[sqlite] I need help making this code run faster

[Brannon King]

I'm wondering if the following query can be done as a single query rather
than running it in a (nested) loop.
 
Suppose a database with five columns; xStart, yStart, xEnd, yEnd, score. I
need the maximum score at the midpoint of the line quantized to a 64x64
grid. Psuedo code:
 
query = prepare("
SELECT score FROM db WHERE
(xStart+xEnd)/2 >= :left AND
(xStart+xEnd)/2 < :right AND
(yStart+yEnd)/2 >= :top AND
(yStart+yEnd)/2 < :bottom
ORDER BY score DESC LIMIT 1
")
 
xJump = max(xEnd in db) / 64.0;
yJump = max(yEnd in db) / 64.0;
for(int x = 0; x < 64; x++){
  for(int y = 0; y < 64; y++){
    left = x*xJump, righ = (x+1)*xJump
    top = y*yJump, bottom = (y+1)*yJump
    bind(query, left, right, top, bottom)
    ret = step(query)
    output[x][y] = score or 0 if no ret
  }
}
 
Thanks for your time. If you see anything else I could do to speed this up,
please mention it.
______________________________
Brannon King
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