EliteIntegrity’s gists

EliteIntegrity / KotlinInvadersActivity.kt

Last active January 12, 2020 03:20

The completed KotlinInvadersActivity class

	package com.gamecodeschool.kotlininvaders

	import android.app.Activity
	import android.graphics.Point
	import android.os.Bundle

	class KotlinInvadersActivity : Activity() {

	// kotlinInvadersView will be the view of the game
	// It will also hold the logic of the game

EliteIntegrity / KotlinInvadersView.kt

Last active March 5, 2019 10:00

This is the KorlinInvadersView class, with a working thread that can be started and stopped from KotlinInvadersActivity. It just draws the score to the screen. As we code the classes that represent the game objects we will add code here to update and draw them. Note that the class inherits from SurfaceView so it has an instance of Holder to lock…

	package com.gamecodeschool.kotlininvaders

	import android.content.Context
	import android.content.SharedPreferences
	import android.graphics.*
	import android.view.SurfaceView
	import android.util.Log
	import android.view.MotionEvent

	class KotlinInvadersView(context: Context,

EliteIntegrity / PlayerShip.kt

Created March 5, 2019 09:14

This class represents the ship that the player controls

	package com.gamecodeschool.kotlininvaders

	import android.content.Context
	import android.graphics.Bitmap
	import android.graphics.RectF
	import android.graphics.BitmapFactory

	class PlayerShip(context: Context,
	private val screenX: Int,
	screenY: Int) {

EliteIntegrity / KotlinInvadersView.kt

Created March 5, 2019 09:21

Adding a new property to the KotlinInvaersView class shown with some context to make it clear where it goes

	...
	...
	// A Canvas and a Paint object
	private var canvas: Canvas = Canvas()
	private val paint: Paint = Paint()

	// The players ship
	private var playerShip: PlayerShip = PlayerShip(context, size.x, size.y)

	// The score

EliteIntegrity / KotlinInvadersView.kt

Created March 5, 2019 09:26

Update the player's ship each frame by calling its update function from the update function of KotlinInvadersView

	private fun update(fps: Long) {
	// Update the state of all the game objects

	// Move the player's ship
	playerShip.update(fps)
	}

EliteIntegrity / KotlinInvadersView.kt

Created March 5, 2019 09:29

Here we add the code to draw the player's ship on each frame of animation inside the draw function

	...
	...
	// Choose the brush color for drawing
	paint.color = Color.argb(255, 0, 255, 0)

	// Draw all the game objects here
	// Now draw the player spaceship
	canvas.drawBitmap(playerShip.bitmap, playerShip.position.left,
	playerShip.position.top
	, paint)

EliteIntegrity / Invader.kt

Created March 5, 2019 09:34

This is the code for the Invader class which will instantiate a whol army of for the player to shoot.

	package com.gamecodeschool.kotlininvaders

	import android.content.Context
	import android.graphics.Bitmap
	import android.graphics.RectF
	import java.util.*
	import android.graphics.BitmapFactory

	class Invader(context: Context, row: Int, column: Int, screenX: Int, screenY: Int) {
	// How wide, high and spaced out are the invader will be

EliteIntegrity / KotlinInvadersView.kt

Created March 5, 2019 09:40

Add two properties to KotlinInvadersView to represent and control the numbers of the invaders

	...
	...
	// The players ship
	private var playerShip: PlayerShip = PlayerShip(context, size.x, size.y)

	// Some Invaders
	private val invaders = ArrayList<Invader>()
	private var numInvaders = 0

	// The score

EliteIntegrity / KotlinInvadersView.kt

Created March 5, 2019 09:42

Initialize all the Invader instances in the prepareLevel function

	private fun prepareLevel() {
	// Here we will initialize the game objects
	// Build an army of invaders
	Invader.numberOfInvaders = 0
	numInvaders = 0
	for (column in 0..10) {
	for (row in 0..5) {
	invaders.add(Invader(context,
	row,
	column,

EliteIntegrity / KotlinInvadersView.kt

Last active March 5, 2019 12:17

Adding code to the update function to control the movement of the invaders including when they drop down a row and head in the opposite direction.

	private fun update(fps: Long) {
	// Update the state of all the game objects

	// Move the player's ship
	playerShip.update(fps)

	// Did an invader bump into the side of the screen
	var bumped = false

	// Has the player lost

Game Code School EliteIntegrity