Design And Implementation Of CAD Software Based On Mobile Internet

Nowadays,the Internet plays a very important role in people's work and life.With the advent of the 4G era and the popularity of mobile devices,we have entered the era of mobile Internet.The application of CAD software in mobile terminal will greatly facilitate the customers,so AutoCAD and some domestic manufacturers are provide mobile CAD software as the situation required.By comparing and analyzing AutoCAD and many domestic CAD software,we can see the difference in user groups.There is big room for optimizing CAD in drawing acceleration,font garbled and so on.According to the actual needs in viewing pictures for professional and ordinary users,this thesis designs and implements an iOS-based CAD software based on ODA(Open Design Alliance),which combined with user's operating habits,hot technology and innovative ideas.It is not only small,fast and free,but also can browse two-dimensional DWG completely without AutoCAD.In additional,it is optimized in drawing acceleration and font garbled.Firstly,this paper analyzes the software user groups,application scenarios and common functions of users,and then divide the functional modules into five parts: login registration,drawing operation,file management,drawing transmission and drawing library,every part has established a detailed use case model,the non-functional requirements of the software are defined from performance requirements and compatibility requirements.The CAD viewing software is developed in Xcode by using the programming language objective-c with Cocoa Touch as the framework in Mac OS X system.Using three-tier architecture pattern,from top to bottom: the presentation layer,application layer and data layer,which effectively reduces the dependence between layers.In order to properly use ODA's Teigha for.dwg function,you need to set up the project's link object link to the link library provided by Teigha for.dwg so that can include the Teigha for.dwg file in the project.Drawing acceleration,hierarchical preprocessing is performed according to the size of the entity,each entity in the drawing has a corresponding level,and then use R-tree to filter the entities in the screen.The display data is finally generated according to the distance and the hierarchy.The data will be classified and then drawn by the GPU batch processing.Font optimization is based on the general font processing,combined with Internet users' operating habits and the concept of cloud sharing,adding a link to query the cloud font library.On the premise of satisfying the user's need for viewing drawings,it is necessary to reduce unnecessary functions as far as possible,thus effectively reducing the size of the installation package and facilitating the user to quickly install and use.Therefore,this paper customizes and designs the functions of login registration,drawing operation,file management,drawing transmission and drawing library.In this paper,we use flow chart,class diagram,sequence diagram,swimming lane diagram to design and to implement various modules for drawing acceleration,font optimization and basic functions in detail.Finally,the software is tested from its function,performance and compatibility.We use black-box test to cover all functional test cases.Performance testing covers three dimensions: response time of open drawing,response time of drawing operation,response time of high frequency interfaces which are tested by JMeter.Test results are expected.Compatibility testing covers the system,model,network and other software with good compatibility.It achieves a certain effect in CAD font and drawing acceleration part by comparing with the previous functions.