StarCall

Overview

In this lesson we will learn to make a game using the canvas, imagesprites, procedures, and timer.

New Concepts

Canvas:

A surface where you can put objects on a given location.

Image Sprite

An interactive image that can be put on a canvas. It reacts to collisions and touches.

Clock

Keeping track of timing and current time.

Let's Get Started

Designer

We will need:

• Canvas (x1)
• Image sprite (x3)

For the score counter:

• Horizontal layouts (x3)
• Labels (x4)
• Button (x1)
• Timer (x1)

For music:

• Player(x1)

##Specific Properties

• set screen orientation at Screen to be portrait
• set layer (z) for meteor sprite above the earth sprite
• set layer (z) for gameover sprite above all
• set timerInterval to a small number (i.e. 100) for responsive time tracking.

Blocks

1. Generate meteor at random location
2. Handle touch event for the meteor
3. Increment score and keep track of time
4. Handle Edge collision
5. Reset button

Stretch Goals

• More random behavior!
  • Angle of launch
  • Changing direction
    • Zig-zag
    • Slow curve
    • Simple change
  • Teleporting?
  • Slow-down/speed-up
• Difficulty Curve Tweaks (The Current difficulty is linear, It gets really hard!)
  • Easier
    • Square-root/logarithmic functions
    • Piece-wise linear functions (for example, from speed 1-10 growth is 0.5, 10-50 is 0.3, 50+ is 0.1)
  • Harder
    • exponential/power functions
• New features/mechanics!
  • Meteor size variable
  • New Type of meteors
  • Other interaction methods
  • Gyroscope for tilting
  • Long touches for special meteors

Media & Assets

1. Starsinthesky.jpg
2. fireball.png
3. game-over.png
4. Magellanic Clouds.mp3

5.  [earth.png](https://raw.githubusercontent.com/cppignite/lessons/master/StarCall/Media/earth.png)
   

External References

• Canvas
• Image Sprites
• Java Random

APK Download