INTERACTIVE COMPUTER GRAPHICS
USING THE X WINDOW SYSTEM

This page describes a book for teaching graphics in an X environment without having to struggle with the complexity of X. A Starter Toolkit makes programming in X easy, at least for the type of programs required in a basic graphics course. The book emphasizes video games and drawing programs (such as the one that produced the picture to the right) as means to introduce students both to concepts of graphics and to event driven programming.

T. Pavlidis, Interactive Computer Graphics in X,
PWS Publishing Co., 1996 (ISBN 0-534-94986-X)

It can be ordered from the ITP Distribution Center 800-842-3636.

Click here for publisher's web page of the book

A list of chapters and topics is given next. Chapters marked with a (*) deal with features of X beyond the Starter Toolkit and they are optional.

Chapter 1: Windows and Graphics (page 1)

• Overview of window systems from a users viewpoint
• Hardware for such systems
• What is the X Window System
• The Starter Toolkit as means to do simple graphics within the X Window System environment
• Primitive graphics functions of the Starter Toolkit
• Simple visualization programs.

Chapter 2: Event Driven Computing (page 31)

• User driven computing: interrupts and events
• Means of handling user input or other external actions (event handling)
• Functions of the Starter Toolkit for handling input from the mouse and the keyboard
• Example programs: Painting with Pixels; Drawing Lines (``Rubber banding''); Typing words at positions pointed by the mouse; Using a Color Palette.

Chapter 3: Icons and Games (page 65)

• Creating and using icons
• cursor icons and icon masks
• Animation and video games built from icons

Chapter 4(*): Fundamentals of the X Window System (page 95)

• Major features of the X Window System, especially those pertinent to creating graphic displays
• X Protocol and Xlib
• Clients and Servers
• Window Managers
• Window creation, mapping, and reparenting
• Attributes, Properties, and Atoms

Chapter 5(*): Drawing on the X Window System (page 114)

• Drawables
• Pixmaps
• Graphics Context
• Primitive graphics functions of Xlib
• Icons
• Color
• Fonts

Chapter 6(*): Event Handling in the X Window System (page 131)

• Dealing with the event queue
• the XEvent structure
• Types of Events: generated by direct user action or by the window manager
• Event Selection
• Implementation of a Simple Programs for Visualization and Drawing.

Chapter 7: Graphical Computing (page 151)

• Graphics as means of human-computer communication
• Menus, Buttons, and Panels
• Facilities of the Starter Toolkit for constructing selection panels
• Examples of using panel buttons to select the event handler or to select the values of parameters
• Use of pipes for graphic interfaces to existing programs.

Chapter 8(*): The X Window System Toolkit (page 188)

• Window objects
• Associating events with window objects
• The X Window System Toolkit: Intrinsics and Widgets
• Relationship between the X Toolkit, Xlib, and Widget Sets such as Motif
• Widget Class Hierarchy and Widget Trees
• Resources
• Callbacks
• Event Handlers

Chapter 9(*): Using Toolkits (page 212)

• Creating Widgets
• Starting an Application
• The Starter Toolkit
• The Tk Toolkit

Chapter 10: Plotting Lines and Circles (page 241)

• Plotting of lines on bitmaps
• Plotting of circular arcs on bitmaps
• Plotting arcs through straight lines
• Using of the plotting functions in the pixel painting program.

Chapter 11: Filling Areas (page 264)

• Filling the interior of an irregular area surrounded by pixels
• Connectivity or Flood Filling.

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Chapter 12: Filling Polygons (page 277)

• Filling Polygons using a Parity Rule
• Singular Cases
• Facilities of the Starter Toolkit for polygon filling

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Chapter 13: Geometrical Objects and Transformations (page 296)

• Representation of shapes as geometric objects rather than pixel arrays
• Scaling
• Translation
• Rotation
• Pointing to objects
• Pointing to line segments.

Chapter 14: Programs for Drawing (page 321)

• Drawing various shapes
• Usage functions
• Grabbing and dragging Selecting the object pointed by the user
• Selection and Operations on groups of objects
• Callback Structures for buttons that select editing operations.

Chapter 15: Operations on Lines (page 341)

• Extracting information about the geometric arrangements of various geometrical figures
• Mathematics of homogeneous coordinates
• Relative position of points and/or line segments
• Ideas for enhancing the video game of Chapter 3.

Chapter 16: Operations on Polygons (page 363)

• Window clipping
• Position of a point with respect to a convex or nonconvex polygon
• Clipping a line segment by a convex polygon
• Clipping of Polygons

Chapter 17: Splines (page 384)

• Need for Curves whose shape can be determined through simple user interaction
• Examples of interactive curve drawing and editing
• Parabolic splines
• Cubic splines

Chapter 18(*): Advanced Plotting through Xlib (page 411)

• Arc Plotting
• Polygon Plotting
• Use of Pixmaps for intermediate plotting
• Polygon Filling
• Fill Patterns Regions
• Region Algebra

Chapter 19: Projections and Visibility (page 430)

• Introduction to three dimensional graphics
• Homogeneous coordinates in three dimensions
• Projections (finding plane descriptions for objects defined in space)
• Brief discussion of visibility (finding which objects may obscure others) and ray tracing (finding what is seen from a point on the display screen).

Chapter 20: Full Pictures (page 452)

• Definition of the term Full Pictures
• Real and synthetic full pictures
• Scanning and Displaying
• Dealing with Jaggies (``anti-aliasing'')
• Colormaps for full pictures
• Display tools

Chapter 21: Halftoning (page 474)

• Techniques for displaying full pictures in a way that they appear to have a larger variety of colors and intensity than the display device is capable of providing
• Dither halftoning
• Error Diffusion Halftoning
• Color halftoning.

Chapter 22(*): Image Display through Xlib (page 494)

• Colormaps and Visuals
• The Xlib XImage function and its use to display full images and halftones
• Drawing on Tiles