html5 canvas map example

canvas by operating on it. Basic API:String Use the filltext () method of the context object to draw strings in the canvas. The following is a prototype of the filltext () method: Void filltext (text, left, top, [maxwidth]); The meanings of the four parameters are as follows: the string to be drawn, the horizontal and vertical coordinates in the upper left corner of the

In HTML5 canvas, three-and second-order Bezier curves can be depicted in the following ways: The code is as follows: Context.beziercurveto (cp1x, cp1y, CP2X, cp2y, X, y) Context.quadraticcurveto (CPX, cpy, X, y) A Bezier curve is a curve defined by a "starting point", an "end point", and one or more "control points" on a two-dimensional plane. The normal Sanche Besel curve uses two control points, while

Recently have time to understand the next HTML5 of the API, found that Sina Weibo's avatar set is the use of canvas to achieve screenshots, coupled with the previous period of time to understand the next HTML5 file API FileReader implementation files upload "JavaScript File API files Upload Preview, more feel HTML5 fun

Dom is a very important part of the Web front-end domain, not only when working with HTML elements, but also with the use of the DOM, as well as graphical programming. SVG drawings, for example, are inserted into the page as DOM nodes, which means that the DOM method can be used to manipulate the graph. For example, there is a HTML5

HTML5 object, which contains many methods for drawing and adjusting the image. In JavaScript, you can draw the desired image in the Canvas by operating on it.String Use the fillText () method of the Context object to draw strings in the canvas. The following is a prototype of the fillText () method: Void fillText (text, left, top, [maxWidth]); The meanings of th

JavaScript + html5 canvas implementation local tutorial, html5canvas I recently learned about html5 APIs and found that Sina Weibo's profile picture settings are implemented using canvas, in addition, I learned some time ago about the html5 File API and used the File API Fil

In-depth research on HTML5 canvas for Image Compression and uploading, As mentioned in the previous article, we know that the traffic is still very expensive, and the pixels of mobile phones are getting higher and higher. Taking a photo is just several MB, which is hard to hurt. Although the client can easily compress and upload images, our applications may be opened in the browser. What should we do? compr

In-depth analysis of HTML5 Canvas to control the graphic matrix transformation method, html5canvas Before introducing matrix transformation transform (), let's talk about transformation matrices. The above is the transformation matrix corresponding to the transform () method in the Canvas. This method is the six parameters shown in the input graph, specifically c

depends on the direction of the drawing (that is, anticlockwise the value of the parameter), and if it is drawn clockwise ( false ), a complete circle will be drawn, and if drawn counterclockwise, radians greater than 2 π will be converted to a radian equal to, but not greater than, 2 π. For example, set the ending Radian in the above code to 3π (), and if so, it will appear Math.PI * 3 anticlockwise false as a complete circle, and if true so, its di

, because I think all the demo is not a program!One of the most attractive parts of HTML5 is the canvas, which provides a range of interfaces for manipulating the Web page canvas, and you can manipulate the graphics directly on the HTML and control every pixel in the area! For example: Generate thumbnails, mosaic, resi

Some of China's precision marketing companies are going to steal the music. = = from the previous tracking cookie to the trailing Flashcookie, some businesses are always tracking user behavior and even privacy, turning it into so-called "business value." We are forced to face the "deteriorating, moral perish" dilemma, but the author later let go, anyway in China online there is no privacy. After all, the state machinery is still working legally ...In other words, the core principle of the

. Follow the standards. PhoneGap is the de facto standard for mixed HTML5 and Native programming. The cantk-runtime is provided in the form of the PhoneGap plug-in, allowing you to use thousands of PhoneGap plug-ins. The rendering API is provided in the standard HTML5 Canvas 2D API mode, and the music and sound effects are provided in a way compatible with

front end, it is not necessary to theoretically limit the size of the picture. Second, the picture front-end JS compression and upload function experienceSpecially made a picture front-end compression and upload the full demo, you can ruthlessly click here: Use canvas to compress images in the front and upload the demoEnter the demo to see a plain File entry box:Ah, no, it should be this picture:Click on the File selection box, we may wish to ch

The example of this article describes the method of JS+HTML5 to realize canvas drawing simple rectangle. Share to everyone for your reference. The implementation methods are as follows: ? 1 2 3 4, 5 6 7 8 9 10 11 12 13 14 15 I hope this article will help you with your Web programming.

The example of this article tells the JAVASCRIPT+HTML5 canvas to draw the colorful triangle effect. Share to everyone for your reference, specific as follows: The screenshot of the running effect is as follows: The specific code is as follows: More about JS effects related content Readers can view the site topics: "jquery animation and special effect

The example of this article describes the method of JS+HTML5 to realize canvas drawing circular pattern. Share to everyone for your reference. The implementation methods are as follows: I hope this article will help you with your Web programming.

information var startx = IMG. width/2; // The original value is 0 var starty = IMG. width/2; // The original value is 0 var CT =$ ('get _ image_canvas '). getcontext ('2d '); $ ('get _ image_canvas '). width = IMG. width; $ ('get _ image_canvas '). height = IMG. height; Ct. putimagedata (imgagedata, startx, starty );});} Demo_3 shows the following results. However, you may have a better understanding of several parameters by yourself: 3. Create canvas