Bubble Fish

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-- Target Shooter
-- Ryan Bains-Jordan
--
-- Main
-----------------------------------------------------------------------------------------

display.setStatusBar( display.HiddenStatusBar )

-- Get the screen metrics (use the entire device screen area)
local WIDTH = display.actualContentWidth
local HEIGHT = display.actualContentHeight
local xMin = display.screenOriginX
local yMin = display.screenOriginY
local xMax = xMin + WIDTH
local yMax = yMin + HEIGHT
local xCenter = (xMin + xMax) / 2
local yCenter = (yMin + yMax) / 2

--------------------
--Objects
--------------------

local blowBubble
local popBubble
local trapFish
local bubbleDone
local newFrame
local spawnFish
local hitTest
local hasCollidedCircle

local hits = {}
local misses = {}
local percent = {}
local percentUpdate

--------------------
--Display Groups
--------------------
local background = display.newGroup( )
local bubbles = display.newGroup( )
local fishes = display.newGroup( )
local traps = display.newGroup( )


-----------------------------------------------------------------------------------------
-- Init Game
-----------------------------------------------------------------------------------------

local function initGame()

	--Background
	local bg = display.newImage( background, "background.png", 380, 570 )
	bg.x, bg.y = xCenter, yCenter

	local water = display.newImageRect( background, "waves.png", 760, 130 )
	water.anchorX = 0
	water.y = 50
	local function waterAnimation()
		water.x = -380
		transition.to( water, { x = 0, time = 5000, onComplete = waterAnimation, onCancel = waterAnimation } )
	end
	background:toBack( )
	waterAnimation()

	-- Text Color
	local color = 
	{
		hightlight = { r=0.2, g=0.2, b=0.2 },
		shadow = { r=0.5, g=0.5, b=0.5 }
	}

	-- Hit Score
	hits.number = 0

	hits.image = display.newImage( "trapped_fish.png" )
	hits.image:scale( .5, .5 )
	hits.image.x = xMin + 30
	hits.image.y = yMin + 30

	hits.text = display.newEmbossedText( "'s = 0", xMin + 60, yMin + 30, native.systemFont, 25 )
	hits.text:setFillColor( 0.3, 0.4, 0.5 )
	hits.text:setEmbossColor( color )
	hits.text.anchorX = 0

	--Miss text
	misses.number = 0

	misses.image = display.newImage( "bubble.png" )
	misses.image:scale( .6, .6 )
	misses.image.x = xMin + 30
	misses.image.y = yMin + 80

	misses.text = display.newEmbossedText( "'s = 0", xMin + 60, yMin + 80, native.systemFont, 25 )
	misses.text:setFillColor( 0.3, 0.4, 0.5 )
	misses.text:setEmbossColor( color )
	misses.text.anchorX = 0


	--Percentage text
	percent.number = 0
	percent.text = display.newEmbossedText( string.format( "%3.f", percent.number ) .. "%", xMax-50, yMin+30, native.systemFontBold, 25 )
	percent.text:setFillColor( 0.3, 0.4, 0.5 )
	percent.text:setEmbossColor( color )

	--------------------
	--Listeners
	--------------------
	bg:addEventListener( "touch", blowBubble )
	Runtime:addEventListener( "enterFrame", newFrame )
end

-----------------------------------------------------------------------------------------
-- Main Functions
-----------------------------------------------------------------------------------------

-- Main Loop
function newFrame()
	spawnFish()
	hitTest()
	percentUpdate()
end

-- Spawn the bubble when sand is touched
function blowBubble( event )
	if event.phase == "began" and event.y > 430 then
		local bubble = display.newImage( bubbles, "bubble.png", true )
		bubble.x = event.x
		bubble.y = event.y
		transition.to( bubble, { time = 3000, y = yMin - 40, onComplete = popBubble, onCancel = bubbleDone } )

		return true
	end
end

-- Pop the bubble when it reaches the surface
function popBubble( object )
	object:removeSelf( )
	misses.number = misses.number + 1
	misses["text"].text = "'s = " .. misses.number
end

-- Spawns the fish
function spawnFish()
	if math.random( 1, 50 ) == 1 then
		fish = display.newImage(fishes, "fish.png", true)
		fish.x = xMin - 40
		fish.y = math.random( yMin + 150, 360 )
		transition.to( fish, { time = math.random( 2000, 5000 ), x = xMax + 40, onComplete = bubbleDone } )
	end
end

-- Trap the fish if the bubble hits it
function trapFish( object )
	object:removeSelf( )
	bubbleTrap = display.newImage( traps, "trapped_fish.png", true )
	bubbleTrap.x = object.x
	bubbleTrap.y = object.y
	transition.to( bubbleTrap, { y = 20 , time = 2000, onComplete = blowUp } )
	hits.number = hits.number + 1
	hits["text"].text = "'s = " .. hits.number
end

-- Blow up the bubble with the fish when it reaches the surface
function blowUp( object )
	transition.to( object, { xScale = 2, yScale = 2, alpha = 0, time = 250, onComplete = bubbleDone } )
end

-- Remove the bubble object when completed
function bubbleDone( object )
	object:removeSelf( )
end

-- Check for hits every frame
function hitTest()
	for b = 1, bubbles.numChildren do
		for f = 1, fishes.numChildren do
			if hasCollidedCircle( bubbles[b], fishes[f] ) then
				transition.cancel( bubbles[b] )
				transition.cancel( fishes[f] )
				trapFish(fishes[f])
			end
		end
	end
end


-- Circle-based collision detection (From Corona Docs)
function hasCollidedCircle( obj1, obj2 )
    if ( obj1 == nil ) then  -- Make sure the first object exists
        return false
    end
    if ( obj2 == nil ) then  -- Make sure the other object exists
        return false
    end

    local dx = obj1.x - obj2.x
    local dy = obj1.y - obj2.y

    local distance = math.sqrt( dx*dx + dy*dy )
    local objectSize = (obj2.contentWidth/2) + (obj1.contentWidth/2)

    if ( distance < objectSize ) then
        return true
    end
    return false
end

-- Update the percentage each frame
function percentUpdate()
	if hits.number + misses.number == 0 then
		percent.number = 100
	else
		percent.number = ( hits.number / ( hits.number + misses.number ) ) * 100
	end
	percent["text"].text = string.format( "%3.f", percent.number ) .. "%"
end

-----------------------------------------------------------------------------------------
-- InitGame Call
-----------------------------------------------------------------------------------------
initGame()