StackBlur.js代码:
(function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.StackBlur = f()}})(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o
/*
StackBlur - a fast almost Gaussian Blur For Canvas
Version: 0.5
Author: Mario Klingemann
Contact: [email protected]
Website: http://www.quasimondo.com/StackBlurForCanvas
Twitter: @quasimondo
In case you find this class useful - especially in commercial projects -
I am not totally unhappy for a small donation to my PayPal account
[email protected]
Or support me on flattr:
https://flattr.com/thing/72791/StackBlur-a-fast-almost-Gaussian-Blur-Effect-for-CanvasJavascript
Copyright (c) 2010 Mario Klingemann
Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.
*/
var mul_table = [
512,512,456,512,328,456,335,512,405,328,271,456,388,335,292,512,
454,405,364,328,298,271,496,456,420,388,360,335,312,292,273,512,
482,454,428,405,383,364,345,328,312,298,284,271,259,496,475,456,
437,420,404,388,374,360,347,335,323,312,302,292,282,273,265,512,
497,482,468,454,441,428,417,405,394,383,373,364,354,345,337,328,
320,312,305,298,291,284,278,271,265,259,507,496,485,475,465,456,
446,437,428,420,412,404,396,388,381,374,367,360,354,347,341,335,
329,323,318,312,307,302,297,292,287,282,278,273,269,265,261,512,
505,497,489,482,475,468,461,454,447,441,435,428,422,417,411,405,
399,394,389,383,378,373,368,364,359,354,350,345,341,337,332,328,
324,320,316,312,309,305,301,298,294,291,287,284,281,278,274,271,
268,265,262,259,257,507,501,496,491,485,480,475,470,465,460,456,
451,446,442,437,433,428,424,420,416,412,408,404,400,396,392,388,
385,381,377,374,370,367,363,360,357,354,350,347,344,341,338,335,
332,329,326,323,320,318,315,312,310,307,304,302,299,297,294,292,
289,287,285,282,280,278,275,273,271,269,267,265,263,261,259];
var shg_table = [
9, 11, 12, 13, 13, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 17,
17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 18, 19,
19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 20, 20, 20,
20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 21,
21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21,
21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22,
22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22,
22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 23,
23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24 ];
function processImage(img, canvas, radius, blurAlphaChannel, w, h)
{
var c = document.getElementById(canvas);
c.getContext("2d").clearRect(0,0,c.width,c.height);
if (typeof(img) == 'string') {
var img = document.getElementById(img);
}
else if (typeof HTMLImageElement !== 'undefined' && !img instanceof HTMLImageElement) {
return;
}
//自己修改部分,canvas大小通过传参设置
// var w = img.naturalWidth;
// var h = img.naturalHeight;
if (typeof(canvas) == 'string') {
var canvas = document.getElementById(canvas);
}
else if (typeof HTMLCanvasElement !== 'undefined' && !canvas instanceof HTMLCanvasElement) {
return;
}
canvas.style.width = w + 'px';
canvas.style.height = h + 'px';
canvas.width = w;
canvas.height = h;
var context = canvas.getContext('2d');
context.clearRect(0, 0, w, h);
//context.drawImage(img, 0, 0); 自己修改部分,为了图片适应canvas的大小
context.drawImage(img, 0, 0, w, h);
if (isNaN(radius) || radius < 1) return;
if (blurAlphaChannel)
processCanvasRGBA(canvas, 0, 0, w, h, radius);
else
processCanvasRGB(canvas, 0, 0, w, h, radius);
}
