2
我最近想出了创建标签云的想法，就像动画像地球一样。我已经从ngdc.noaa.gov提取海岸线坐标，并编写了一个脚本，在浏览器中显示它。现在，您可以想象，整个海岸线由大约48919个点组成，我的脚本将单独渲染（每个坐标由一个跨度表示）。显然，没有浏览器能够流利地渲染 - 但如果我能够在我的旧版P4 2.8 Ghz（作为代表性基准）上渲染200个跨度（现在的两倍），那将是一件好事。有什么JavaScript优化，我可以用来加快显示这些跨度？优化3D世界的Javascript动画
一个“坐标”：
<div id="world_pixels">
<span id="wp_0" style="position:fixed; top:0px; left:0px; z-index:1; font-size:20px; cursor:pointer;cursor:hand;" onmouseover="magnify_world_pixel('wp_0');" onmouseout="shrink_world_pixel('wp_0');" onClick="set_askcue_bar('', 'new york')">new york</span>
</div>
脚本：
$(document).ready(function(){
world_pixels = $("#world_pixels span");
world_pixels.spin();
setInterval("world_pixels.spin()",1500);
});
z = new Array();
$.fn.spin = function() {
for(i=0; i<this.length; i++) {
/*actual screen coordinates: x/y/z --> left/font-size/top
300/13/0 300/6/300
|/
|/
0/13/300 ----|---- 600/13/300
/|
/|
300/20/300 300/13/600
*/
/*scale font size*/
var resize_x = 1;
/*scale width*/
var resize_y = 2.5;
/*scale height*/
var resize_z = 2.5;
var from_left = 300;
var from_top = 20;
/*actual math coordinates:
1 -1
|/
|/
1 ----|---- -1
/|
/|
1 -1
*/
//var get_element = document.getElementById();
//var font_size = parseInt(this.style.fontSize);
var font_size = parseInt($(this[i]).css("font-size"));
var left = parseInt($(this[i]).css("left"));
if (coast_line_array[i][1]) {
} else {
var top = parseInt($(this[i]).css("top"));
z[i] = from_top + (top - (300 * resize_z))/(300 * resize_z);
//global beacause it's used in other functions later on
var top_new = from_top + Math.round(Math.cos(coast_line_array[i][2]/90*Math.PI) * (300 * resize_z) + (300 * resize_z));
$(this[i]).css("top", top_new);
coast_line_array[i][3] = 1;
}
var x = resize_x * (font_size - 13)/7;
var y = from_left + (left- (300 * resize_y))/(300 * resize_y);
if (y >= 0) {
this[i].phi = Math.acos(x/(Math.sqrt(x^2 + y^2)));
} else {
this[i].phi = 2*Math.PI - Math.acos(x/(Math.sqrt(x^2 + y^2)));
i
}
this[i].theta = Math.acos(z[i]/Math.sqrt(x^2 + y^2 + z[i]^2));
var font_size_new = resize_x * Math.round(Math.sin(coast_line_array[i][4]/90*Math.PI) * Math.cos(coast_line_array[i][0]/180*Math.PI) * 7 + 13);
var left_new = from_left + Math.round(Math.sin(coast_line_array[i][5]/90*Math.PI) * Math.sin(coast_line_array[i][0]/180*Math.PI) * (300 * resize_y) + (300 * resize_y));
//coast_line_array[i][6] = coast_line_array[i][7]+1;
if ((coast_line_array[i][0] + 1) > 180) {
coast_line_array[i][0] = -180;
} else {
coast_line_array[i][0] = coast_line_array[i][0] + 0.25;
}
$(this[i]).css("font-size", font_size_new);
$(this[i]).css("left", left_new);
}
}
resize_x = 1;
function magnify_world_pixel(element) {
$("#"+element).animate({
fontSize: resize_x*30+"px"
}, {
duration: 1000
});
}
function shrink_world_pixel(element) {
$("#"+element).animate({
fontSize: resize_x*6+"px"
}, {
duration: 1000
});
}
我会很感激的任何建议，以优化我的剧本，也许甚至有关于如何去一个完全不同的方法这个。 存储阵列的所有坐标整个.js文件可我的网页上，该文件是大约2.9 MB，所以你可以考虑拉的.zip本地测试：
metaroulette.com/files/31218.zip
metaroulette。 com/files/31218.js
PS我用来创建跨度的php：
<?php
//$arbitrary_characters = array('a','b','c','ddsfsdfsdf','e','f','g','h','isdfsdffd','j','k','l','mfdgcvbcvbs','n','o','p','q','r','s','t','uasdfsdf','v','w','x','y','z','0','1','2','3','4','5','6','7','8','9',);
$arbitrary_characters = array('cat','table','cool','deloitte','askcue','what','more','less','adjective','nice','clinton','mars','jupiter','testversion','beta','hilarious','lolcatz','funny','obama','president','nice','what','misplaced','category','people','religion','global','skyscraper','new york','dubai','helsinki','volcano','iceland','peter','telephone','internet', 'dialer', 'cord', 'movie', 'party', 'chris', 'guitar', 'bentley', 'ford', 'ferrari', 'etc', 'de facto');
for ($i=0; $i<96; $i++) {
$arb_digits = rand (0,45);
$arbitrary_character = $arbitrary_characters[$arb_digits];
//$arbitrary_character = ".";
echo "<span id=\"wp_$i\" style=\"position:fixed; top:0px; left:0px; z-index:1; font-size:20px; cursor:pointer;cursor:hand;\" onmouseover=\"magnify_world_pixel('wp_$i');\" onmouseout=\"shrink_world_pixel('wp_$i');\" onClick=\"set_askcue_bar('', '$arbitrary_character')\">$arbitrary_character</span>\n";
}
?>
检查了这一点 - 我了解它，并可能能够帮助您http://code.google.com/closure/ – 2010-04-20 22:22:22