Semantic feedback in the Higgens UIMS

Almost all applications using interactive graphics contain important structures and concepts which are deeper than the geometres used to display them to the user. One of the major tasks of the system implementer is to cause the user interface to reflect this deeper structure accurately so that it may be directly manipulated by the user. The authors describe a tool, the Higgens user interface management system (UIMS), which can automate much of this task for a wide class of systems using interactive graphics. It is able to generate graphical user interfaces automatically from a high-level interface specification. These specifications are primarily nonprocedural in nature. They describe how graphical images can be automatically derived and updated based on applications entities, and how graphical inputs can be translated back into terms which are appropriate to the application     

An approach to the formal specification of computer graphics systems

This paper discusses the approach to formal specification of computer graphics systems developed by the ANSI X3H3 committee (Computer Graphics Programming Languages) in the United States. ANSI's specification philosophy aims to gradually replace existing informal English language specifications with more formal ones without sacrificing the readibility and usefulness of standards documents. The specification techniques used are derived from those presently employed in the specification of computer communication protocols and the specification of software systems, not those used for the specification of programming languages. The specifications consist of three parts: the interface between both graphics and the host language and graphics and the graphical display device, the structure of the graphics system, and the functions that are performed by the graphics system. The specifications are based on abstract data types. These data types, together with the operations which can be performed on them, are used to describe the structure and functions of the graphics system. Using these techniques, X3H3 has developed a complete formal specification for a minimal graphics system. Extracts from this specification are included here.     

Factoring a Homogeneous Transformation for a more Efficient Graphics Pipeline

We identify an intermediate coordinate system situated between world coordinates and display coordinates, which exhibits unique features for lighting calculations and for clipping in homogeneous coordinates. Our key contribution is an algorithm for extracting such a coordinate system from a homogeneous viewing transformation that relates WC to DC. The algorithm is based on factoring the transformation into a product of a Euclidean factor and a sparse (computationally cheap) but non-Euclidean factor.
A particularly strong application of the proposed technique is the graphical processing of curved surface primitives, such as what is needed in the PHIGS PLUS viewing pipeline. Furthermore, in PHIGS PLUS the graphical data is retained by the graphics system, therefore, it is possible to perform the factoring of the viewing transformation at creation time, and to take advantage of this factored form at traversal time.     

HAGI, a High-level Application/Graphics Interface

HAGI is an object-oriented graphics system developed on top of the X window system. In addition to providing facilities that structured graphics systems such as GKS usually have, HAGI supports a high- level graphics paradigm with the following features:

• + In addition to graphical objects, the system provides a class of application objects with a higher level of abstraction than graphical objects.
• + Graphics manipulation operations can be issued simplyfrom application objects without explicitly referring to specific graphical objects. Thus graphics manipulation appears to be transparent to application programmers.
• + Graphical objects are designed to encompass more semantics, thus are at a level close to the application. For example, they useflexible visual objects to determine their visual appearance.

HAGI provides such a high-level application/graphics interface by maintaining a dependency relationship between graphical objects and application objects.     

Coordinate-free computer graphics

This paper describes the graphical programming language tuna. tuna is a superset of fortran IV, designed for the writing of interactive graphics programs. The datatype graphical has been added to fortran along with operators which allow the writing of graphical expressions. These operators perform coordinate-free operations such as intersection, concatenation, rotation, and superposition. Other extensions include graphical Boolean operators and statements for communicating with an interactive terminal and light pen.Graphical entities are treated as primitive, rather than as sequences of Cartesian coordinate pairs. The construction operators in tuna are more closely related to the operations of the draftsman than to the algebraic operations of analytic geometry.Pictures are logical trees of points, lines, and subpictures; either DYNAMIC (changing as their subcomponents change) or STATIC. The data structure required to implement this is completely transparent to the programmer.     

