INTERACTIVE COMPUTER GRAPHICS Data Structures, Algorithms, Languages

Transcription

1 INTERACTIVE COMPUTER GRAPHICS Data Structures, Algorithms, Languages Wolfgang K. Glloi Technical University of Berlin and University of Minnesota Tochnisths BodischBle Dnrmstadt FACHEEKE1CH 1NFORMATIK BIBLIOTHEK Inventar-Nr.: Sachgebiete: Standortt PRENTICE-HALL, INC., Englewood Cliffs, New Jersey 07632

2 Contents Preface far Acknowledgements For Illustrations xll PARTI: DATA STRUCTURES AND ALGORITHMS 1 1 Introduction What is computer graphics? The motivation for interactive computer graphics 7 i/1.3 Model of interactive graphics systems 8 )/ 1.4 The display file 12 vl.5 The necessity of a dual representation of graphic objects The problem of picture transformations Taxonomy of display systems Stand-alone versus satellite systems 23 Exercises 24 2 Data Structures, Data Bases, and List Handling Formal definition of data structures A data structure definition Definitions of relations and their properties Linear lists Tree structures Generalized list structures Associative structures 36

3 vi Contents 2.2 Representation of data structures in a computer Sequential or linked memory allocation Representation of arrays Representation of trees Representation of generalized lists (hierarchical structures) Representation of associative structures Data models and data base organization Objectives of data base management systems Conceptual data models List handling Implementation of linear lists List construction and manipulation Searching and sorting of lists Hash coding 73 Exercises 74 3 Picture Structure and Picture Transformations Picture structure Domain transformations Geometric transformations Rotation Translation Scaling The perspective representation of three-dimensional objects The "4x4-matrix" for rotation, scaling, translation, and perspective A standard transformation system 107 Exercises Interpolation and Approximation of Curves and Surfaces Introductory remarks Classical methods: Lagrange and Hermite interpolation Interpolation with 5-splines Bezier approximation of curves General principles of surface construction 140 Exercises Rendering of Surfaces and Solids The hidden-surface problem The set of transition functions {PM,IS,CT,DT,VT} The projective mapping PM The function class IS The containment test CT The depth test DT The visibility test VT 164

4 Contents vii 5.3 Description of four hidden-surface algorithms General remarks Appel's method of quantitative invisibility Encarnacao's priority method Watkins'scan-line algorithm Encarnacao's scan-grid algorithm Comparison Sorting 184 Exercises 185 PART II LANGUAGES AND THEIR INTERPRETERS Interaction Handling Interactive input devices Lightpen Joystick, control ball, and "mouse" Tablet Keyboards Lightpen vs. cursor control devices A pen track procedure Device independence Attention handling The role of interrupts in display systems Attention queue and task scheduler The finite state model of an interactive program 205 Exercises The Display Processor The display console Typical CRT specifications Input devices The display generator Position generator and dot generator Character generator Vector generator Time'requirements The display controller Typical display processor instruction set Instruction formats The controller Analog scissoring High-performance display systems 239» 7.5 Low-cost displays Storage tube displays and plasma displays TV raster displays for text and simple graphics TV raster graphic display systems 252 Exercises 256

5 viii Contents 8 Display File and Picture File Organization Data base and display file revisited Display file without subpicture calls Display file with subpicture calls Display file and picture file 267 Exercises Language Concepts for Interactive Computer Graphics High-level graphic programming languages An example Language extensions vs. subroutine packages The "prefabricated-structure" vs. the "building-block" concept High-level graphic languages: two cases in point LEAP-an ALGOL 60 extension based on the prefabricated-structure concept EX. GRAF-a FORTRAN extension based on the building-block concept L 4 -an intermediate language for device-independence and intra system communication Hlgn-Level Language Implementation of Display Programming Systems Tasks of a graphical programming package Language structures Interaction handling routines GRIP (Graphic Procedures for Instructional Purposes) The instant of object creation Command languages Implementation the GRIP philosophy in existing high-level languages FORTRAN ALGOL PASCAL PL/ APL 312 Exercises 314 BIBLIOGRAPHY 320 Appendix: Implementation of the GRIP Concept 330 Index 351 A.I General considerations 330 A.2 Terminal graphics software 334 A.2.1 Data flow in the terminal 334 \ A.2.2 Display file overview and L 4 interpreter data structures 335 * A.2.3 L 4 interpreter 341 A.3 High-level graphic programming packages 346 A.3.1 Introduction 346 A.3.2 FORTRAN Graphics Package (GRAP) 346 A.3.3 APL Graphics Package (APL-G) 349