嵌入式浏览器图形处理引擎研究与设计

发布时间：2018-01-26 15:06

本文关键词： 嵌入式浏览器渲染架构图形引擎硬件加速 CORDIC算法　出处：《电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着互联网的飞速发展,HTML5标准的提出并广泛被各种浏览器所支持,传统的基于二维图形的网络页面已经不能满足用户的视觉和交互需求。在这一趋势下,通过HTML5引入并实现的WebGL很好的解决三维图形的绘制需要插件支持和难以跨平台的问题。嵌入式设备的飞速发展,例如平板、手机和智能电视的广泛普及,使得用户渴望时刻享受到来自互联网应用的便利。因此,基于呈现容器—浏览器的对于Web应用程序的响应速度和渲染效率直接影响着用户的体验。但嵌入式设备有着匮乏的硬件资源,低功耗等特点。特别是缺乏3D图形处理器或其它相关的协处理器,对于浏览器的图形处理的优化就显得特别的必要。本文通过对现有的浏览器内核WebKit的分析,研究基于WebKit的二维图形与三维图形渲染流程。实现一种与平台和浏览器内核无关的图形库架构。WebKit通过该图形库渲染架构向不同图形引擎分发图形渲染请求。针对特定平台测试不同图形处理引擎绘制效率,利用不同图形库的各自优势指定浏览器通过该架构调用到指定的图形渲染函数,有效的提高了浏览器的渲染效率。同时运用多线程技术在特定平台上实现特定图形库的硬件加速。利用Direct FB和Skia混合渲染二维图形的方式,更加合理的利用嵌入式设备的硬件资源,优化用户的体验。另外,针对部分嵌入式平台缺乏浮点乘法处理器,而三维图形渲染中涉及大量的三角函数的计算的特点。利用CORDIC算法仅使用加减和移位运算的优势,实现正余弦函数的计算,替换需要通过级数展开计算的三角函数,优化在WebGL中的正余弦函数,避免在计算三角函数的时候使用浮点运算,降低计算复杂度,节约硬件资源,加速三维图形在浏览器中的绘制。并对比测试该改进算法的可行性。本文通过对当前热门的浏览器内核与图形库的研究分析,提出的基于平台无关的浏览器图形库架构,是利用多图形引擎实现图形渲染的一种尝试。对于浏览器或其它需要图形渲染的平台进一步设计优化具有参考和借鉴意义。同时,针对嵌入式平台特定算法的优化,为较低端的嵌入式设备实现三维图形渲染的优化,提供了一定的思路。
[Abstract]:With the rapid development of the Internet, the HTML5 standard is proposed and widely supported by all browsers, the traditional two-dimensional graphics, web page has been unable to meet the user's visual and interactive demand. Based on this trend, through the introduction and implementation of the HTML5 WebGL is a good solution to 3D graphics rendering plug-in support and difficult to cross platform the problem. The rapid development of embedded devices such as tablet, popularity of the mobile phone and smart TV, allows users to enjoy the Internet from time for the convenience of application. Therefore, the present container browser for Web applications based on the response speed and the rendering efficiency directly affects the user experience. But there is lack of embedded devices the hardware resources and low power consumption. Especially the lack of 3D graphics processor or other related coprocessor for optimizing graphics browser It is especially necessary. Based on the analysis of the existing WebKit browser kernel, WebKit of 2D graphics and 3D graphics rendering process. Based on the implementation of a graphics library architecture has nothing to do with the platform and browser kernel.WebKit through the graphics rendering architecture to different graphics engine distributed graphics rendering for a specific platform to test different requests. Graphics rendering engine, use of the advantages of different graphics library browser specified through the architecture call to the specified graphics rendering function, effectively improves the rendering efficiency. At the same time, the browser uses multithreading technology to achieve specific graphics library on a specific platform of hardware acceleration. The use of Direct FB and Skia hybrid two-dimensional graphics rendering method the embedded system hardware, more rational use of resources, optimize the user experience. In addition, some lack of floating platform Point multiplication processor, and the calculation of trigonometric functions involved in 3D graphics rendering. Taking advantage of CORDIC method using only addition and subtraction and shift operation, realize the calculation of sine and cosine function is replaced by series expansion, need trigonometric function calculation, optimization of sine and cosine functions in the WebGL, to avoid the use of floating-point arithmetic in computing trigonometric function, reduce the computational complexity, saving hardware resources, the acceleration of 3D graphics rendering in the browser. The feasibility and contrast test of the improved algorithm. Through the analysis of the current popular browser kernel and graphics library, platform independent graphics library architecture based on browser, is to use multiple graphics engine implementation try graphics rendering. For the browser or other graphics rendering platform for further design optimization has reference and significance. At the same time, according to the The optimization of the specific algorithm of the embedded platform provides a certain way of thinking for the optimization of the 3D graphics rendering of the lower end embedded devices.

【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP393.092;TP391.41

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