VxWorks的三维图形环境的开发

VxWorks作为一种广泛应用于高性能领域中的可裁剪的实时嵌入式操作系统,并没有为用户提供完善的图形界面。为了在VxWorks中实现三维图形的开发和显示,文中通过将OpenGL与WindML（WindRiver Multimedia Library）媒体库相结合,提出VxWorks下三维图形开发环境系统建立和基于该环境的图形开发的方法。完成VxWorks操作系统交叉编译环境的建立、MindML的配置和Mesa3D的编译,并完成VxWorks操作系统下的OpenGL程序开发。通过大量应用程序的测试验证,证明该方法能够完成VxWorks操作系统下的三维图形开发的要求,并且具有操作简单、容易开发等特点。     

基于对象复制的协同绘图并发控制算法

全复制模式下的基于对象的实时协同图形编辑系统支持不同地域的设计人员通过网络同步高效地浏览、操作和修改共享文档和文档中的各种对象，包括图形、图象和文本等，其中操作意愿保证及其并发控制成为复杂而又关键的问题之一，其研究具有挑战性．文中讨论了基于图形对象的并发操作的冲突，提出直接依赖和对象状态概念确定操作的候选对象和相容集合，并改进了对象复制算法．基于此，给出了一个有效的并发控制算法。     

DMS-Dynamic motion simulator

DMS is a graphics program that displays the output of multibody systems programs like DYNACOMBS¹. The menu driven program supports a full range of display options to aid the user in the visualization of his or her output. A small CORE compatible graphics package is included to produce graphical output on Tektronic 4010 terminals or emulators.     

Dynamic illustrative graphics for simulations

In any graphics application, the environment created by the system designer is of utmost importance. A variety of good input devices, effective real time displays, ease of interaction with graphical elements and with system instructions can all contribute to a friendly environment. A graphics system designed for simulations with a facility for adding both abstract dynamic graphics and user control is enhanced by the addition of features uncommon to other graphics systems. These features, and their values and the ways in which they contrast with more traditional graphics systems, will be described.     

一种基于通用计算机的雷达显控终端软件设计

介绍了一种基于通用计算机的雷达显控终端软件的设计方法,软件采用图形化用户界面,且航迹显示具有缩放功能,操作灵活,方便。详细介绍了在VisualC++6.0平台上驱动程序和雷达显示与控制终端的应用程序的编写。     

Solution plans and interactive problem solving

The concept of a ‘solution plan’ is used to characterize the structure of interactive systems in which the user guides the solution process. A formalism for describing and analyzing solution plan structures is presented. The formalism can be used to define the role of the user in an interactive system. The solution plan approach to interaction is particularly applicable to problems which have an obvious graphical representation. An interactive graphics system for solving a class of routing problems is described. Suggestions for the application of the approach to other problems are included.     

新型多通道激光显示系统的设计与实现

已有的激光图形显示系统太单调,图形显示不灵活,不能体现激光应有的显示功能。提出了一个基于计算机控制的多通道激光图形显示系统,该系统通过分光控制完成了振镜、转镜和步镜的协调工作,更好地展现了3种不同功能的电机工作模式,解决了分光系统中电机的响应失真问题,从而丰富和完善了激光图形显示功能。改进后的激光图形显示系统的试验结果表明,多通道激光图形显示系统提高了图形质量,使显示更便利,内容更丰富。     

一种用于图形设备接口的笔画模型方法

视频监控的在屏交互过程中,需要快速地对交互控件、感兴趣区域、活动标记等图形和图像进行绘制,为避免画面的停滞感,要求图形设备接口能快速进行绘制.为此,提出了一种笔画模型方法.利用 DirectX的原始绘制能力,该方法将绘制任务转换成笔画对象,使视频系统在实时运行过程中,只需将已转换的笔画对象的绘制数据提交给 DirectX 进行渲染和显示即可,降低重复绘制时间,满足系统的快速绘制要求.基于笔画模型方法,开发了一种可快速绘制的图形设备接口.     

