//对象值
var objSunDiv;
//获得旋转角度的正弦值和余弦值
function getValue() {
var deg = document.getElementById("txt2").value;
objSunDiv = document.all("idSunDiv");
var pi = Math.PI;
var deg2rad = Math.PI * 2 / 360;
rad = deg * deg2rad;
costheta = Math.cos(rad);
var xx = Math.cos(23);
sintheta = Math.sin(rad);
with (objSunDiv.filters.item(0)) {
M11 = costheta; M12 = -sintheta; M21 = sintheta; M22 = costheta; }
}--为什么只在ie下能用,火狐里怎么不行
var objSunDiv;
//获得旋转角度的正弦值和余弦值
function getValue() {
var deg = document.getElementById("txt2").value;
objSunDiv = document.all("idSunDiv");
var pi = Math.PI;
var deg2rad = Math.PI * 2 / 360;
rad = deg * deg2rad;
costheta = Math.cos(rad);
var xx = Math.cos(23);
sintheta = Math.sin(rad);
with (objSunDiv.filters.item(0)) {
M11 = costheta; M12 = -sintheta; M21 = sintheta; M22 = costheta; }
}--为什么只在ie下能用,火狐里怎么不行
var objSunDiv;
//获得旋转角度的正弦值和余弦值
function getValue() {
var deg = document.getElementById("txt2").value;//旋转角度
objSunDiv = document.getElementById("idSunDiv");
var pi = Math.PI;
if (isIE) {
var deg2rad = Math.PI * 2 / 360;
rad = deg * deg2rad;
costheta = Math.cos(rad);
var xx = Math.cos(23);
sintheta = Math.sin(rad);
with (objSunDiv.filters.item(0)) {
M11 = costheta; M12 = -sintheta; M21 = sintheta; M22 = costheta; }
} else {
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var img = new Image();//还有这里,一定要在新申明一个img吗
//怎么把旋转角度传进来呢? ctx.translate(150, 150);//这里的两个值是什么意思,
ctx.rotate(pi / 2); ctx.drawImage(img, 0, 0); }
}
https://developer.mozilla.org/en/Canvas_tutorial/Transformations
http://mugtug.com/sketchpad/
canvas的语法请参考mozilla文档上的,
http://dev.w3.org/html5/canvas-api/canvas-2d-api.html#transformations
里面有各个参数的介绍。