programming

Programming  Project  2   30  points     Submission  Instructions   Open  Eclipse  and  create  a  Java  Project  called  Project2.  Add  a  class  named   RectangleIntersection  to  this  project.     At  the  top  of  your  file,  enter  a  comment  with  your  name,  the  assignment  number,   the  date,  and  a  short  description  of  what  the  program  does.       When  you  are  finished,  export  your  project  from  Eclipse  and  upload  it  to  Canvas   before  the  due  date.  To  do  this,  right  click  on  the  project  name  and  select  Export.   Select  General-­‐>Archive  File  and  click  Next.  Select  the  project  you  wish  to  export   (Project2  in  this  case)  and  click  Browse  to  browse  to  a  location  to  save  your  file.   Name  this  file  YourLastNameYourFirstNameProject2.  Upload  this  file  to  Canvas.   Remember  that  late  assignments  are  not  accepted  in  this  course.     Assignment     In  this  project  we  are  going  to  solve  a  geometric  problem.    Geometric  problems  are   important  for  many  applications  including  data  visualization,  geographic   information  systems,  integrated  circuits,  computer  graphics,  and  video  games.     If  boxes  are  "axis-­‐aligned,"  meaning  the  edges  are  parallel  to  the  x-­‐  and  y-­‐axes,  we   can  actually  figure  out  whether  or  not  they  intersect  with  some  very  simple  tests.     Write  a  program  that  prompts  the  user  to  enter  the  center  coordinates,  widths  and   heights  of  two  rectangles.  Your  program  should  draw  the  two  rectangles  to  the   screen.  If  the  rectangles  do  not  intersect,  they  should  be  colored  green.  If  they  do   overlap,  they  should  be  colored  red.     How  can  we  tell  if  the  two  rectangles  overlap?    There  is  a  simple  and  elegant   solution.  It  focuses  on  when  we  are  sure  that  there  is  no  overlap.         For  example,  what  can  we  say  about  the  right  edge  of  box  1  and  the  left  edge  of  box   2?          

       

What  can  we  say  about  the  edges  now?    

        There  are  four  conditions  that  guarantee  that  we  have  no  overlap  (two  for  the  left   and  right  edges,  two  for  the  top  and  bottom  edges).    If  any  of  those  conditions  are   true,  that  means  we  do  not  have  an  intersection.    If  none  of  them  are  true,  it  means   we  have  an  intersection.       The  left  and  right  conditions  are  illustrated  above.  Go  ahead  and  draw  the  top  and   bottom  conditions.     I  recommend  you  work  in  small  steps  to  solve  this  problem:    

• I  would  approach  the  problem  by  first  creating  variables  the  represent  the   centers,  widths,  and  heights  of  each  rectangle  and  then  assigning  these   variables  values  within  your  code.    

• I  would  then  write  code  draw  these  rectangles  and  verify  that  each  rectangle   is  drawn  correctly.    

• I  would  then  write  code  that  determines  the  position  of  each  edge  (top,   bottom,  left,  right)  of  each  rectangle.    

• Next,  I  would  add  the  code  that  checks  to  see  if  the  rectangles  intersect  and   print  out  the  result  (“intersection”  or  “no  intersection”)  to  the  screen.  I  would   test  this  code  for  all  four  cases  in  which  the  rectangles  do  not  intersect  as   well  as  several  cases  in  which  they  do  intersect.  

• I  would  then  color  the  rectangles  appropriately.   • Finally,  I  would  add  the  user  input.  

     

Grading  Criteria  (30  points  possible)     Points   Criteria  

0-­‐5  points   Input:  Does  the  program  clearly  prompt  the  user  for  the  required   values  and  correctly  read  in  these  values  from  the  keyboard?  

0-­‐10  points   Correctness:  Does  the  program  correctly  calculate  if  the  two   rectangles  intersect?  

0-­‐10  points   Output:  Are  the  rectangles  drawn  in  the  proper  locations?  Are  the   rectangles  drawn  with  the  correct  widths  and  heights?  Are  they   colored  properly?  

0-­‐5  points   Style:  Is  the  code  easy  to  read?  Is  the  code  indented  in  a  style  similar   to  that  shown  in  the  textbook?  Are  blank  lines  used  to  divide  the  code   into  sections?  Is  a  comment  with  the  required  information  included  at   the  top  of  the  file?  Are  comments  used  to  provide  details  that  are  not   obvious?  Are  meaningful  variable  names  used?  (See  Section  1.4  of  the   textbook  for  documentation  and  style  guidelines.)