More defense.

Author: tychedelia

crates/processing_pyo3/src/glfw.rs

@@ -81,10 +81,16 @@ impl GlfwContext {
 
         for (_, event) in glfw::flush_messages(&self.events) {
             if event == WindowEvent::Close {
+                self.window.hide();
                 return false;
             }
         }
 
-        !self.window.should_close()
+        if self.window.should_close() {
+            self.window.hide();
+            return false;
+        }
+
+        true
     }
 }

crates/processing_pyo3/src/python/jupyter_post_execute.py

@@ -2,9 +2,10 @@
 import IPython.display as _ipy_display
 
 def _processing_post_execute(result):
-    processing._end_draw()
+    if getattr(processing, '_graphics', None) is None:
+        return
+    processing._present()
     png_data = processing._readback_png()
     _ipy_display.display(_ipy_display.Image(data=bytes(png_data)))
-    processing._begin_draw()
 
 get_ipython().events.register('post_run_cell', _processing_post_execute)

crates/processing_render/src/image.rs

@@ -77,7 +77,8 @@ pub fn create(
         texture_format,
         RenderAssetUsages::all(),
     );
-    // When used as a render target (offscreen surface), the texture needs RENDER_ATTACHMENT
+    // we need to mark this as a render attachment so it can be used as a render target for
+    // drawing and readback
     image.texture_descriptor.usage |= TextureUsages::RENDER_ATTACHMENT;
 
     let handle = images.add(image);