Chapter 7 - PowerPoint PPT Presentation

plato
chapter 7 n.
Skip this Video
Loading SlideShow in 5 Seconds..
Chapter 7 PowerPoint Presentation
play fullscreen
1 / 10
Download Presentation
102 Views
Download Presentation

Chapter 7

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Chapter 7 Introduction to High-Level Language Programming

  2. Graphical Programming • Textual output vs. graphics • Text-oriented OS: MS-DOS, VMS • Graphical User Interface: Mac OS, MS Windows, X-Window • Related subjects: • Visualization of 3-D surface (Figure 7.30) • Computer graphics • Computer Aided Design (CAD), CAM

  3. Graphic Primitives • Modern computer terminals use bit mapped display. • The screen is made up of picture elements (pixels). • Black-and-white, gray scale display, color display • The memory that stores the actual screen image is called a frame buffer. • Refresh rate

  4. Graphics Library (0,0) • Contains routines for: • Drawing simple geometric shapes (lines, circles) • Creating and selecting colors • Displaying windows • Pull-down menus • buttons (maxX, maxY)

  5. Ex: Small Graphics Library • clearscreen(I) • moveto(x,y) • getmaxx() • getmaxy() • setcolor(I) • lineto(x,y) • rectangle(x1,y1,x2,y2) • circle(x,y,r) • writedraw(value,x,y) • getmouse(x,y)


  6. Examples • Move to center of screenX=getmaxx();Y=getmaxy();moveto(X/2,Y/2); • Draw a line from (20,20) to (100,100)clearscreen(0);setcolor(1);moveto(20,20);lineto(100,100);

  7. Creating a titled window Clearscreen(0); Setcolor(1); Rectangle(50,50,350,80); Rectangle(50,80,350,300); Moveto(50,60); Lineto(150,60); Moveto(50,70); Lineto(150,70); Moveto(250,60); Lineto(350,60); Moveto(250,70); Lineto(350,70); Writedraw(“Title”,180,70); Title

  8. The Big Picture • Software engineering • Coding (implementation) is a small part of the software life cycle. • May occupy only 10-20% of the total time spent by programmers and designers. • What are the other important steps?

  9. Software Development Cycle • Before implementation • Feasibility study • Problem specification • Program design • Algorithm selection or development, and analysis • Implementation • Coding • Debugging • After implementation • Testing,verification and benchmarking • Documentation • Maintenance

  10. Scaling Up • Programs that students write in a first programming course may be a few hundred lines. • Truly large software systems may contains millions of lines of code. • Refer to Figure 7.35.