Let's say i have a image
i want to fill this with with 25 degree.
i rotate the image in php GD which gave me
then when i create a new pattern and apply. i got the
below is the code
Html
<h1>sleeve long normal</h1>
<canvas id="sleevelongnormal" width=436 height=567></canvas>
js
function doD(var1,var2,var3) //var1=convas var2=img1 var3=img aka design
{
// alert(var3);
t = document.getElementById(''+var1+'');
ctxt = t.getContext('2d');
var img1 = new Image();
var img = new Image();
img.onload = function () {
img1.onload = function () {
//start();
ctxt.drawImage(img1, 0, 0);
ctxt.globalCompositeOperation = "source-atop";
var pattern = ctxt.createPattern(img, 'repeat');
ctxt.rect(0, 0, sourceCanvas.width, sourceCanvas.height);
ctxt.fillStyle = pattern;
//var rotation = 90;
//ctxt.rotate(rotation * Math.PI/180);
ctxt.fill();
ctxt.globalAlpha = .10;
ctxt.drawImage(img1, 0, 0);
ctxt.drawImage(img1, 0, 0);
ctxt.drawImage(img1, 0, 0);
}
img1.src = var2;
}
img.src = var3;
//alert(t);
}
i want to achieve more or less like this
Related
I need some help with code review and re-translate it out of jQuery to plain JS.
I've tried to translate this into pure JS, but I don't get clearly why it doesn't work. If needed, I can show what I've made.
After the user selects an image from the first input, it should be rendered on canvas.
After the user selects an image from the second input, it should be rendered on the same canvas to the right of the first image.
Images should be rendered in scale, so two pictures will have the same height on canvas, but with the original aspect ratio.
User can select images in any order, but rendering order should stay the same: image from first input appears on canvas before image from the second input.
Inputs should accept only images.
$('.file1, .file2').on('change', function() {
var reader = new FileReader(),
imageSelector = $(this).data('image-selector');
if (this.files && this.files[0]) {
reader.onload = function(e) {
imageIsLoaded(e, imageSelector)
};
reader.readAsDataURL(this.files[0]);
}
});
$('.btn-merge').on('click', merge);
function imageIsLoaded(e, imageSelector) {
$(imageSelector).attr('src', e.target.result);
$(imageSelector).removeClass('hidden');
};
function merge() {
var canvas = document.getElementById('canvas'),
ctx = canvas.getContext('2d'),
imageObj1 = new Image(),
imageObj2 = new Image();
imageObj1.src = $('.image1').attr('src');
imageObj1.onload = function() {
ctx.globalAlpha = 1;
ctx.drawImage(imageObj1, 0, 0, 328, 526);
imageObj2.src = $('.image2').attr('src');;
imageObj2.onload = function() {
ctx.globalAlpha = 0.5;
ctx.drawImage(imageObj2, 15, 85, 300, 300);
var img = canvas.toDataURL('image/jpeg');
$('.merged-image').attr('src', img);
$('.merged-image').removeClass('hidden');
}
};
}
You should define the onload before changing source and not inside another onload
function merge() {
var canvas = document.getElementById('canvas'),
ctx = canvas.getContext('2d'),
imageObj1 = new Image(),
imageObj2 = new Image();
imageObj1.onload = function() {
ctx.globalAlpha = 1;
ctx.drawImage(imageObj1, 0, 0, 328, 526);
}
imageObj2.onload = function() {
ctx.globalAlpha = 0.5;
ctx.drawImage(imageObj2, 15, 85, 300, 300);
var img = canvas.toDataURL('image/jpeg');
$('.merged-image').attr('src', img);
$('.merged-image').removeClass('hidden');
}
imageObj1.src = $('.image1').attr('src');
imageObj2.src = $('.image2').attr('src');
}
Below is provided a script for changing image on click, changes will be affected in canvas.
The script is working properly in Firefox and Chrome but not in Safari
What could be the reason?
