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112 lines
1.7 KiB
JavaScript

1 year ago
'use strict';
var s = [0x0000, 0x0000, 0x0000, 0x0000];
function mul(a, b) {
var r = [0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000];
for (var j = 0; j < 4; j++) {
var k = 0;
for (var i = 0; i < 4; i++) {
var t = a[i] * b[j] + r[i+j] + k;
r[i+j] = t & 0xffff;
k = t >>> 16;
}
r[j+4] = k;
}
r.length = 4;
return r;
}
function add(a, n) {
var r = [0x0000, 0x0000, 0x0000, 0x0000],
k = n;
for (var i = 0; i < 4; i++) {
var t = a[i] + k;
r[i] = t & 0xffff;
k = t >>> 16;
}
return r;
}
function shr(a, n) {
var r = [a[0], a[1], a[2], a[3], 0x0000],
i = 4,
k = 0;
for (; n > 16; n -= 16, i--)
for (var j = 0; j < 4; j++)
r[j] = r[j+1];
for (; i > 0; i--) {
var s = r[i-1];
r[i-1] = (s >>> n) | k;
k = ((s & ((1 << n) - 1)) << (16 - n));
}
r.length = 4;
return r;
}
return L.Class.extend({
seed: function(n) {
n = (n - 1)|0;
s[0] = n & 0xffff;
s[1] = n >>> 16;
s[2] = 0;
s[3] = 0;
},
int: function() {
s = mul(s, [0x7f2d, 0x4c95, 0xf42d, 0x5851]);
s = add(s, 1);
var r = shr(s, 33);
return (r[1] << 16) | r[0];
},
get: function() {
var r = (this.int() % 0x7fffffff) / 0x7fffffff, l, u;
switch (arguments.length) {
case 0:
return r;
case 1:
l = 1;
u = arguments[0]|0;
break;
case 2:
l = arguments[0]|0;
u = arguments[1]|0;
break;
}
return Math.floor(r * (u - l + 1)) + l;
},
derive_color: function(string) {
this.seed(parseInt(sfh(string), 16));
var r = this.get(128),
g = this.get(128),
min = 0,
max = 128;
if ((r + g) < 128)
min = 128 - r - g;
else
max = 255 - r - g;
var b = min + Math.floor(this.get() * (max - min));
return '#%02x%02x%02x'.format(0xff - r, 0xff - g, 0xff - b);
}
});