## BlockMap Class

erwin
2012-09-05
2012-09-16
• erwin - 2012-09-05

Dear Robert,

I have difficulties to visualize the BlockMap class in my mind,

BlockCount : the size of the block

CornerCount : the size of the corner block

AllBlocks : the block rectangle in Cartesian Coordinate

AllCorners : the corner block rectangle in Cartesian Coordinate

Corners : ?

BlockAreas : ?

BlockCenters : ?

CornerAreas : ?

Would you give me hints about it ?

Thanks Robert.

• Robert Važan - 2012-09-05

Dear Erwin,

Try to render it to bitmap then :-) That will make it easy to visualize.

I know it would take time, so here's a quick explanation instead. BlockMap
represents an NxM checkerboard. Its properties then mean the following:

Corners : (N+1)x(M+1) corners of checkerboard fields

BlockAreas : NxM rectangles describing location and size of each field on the
checkerboard

BlockCenters : NxM points representing centers of checkerboard fields

CornerAreas : tricky, see below

CornerAreas represents secondary checkerboard (let's call it B) overlaid on
top of the original checkerboard (let's call it A). Imagine making a copy of
checkerboard A and shifting it by half of a field right and down. B's corners
are now where A's centers are. Checkerboard B has 1 extra row and 1 extra
column, because it contains half-size fields on all its 4 sides.

If you cannot understand it after this explanation, I suggest rendering it so
that you can see for yourself.

Kind Regards,

Robert

• erwin - 2012-09-06

Hi Robert,

I'm trying to figure out from the code. It looks like Corners is the PointGrid
structure that holds the block point, BlockAreas is the RectangleGrid
structure that returns Cartesian coordinates for each point, BlockCenters
holds the center block point, CornerAreas returns the center block point
coordinates with top and left half of the field, right and bottom one and half
of the field. All of it NxM. Is this what you meant ?

Thanks Robert.

• Robert Važan - 2012-09-06

Hi Erwin,

You are wrong in several points. I suggest you render it into bitmap after
all. It will be much faster than email ping-pong.

Kind Regards,

Robert

• erwin - 2012-09-06

OK,

Thanks Robert.