Programming games

1
Programming games

• Flash concepts
• Filezilla upload your project(s)
• Homework Prepare Flash rock paper scissors
  (build on partial implementation on-line).

2
Review

• Flash has Scene 1 (main movie) Stage and Timeline
• Place code in specific frame using Actions panel
• Place on Stage at specific frame
• Movie clip symbol instances(s)
• Button(s)
• Graphic symbol instance(s)
• AND place directly on Stage
• Text fields
• graphics (drawings)

3
Important

• Where code and instances go is critical!
• Movie instances and buttons and text fields must
  be named to be used (referenced) by code!
• Generally, it is the ATTRIBUTEs of objects that
  are changed
• head.visible, head.rotation, headcount.text
• Beware of things inside of things.

4
OLD Flash

• Movie clip attributes had underscore
• head._visible
• Code could be put in an object, including
  buttons
• on(Release)
• Different names for setting up events in frame
  code
• flipbtn.onRelease flip
• Weakly typed, like JavaScript
• Did not have to specify datatype for variables.
  Looser on parameters to functions.

5
This class

• We will stick to ActionScript 3.0.
• You need to use ActionScript 3.0 for your
  project.
• (After class, if you need help understanding and
  converting old code, I will try to help.)

6
Demonstrate

• 'full' rock paper scissors
• download and show partial rps (.fla file)
• You can complete this OR start from scratch OR
  use this, but change the graphics

7
Cel animation

• Aka frame by frame animation
• Animation (that look of movement) achieved by
  showing different frames
• Each hand drawn or
• Produced by built-in tweening facility
• in succession
• Computer (computed) animation achieved by coding
  that moves or modifies objects.
• Flash applications can have both!

8
Flash

• Control goes frame to frame (and loops back)
  UNLESS your code includes something like
• stop() or
• goToAndPlay(framenum)
• Code is 'in frame' or in separate .as file as
  part of a class definition
• NOTE a function definition is not a call to
  execute (invoke, run) the function.

9
Adding frames

• Insert/Timeline/Keyframe if you want to copy over
  material in previous frame.
• Insert/Timeline/Blank Keyframe if you DON'T.
• NOTE if you insert a keyframe and then go back
  and add material to earlier frame, it will NOT be
  automatically added to the following frames.

10
Fix

• If you need to remove a frame, select frame and
  then
• PC right click, dropdown menu giving options
• MAC command click, dropdown menu giving options
• Note also Edit/Undo is helpful.

11
Instances

• The cross-hairs denotes the origin of the object.
  It is the thing corresponding to the x and y
  positions
• X from the left
• Y from the top
• Rotation is around the origin
• Your head movie clip instance rotates around this
  origin.

12
Text fields

• Static label parts of screen
• Dynamic can be changed by code
• Input player can enter values
• Dynamic and Input fields need instance names
• To change the text of a Text field named score
  score.text " "

13
Movie Clips

• Symbols in Library
• Instances (copies of) are placed in frames (in
  layers) on Stage (can be 'off stage'). Instances
  are named.
• Can position instances (and do other things!)
• clip.x
• clip.y
• clip.rotation .

14
Other movie clip properties

• clip.alpha transparency
• clip.height
• clip.width
• clip.name returns name as a string
• clip.visible
• more

15
Movie clip methods

• target.stop()
• target.goToAndPlay(fn)
• target.hitTestPoint(ball.x,ball.y,true)
• Returns true if the point is on material in the
  target
• wall.hitTestObject(thing)
• Returns true if a bounding rectangle around thing
  overlaps a bounding rectangle around wall.
• Note there are also global functions stop() and
  goToAndPlay(). These apply to the current movie
  clip.

16
Multiple movie clips

• If there are multiple movie clips, they are all
  running
• going from frame to frame
• UNLESS stop() is used.

17
Recommendation

• Work on logic, then build up the graphics and
  interaction
• Rock paper scissors
• create the 3 buttons, write logic, display
  results in Dynamic Text fields
• THEN add graphical display

18
Buttons

• Coinflip used button from library
• changed text
• Rock paper scissors made our own buttons
• Lesson make your own only when it is necessary.

19
Random effects

• Also called pseudo-random, stochastic,
  probabilistic
• SAME AS JAVASCRIPT
• Math.random() is a method of the Math object that
  produces a fraction from zero to less than one.

20
Flash

• For development, the Flash file is .fla
• For distribution, you publish your project. This
  produces an .html file and a .swf file, both of
  which need to be uploaded.
• Jigsaw will make user of .as files
• Bouncing things, shooter, others, also make use
  of .as files
• more complex projects make use of (external)
  sound, image and movie clips. None of ours will.

21
Homework

• Finish and show coin toss with rotation and with
  counts.
• Work on Flash
• lessons (help with drawing)
• rock-paper-scissors
• You can download .fla file with partial program