<script>
$(function() {
var house = document.getElementById("house");
var ctxHouse = house.getContext("2d");
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var canvas2 = document.getElementById("canvas2");
var ctxHand = canvas2.getContext("2d");
var FabricLink;
var imageObj = new Image();
var red = new Image();
red.onload = function() {
canvas.width = red.width;
canvas.height = red.height;
var houseImage = new Image();
houseImage.onload = function() {
house.width = houseImage.width;
house.height = houseImage.height;
ctxHouse.drawImage(houseImage, 0, 0);
}
houseImage.src = "images/img.jpg";
ctx.drawImage(red, 0, 0);
imageObj.onload = function() {
var pattern = ctx.createPattern(imageObj, 'repeat');
ctx.globalCompositeOperation = 'source-in';
ctx.rect(0, 0, canvas.width, canvas.height);
ctx.fillStyle = pattern;
ctx.fill();
};
$(imageObj).attr('src', 'images/' + FabricLink + '.png');
}
red.src = "images/img.png";
var imageObj2 = new Image();
var blue = new Image();
blue.onload = function() {
canvas2.width = blue.width;
canvas2.height = blue.height;
var houseImage = new Image();
houseImage.onload = function() {
house.width = houseImage.width;
house.height = houseImage.height;
ctxHouse.drawImage(houseImage, 0, 0);
}
houseImage.src = "images/img.jpg";
ctxHand.drawImage(blue, 0, 0);
imageObj2.onload = function() {
var pattern = ctx.createPattern(imageObj2, 'repeat');
ctxHand.globalCompositeOperation = 'source-in';
ctxHand.rect(0, 0, canvas2.width, canvas2.height);
ctxHand.fillStyle = pattern;
ctxHand.fill();
};
$(imageObj2).attr('src', 'images/' + FabricLink + '.png');
}
blue.src = "images/img.png";
$('#style li').click(
function() {
//we get our current filename and use it for the src
var linkIndex = $(this).attr("data-filename");
$(red).attr('src', 'images/' + linkIndex + '.png');
}
);
$('#Sleeves li').click(
function() {
$("#canvas2").addClass("show-z");
//we get our current filename and use it for the src
var SleevesLink = $(this).attr("data-filename");
$(blue).attr('src', 'images/' + SleevesLink + '.png');
}
);
$('#Fabric li').click(
function() {
//we get our current filename and use it for the src
FabricLink = $(this).attr("data-filename");
$(imageObj2).attr('src', 'images/' + FabricLink + '.png');
$(imageObj).attr('src', 'images/' + FabricLink + '.png');
}
);
$("#Fabric li:first-child").click();
}); // end $(function(){});
</script>
While debugging, we could see that imageObj.onload is not getting fired in the first click , only on refresh the change occurs in Safari.
jsfiddle.net/qvfx3kz7 (In the fiddle images are not loading, but the complete code is added)
I am not sure what is exactly the problem with Safari, but what I can see is that you are over-complicating everything by trying to load your assets only when requested, which leads to this callback nightmare you have set up.
Instead, prepare your assets so that you can load it only once. Since you are using patterns, I will assume that each pattern is actually a small image.
So instead of loading every little pattern images, load a single sprite-sheet, which will contain all your patterns.
From there, you'll be able to generate dynamically your CanvasPattern synchronously, without having to care for any loading callback. In order to do this, you will have to use a second, off-screen, canvas, that you will use as he source of createPattern() method:
// really dummy implementation...
