dukle/cloudjumper

Corona game using clouds

Cloud Jumper

A horizontal scrolling Corona game using basic physics.

Developed by: Shawn Grimes for APPlied Club

Artwork provided by Vicki Wenderlich

Image Scaling

1. Run ScalingSample project
2. Open config.lua, change scale="letterBox"
3. Demo difference on each device

Creating a Game

1. Open CloudJumper base

2. The code in the CloudJumper base scrolls random clouds across the background.

3. Open Physics Editor

4. Drag in Cloud1,2,3 and char_walk_2

5. Create physics objects See this Corona Physics Editor Tutorial for more information on using Physics Editor

6. Add physics library to CloudJumper base

   -- init physics
   local physics = require("physics")
   physics.start()
   
   

7. Now add our exported physics file from Physics Editor

   local physicsData = (require "CloudPhysics").physicsData(1.0)
   

8. Add score label

   ------Create Clouds to walk on
   --create display group for walking clouds
   local walkingCloudDisplayGroup=display.newGroup()
   
   local walkingCloudSpeed=.05
   
   --Create a label to count how many clouds have passed
   local scoreCount=0
   local scoreLabel=display.newText("Score: 0", 10,40, native.systemFontBold , 48)
   scoreLabel:setTextColor(255, 255, 255)
   
   walkingCloudDisplayGroup:insert(scoreLabel)
   

9. Run the app in the simulator, you should see the new score label added to the scene.

10. Create initial platforms

	--Create function to remove clouds when they travel off the scene
    local function removeWalkingCloud(cloudToRemove)
	    scoreCount=scoreCount+1
	    scoreLabel.text="Score: "..scoreCount
	    cloudToRemove:removeSelf()
	    cloudToRemove=nil
    end
	
	--Create variables to track the location of the last cloud
	local lastX=0
	local lastY=display.contentWidth/2
	
	local function createStartingWalkingClouds()
	    for i=1,5 do
		    local walkingCloud=display.newImage("cloud2.png")
		    physics.addBody(walkingCloud,physicsData:get("cloud2"))
		    walkingCloud.bodyType="static"
		    walkingCloud.x=lastX+walkingCloud.contentWidth/2
		    lastX=lastX+walkingCloud.contentWidth
		    walkingCloud.y=lastY
    
		    local walkingCloudDistance=- walkingCloud.x - walkingCloud.contentWidth/2
		    local walkingCloudTravelSpeed= math.abs(walkingCloudDistance/walkingCloudSpeed)
		    walkingCloud.transition=transition.to(walkingCloud,{time=walkingCloudTravelSpeed, x=-walkingCloud.x-walkingCloud.contentWidth/2, onComplete=removeWalkingCloud})
		    walkingCloudDisplayGroup:insert(walkingCloud)
	    end
    end

	createStartingWalkingClouds()

11. Run the app in the simulator, you should see the foreground clouds.
12. Add our hero

    --Create hero object
    --include movieclip object
    local movieClip=require("movieclip")

