What is "VML", the base knowledge of VML _VML related

HTML is the standard format for Web pages, and the pages we see are written in HTML markup, but the tags are limited
-VML is a markup language that uses code tags to draw inside a Web page, like HTML, or a complement to HTML.
-The output image is a vector graphic format that supports 2D, 3D and animated animations.
-It is very good for HTML, CSS2 (style sheets), which means that these 3 people are easily mixed up and complementary
-it is equally compatible with DHTML (HTML object-based programming language), Js&vbs (scripting)
-It is well-compatible with XML (universal Web Data Description Language), XSL (stylesheet), DOM (object interface), etc.
-it can be directly parsed and output by the browser that supports it, but only IE browsers support VML at this time

-It is based on XML format with PGML, SVG, etc., and is similar to SWF (Flash), PDF and other graphic effects
-VML is Microsoft 1999 years ago (specific time I was unknown) production launched, and integrated into the ie5+ browser
-also the core structure of Microsoft Office Art (art type, such as word)
-VML by Microsoft Visio, Autodesk, Macromedia and other enterprises recommended to the Web (WWW Supreme Rights Association)
-The adoption and synthesis of the recommendations of the various parties, the development of the new SVG in early 1999, and shortly thereafter launched
-svg is an improvement (output efficiency, pattern quality, markup extension) of the integrated VML, GML, and is recommended as a standard
-but SVG requires a dedicated image reader such as (Adobe SVG Viewer) that cannot be directly parsed by the browser engine
-In my opinion, SVG is more suitable for the development of precision vector graphic application software, and VML is suitable for application in Web page
-There are a lot of articles saying that VML is obsolete, but the benevolent see, the VML I feel quite sound (picture type
Output speed) and its easy to write, browser can parse, and HTML and other languages such as compatibility, real
Feasibility of the application of the Web page and the feasibility of the deep development

-but not to mention the advantages of VML, VML in my deep application development, encountered the "efficiency" shortcomings, of course, only
It is said that deep application (large sub-precision vector image, VML animation, gorgeous 2d/3d effect, etc...), a
Simple application, is not feel, or can be said that the general application is a cinch.
-Hardware efficiency: Perhaps VML describes a vector graphic in just a single line, a few lines of code, no reason to cause
The problem of slow output efficiency. But in fact, the output of the VML vector pattern (2d/3d) is integrated graphics, memory
, CPU, screen refresh rate and so on, which directly related to the performance of the hardware, the need for certain settings, but also
The larger the VML vector pattern, the more colors, the more complex the pattern processing, the faster the animation updates, the more
It is easy to cause cpu100%, the slower the output efficiency problem, otherwise it will be very fast.
-Data efficiency: the larger the above pattern, the more colors and so on, not only related to the hardware. In fact, a few line generations
Code description of the pattern, after the browser parsing, it becomes a veritable "digital image." Just browsing
After the analysis of the data, we see the pattern, who knows how many "numbers" to output this
A pattern? The display refreshes once, that is, the repetition of these "numbers" .... That's what you don't
Look at this pattern (switch to another Web page) The machine works faster, and conversely you see, the machine slows down.
The reason.
-Image vector efficiency: In future chapters, you'll learn about VML's image, ImageData, fill, etc.
The file:///(online), the local path protocol jpg, GIF,
Images such as BMP are inserted into a Web page in a vector format. You will find that if the image being inserted is bigger (
Number of bytes), the slower it will be and the sooner it will be.
-Integrating the above-mentioned efficiency issues is the biggest drawback of VML. Understand the shortcomings of VML, in the future to learn, apply
In VML, we should try our best to avoid hitting the nails on this shortcoming and mastering the VML technology
, it is not difficult, not enough to fear. At least, the output efficiency of the VML graph is fast enough:)

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