1. UMass Lowell Computer Science 91.460 Java and Distributed Computing Prof. Karen Daniels Fall, 2000 Lecture 14 Java Fundamentals 2D Graphics Wed. 10/11/00

2. Homework #4 1 Fri, 9/8 Fri, 9/15 Part 1 Mon, 9/18 Part 2 Mon, 9/18 Part 2 2Fri, 9/15 Fri, 9/22 Part 1 & Part 2 3Fri, 9/22 Fri, 9/29Part 1 & Part 2 4Fri, 10/6Fri, 10/13Part 1 & Part 2 HW# Assigned Due Content We’ll discuss any questions about HW#4 at end of lecture.

3. Exam 1: To be returned today

4. 2D Graphics

5. Some Java Graphics Class Libraries (partial taxonomy) javax.swing JApplet JOptionPane  java.awt  Component Graphics JLabel JButton JFrame Graphics2D abstract Component  JColorChooser

6. Graphics Context ä Can draw from within an applet or application ä Graphics context: allows drawing on screen ä contains state of graphics drawing environment ä drawing color, “pen position”, window size, etc.

7. Java Abstract Windowing Toolkit Some Graphics Methods (from java.awt package) ä java.awt.Graphics (see list on p. 530-531) ä Given an object g of Graphics class: ä g.setColor( Color.red ); // Sets current drawing color to red ä g.drawString(“hello”, 200, 25); // Draws String starting at (200,25) ä g.drawLine(20, 28, 40, 10 ); // Draws line from (20,28) to (40,10) ä g.fillRect(100, 5, 20, 15); // Draws filled rectangle whose upper left // corner is at (100, 5). Width = 20. Height = 15 // corner is at (100, 5). Width = 20. Height = 15 ä g.drawOval(60, 9, 20, 13); // Draws oval whose bounding box upper left // corner is at (60, 9). Width = 20. Height = 13 // corner is at (60, 9). Width = 20. Height = 13 (0,0)x y hello usescurrentcolor

8. Drawing Arcs ä Given an object g of Graphics class: ä g.drawArc( x, y, width, height, startAngle, arcAngle ); ä // Arc is part of an oval ä // Arc sweeps starting at startAngle (0 degrees is at +x 90 is at +y). ä // ArcAngle is amount of sweep in degrees (CCW is positive CW is negative). ä // Arc’s bounding box has top-left corner at (x,y) and has width, height (0,0)xy width height (x,y)

9. Java Color Model ä RGB model is additive ä RGB unit cube: Magenta= (1,0,1) Black = (0,0,0) White = (1,1,1) Shades of gray Blue= (0,0,1) Red= (1,0,0) Green= (0,1,0)Cyan= (0,1,1) Yellow= (1,1,0)

10. Java Color Model (continued) ä Perceptual Term ä Hue ä distinguishes among colors such as red, green, blue, yellow... ä Saturation ä distance from gray of equal intensity ä Brightness ä perceived intensity of s self- luminous object Source: Foley & van Dam, 2nd edition ä Colorimetry (physics) ä Dominant wavelength ä Excitation purity ä Luminance

11. Graphics Demos Deitel Code (Chapter 11)

12. Graphics (appletviewer) Demos - jdk1.2.2\demo\jfc\Java2D - jdk1.2.2\demo\applets\GraphicsTest

13. Graphics Demos Random (multi-threaded) Waves

14. HW#4 Demo Program Mobile Communications Class & Interface Hierarchy Any questions?

15. Mobile Communications Class & Interface Hierarchy

16. Exam 1: Return Graded Exams & Solution