    local heroAngel=movieClip.newAnim({"char_jump_1.png","char_jump_2.png","char_shoot_1.png","char_shoot_2.png","char_walk_1.png","char_walk_2.png"})
    heroAngel.x=heroAngel.contentWidth
    heroAngel.y=50
    heroAngel:setSpeed(0.4)
    heroAngel:play({startFrame=1,endFrame=2,loop=0,remove=false})
    physics.addBody(heroAngel,physicsData:get("char_walk_2"))

	````
11. Run the app in the simulator, you should see the hero character fall from the sky and land on the foreground clouds.  Then he falls over :( 
11. Fix the hero so he's upright and doesn't fall over.  We are going to attach him to a rectangle object below with a pivot joint.  Pivot joints can only move up and down and this will prevent the hero angel from rotating.

--This physics joint keeps our angel upright
local rect = display.newRect( 50, 50, 100, 100 )
rect:setFillColor( 255, 255, 255, 100 )
rect.isVisible = true  -- optional
rect.y=display.contentHeight
physics.addBody( rect, "static",{ isSensor = true } )
local pistonJoint=physics.newJoint("piston",heroAngel, rect,heroAngel.x,heroAngel.y,0,-100)

12. Now set the rect.isVisible = false to hide it on the scene.

12. Let's make the hero jump when we touch the screen

--Function to make the angel jump when the screen is tapped
local function jumpAngel(event)
 	heroAngel:applyLinearImpulse( 0, -225, heroAngel.x, heroAngel.y )
end
Runtime:addEventListener("tap", jumpAngel)

13.  Let's add a better jump function to make sure you can't infinite jump with collision detection:

--Function to make the angel jump when the screen is tapped
local isJumping=false
local function jumpAngel(event)
    if(isJumping ~= true) then
    	--Change to flying frames
	    heroAngel:play({startFrame=1,endFrame=2,loop=0,remove=false})
	    isJumping=true
		 heroAngel:applyLinearImpulse( 0, -200, heroAngel.x, heroAngel.y )
    end
end
Runtime:addEventListener("tap", jumpAngel)

--Reset the angel when he lands
local function onLocalCollision(self, event)
    if ( event.phase == "began" ) then
	    isJumping=false
	    --Change back to walking frames
	    heroAngel:play({startFrame=5,endFrame=6,loop=0,remove=false})
    end
end
heroAngel.collision = onLocalCollision
heroAngel:addEventListener( "collision", heroAngel )

14. Adjust gravity if tap is held

--Function to adjust gravity if touching and flying local function adjustGravityForTouch(event) if ( event.phase=="began" ) then print("changing gravity") physics.setGravity( 0, 2.4 ) elseif(event.phase=="ended") then print("gravity normal") physics.setGravity( 0, 9.8 ) end end Runtime:addEventListener("touch", adjustGravityForTouch)

Adding Polish
------
1. Open CloudJumper-NeedsPolish
2. Run and show current state of game
3. Introduce [Corona Director Class](http://developer.anscamobile.com/code/director-class-10)
4. Rename main.lua to GameScene.lua
5. Create new main.lua
6. Copy code to main.lua

-------------------------------------------------------------------------------------
--
-- main.lua
--

---

-- Your code here

-- IMPORT DIRECTOR CLASS
local director = require("director")
    
-- CREATE A MAIN GROUP
local mainGroup = display.newGroup()

-- MAIN FUNCTION
local main = function ()
    -- Add the group from director class
    mainGroup:insert(director.directorView)
    
    director:changeScene("MainMenuScene")
    
    -- Return true to signal that the function was successful
    return true
end

main()

7. Create MainMenuScene.lua
8. Copy template.lua code into MainMenuScene.lua
9. Create background image in MainMenuScene.lua

local mainMenuBackground=display.newImage("Cloud_Jumper_TitleScreen.png")
localGroup:insert(mainMenuBackground)

10. Run the app, you should see the MainMenu Scene now.
10. Add a play button:

local ui = require("ui")

local playButtonPressed = function (event )
		if event.phase == "release" then
			director:changeScene( "GameScene", "overFromRight" )
		end
end

local playButton = ui.newButton{
	default = "button_play_up.png",
	over = "button_play_down.png",
	onEvent = playButtonPressed,
	id = "btn001",
	text = "",
	font = "Trebuchet-BoldItalic",
	textColor = { 51, 51, 51, 255 },
	size = 22,
	emboss = true
}

playButton:setReferencePoint(display.CenterReferencePoint)
playButton.x=display.contentWidth/2
playButton.y=display.contentHeight-display.contentHeight/5

--Add start button to local group
localGroup:insert(playButton)

11. Now open GameScene.lua
12. At the top add:

module(..., package.seeall)

new = function ()

13. At the bottom add:

return localGroup
    
end

14. Run the game.  You should be able to launch the gameplay scene now.
14. Restarting the game
15. Let's add a restart button to our game over logic.  Line 215, add:

--Show restart button
local ui=require("ui")
local restartButtonPressed = function (event )
    if event.phase == "release" then
	    --Clean up the scene before we start it again
	    cleanUpScene()
	    director:changeScene( "GameScene", "overFromRight" )
    end
end

--Create a restart Button
local restartButton = ui.newButton{
    default = "button_restart_up.png",
    over = "button_restart_down.png",
    onEvent = restartButtonPressed,
    id = "btn001",
    text = "",
    font = "Trebuchet-BoldItalic",
    textColor = { 51, 51, 51, 255 },
    size = 22,
    emboss = true
}
	    
restartButton:setReferencePoint(display.CenterReferencePoint)
restartButton.x=display.contentWidth/2
restartButton.y=restartButton.y + restartButton.contentHeight
localGroup:insert(restartButton)	

16. How about some background music?
17. Open main.lua and add the following around line 17 (after `local main = function ()` ):

--Play background music
local backgroundMusicObject = audio.loadStream("backgroundMusic.mp3")
audio.play(backgroundMusicObject)

18. Run the game now