function getImageDataFromCanvas(canvas, top_x, top_y, width, height)
{
if (typeof(canvas) == 'string')
var canvas = document.getElementById(canvas);
else if (typeof HTMLCanvasElement !== 'undefined' && !canvas instanceof HTMLCanvasElement)
return;
var context = canvas.getContext('2d');
var imageData;
try {
try {
imageData = context.getImageData(top_x, top_y, width, height);
} catch(e) {
throw new Error("unable to access local image data: " + e);
return;
}
} catch(e) {
throw new Error("unable to access image data: " + e);
}
return imageData;
}
function processCanvasRGBA(canvas, top_x, top_y, width, height, radius)
{
if (isNaN(radius) || radius < 1) return;
radius |= 0;
var imageData = getImageDataFromCanvas(canvas, top_x, top_y, width, height);
imageData = processImageDataRGBA(imageData, top_x, top_y, width, height, radius);
canvas.getContext('2d').putImageData(imageData, top_x, top_y);
}
function processImageDataRGBA(imageData, top_x, top_y, width, height, radius)
{
var pixels = imageData.data;
var x, y, i, p, yp, yi, yw, r_sum, g_sum, b_sum, a_sum,
r_out_sum, g_out_sum, b_out_sum, a_out_sum,
r_in_sum, g_in_sum, b_in_sum, a_in_sum,
pr, pg, pb, pa, rbs;
var div = radius + radius + 1;
var w4 = width << 2;
var widthMinus1 = width - 1;
var heightMinus1 = height - 1;
var radiusPlus1 = radius + 1;
var sumFactor = radiusPlus1 * (radiusPlus1 + 1) / 2;
var stackStart = new BlurStack();
var stack = stackStart;
for (i = 1; i < div; i++)
{
stack = stack.next = new BlurStack();
if (i == radiusPlus1) var stackEnd = stack;
}
stack.next = stackStart;
var stackIn = null;
var stackOut = null;
yw = yi = 0;
var mul_sum = mul_table[radius];
var shg_sum = shg_table[radius];
for (y = 0; y < height; y++)
{
r_in_sum = g_in_sum = b_in_sum = a_in_sum = r_sum = g_sum = b_sum = a_sum = 0;
r_out_sum = radiusPlus1 * (pr = pixels[yi]);
g_out_sum = radiusPlus1 * (pg = pixels[yi+1]);
b_out_sum = radiusPlus1 * (pb = pixels[yi+2]);
a_out_sum = radiusPlus1 * (pa = pixels[yi+3]);
r_sum += sumFactor * pr;
g_sum += sumFactor * pg;
b_sum += sumFactor * pb;
a_sum += sumFactor * pa;
stack = stackStart;
for (i = 0; i < radiusPlus1; i++)
{
stack.r = pr;
stack.g = pg;
stack.b = pb;
stack.a = pa;
stack = stack.next;
}
for (i = 1; i < radiusPlus1; i++)
{
p = yi + ((widthMinus1 < i ? widthMinus1 : i) << 2);
r_sum += (stack.r = (pr = pixels[p])) * (rbs = radiusPlus1 - i);
g_sum += (stack.g = (pg = pixels[p+1])) * rbs;
b_sum += (stack.b = (pb = pixels[p+2])) * rbs;
a_sum += (stack.a = (pa = pixels[p+3])) * rbs;
r_in_sum += pr;
g_in_sum += pg;
b_in_sum += pb;
a_in_sum += pa;
stack = stack.next;
}
stackIn = stackStart;
stackOut = stackEnd;
for (x = 0; x < width; x++)
{
pixels[yi+3] = pa = (a_sum * mul_sum) >> shg_sum;
if (pa != 0)
{
pa = 255 / pa;
pixels[yi] = ((r_sum * mul_sum) >> shg_sum) * pa;
pixels[yi+1] = ((g_sum * mul_sum) >> shg_sum) * pa;
pixels[yi+2] = ((b_sum * mul_sum) >> shg_sum) * pa;
} else {
pixels[yi] = pixels[yi+1] = pixels[yi+2] = 0;
}
r_sum -= r_out_sum;
g_sum -= g_out_sum;
b_sum -= b_out_sum;
a_sum -= a_out_sum;
r_out_sum -= stackIn.r;
g_out_sum -= stackIn.g;
b_out_sum -= stackIn.b;
a_out_sum -= stackIn.a;
p = (yw + ((p = x + radius + 1) < widthMinus1 ? p : widthMinus1)) << 2;
r_in_sum += (stackIn.r = pixels[p]);
g_in_sum += (stackIn.g = pixels[p+1]);
b_in_sum += (stackIn.b = pixels[p+2]);
a_in_sum += (stackIn.a = pixels[p+3]);
r_sum += r_in_sum;
g_sum += g_in_sum;
b_sum += b_in_sum;
a_sum += a_in_sum;
