Find the UpperRightCorner & LowerLeftCorner - rotated Rect

[switchblade_77]

How do I find the UpperRightCorner and the LowerLeftCorner of a rotated Rect?

I know that I can find the UpperLeftCorner and the LowerRightCorner of the irr rect,
from that can I find the URC and the LLC ?
The center of rotation is the middle of the rect or could be any of the 4 vertex of the rect..
eg : Like If I have a trash can sprite and want to rotate it according to the lowerRight vertex if a player kicks it from the left .. or a missle projectile.. etc

Can anyone explain me how to get it, I would be really grateful...

[Markhor]

I've not actually looked but I think I get the concept. Can't you just copy/paste and make a new function, to reverse the side? Like it's taking the same top, but you've "swapped" the left or right for it?
Maybe someone who knows what they're saying should answer.

[RdR]

If you want the accurate coordinates you can try this:

Code: Select all

 
        irr::core::vector3df rotation = irr::core::vector3df(0, 45, 0); // Rotation only around Y axis
        irr::core::rectf rect = irr::core::rectf(0, 0, 10, 10);  // Rectangle
 
        // Create a 3D box from your rectangle
        irr::core::vector3df minEdge = irr::core::vector3df(rect.UpperLeftCorner.X, 0, rect.UpperLeftCorner.Y);
        irr::core::vector3df maxEdge = irr::core::vector3df(rect.LowerRightCorner.X, 0, rect.LowerRightCorner.Y);
        irr::core::aabbox3df box = irr::core::aabbox3df(minEdge, maxEdge);
 
        // Transformation matrix
        irr::core::matrix4 m;
        m.setRotationDegrees(rotation);
        m.setRotationCenter(box.getCenter(), irr::core::vector3df());
 
        // Get edges from box
        irr::core::vector3df edges[8];
        box.getEdges(edges);
 
        // Transform edges
        for(irr::u32 i = 0; i < 8; i++) {
                irr::core::vector3df edge = edges[i];
 
                if(i == 1 || i == 3 || i == 5 || i == 7) {
                        m.transformVect(edge);
                }
        }
 
        // The edges you need are 1, 3, 5, and 7
 

Just get edges 1, 3, 5 and 7 to get the correct coordinates from your rotated rectangle.