How to detect if a certain range resides (partly) within an other range?
- by Tom
Lets say I've got two squares and I know their positions, a red and blue square:
redTopX;
redTopY;
redBotX;
redBotY;
blueTopX;
blueTopY;
blueBotX;
blueBotY;
Now, I want to check if square blue resides (partly) within (or around) square red. This can happen in a lot of situations, as you can see in this image I created to illustrate my situation better:
Note that there's always only one blue and one red square, I just added multiple so I didn't have to redraw 18 times.
My original logic was simple, I'd check all corners of square blue and see if any of them are inside square red:
if (
((redTopX >= blueTopX) && (redTopY >= blueTopY) && (redTopX <= blueBotX) && (redTopY <= blueBotY)) || //top left
((redBotX >= blueTopX) && (redTopY >= blueTopY) && (redBotX <= blueBotX) && (redTopY <= blueBotY)) || //top right
((redTopX >= blueTopX) && (redBotY >= blueTopY) && (redTopX <= blueBotX) && (redBotY <= blueBotY)) || //bottom left
((redBotX >= blueTopX) && (redBotY >= blueTopY) && (redBotX <= blueBotX) && (redBotY <= blueBotY)) //bottom right
) {
//blue resides in red
}
Unfortunately, there are a couple of flaws in this logic. For example, what if red surrounds blue (like in situation 1)?
I thought this would be pretty easy but am having trouble coming up with a good way of covering all these situations.. can anyone help me out here?
Regards,
Tom
