INQ241B
Mobile Apps

Rectangle and Elipse

• Create a new script
• Add the game libarary

• In addition to pictures, can add rectangles and ellipses

  var square board→create rectangle(100, 100)
  var circle board→create ellipse(100, 100)

• Inputs are the width and height of the rectangle and ellipse

• Rectangles and ellipses are sprites just like pictures, but can also change their color

  square→set color(colors→random)

Touch Input

• Can get the location of the user’s finger

  var point := board→touch current

• The variable point is a new type we haven’t seen yet, a Vector3
• It represents a point in 3 dimensions

• Vectors have x and y values just like sprites

  square→set x(point→x)
  square→set y(point→y)

• But notice that the square moves into the upper left corner of the sreen when the app first starts
• Recall that the upper left is 0, 0, that is the value of touch→current before the user actually touches the screen

• To fix this, we need to check if the user is actually touching the screen

  if board→touched then
      var point := board→touch current
      square→set pos(point→x, point→y)
  else do nothing end if

Overlap

• It wouldn’t be much of a game if we couldn’t test if sprites were interacting with each other

  if square→overlaps with(circle) then
      rectangle→set color(colors→random)
  else do nothing end if

Quiz

• m.socrative.com
• Room name ‘INQ241’

Activity

• Activity 7