/**
* StackBlur - a fast almost Gaussian Blur For Canvas
*
* In case you find this class useful - especially in commercial projects -
* I am not totally unhappy for a small donation to my PayPal account
* mario@quasimondo.de
*
* Or support me on flattr:
* {@link https://flattr.com/thing/72791/StackBlur-a-fast-almost-Gaussian-Blur-Effect-for-CanvasJavascript}
* @module StackBlur
* @version 0.5
* @author Mario Klingemann
* Contact: mario@quasimondo.com
* Website: {@link http://www.quasimondo.com/StackBlurForCanvas/StackBlurDemo.html}
* Twitter: @quasimondo
*
* @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.
*/
const mulTable = [
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];
const shgTable = [
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];
/**
* @param {string|HTMLImageElement} img
* @param {string|HTMLCanvasElement} canvas
* @param {Float} radius
* @param {boolean} blurAlphaChannel
* @returns {undefined}
*/
function processImage (img, canvas, radius, blurAlphaChannel) {
if (typeof img === 'string') {
img = document.getElementById(img);
}
if (!img || !('naturalWidth' in img)) {
return;
}
const w = img.naturalWidth;
const h = img.naturalHeight;
if (typeof canvas === 'string') {
canvas = document.getElementById(canvas);
}
if (!canvas || !('getContext' in canvas)) {
return;
}
canvas.style.width = w + 'px';
canvas.style.height = h + 'px';
canvas.width = w;
canvas.height = h;
const context = canvas.getContext('2d');
context.clearRect(0, 0, w, h);
context.drawImage(img, 0, 0);
if (isNaN(radius) || radius < 1) { return; }
if (blurAlphaChannel) {
processCanvasRGBA(canvas, 0, 0, w, h, radius);
} else {
processCanvasRGB(canvas, 0, 0, w, h, radius);
}
}
/**
* @param {string|HTMLCanvasElement} canvas
* @param {Integer} topX
* @param {Integer} topY
* @param {Integer} width
* @param {Integer} height
* @throws {Error|TypeError}
* @returns {ImageData} See {@link https://html.spec.whatwg.org/multipage/canvas.html#imagedata}
*/
function getImageDataFromCanvas (canvas, topX, topY, width, height) {
if (typeof canvas === 'string') {
canvas = document.getElementById(canvas);
}
if (!canvas || typeof canvas !== 'object' || !('getContext' in canvas)) {
throw new TypeError('Expecting canvas with `getContext` method in processCanvasRGB(A) calls!');
}
const context = canvas.getContext('2d');
try {
return context.getImageData(topX, topY, width, height);
} catch (e) {
throw new Error('unable to access image data: ' + e);
}
}
/**
* @param {HTMLCanvasElement} canvas
* @param {Integer} topX
* @param {Integer} topY
* @param {Integer} width
* @param {Integer} height
* @param {Float} radius
* @returns {undefined}
*/
function processCanvasRGBA (canvas, topX, topY, width, height, radius) {
if (isNaN(radius) || radius < 1) { return; }
radius |= 0;
let imageData = getImageDataFromCanvas(canvas, topX, topY, width, height);
imageData = processImageDataRGBA(imageData, topX, topY, width, height, radius);
canvas.getContext('2d').putImageData(imageData, topX, topY);
}
/**
* @param {ImageData} imageData
* @param {Integer} topX
