add force redraw flag and redraw whenever visibility is restored in case framebuffer is destroyed

1 files changed, 11 insertions, 2 deletions

diff --git a/window.py b/window.py
index 8b34989..8e04225 100644
--- a/window.py
+++ b/window.py
@@ -27,6 +27,8 @@ class PixDisplay:
         self.tex = None
         self.text_next = None
 
+        self._force_redraw = False
+
     @property
     def max_framerate(self):
         return self._max_fps
@@ -76,9 +78,10 @@ class PixDisplay:
 
         # Draw static image except during a transition
         if self.image_time < self.image_duration:
-            # Avoid redraw unless window size has changed
-            if self.win_w != old_win_w or self.win_h != old_win_h:
+            # Avoid unforced-redraw unless window size has changed
+            if self._force_redraw or self.win_w != old_win_w or self.win_h != old_win_h:
                 self.renderer.draw_static(self.tex, self.win_w, self.win_h, 1.0)
+                self._force_redraw = False
             return
 
         # Start drawing transition once image_time >= image_duration
@@ -110,6 +113,11 @@ class PixDisplay:
         elif key == GLUT_KEY_RIGHT:
             self.skip(1)
 
+    def handle_visibility_change(self, state):
+        if state == GLUT_VISIBLE:
+            self._force_redraw = True
+            glutPostRedisplay()
+
     # Initialization and main loop
     def main(self, glut_args):
         # Initialize the window
@@ -137,6 +145,7 @@ class PixDisplay:
         # Run display
         glutDisplayFunc(self.display)
         glutTimerFunc(self.frame_time, self.timer, 0)
+        glutVisibilityFunc(self.handle_visibility_change)  # Redraw in case framebuffer gets destroyed when window is obscured
         glutSpecialFunc(self.handle_special_key)
         glutMainLoop()