- Also, before using the updated bitmap data, make sure to select it out
- of context first (for example by selecting ::wxNullBitmap into the device
- context).
+ Before using the updated bitmap data, make sure to select it out of
+ context first either by selecting ::wxNullBitmap into the device
+ context or destroying the device context entirely.
+
+ If the bitmap is already selected in this device context, nothing is
+ done. If it is selected in another context, the function asserts and
+ drawing on the bitmap won't work correctly.