stackIn = stackIn.next;
r_out_sum += (pr = stackOut.r);
g_out_sum += (pg = stackOut.g);
b_out_sum += (pb = stackOut.b);
a_out_sum += (pa = stackOut.a);
r_in_sum -= pr;
g_in_sum -= pg;
b_in_sum -= pb;
a_in_sum -= pa;
stackOut = stackOut.next;
yi += 4;
}
yw += width;
}
for (x = 0; x < width; x++)
{
g_in_sum = b_in_sum = a_in_sum = r_in_sum = g_sum = b_sum = a_sum = r_sum = 0;
yi = x << 2;
r_out_sum = radiusPlus1 * (pr = pixels[yi]);
g_out_sum = radiusPlus1 * (pg = pixels[yi+1]);
b_out_sum = radiusPlus1 * (pb = pixels[yi+2]);
a_out_sum = radiusPlus1 * (pa = pixels[yi+3]);
r_sum += sumFactor * pr;
g_sum += sumFactor * pg;
b_sum += sumFactor * pb;
a_sum += sumFactor * pa;
stack = stackStart;
for (i = 0; i < radiusPlus1; i++)
{
stack.r = pr;
stack.g = pg;
stack.b = pb;
stack.a = pa;
stack = stack.next;
}
yp = width;
for (i = 1; i <= radius; i++)
{
yi = (yp + x) << 2;
r_sum += (stack.r = (pr = pixels[yi])) * (rbs = radiusPlus1 - i);
g_sum += (stack.g = (pg = pixels[yi+1])) * rbs;
b_sum += (stack.b = (pb = pixels[yi+2])) * rbs;
a_sum += (stack.a = (pa = pixels[yi+3])) * rbs;
r_in_sum += pr;
g_in_sum += pg;
b_in_sum += pb;
a_in_sum += pa;
stack = stack.next;
if(i < heightMinus1)
{
yp += width;
}
}
yi = x;
stackIn = stackStart;
stackOut = stackEnd;
for (y = 0; y < height; y++)
{
p = yi << 2;
pixels[p+3] = pa = (a_sum * mul_sum) >> shg_sum;
if (pa > 0)
{
pa = 255 / pa;
pixels[p] = ((r_sum * mul_sum) >> shg_sum) * pa;
pixels[p+1] = ((g_sum * mul_sum) >> shg_sum) * pa;
pixels[p+2] = ((b_sum * mul_sum) >> shg_sum) * pa;
} else {
pixels[p] = pixels[p+1] = pixels[p+2] = 0;
}
r_sum -= r_out_sum;
g_sum -= g_out_sum;
b_sum -= b_out_sum;
a_sum -= a_out_sum;
r_out_sum -= stackIn.r;
g_out_sum -= stackIn.g;
b_out_sum -= stackIn.b;
a_out_sum -= stackIn.a;
p = (x + (((p = y + radiusPlus1) < heightMinus1 ? p : heightMinus1) * width)) << 2;
r_sum += (r_in_sum += (stackIn.r = pixels[p]));
g_sum += (g_in_sum += (stackIn.g = pixels[p+1]));
b_sum += (b_in_sum += (stackIn.b = pixels[p+2]));
a_sum += (a_in_sum += (stackIn.a = pixels[p+3]));
stackIn = stackIn.next;
r_out_sum += (pr = stackOut.r);
g_out_sum += (pg = stackOut.g);
b_out_sum += (pb = stackOut.b);
a_out_sum += (pa = stackOut.a);
r_in_sum -= pr;
g_in_sum -= pg;
b_in_sum -= pb;
a_in_sum -= pa;
stackOut = stackOut.next;
yi += width;
}
}
return imageData;
}
function processCanvasRGB(canvas, top_x, top_y, width, height, radius)
{
if (isNaN(radius) || radius < 1) return;
radius |= 0;
var imageData = getImageDataFromCanvas(canvas, top_x, top_y, width, height);
imageData = processImageDataRGB(imageData, top_x, top_y, width, height, radius);
canvas.getContext('2d').putImageData(imageData, top_x, top_y);
}
function processImageDataRGB(imageData, top_x, top_y, width, height, radius)
{
var pixels = imageData.data;
var x, y, i, p, yp, yi, yw, r_sum, g_sum, b_sum,
r_out_sum, g_out_sum, b_out_sum,
r_in_sum, g_in_sum, b_in_sum,
pr, pg, pb, rbs;
var div = radius + radius + 1;
var w4 = width << 2;
var widthMinus1 = width - 1;
var heightMinus1 = height - 1;
var radiusPlus1 = radius + 1;
var sumFactor = radiusPlus1 * (radiusPlus1 + 1) / 2;
var stackStart = new BlurStack();
var stack = stackStart;
for (i = 1; i < div; i++)
{
stack = stack.next = new BlurStack();
if (i == radiusPlus1) var stackEnd = stack;
}
stack.next = stackStart;
var stackIn = null;
var stackOut = null;
yw = yi = 0;
var mul_sum = mul_table[radius];
var shg_sum = shg_table[radius];