* @param {Integer} topY
* @param {Integer} width
* @param {Integer} height
* @param {Float} radius
* @returns {ImageData}
*/
function processImageDataRGBA (imageData, topX, topY, width, height, radius) {
const pixels = imageData.data;
let x, y, i, p, yp, yi, yw, rSum, gSum, bSum, aSum,
rOutSum, gOutSum, bOutSum, aOutSum,
rInSum, gInSum, bInSum, aInSum,
pr, pg, pb, pa, rbs;
const div = 2 * radius + 1;
// const w4 = width << 2;
const widthMinus1 = width - 1;
const heightMinus1 = height - 1;
const radiusPlus1 = radius + 1;
const sumFactor = radiusPlus1 * (radiusPlus1 + 1) / 2;
const stackStart = new BlurStack();
let stack = stackStart;
let stackEnd;
for (i = 1; i < div; i++) {
stack = stack.next = new BlurStack();
if (i === radiusPlus1) {
stackEnd = stack;
}
}
stack.next = stackStart;
let stackIn = null;
let stackOut = null;
yw = yi = 0;
const mulSum = mulTable[radius];
const shgSum = shgTable[radius];
for (y = 0; y < height; y++) {
rInSum = gInSum = bInSum = aInSum = rSum = gSum = bSum = aSum = 0;
rOutSum = radiusPlus1 * (pr = pixels[yi]);
gOutSum = radiusPlus1 * (pg = pixels[yi + 1]);
bOutSum = radiusPlus1 * (pb = pixels[yi + 2]);
aOutSum = radiusPlus1 * (pa = pixels[yi + 3]);
rSum += sumFactor * pr;
gSum += sumFactor * pg;
bSum += sumFactor * pb;
aSum += 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);
rSum += (stack.r = (pr = pixels[p])) * (rbs = radiusPlus1 - i);
gSum += (stack.g = (pg = pixels[p + 1])) * rbs;
bSum += (stack.b = (pb = pixels[p + 2])) * rbs;
aSum += (stack.a = (pa = pixels[p + 3])) * rbs;
rInSum += pr;
gInSum += pg;
bInSum += pb;
aInSum += pa;
stack = stack.next;
}
stackIn = stackStart;
stackOut = stackEnd;
for (x = 0; x < width; x++) {
pixels[yi + 3] = pa = (aSum * mulSum) >> shgSum;
if (pa !== 0) {
pa = 255 / pa;
pixels[yi] = ((rSum * mulSum) >> shgSum) * pa;
pixels[yi + 1] = ((gSum * mulSum) >> shgSum) * pa;
pixels[yi + 2] = ((bSum * mulSum) >> shgSum) * pa;
} else {
pixels[yi] = pixels[yi + 1] = pixels[yi + 2] = 0;
}
rSum -= rOutSum;
gSum -= gOutSum;
bSum -= bOutSum;
aSum -= aOutSum;
rOutSum -= stackIn.r;
gOutSum -= stackIn.g;
bOutSum -= stackIn.b;
aOutSum -= stackIn.a;
p = (yw + ((p = x + radius + 1) < widthMinus1 ? p : widthMinus1)) << 2;
rInSum += (stackIn.r = pixels[p]);
gInSum += (stackIn.g = pixels[p + 1]);
bInSum += (stackIn.b = pixels[p + 2]);
aInSum += (stackIn.a = pixels[p + 3]);
rSum += rInSum;
gSum += gInSum;
bSum += bInSum;
aSum += aInSum;
stackIn = stackIn.next;
rOutSum += (pr = stackOut.r);
gOutSum += (pg = stackOut.g);
bOutSum += (pb = stackOut.b);
aOutSum += (pa = stackOut.a);
rInSum -= pr;
gInSum -= pg;
bInSum -= pb;
aInSum -= pa;
stackOut = stackOut.next;
yi += 4;
}
yw += width;
}
for (x = 0; x < width; x++) {
gInSum = bInSum = aInSum = rInSum = gSum = bSum = aSum = rSum = 0;
yi = x << 2;
rOutSum = radiusPlus1 * (pr = pixels[yi]);
gOutSum = radiusPlus1 * (pg = pixels[yi + 1]);
bOutSum = radiusPlus1 * (pb = pixels[yi + 2]);
aOutSum = radiusPlus1 * (pa = pixels[yi + 3]);
rSum += sumFactor * pr;
gSum += sumFactor * pg;
bSum += sumFactor * pb;