function AssetsLoader() {}
AssetsLoader.prototype = Object.create({
addImage: function(objs, cb) {
if (!objs || typeof objs !== 'object') return;
if (!Array.isArray(objs)) objs = [];
var toLoad = objs.length,
imgs = objs.map(loadImage, this);
function loadImage(obj) {
if (!obj.src) return;
this.toLoad++;
var img = new Image();
img.src = obj.src;
img.onload = onimgload;
img.onerror = onimgerror;
return obj.img = img;
}
function onimgload(evt) {
if (--toLoad <= 0 && typeof cb === 'function') cb(imgs);
}
function onimgerror(evt) {
console.warn('failed to load image at ', evt.target.src);
}
}
});
// Some info about our assets, there are an infinity of ways to deal with it,
// You would have to determine yourself what's best for your own case
var dests = {
sofa: {
name: 'sofa',
src: 'https://i.stack.imgur.com/ryO42.png'
},
shirt: {
name: 'shirt',
src: 'https://i.stack.imgur.com/cPNbe.png'
}
};
var patterns = {
name: 'patterns',
src: 'https://i.stack.imgur.com/TdIAJ.png',
positions: {
orange: {
x: 0,
y: 0,
width: 173,
height: 173,
out_width: 75,
out_height: 75
},
violet: {
x: 173,
y: 0,
width: 173,
height: 173,
out_width: 35,
out_height: 35
},
psyche: {
x: 0,
y: 173,
width: 173,
height: 173,
out_width: 25,
out_height: 25
},
pink: {
x: 173,
y: 173,
width: 173,
height: 173,
out_width: 125,
out_height: 125
}
}
}
var assets = new AssetsLoader();
// first load all our images, and only then, start the whole thing
assets.addImage([dests.shirt, dests.sofa, patterns], init);
function init() {
// populate our selects
for (var key in dests) {
dest_select.appendChild(new Option(key, key));
}
for (var key in patterns.positions) {
pat_select.appendChild(new Option(key, key));
}
dest_select.onchange = pat_select.onchange = draw;
var ctx = canvas.getContext('2d');
var offscreenCtx = document.createElement('canvas').getContext('2d');
draw();
function draw() {
var dest = dests[dest_select.value].img;
ctx.canvas.width = dest.width;
ctx.canvas.height = dest.height;
ctx.globalCompositeOperation = 'source-over';
ctx.clearRect(0, 0, canvas.width, canvas.height);
ctx.drawImage(dest, 0, 0, canvas.width, canvas.height);
ctx.globalCompositeOperation = 'source-in';
// here we generate the CanvasPattern
ctx.fillStyle = getPattern(pat_select.value);
ctx.fillRect(0, 0, canvas.width, canvas.height);
ctx.globalCompositeOperation = 'luminosity';
ctx.drawImage(dest, 0, 0, canvas.width, canvas.height);
}
// now that we have our patterns loaded in a single sprite-sheet,
// we can generate the CanvasPatterns synchronously
function getPattern(key) {
var pos = patterns.positions[key]; // get our pattern's position in our dictionary
// resize the offscreen canvas so it matches our pattern
offscreenCtx.canvas.width = pos.out_width;
offscreenCtx.canvas.height = pos.out_height;
offscreenCtx.drawImage(patterns.img, pos.x, pos.y, pos.width, pos.height, 0, 0, pos.out_width, pos.out_height);
return offscreenCtx.createPattern(offscreenCtx.canvas, 'repeat');
}
}
<select id="dest_select"></select>
<select id="pat_select"></select>
<br><br><br>
<canvas id="canvas"></canvas>
I would like to use threshold filter on base64 string (data:image/png;base64,iVBOR...) using javaScript like this:
function threshold(base64) {
some action whith base64 string...
return base64; //base64 is updated by threshold filter
}
Is it possible and if it is, how can I do this?
var base64string = "data:image/png;base64,iVBOR..........",
threshold = 180, // 0..255
ctx = document.createElement("canvas").getContext("2d"),
image = new Image();
image.onload = function() {
var w = ctx.canvas.width = image.width,
h = ctx.canvas.height = image.height;
ctx.drawImage(image, 0, 0, w, h); // Set image to Canvas context
var d = ctx.getImageData(0, 0, w, h); // Get image Data from Canvas context
for (var i=0; i<d.data.length; i+=4) { // 4 is for RGBA channels
// R=G=B=R>T?255:0
d.data[i] = d.data[i+1] = d.data[i+2] = d.data[i+1] > threshold ? 255 : 0;
}
ctx.putImageData(d, 0, 0); // Apply threshold conversion