for (y = 0; y < height; y++)
{
r_in_sum = g_in_sum = b_in_sum = r_sum = g_sum = b_sum = 0;
r_out_sum = radiusPlus1 * (pr = pixels[yi]);
g_out_sum = radiusPlus1 * (pg = pixels[yi+1]);
b_out_sum = radiusPlus1 * (pb = pixels[yi+2]);
r_sum += sumFactor * pr;
g_sum += sumFactor * pg;
b_sum += sumFactor * pb;
stack = stackStart;
for (i = 0; i < radiusPlus1; i++)
{
stack.r = pr;
stack.g = pg;
stack.b = pb;
stack = stack.next;
}
for (i = 1; i < radiusPlus1; i++)
{
p = yi + ((widthMinus1 < i ? widthMinus1 : i) << 2);
r_sum += (stack.r = (pr = pixels[p])) * (rbs = radiusPlus1 - i);
g_sum += (stack.g = (pg = pixels[p+1])) * rbs;
b_sum += (stack.b = (pb = pixels[p+2])) * rbs;
r_in_sum += pr;
g_in_sum += pg;
b_in_sum += pb;
stack = stack.next;
}
stackIn = stackStart;
stackOut = stackEnd;
for (x = 0; x < width; x++)
{
pixels[yi] = (r_sum * mul_sum) >> shg_sum;
pixels[yi+1] = (g_sum * mul_sum) >> shg_sum;
pixels[yi+2] = (b_sum * mul_sum) >> shg_sum;
r_sum -= r_out_sum;
g_sum -= g_out_sum;
b_sum -= b_out_sum;
r_out_sum -= stackIn.r;
g_out_sum -= stackIn.g;
b_out_sum -= stackIn.b;
p = (yw + ((p = x + radius + 1) < widthMinus1 ? p : widthMinus1)) << 2;
r_in_sum += (stackIn.r = pixels[p]);
g_in_sum += (stackIn.g = pixels[p+1]);
b_in_sum += (stackIn.b = pixels[p+2]);
r_sum += r_in_sum;
g_sum += g_in_sum;
b_sum += b_in_sum;
stackIn = stackIn.next;
r_out_sum += (pr = stackOut.r);
g_out_sum += (pg = stackOut.g);
b_out_sum += (pb = stackOut.b);
r_in_sum -= pr;
g_in_sum -= pg;
b_in_sum -= pb;
stackOut = stackOut.next;
yi += 4;
}
yw += width;
}
for (x = 0; x < width; x++)
{
g_in_sum = b_in_sum = r_in_sum = g_sum = b_sum = r_sum = 0;
yi = x << 2;
r_out_sum = radiusPlus1 * (pr = pixels[yi]);
g_out_sum = radiusPlus1 * (pg = pixels[yi+1]);
b_out_sum = radiusPlus1 * (pb = pixels[yi+2]);
r_sum += sumFactor * pr;
g_sum += sumFactor * pg;
b_sum += sumFactor * pb;
stack = stackStart;
for (i = 0; i < radiusPlus1; i++)
{
stack.r = pr;
stack.g = pg;
stack.b = pb;
stack = stack.next;
}
yp = width;
for (i = 1; i <= radius; i++)
{
yi = (yp + x) << 2;
r_sum += (stack.r = (pr = pixels[yi])) * (rbs = radiusPlus1 - i);
g_sum += (stack.g = (pg = pixels[yi+1])) * rbs;
b_sum += (stack.b = (pb = pixels[yi+2])) * rbs;
r_in_sum += pr;
g_in_sum += pg;
b_in_sum += pb;
stack = stack.next;
if(i < heightMinus1)
{
yp += width;
}
}
yi = x;
stackIn = stackStart;
stackOut = stackEnd;
for (y = 0; y < height; y++)
{
p = yi << 2;
pixels[p] = (r_sum * mul_sum) >> shg_sum;
pixels[p+1] = (g_sum * mul_sum) >> shg_sum;
pixels[p+2] = (b_sum * mul_sum) >> shg_sum;
r_sum -= r_out_sum;
g_sum -= g_out_sum;
b_sum -= b_out_sum;
r_out_sum -= stackIn.r;
g_out_sum -= stackIn.g;
b_out_sum -= stackIn.b;
p = (x + (((p = y + radiusPlus1) < heightMinus1 ? p : heightMinus1) * width)) << 2;
r_sum += (r_in_sum += (stackIn.r = pixels[p]));
g_sum += (g_in_sum += (stackIn.g = pixels[p+1]));
b_sum += (b_in_sum += (stackIn.b = pixels[p+2]));
stackIn = stackIn.next;
r_out_sum += (pr = stackOut.r);
g_out_sum += (pg = stackOut.g);
b_out_sum += (pb = stackOut.b);
r_in_sum -= pr;
g_in_sum -= pg;
b_in_sum -= pb;
stackOut = stackOut.next;
yi += width;
}
}
return imageData;
}
function BlurStack()
{
this.r = 0;
this.g = 0;
this.b = 0;
this.a = 0;
this.next = null;
}
module.exports = {
image: processImage,
canvasRGBA: processCanvasRGBA,
canvasRGB: processCanvasRGB,
imageDataRGBA: processImageDataRGBA,
imageDataRGB: processImageDataRGB
};
},{}]},{},[1])(1)
});