html canvas performance

(The_canvas); //Initialize Canvas sizeset_canvas_size (); Window.onresize=set_canvas_size; //when the mouse position is stored, leaving the current location information is releasedWindow.onmousemove =function(e) {e= e | |window.event; Current_point.x=E.clientx; Current_point.y=E.clienty; }, Window.onmouseout=function() {current_point.x=NULL; Current_point.y=NULL; }; //randomly generate CONFIG.N line position Information for(varRandom_point

ColorsCreatelineargradient (x1,y1,x2,y2) draws a linear gradient from the beginning of the x1,y1, x2,y2 terminates, such as (0,0,0,100) a linear gradient from top to bottom, (0,0,100,0) from left to rightvar canvas = document.getElementById (' MyCanvas '); if (canvas.getcontext) { var ctx = Canvas.getcontext (' 2d ');} var // a linear gradient from top to bottom Mygradient.addcolorstop (0, "#BABABA"); Mygradient.addcolorstop (1, "#636363"= Mygradi

(The_canvas); //Initialize Canvas sizeset_canvas_size (); Window.onresize=set_canvas_size; //when the mouse position is stored, leaving the current location information is releasedWindow.onmousemove =function(e) {e= e | |window.event; Current_point.x=E.clientx; Current_point.y=E.clienty; }, Window.onmouseout=function() {current_point.x=NULL; Current_point.y=NULL; }; //randomly generate CONFIG.N line position Information for(varRandom_point

Canvas is a canvas API in HTML5 to help you quickly draw images in your browser.What is canvas? HTML5 A canvas is an HTML-defined area that can be drawn and has attributes such as height and width. Canvas has several ways to draw

Recently drawing, you need to dynamically change the canvas size based on the user's input.But after using JS to change the size of the canvas, it is found that the graphics are stretched.Thought for a while did not understand, and then searched the next solution. The original is not allowed to use JS to control the canvas's length and width. The default length width of the

(0,10,100,200);FillRect (0,10,100,200);Drawing curvesvar canvas = document.getElementById (' C1 ');var context = Canvas.getcontext (' 2d ');drawing ArcsContext.moveto (62,24);var control1_x = 187;var control1_y = 32;var control2_x = 429;var control2_y = 480;var endpointx = 365;var endpointy = 133;Drawing CurvesContext.beziercurveto (control1_x, control1_y, control2_x, control2_y, Endpointx, Endpointy);Context.stroke ();Draw a squarevar

, C, D, E, f);Set TransformContext.settransform (A, B, C, D, E, f);ShearContext.transform (1, SY, SX, 1, 0, 0);ResetContext.settransform (1, 0, 0, 1, 0, 0); State Stackpush state onto StackContext.save ();Pop state off of StackContext.restore (); ClippingclipDraw path Herecontext.clip (); Image Dataget Image Datavar imageData = Context.getimagedata (x, y, width, height); var data = Imagedata.data;Loop Through Image Pixelsvar imageData = Context.getimagedata (x, y, width, height); var data

This article introduces how to use convolution matrix in Canvas of HTML 5 to process images. For more information, see. The canvas Element in HTML 5 is quite powerful, and its getImageData method can be used to directly bitmap the loaded image. However, bitmap operations are difficult. If you use the convolution matrix

React ' s abstraction over the DOM means that it's not always obvious how does dom-related things, like working with the HT ML Canvas API.When working with HTML Canvas, HiDPI displays like Apple's Retina display require a bit of extra coaxing, to make sure the Y look crisp and sharp. This lesson covers how to write a method that automatically scales we component

A small case to practice canvas. If there is a small problem, welcome the big God to shoot bricks ... ^_*Code effect preview Address: http://code.w3ctech.com/detail/2500. 1 div class = "Container" > 2 id = "MyCanvas" width = " height = "" " > canvas > 3 div > 1 * {2 padding:0;3 margin:0;4}5 6 Body{7 Background-color:#d5d3d4;8}9 Ten . Container{ One width:500px; A Height:500px; -

DOCTYPE HTML Public "-//W3C//DTD XHTML 1.0 transitional//en" "http://www.w3.org/TR/xhtml1/DTD/ Xhtml1-transitional.dtd ">HTMLxmlns= "http://www.w3.org/1999/xhtml">Head>Metahttp-equiv= "Content-type"content= "text/html; charset=utf-8" />title>Untitled Documenttitle>Head>Body> CanvasID= "MyCanvas"width= "All"Height= "All"style= "border:1px solid blue;">Canvas> Sc

1. Canvas canvas is usually depicted with JS"en"> " UTF-8"> varCanvas_width = $;varCanvas_height = $;varMyCanvas;varMycontext;window.onload=function () {Createcanvas (); DrawRect ();} function Createcanvas () {Document.body.innerHTML=" ""+Canvas_width+"\ "Height=\""+ Canvas_height +"\ ">"; MyCanvas= document.getElementById ("MyCanvas"); Mycontext= Mycanvas.getcontext ("2d");} function DrawRect () {My

Parse html and use canvas for renderingWhen learning html5, canvas is used to parse and render html text, the supported tags include

The canvas element in HTML 5 is quite powerful, using his Getimagedata method to directly bitmap the loaded image. But directly to the bitmap operation is more troublesome, if the use of convolution matrix this tool, you can through a few simple parameters to achieve complex results. The convolution of the so-called matrix, as shown in the following figure, when the value in the red box is computed

defining and Using methodsExampleHow to display a red rectangle with a canvas element: Copyright notice: This article Bo Master original articles, blogs, without consent may not be reproduced. HTML tags for canvas

Canvas-star7.html, html5canvas

[HTML drawImage createpattern] Canvas drawing picture DrawImage property picture Tiling Way Instance Demo

[HTML drawImage drawing picture] Canvas drawing Picture DrawImage Property Instance Demo

1 [HTML Createpattern Drawing background tiling method] Canvas drawing picture Createpattern Drawing Background Tiling Mode Property instance

Draw ShadowsContext.shadowoffetx: Shadow lateral displacement amountContext.shadowoffety: Shadow longitudinal displacement amountContext.shadowcolor: Shadow colorContext.shadowblur Blur range of shadowsDraw textcontext.fillstyle= ' #00F ';Context.font= "Bold 30px Sans-serif";Context.filltext ("Hello World", 0,0);Context.stroketext ("Hello World", 0,0);Var metrics=context.measuretext (text);　　Canvas 8 of HTML