基于FPGA的座舱仪表图形反走样技术研究

随着现代战斗机座舱仪表向大屏化、综合化方向发展,对图形显示的质量和速度提出了更高的要求。该文从分析有源矩阵液晶显示器(AMLCD)图形走样现象的根本原因入手,分析并阐述了图形反走样技术的基本原理和常见方法。提出了利用二维圆锥滤波器实现座舱仪表图形反走样,并详细阐述了实现方法。最后,为了提高座舱仪表的图形生成速度,提出了一种基于FPGA的嵌入式硬件图形反走样方案,并成功应用于所研制的飞机座舱仪表显示系统中,提高了飞机座舱仪表图形显示的质量与速度。     

Customizing Graphics for Tiny Displays of Mobile Devices

Advances in mobile devices and wireless telecommunication infrastructure already provide mobile users with access to online information sources and services. Compared to the PC world, however, mobile access is still quite restricted, especially with regard to the display of graphical representations, such as images, drawings, diagrams, maps and logos. Since graphical representations are increasingly used in the World Wide Web for the purpose of information presentation, the adaptation of graphics for tiny displays is a challenge that should not be neglected. The current contribution discusses several transformation approaches which might be employed to accomplish this adaptation task.     

How map designers can represent their ideas in thematic maps

Problem analysis in designing thematic maps and user interfaces which assist map designers in incorporating their ideas into maps are presented. Problems in designing choropleth maps are analyzed from the map designers point of view. A graphical user interface, called “Histogram Interface”, is implemented as countermeasure for problems in designing choropleth maps. The user interface can assist map designers in representing their ideas and achieving the desired maps through the designing process. The user interface operations, which correspond to the map designer's ideas, are explained. The user interface effectiveness is confirmed by resulting map examples and the corresponding graphical patterns on the interface. A concept is proposed concerning the importance in any computer graphics field, which the designers should consider in determining how to incorporate their ideas into pictures.     

A graphical editor and process visualization system for man-machine interfaces of dynamic systems

The process visualization system of a manmachine interface is presented. It allows human operator(s) to interact with a dynamic technical system, here a thermal power plant. Also, a graphical editor for designing dynamic pictures of the process visualization system is explained. Both new systems have a common architecture and are based on the computer graphics standard PHIGS-2D with extensions for handling non-graphical and graphical information. The hierarchical information structures are manipulated with lists and pointers in a dynamic visual database. The two menu-driven interfaces for designers and for operators are described with their multi-window display layouts. The software of both systems is highly portable to different hardware and to other application domains.     

Attribute grammars in constraint-based graphics systems

A constraint-based graphics system provides a flexible, intuitive framework for describing relationships among graphical objects in applications such as document preparation, fount design and solid modelling. This paper describes two constraint-based graphics systems, micro-COSM and the IDEAL Synthesizer, and their implementation in terms of attribute grammars. Our experiences with attribute grammars suggest that they provide a powerful framework for representing constraints and extracting important semantic information such as the equations to be solved by the constraint solver. We discuss the advantages of using attribute grammars in constraint-based graphics and from our experiences make several observations about the way attribute grammars should be used.     

基于抽象工厂模式的机载显示系统图形生成技术研究

机载显示系统直接关系到先进航电系统的性能和成本,针对机载显示系统的特点、性能要求,分析了目前机载显示系统存在的复用率低、不易于移植、继承性差、无法重构、成本高等缺陷。提出了基于抽象工厂模式的图形生成设计新思想,对机载显示系统图形库进行分类、分级抽象,建立图形处理模型、图形绘制模型和显示模型三级架构,统一了字符、图形、窗口的模型处理方法。基于OpenGL实现了图形模型开发库和机载显示系统图形生成架构,以该方法实现了某型飞机显示系统的开发,实验证明,该方法实现了显示系统通用开发技术和软件重构技术。     

The evolution of standards for computer graphics

Although work towards international standards for computer graphics was started in 1976, it is in the last 2 years that real agreement and progress have been achieved. The first target, the functional specification of a graphics system, is satisfied by the graphical kernel system (GKS), which is now being processed as an International Organization for Standardization (ISO) draft international standard. GKS provides a reference model for two-dimensional graphics and an agreed vocabulary of terms covering the field. Many implementations of GKS as a package are now being produced. In addition to such a functional specification, two forms of communication are appropriate for graphics: a metafile and a virtual device interface. ISO is now reviewing a proposal for a metafile standard developed by the American National Standards Institute and closely related to GKS. Standards for a graphics virtual device interface and for three-dimensional graphics systems are also being actively developed. All these efforts and their interrelationships are described and examined.