yscale = ysize / height
scale = [xscale, yscale].max
- xpad = width * scale - xsize
- ypad = height * scale - ysize
+ xpad = (width * scale) - xsize
+ ypad = (height * scale) - ysize
@width = width
@height = height
- @tx = xsheet(min_lon) - xpad / 2
- @ty = ysheet(min_lat) - ypad / 2
+ @tx = xsheet(min_lon) - (xpad / 2)
+ @ty = ysheet(min_lat) - (ypad / 2)
- @bx = xsheet(max_lon) + xpad / 2
- @by = ysheet(max_lat) + ypad / 2
+ @bx = xsheet(max_lon) + (xpad / 2)
+ @by = ysheet(max_lat) + (ypad / 2)
end
# the following two functions will give you the x/y on the entire sheet
def ysheet(lat)
- log(tan(PI / 4 + (lat * PI / 180 / 2))) / (PI / 180)
+ log(tan((PI / 4) + (lat * PI / 180 / 2))) / (PI / 180)
end
def xsheet(lon)
def distance(lat, lon)
lat = lat * PI / 180
lon = lon * PI / 180
- 6372.795 * 2 * asin(sqrt(sin((lat - @lat) / 2)**2 + cos(@lat) * cos(lat) * sin((lon - @lon) / 2)**2))
+ 6372.795 * 2 * asin(sqrt((sin((lat - @lat) / 2)**2) + (cos(@lat) * cos(lat) * (sin((lon - @lon) / 2)**2))))
end
# get the worst case bounds for a given radius from the base position
latradius = 2 * asin(sqrt(sin(radius / 6372.795 / 2)**2))
begin
- lonradius = 2 * asin(sqrt(sin(radius / 6372.795 / 2)**2 / cos(@lat)**2))
+ lonradius = 2 * asin(sqrt((sin(radius / 6372.795 / 2)**2) / (cos(@lat)**2)))
rescue Errno::EDOM, Math::DomainError
lonradius = PI
end