html canvas performance

Brief introduction In part 1th of this series, you will create an application that combines the advantages of the canvas API and the HTML/CSS two models. The canvas API is an ideal choice for WEB applications that require high-performance, low load graphics. However, it is short-sighted to overlook the advantages of t

);Correct code: Context.fillrect (20, 20, 100, 100);Five. Use multilayer canvas for complex scenesSix. Do not use ShadowContext.shadowoffsetx = 5;Context.shadowoffsety = 5;Context.shadowblur = 4;Context.shadowcolor = ' Rgba (255, 0, 0, 0.5) ';Context.fillrect (20, 20, 150, 100);Seven. Clear CanvasDetailed Performance differences:Http://simonsarris.com/blog/346-how-you-clear-your-

Canvas code is also some optimization techniques, my previous several canvas articles simply about how to do using canvas, below to see how others say optimization canvas performance. One: Use cache technology to implement the pre-drawing, reduce the repeated drawing Canvs

;(function ($) {$. Loading = function (options) {Burst plug-in default value$. Loading.defaults = {Speed:200,//eject Layer fade-out SpeedBgcolor: ' Rgba (0,0,0,.7) ',//mask layer color, requires RGBA format, default black 0.5 transparencyType: html,//default HTML style, or canvasMsg: ' Loading ... ',//default loading informationLoadpicnum:2,//for HTML when loadin

Analytical:We can save the state of the current canvas before we do the translation transformation, but the canvas gives us support for layers (layers) that are managed by the stack structure.When we call the Save () method, the state of the current canvas is saved and then added to the canvas stack as a layer, and thi

important point is that the x1,y1 in the code, as long as he to the circle tangent distance, more than his distance to the starting point (x0,y0), the reversal occurs.As we can see, the coordinates of this point can be infinitely varied, so long as he is always a point on the tangent, then the shape of the arcto will not change if the radius of the circle is constant. This requires special attention.Let me validate this proposition with the geometrical knowledge that I do not take to the stage.

-coordinate of Control point 1 and 2 is the same.Now draw an S-shaped curve to prove that Beziercurveto is different: 12 var x1 = ;... In fact, just change the coordinates of the control point 1 a bit. If the coordinates of Control point 1 and Control point 2 are on both sides of the baseline, the curve of the S-shape is drawn, and if it is on one side of the baseline, it is similar to the Quadraticcurveto effect.The case is relatively simple, the base line (the s

Html canvas non-square rotation and scaling... most of the content is written in the square. Some people say they have been reading the square. canvas Scaling

123456789Ten - the + - $ $[HTML canvas transparency Globalapha] Canvas drawing properties Transparency Globalapha Properties Demo

123456789Ten at - About $ - -[HTML canvas drawing text] Canvas drawing implements drawing text Stroketext Filltext method and TextAlign textbaseline Font Property Instance Demo

[HTML Canvas rotation zoom pan] Canvas Drawing implementation Rotation Copy instance Demo

123456789Ten at the - the the the[HTML canvas drawing curve three ways] canvas drawing curves Three methods attribute instance demonstration

[HTML canvas createlineargradient createradialgradient] Canvas drawing gradient createlineargradient createradialgradient Way Instance Demo

1 [HTML drawing Translate] Canvas drawing properties Translate setting Canvas Center Point Properties Instance Demo

situation.Of course, if you pull the control point very far, maybe the graph will become you don't know. Let's try it out: y1 = 950; I just changed the Y1 a bit, and then the curve went beyond the canvas.However, Quadraticcurveto draw the range of the curve, can never reach or exceed the coordinates of the control point, we only have to "control" the control point is good, do not worry.I have written a simple, movable example page that shows the process of drawing a curve in Quadr

123456789Ten - the the - in the[HTML canvas createimagedata create kaleidoscope effects] Canvas drawing properties Createimagedata Properties Explain and create kaleidoscope effects

123456789Ten - - $ $ - -[HTML canvas font textAlign textbaseline measuretext (). Width] Canvas Drawing properties Font textAlign textbaseline measuretext (). Width Properties Demo

Html, canvas, video grayscale, reversed color, canvas grayscale : Code: Note: In this example, you need to run it on the server to see the effect and change the video file to a local video (HBuilder has an integrated server or wampmanager can also be used)

Document directory 2. Method for Calculating the range of Path. 1. With such a framework, it is very easy to add new graphic elements, as is the image class. For more information about the series of directories, see. This section mainly solves three problems: finding the external rectangle of any geometric image. This external rectangle will be used in performance optimization. Of course, it is not only used in this aspect. Finally, the pressure

ArticleDirectory Height attribute Width attribute HTML Dom tutorial 20-html Dom canvas object 1: canvas object The canvas object represents an HTML Canvas Elem