aSum += 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;
rSum += (stack.r = (pr = pixels[yi])) * (rbs = radiusPlus1 - i);
gSum += (stack.g = (pg = pixels[yi + 1])) * rbs;
bSum += (stack.b = (pb = pixels[yi + 2])) * rbs;
aSum += (stack.a = (pa = pixels[yi + 3])) * rbs;
rInSum += pr;
gInSum += pg;
bInSum += pb;
aInSum += 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 = (aSum * mulSum) >> shgSum;
if (pa > 0) {
pa = 255 / pa;
pixels[p] = ((rSum * mulSum) >> shgSum) * pa;
pixels[p + 1] = ((gSum * mulSum) >> shgSum) * pa;
pixels[p + 2] = ((bSum * mulSum) >> shgSum) * pa;
} else {
pixels[p] = pixels[p + 1] = pixels[p + 2] = 0;
}
rSum -= rOutSum;
gSum -= gOutSum;
bSum -= bOutSum;
aSum -= aOutSum;
rOutSum -= stackIn.r;
gOutSum -= stackIn.g;
bOutSum -= stackIn.b;
aOutSum -= stackIn.a;
p = (x + (((p = y + radiusPlus1) < heightMinus1 ? p : heightMinus1) * width)) << 2;
rSum += (rInSum += (stackIn.r = pixels[p]));
gSum += (gInSum += (stackIn.g = pixels[p + 1]));
bSum += (bInSum += (stackIn.b = pixels[p + 2]));
aSum += (aInSum += (stackIn.a = pixels[p + 3]));
stackIn = stackIn.next;
rOutSum += (pr = stackOut.r);
gOutSum += (pg = stackOut.g);
bOutSum += (pb = stackOut.b);
aOutSum += (pa = stackOut.a);
rInSum -= pr;
gInSum -= pg;
bInSum -= pb;
aInSum -= pa;
stackOut = stackOut.next;
yi += width;
}
}
return imageData;
}
/**
* @param {HTMLCanvasElement} canvas
* @param {Integer} topX
* @param {Integer} topY
* @param {Integer} width
* @param {Integer} height
* @param {Float} radius
* @returns {undefined}
*/
function processCanvasRGB (canvas, topX, topY, width, height, radius) {
if (isNaN(radius) || radius < 1) { return; }
radius |= 0;
let imageData = getImageDataFromCanvas(canvas, topX, topY, width, height);
imageData = processImageDataRGB(imageData, topX, topY, width, height, radius);
canvas.getContext('2d').putImageData(imageData, topX, topY);
}
/**
* @param {ImageData} imageData
* @param {Integer} topX
* @param {Integer} topY
* @param {Integer} width
* @param {Integer} height
* @param {Float} radius
* @returns {ImageData}
*/
function processImageDataRGB (imageData, topX, topY, width, height, radius) {
const pixels = imageData.data;
let x, y, i, p, yp, yi, yw, rSum, gSum, bSum,
rOutSum, gOutSum, bOutSum,
rInSum, gInSum, bInSum,
pr, pg, pb, rbs;
const div = 2 * radius + 1;
// const w4 = width << 2;
const widthMinus1 = width - 1;
const heightMinus1 = height - 1;
const radiusPlus1 = radius + 1;
const sumFactor = radiusPlus1 * (radiusPlus1 + 1) / 2;
const stackStart = new BlurStack();
let stack = stackStart;
let stackEnd;
for (i = 1; i < div; i++) {
stack = stack.next = new BlurStack();
if (i === radiusPlus1) {
stackEnd = stack;
}
}
stack.next = stackStart;
let stackIn = null;
let stackOut = null;
yw = yi = 0;
const mulSum = mulTable[radius];
const shgSum = shgTable[radius];
for (y = 0; y < height; y++) {
rInSum = gInSum = bInSum = rSum = gSum = bSum = 0;
rOutSum = radiusPlus1 * (pr = pixels[yi]);
gOutSum = radiusPlus1 * (pg = pixels[yi + 1]);
bOutSum = radiusPlus1 * (pb = pixels[yi + 2]);
rSum += sumFactor * pr;
gSum += sumFactor * pg;
