from sys import stderr
+from time import time
+
+
+class FrameCounter:
+    """Creates a main loop and ensures that the framerate is static"""
+
+    def __init__(self, canvas, target_fps):
+        """Initialise the frame counter
+
+        :param canvas: The canvas which to call after on
+        :param target_fps: The fps to aim to achieve
+        """
+        self.canvas = canvas
+        self.fps = target_fps
+        self.frame_time = 1 / target_fps
+        self.last_frame = time()
+
+        self.current_fps = 1
+
+    def next_frame(self, callback):
+        """Calculate when the next frame should be called
+
+        :param callback: function to call for the next frame
+        """
+        t = time()
+        ft = t - self.last_frame
+
+        delay = 0
+
+        if ft > self.frame_time:
+            if ft - self.frame_time > self.frame_time / 5:
+                print(
+                    f"Help! Running {ft - self.frame_time} seconds behind!",
+                    file=stderr)
+        else:
+            delay = self.frame_time - ft
+
+        self.canvas.after(int(delay*1000), callback)
+        self.current_fps = 1 / (delay+ft)
+        self.last_frame = t