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- import asin/acos/mod from the new math.nas

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- drop parentheses where not necessary (looks cleaner :-)
This commit is contained in:
mfranz 2007-06-18 10:33:37 +00:00
parent b2750d8a05
commit 870830b4a7
1 changed files with 31 additions and 39 deletions
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70
Nasal/geo.nas
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@ -61,13 +61,9 @@ var sin = math.sin;
var cos = math.cos;
var atan2 = math.atan2;
var sqrt = math.sqrt;
var asin = func(v) { math.atan2(v, math.sqrt(1 - v * v)) }
var acos = func(v) { math.atan2(math.sqrt(1 - v * v), v) }
var mod = func(v, w) {
var x = v - w * int(v / w);
return x < 0 ? x + abs(w) : x;
}
var asin = math.asin;
var acos = math.acos;
var mod = math.mod;
# class that maintains one set of geographical coordinates
@ -83,9 +79,9 @@ var Coord = {
m._x = nil; # in m
m._y = nil;
m._z = nil;
if (copy != nil) {
if (copy != nil)
m.set(copy);
}
return m;
},
_cupdate : func {
@ -154,10 +150,10 @@ var Coord = {
dist /= ERAD;
me._lat = asin(sin(me._lat) * cos(dist) + cos(me._lat) * sin(dist) * cos(course));
if (cos(me._lat) > EPSILON) {
if (cos(me._lat) > EPSILON)
me._lon = math.pi - mod(math.pi - me._lon - asin(sin(course) * sin(dist)
/ cos(me._lat)), 2 * math.pi);
}
me._cdirty = 1;
me;
},
@ -165,9 +161,9 @@ var Coord = {
me._pupdate();
dest._pupdate();
if (me._lat == dest._lat and me._lon == dest._lon) {
if (me._lat == dest._lat and me._lon == dest._lon)
return 0;
}
var dlon = dest._lon - me._lon;
return mod(atan2(sin(dlon) * cos(dest._lat), cos(me._lat) * sin(dest._lat)
- sin(me._lat) * cos(dest._lat) * cos(dlon)), 2 * math.pi) * R2D;
@ -177,9 +173,9 @@ var Coord = {
me._pupdate();
dest._pupdate();
if (me._lat == dest._lat and me._lon == dest._lon) {
if (me._lat == dest._lat and me._lon == dest._lon)
return 0;
}
var a = sin((me._lat - dest._lat) * 0.5);
var o = sin((me._lon - dest._lon) * 0.5);
return 2.0 * ERAD * asin(sqrt(a * a + cos(me._lat) * cos(dest._lat) * o * o));
@ -196,9 +192,9 @@ var Coord = {
return !(me._cdirty and me._pdirty);
},
dump : func {
if (me._cdirty and me._pdirty) {
if (me._cdirty and me._pdirty)
print("Coord.print(): coord undefined");
}
me._cupdate();
me._pupdate();
printf("x=%f y=%f z=%f lat=%f lon=%f alt=%f",
@ -210,48 +206,45 @@ var Coord = {
# normalize degree to 0 <= angle < 360
#
var normdeg = func(angle) {
while (angle < 0) {
while (angle < 0)
angle += 360;
}
while (angle >= 360) {
while (angle >= 360)
angle -= 360;
}
return angle;
}
var bucket_span = func(lat) {
if (lat >= 89.0 ) {
if (lat >= 89.0)
360.0;
} elsif (lat >= 88.0 ) {
elsif (lat >= 88.0)
8.0;
} elsif (lat >= 86.0 ) {
elsif (lat >= 86.0)
4.0;
} elsif (lat >= 83.0 ) {
elsif (lat >= 83.0)
2.0;
} elsif (lat >= 76.0 ) {
elsif (lat >= 76.0)
1.0;
} elsif (lat >= 62.0 ) {
elsif (lat >= 62.0)
0.5;
} elsif (lat >= 22.0 ) {
elsif (lat >= 22.0)
0.25;
} elsif (lat >= -22.0 ) {
elsif (lat >= -22.0)
0.125;
} elsif (lat >= -62.0 ) {
elsif (lat >= -62.0)
0.25;
} elsif (lat >= -76.0 ) {
elsif (lat >= -76.0)
0.5;
} elsif (lat >= -83.0 ) {
elsif (lat >= -83.0)
1.0;
} elsif (lat >= -86.0 ) {
elsif (lat >= -86.0)
2.0;
} elsif (lat >= -88.0 ) {
elsif (lat >= -88.0)
4.0;
} elsif (lat >= -89.0 ) {
elsif (lat >= -89.0)
8.0;
} else {
else
360.0;
}
}
@ -270,11 +263,10 @@ var tile_index = func(lat, lon) {
lon = int(int(lon / span) * span);
} else {
lon = int(int((lon + 1) / span) * span - span);
if (lon < -180) {
if (lon < -180)
lon = -180;
}
}
}
var y = int((lat - lat_floor) * 8);
return (lon_floor + 180) * 16384 + (lat_floor + 90) * 64 + y * 8 + x;