bSum += 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);
rSum += (stack.r = (pr = pixels[p])) * (rbs = radiusPlus1 - i);
gSum += (stack.g = (pg = pixels[p + 1])) * rbs;
bSum += (stack.b = (pb = pixels[p + 2])) * rbs;
rInSum += pr;
gInSum += pg;
bInSum += pb;
stack = stack.next;
}
stackIn = stackStart;
stackOut = stackEnd;
for (x = 0; x < width; x++) {
pixels[yi] = (rSum * mulSum) >> shgSum;
pixels[yi + 1] = (gSum * mulSum) >> shgSum;
pixels[yi + 2] = (bSum * mulSum) >> shgSum;
rSum -= rOutSum;
gSum -= gOutSum;
bSum -= bOutSum;
rOutSum -= stackIn.r;
gOutSum -= stackIn.g;
bOutSum -= stackIn.b;
p = (yw + ((p = x + radius + 1) < widthMinus1 ? p : widthMinus1)) << 2;
rInSum += (stackIn.r = pixels[p]);
gInSum += (stackIn.g = pixels[p + 1]);
bInSum += (stackIn.b = pixels[p + 2]);
rSum += rInSum;
gSum += gInSum;
bSum += bInSum;
stackIn = stackIn.next;
rOutSum += (pr = stackOut.r);
gOutSum += (pg = stackOut.g);
bOutSum += (pb = stackOut.b);
rInSum -= pr;
gInSum -= pg;
bInSum -= pb;
stackOut = stackOut.next;
yi += 4;
}
yw += width;
}
for (x = 0; x < width; x++) {
gInSum = bInSum = rInSum = gSum = bSum = rSum = 0;
yi = x << 2;
rOutSum = radiusPlus1 * (pr = pixels[yi]);
gOutSum = radiusPlus1 * (pg = pixels[yi + 1]);
bOutSum = radiusPlus1 * (pb = pixels[yi + 2]);
rSum += sumFactor * pr;
gSum += sumFactor * pg;
bSum += 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;
rSum += (stack.r = (pr = pixels[yi])) * (rbs = radiusPlus1 - i);
gSum += (stack.g = (pg = pixels[yi + 1])) * rbs;
bSum += (stack.b = (pb = pixels[yi + 2])) * rbs;
rInSum += pr;
gInSum += pg;
bInSum += 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] = (rSum * mulSum) >> shgSum;
pixels[p + 1] = (gSum * mulSum) >> shgSum;
pixels[p + 2] = (bSum * mulSum) >> shgSum;
rSum -= rOutSum;
gSum -= gOutSum;
bSum -= bOutSum;
rOutSum -= stackIn.r;
gOutSum -= stackIn.g;
bOutSum -= stackIn.b;
p = (x + (((p = y + radiusPlus1) < heightMinus1 ? p : heightMinus1) * width)) << 2;
rSum += (rInSum += (stackIn.r = pixels[p]));
gSum += (gInSum += (stackIn.g = pixels[p + 1]));
bSum += (bInSum += (stackIn.b = pixels[p + 2]));
stackIn = stackIn.next;
rOutSum += (pr = stackOut.r);
gOutSum += (pg = stackOut.g);
bOutSum += (pb = stackOut.b);
rInSum -= pr;
gInSum -= pg;
bInSum -= pb;
stackOut = stackOut.next;
yi += width;
}
}
return imageData;
}
/**
*
*/
export class BlurStack {
constructor () {
this.r = 0;
this.g = 0;
this.b = 0;
this.a = 0;
this.next = null;
}
}
export {
/**
* @function module:StackBlur.image
* @see module:StackBlur~processImage
*/
processImage as image,
/**
* @function module:StackBlur.canvasRGBA
* @see module:StackBlur~processCanvasRGBA
*/
processCanvasRGBA as canvasRGBA,
/**
* @function module:StackBlur.canvasRGB
* @see module:StackBlur~processCanvasRGB
*/
processCanvasRGB as canvasRGB,
/**
* @function module:StackBlur.imageDataRGBA
* @see module:StackBlur~processImageDataRGBA
*/
processImageDataRGBA as imageDataRGBA,
/**
* @function module:StackBlur.imageDataRGB
* @see module:StackBlur~processImageDataRGB
*/
processImageDataRGB as imageDataRGB
};