javascript - Canvas Oscillating an image -


i'm trying image oscillate. i'm having issues. i'm using tutorial http://www.html5canvastutorials.com/advanced/html5-canvas-oscillation-animation/

and tried changing line 55-61 of tutorial load image src. it's not displaying anything.

any advice?

<canvas id="mycanvas" width="578" height="200"></canvas>     <script>       window.requestanimframe = (function(callback) {         return window.requestanimationframe || window.webkitrequestanimationframe || window.mozrequestanimationframe || window.orequestanimationframe || window.msrequestanimationframe ||         function(callback) {           window.settimeout(callback, 1000 / 60);         };       })();        function drawrectangle(myrectangle, context) {         context.beginpath();         context.rect(myrectangle.x, myrectangle.y, myrectangle.width, myrectangle.height);         context.fillstyle = '#8ed6ff';         context.fill();         context.linewidth = myrectangle.borderwidth;         context.strokestyle = 'black';         context.stroke();       }       function animate(myrectangle, canvas, context, starttime) {         // update         var time = (new date()).gettime() - starttime;         var amplitude = 150;          // in ms         var period = 2000;         var centerx = canvas.width / 2 - myrectangle.width / 2;         var nextx = amplitude * math.sin(time * 2 * math.pi / period) + centerx;         myrectangle.x = nextx;          // clear         context.clearrect(0, 0, canvas.width, canvas.height);          // draw         drawrectangle(myrectangle, context);          // request new frame         requestanimframe(function() {           animate(myrectangle, canvas, context, starttime);         });       }       var canvas = document.getelementbyid('mycanvas');       var context = canvas.getcontext('2d');        var myrectangle = new image();                         myrectangle.src = "http://www.skilledsoldiers.com/e107_plugins/aacgc_gamelist/icons/dota2_icon.png";                         myrectangle.onload = function()       };        drawrectangle(myrectangle, context);        // wait 1 second before starting animation       settimeout(function() {         var starttime = (new date()).gettime();         animate(myrectangle, canvas, context, starttime);       }, 1000);     </script>

you need use context.drawimage instead of trying draw rectangle image.

function drawimage(myrectangle, context) {     context.drawimage(myrectangle.img, myrectangle.x, myrectangle.y, myrectangle.width, myrectangle.height);    }

see fiddle: http://jsfiddle.net/fb4vs/


Comments

Post a Comment

Popular posts from this blog

android - Get AccessToken using signpost OAuth without opening a browser (Two legged Oauth) -

i using signpost oauth access data magento server. have read various tutorials on same , reach point open browser user can enter credentials. however, per requirement have automate part. hence, user should not browser page. have set-up done on server side ( magento ), hit url , returned call page. same through program in android. i have tried below, consumer = new commonshttpoauthconsumer(key, secret); provider = new commonshttpoauthprovider(oauth_init_url,access_token_url, authorize_url); try { provider.retrieverequesttoken(consumer, oauth.out_of_band); log.d("tokens" , consumer.gettoken() + " -- " + consumer.gettokensecret()); } and request tokens. dont know how bypass next step. tried directly accessing accesstoken (stupid of me) provider.retrieveaccesstoken(consumer, "mycallback://callback"); no luck, ends in oauth.signpost.exception.oauthnotauthorizedexception: authorization failed (server replied 401). ...
Read more

org.mockito.exceptions.misusing.InvalidUseOfMatchersException: mockito -

getting error org.mockito.exceptions.misusing.invaliduseofmatchersexception: invalid use of argument matchers! 1 matchers expected, 2 recorded. exception may occur if matchers combined raw values: //incorrect: somemethod(anyobject(), "raw string"); when using matchers, arguments have provided matchers. example: //correct: somemethod(anyobject(), eq("string matcher")); at when( getprogramservice .callservice(any(getprogramtype.class))) .thenreturn(jaxbresponse); please explain error , possible resolution the code posted looks fine; don't see problem it. code before or above causing exception. key here: invalid use of argument matchers! 1 matchers expected, 2 recorded. any , used above, doesn't return "special kind of null" or "special kind of getprogramtype"; don't exist. instead, returns null , side effect puts matcher on stack. whe...
Read more

google shop client API returns 400 bad request error while adding an item -

i'm working on solution add items in google shopping market java application. following tutorial real mess because of missing classes of laste release, after setting 1.5-beta maven managed make base example typecheck correctly classes. still can make simple task of adding 1 item. instead of posting whole code i'm posting part creates product feed. private product createproduct(string id) { product product = new product(); product.title = "red wool sweater"; product.content = new content( "text", "comfortable , soft, sweater keep warm on " + "cold winter nights. red , blue stripes."); product.appcontrol = new appcontrol(); product.appcontrol.addrequireddestination("productads"); product.externalid = id; product.lang = "it"; product.country = "it"; product.condition = "nuovo"; product.price = new price("eu...
Read more