javascript - Slideshow-banner (effect: easing images out through canvas border) -


i'm trying create banner such above mentioned swapping out 2 images , using them fillstyle (pattern) on buffer canvas. idea have image1 trail behind image2 many pixels width of canvas, , update position simultaneously on buffer canvas before drawing on canvas visible on page. , of course, when 1 image moves out of border, new source image set while x position set negative many pixels width of canvas.

the values i'm using x_incr might seem mysterious, they're temporary, arbitrary values makes smooth, increasing speed haven't yet found better way simulate effect.

i had working 1 image, added another, canvas black while script running. why happening? , going wrong? might better obtained/maintained css3 transformations?

i'm pretty new of languages i'm using here, i've tried follow standards know.

please let me know if parts of following code redundant in regards question.

thanks in advance!

javascript:

var pattern1; var pattern2; var x1 = 0.1; var x2 = 0.1; var x1_incr = 0.1; var x2_incr = 0.1; var canvas = null; var context = null; var buffercanvas = null; var buffercanvasctx = null; var img1 = new image(); var img2 = new image(); var currentimg = 0; var imgarray = [     "images/1.jpg", "images/2.jpg", "images/3.jpg", "images/4.jpg" ];  function init () {     canvas = document.getelementbyid('canvas1');     context = canvas.getcontext("2d");      buffercanvas = document.createelement("canvas");     buffercanvasctx = buffercanvas.getcontext("2d");     buffercanvasctx.canvas.width = context.canvas.width;     buffercanvasctx.canvas.height = context.canvas.height;      loadpattern(img1, pattern1);     loadpattern(img2, pattern2);      switchimage(img1);      draw();      setinterval(animate, 10); }  function loadpattern(image, pattern) {     image.onload = function () {         pattern = buffercanvasctx.createpattern(image, "no-repeat");     }; }  function switchimage(obj) {     obj.setattribute('src', imgarray[currentimg++]);     if (currentimg >= imgarray.length) {         currentimg = 0;     } }  function animate () {     update(img1, x1, x1_incr);     update(img2, x2, x2_incr);     draw(); }  function update (image, x, x_incr) {     x_incr += 0.1;     x += x_incr;      if (x > context.canvas.width) {         switchimage(image);         x = -context.canvas.width;         x_incr = 0.1;     }    }  function draw() {     context.save();       if (x1 < x2) {         buffercanvasctx.fillstyle = pattern1;         buffercanvasctx.fillrect(x1, 0, context.canvas.width, context.canvas.height);         buffercanvasctx.fillstyle = pattern2;         buffercanvasctx.fillrect(x2, 0, context.canvas.width, context.canvas.height);      }     else {         buffercanvasctx.fillstyle = pattern2;         buffercanvasctx.fillrect(x2, 0, context.canvas.width, context.canvas.height);         buffercanvasctx.fillstyle = pattern1;         buffercanvasctx.fillrect(x1, 0, context.canvas.width, context.canvas.height);      }      context.drawimage(buffercanvas, 0, 0, context.canvas.width, context.canvas.height);      context.restore();     } }

html: 

<!doctype html> <html lang="en">     <head>         <title>home</title>         <link href="mypage.css" rel="stylesheet" type="text/css">     </head>     <body onload="init()">         <div class="container">             <canvas id="canvas1" class="slideshow">your browser not support canvas.</canvas>         </div>         <script src="mypage.js">         </script>     </body> </html>

css:

.container {     margin: auto;     width: 1024px; }  .slideshow {     background-color: lightgray;     height: 90px;     width: 728px;     margin: 0 auto 0 auto;     display: block; }


-

Comments

Post a Comment

Popular posts from this blog

html - Sizing a high-res image (~8MB) to display entirely in a small div (circular, diameter 100px) -

first of all, thank being patient know simple question more couple of weeks' experience figure out. i've seen folks persevere , helpful on here , hope you're willing me. here fiddle: http://jsfiddle.net/65uzf/ here 1 of places searched answers on here: ( vertically center image thumbnails fix-sized div ) tried solutions on there , didn't work out me. i've searched ~4 or 5 others, , been unsuccessful those, too. what want take large image (what linked background-image #ysypic , #tabpic divs) , display thumbnail version of image in confines of divs have set it. is, using background properties have laid out in css, portion of image displays inside of circular divs. without these properties, display defaults smaller section of image [presumably pi*(50^2) area in top left] terrible resolution. i not care if entire image doesn't display inside of circles (it won't, given difference in shape), , overflow not being displayed fine. want able see figu
Read more

java - IntelliJ - No such instance method -

using intellij's 12 ultimate, i'm running following code in debugger: java import play.api.libs.json.jsvalue; public class foo { ... public jsvalue tojson() { ... } public class fooexample { ... foo foo = new foo(); system.out.println("...); //<-- breakpoint at breakpoint, right-clicked source code , picked "evaluate expression," typing in: foo.tojson() . but following error showed up: no such instance method: play.api.libs.json.jsvalue$class.com.foo.foo.tojson () am doing wrong? foo#tojson calls scala code, if matters. edit had breakpoint after instantiation of foo. downvoted it, deserved it. edit my answer no longer valid after op modified question (i.e. moved breakpoint actual is).. a breakpoint hit before line executed. in case foo has not yet been declared or instantiated (i.e. foo constructor has not yet been called). you'll need put breakpoint @ next line (or step on current line) if want evaluate foo .
Read more

identifier - Is it possible for an html5 document to have two ids? -

i wondering if html5 element can have 2 ids, this: <button id="thing1" id="thing2" name="button1" onclick="change()">click here</button> or this: <button id="thing1, thing2" name="button1" onclick="change()">click here</button> also, if 1 of ids said 1 thing, , other id said thing, 1 used? tl;dr : no. in versions of html, each element can have 1 id. see the spec : the id attribute specifies element's unique identifier (id). [dom] the value must unique amongst ids in element's home subtree , must contain @ least 1 character. the value must not contain space characters. note: there no other restrictions on form id can take; in particular, ids can consist of digits, start digit, start underscore, consist of punctuation , etc. note: element's unique identifier can used variety of purposes, notably way link specific parts of document usin
Read more