Cube-Cube collision detection

Hi.

Im currently writing an FPS. I allready have a working level and collisions between the player and the floor/walls work fine. I Test the players collision box with the floors/walls collision boxes using this simple logic.


boolean valueInRange(float value, float min, float max)
{ return (value >= min) && (value <= max); }

boolean rectOverlap(Rect A, Rect B)
{
boolean xOverlap = valueInRange(A.x, B.x, B.x + B.width) ||
valueInRange(B.x, A.x, A.x + A.width);

boolean yOverlap = valueInRange(A.y, B.y, B.y + B.height) ||
valueInRange(B.y, A.y, A.y + A.height);

boolean zOverlap = valueInRange(A.z, B.z, B.z + B.depth) ||
valueInRange(B.z, A.z, A.z + A.depth);

return xOverlap && yOverlap && zOverlap;
}


But that obviously doesnt work if i need to test the players collision box against a rotated collision box like for example a ramp.

I can calculate the coordinates of the 8 corners of the rotated colision box in world space but how would i determine if it intersects with the players colision box. Its a givin that the players collision box will never be rotated for incase that helps.

Any help appreciated. Thnx in Advance!

Now, a small comment regarding your code... You could put all those checks in one line. Basically, something like:



return (valueInRange(A.x, B.x, B.x + B.width) ||
valueInRange(B.x, A.x, A.x + A.width)) &&
(valueInRange(A.y, B.y, B.y + B.height) ||
valueInRange(B.y, A.y, A.y + A.height)) &&
(valueInRange(A.z, B.z, B.z + B.depth) ||
valueInRange(B.z, A.z, A.z + A.depth));


It will be faster, since there will be lots of early outs, instead of having to create 3 bools, calculate all of them and then check them.
If you could, however, try using Lewis's version, it has less checks than the whole valueInRange thing.
And it could be done even faster by doing:


return (A.bbMin.x <= B.bbMax.x) &&
(A.bbMax.x >= B.bbMin.x) &&
(A.bbMin.y <= B.bbMax.y) &&
(A.bbMax.y >= B.bbMin.y) &&
(A.bbMin.z <= B.bbMax.z) &&
(A.bbMax.z >= B.bbMin.z);