document.body.appendChild(ctx.canvas); // Show result
};
image.src = base64string;
MDN - putImageData
MDN - getImageData
Here is the code:
var spriteFolder = "../../assets/Painter/sprites/";
var sprites = {};
sprites.background = new Image();
sprites.background.src = spriteFolder + "spr_background.jpg";
sprites.cannon_barrel = new Image();
sprites.cannon_barrel.src = spriteFolder + "spr_cannon_barrel.png";
sprites.cannon_red = new Image();
sprites.cannon_red.src = spriteFolder + "spr_cannon_red.png";
sprites.cannon_green = new Image();
sprites.cannon_green.src = spriteFolder + "spr_cannon_green.png";
sprites.cannon_blue = new Image();
sprites.cannon_blue.src = spriteFolder + "spr_cannon_blue.png";
var Canvas2D = {
canvas: undefined,
canvasContext: undefined
};
Canvas2D.initialize = function(canvasName) {
Canvas2D.canvas = document.getElementById(canvasName);
Canvas2D.canvasContext = Canvas2D.canvas.getContext("2d");
};
Canvas2D.clear = function() {
Canvas2D.canvas.clearRect(0, 0, Canvas2D.canvas.width, Canvas2D.canvas.height);
};
Canvas2D.drawImage = function(sprite, position, rotation, origin) {
Canvas2D.canvasContext.save();
Canvas2D.canvasContext.translate(position.x, position.y);
Canvas2D.canvasContext.rotate(rotation);
Canvas2D.canvasContext.drawImage(sprite,
0, 0, sprite.width, sprite.height,
-origin.x, -origin.y, sprite.width, sprite.height
);
Canvas2D.canvasContext.restore();
};
function init() {
Canvas2D.initialize("myCanvas");
setTimeout(function() {
Canvas2D.canvasContext.drawImage(sprites.background, 0, 0);
}, 1000);
}
document.addEventListener("DOMContentLoaded", init);
If I don't use setTimeout, then the image is not drawn. Why?
Because your images were not yet loaded.
Thanks to your 1sec timeout they have enough time to load.
Have a look at this example from MDN https://developer.mozilla.org/en-US/docs/Web/API/Canvas_API/Tutorial/Using_images
You need to use similar approach - see img.onload()
function draw() {
var ctx = document.getElementById('canvas').getContext('2d');
var img = new Image();
img.onload = function(){
ctx.drawImage(img,0,0);
ctx.beginPath();
ctx.moveTo(30,96);
ctx.lineTo(70,66);
ctx.lineTo(103,76);
ctx.lineTo(170,15);
ctx.stroke();
};
img.src = 'https://mdn.mozillademos.org/files/5395/backdrop.png';
}
I need help with the following resource http://www.filmfans.cz/test/index2.html
I don't know how to change the colours of the pinquen after the click on the sample.
I would like to do something similar as in the following link http://www.pixelbox.sk/fileadmin/Flash/cosmo_2.swf
Here is my code
$(window).load(function(){
var width = $(window).width();
var height = $(window).height();
var c = document.getElementById("a");
var ctx = c.getContext("2d");
var can2 = document.createElement('canvas');
document.body.appendChild(can2)
can2.width = c.width;
can2.height= c.height;
var ctx2 = can2.getContext("2d");
var test= new Image();
test.src = "tux.png";
test.onload = function() {
ctx2.drawImage(test, 0, 0);
}
var img = new Image();
img.src = "2.png";
img.onload = function(){
ctx2.globalCompositeOperation = "source-in";
var pattern = ctx2.createPattern(img, "repeat");
ctx2.fillStyle=pattern;
ctx2.fillRect(0,0,300,300);
}
});
$(document).ready(function () {
$('.klik').click(function() {
var adresa = $(this).children('img').attr('src');
var canvas = document.getElementById("a");
canvas.width = canvas.width;//blanks the canvas
var c = canvas.getContext("2d");
var img = new Image();
img.src = adresa;
img.onload = function(){
var pattern = c.createPattern(img, "repeat");
//c.globalCompositeOperation = "source-in";
c.fillStyle=pattern;
c.fillRect(0,0,300,300);
}
// c.drawImage(img, 0, 0);
//}
//return false;
});
});
</code>
</pre>
Problem solved !
Using a second, temporary canvas with source-in is the right idea:
ctx2.drawImage(test, 0, 0);
ctx2.globalCompositeOperation = 'source-in';
var ptrn = ctx2.createPattern(pattern,'repeat');
ctx2.fillStyle = ptrn;
ctx2.fillRect(0,0,300,300);
ctx.drawImage(can2,0,0)
live example:
http://jsfiddle.net/UcGrC/