I had asked a question about how to detect an object in the viewport (https://www.construct.net/en/forum/construct-3/how-do-i-8/detect-sprite-viewport-148001). I have a similar question about how to detect all objects currently in the viewport.
I have a scrolling background with eight windows visible at any given time:
I learned from my first question that the "Is on-screen" condition will determine if an object is on the screen. What I would like is, every two seconds, determine which windows are on the viewport. Currently, each window is a separate instance and has "Name" property, though if it's easier, I could just copy so it is the same instance with a different UID value.
The purpose of wanting to see which windows are in the viewport is to randomly have an image appear in one of the eight windows that is visible. Since the "Is on-screen" is condition, not an event, I'm not sure how to do this without having to hack something together by checking every window. What is a better way to do this?