The upper limit of the test area should be the string's maxlength - 1,
otherwise two errors occur when iterating through the area using the <=
operator: 1) addresses beyond the last element are indexed, triggering
UB; this occurs when object.vPos is on the last row of the vWorldMap
matrix. 2) the test area will warp around the screen; this happens when
object.vPos is on the last column of the matrix it will wrongly index
the element from the first column in the next row, potentially detecting
a collision with a rectangle in the wrong position. I believe this error
was not detected because the map is surrounded with walls.
Faisal Saadatmand
Javidx9