On Windows, Qt does not treat queued connections fairly. This is a problem for us, because most of the operations we are doing are asynchronous, for optimization or utility reasons.
For example, the texture sub-rect geometry is a delayed binding as we don't want to apply effect for texture if the result is just going to be dismissed (due to geometry change, effect needs to be applied again).
We also use delayed bindings in complex layouting, such as within the player control bar where controls need to be invisible when they no longer fit into the space (unless expandable).
In summary, this seems to how Qt behave with regard to queued connections:
In the worst case (messages are constantly pushed), they may be delayed forever if Windows keep sending messages. This is the case with window resize, for example.
In the average case (there were messages when event dispatcher encountered with a queued call), they are delayed by 10~ milliseconds.
In the best case, there is no delay, but this is rare for a GUI application, as GUI applications almost always have messages due to user interaction.
Draft because:
Close #29038.
Request review @chub.
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