-- objects: s. http://www.lua.org/pil/16.4.html
--          s. http://www.fh-wedel.de/~si/seminare/ws09/Ausarbeitung/09.lua/lua4.htm#Vererbung
function creature (width,height)
	local self = love.graphics.newCanvas( width, height )
	local w = width
	local h = height
	local xpos     -- [0,800]
	local ypos     -- [0,600]
	local xdir     -- {-1,0,1}
	local ydir     -- {-1,0,1}
	local speed    -- [0.1,1]
	local init = function (xsrc,ysrc,x,y,xd,yd,sp) -- xsrc, ysrc = copy-position (out of .GIF)
		xpos  = x  -- center
		ypos  = y  -- center
		xdir  = xd
		ydir  = yd
		speed = sp
		self:renderTo(function()
			love.graphics.draw(creatures, xsrc,ysrc)
			love.graphics.rectangle( "line",0,0,w,h)
		end)
	end
	local getx = function() return xpos end
	local gety = function() return ypos end
	local getw = function() return w end
  	local draw = function ()
		love.graphics.draw(self, xpos-w/2, ypos-h/2)
	end
  	local move = function ()
		ypos = ypos+(ydir*speed)
		if ypos < 200 then ydir=1 end
		if ypos > 400 then ydir=-1 end
	end
  	local moveto = function (x,y)
		ypos = y
		xpos = x
	end
	local collide = function (x,y)
		return ( (x>xpos-w/2) and (x<xpos+w/2) and (y>ypos-h/2) and (y<ypos+h/2) )
	end
	local devolute = function () end --   <--- 2do
	return {
		init = init,
		getx = getx,
		gety = gety,
		getw = getw,
		draw = draw,
		move = move,
		moveto = moveto,
		collide = collide,
		devolute = devolute
	}
end

function anyshot (width,height)
	local self = love.graphics.newCanvas( width, height )
	local w = width
	local h = height
	local bshot = false
	local xpos     -- [0,800]
	local ypos     -- [0,600]
	local xdir     -- {-1,0,1}
	local ydir     -- {-1,0,1}
	local speed    -- [0.1,1]
	local init = function (xsrc,ysrc,x,y,xd,yd,sp) -- xsrc, ysrc = copy-position (out of .GIF)
		xpos  = x  -- center
		ypos  = y  -- center
		xdir  = xd
		ydir  = yd
		speed = sp
		self:renderTo(function()
			love.graphics.draw(creatures, xsrc,ysrc)
			love.graphics.rectangle( "line",0,0,w,h)
		end)
	end
	local getx = function() return xpos end
	local gety = function() return ypos end
	local getshot = function() return bshot end
	local setshot = function(b) bshot=b end
  	local draw = function ()
		love.graphics.draw(self, xpos-w/2, ypos-h/2)
	end
  	local move = function ()
		xpos = xpos+(xdir*speed)
		if xpos > 800 then xpos=5 end
	end
	local moveto = function(x,y) xpos=x ypos=y end
	local collide = function (x,y)
		return ( (x>xpos-w/2) and (x<xpos+w/2) and (y>ypos-h/2) and (y<ypos+h/2) )
	end
	return {
		init = init,
		getx = getx,
		gety = gety,
		getshot = getshot,
		setshot = setshot,
		draw = draw,
		move = move,
		moveto = moveto,
		collide = collide,
	}
end

function love.load()
    player   = 1 -- 1(fish),2(seal),3(dog),4(man)
    playerx  = 160
    playery  = 250
	speed    = 150
	shotwait = 50 -- entprellen

    creatures = love.graphics.newImage("logo3.gif")
    -- blit in einzelne Figuren
	fish = creature(150,90) -- size
	fish.init(0,-70,playerx,playery,0,-1,0.1) -- xsrc,ysrc,screenpos-x,screenpos-y,xdir,ydir,speed
	seal = creature(120,90)
	seal.init(-150,-80,340,250,0,1,0.1)
	dog  = creature(120,100)
	dog.init(-280,-60,510,250,0,-1,0.2)
	man  = creature(80,150)
	man.init(-390,0,650,250,0,-1,0.3)
    --  + diese unabhängig darstellen
    --  + Fig. bewegen (die springen nach oben und unten)
    --  + schiessen (falls man keinen trifft, kommt der Schuss wieder von hinten)
	-- (+) Kollisionsabfrage
	-- um die Figuren herum bewegen (Decke und Boden!)
--	shot = love.graphics.newCanvas( 14, 14 )
--	shot:renderTo(function()
--		love.graphics.draw(creatures, -132,-96) -- ;-)
--	end)
	shot = {}
	for i=0,10,1 do
		shot[i] = anyshot(14,14)
		shot[i].init(-132,-96,10,10,1,0,0.8)
	end
    -- devolution: Figuren fliegen nach hinten
   
    -- Background: Hintergrund, der nach links scrollt: Boden, Bäume, Wolken,
    --             Sonnenstrahlung (Tageszeit)  
end

function love.update(dt)
    if love.keyboard.isDown("right") then
        playerx = playerx + (speed * dt)
    elseif love.keyboard.isDown("left") then
        playerx = playerx - (speed * dt)
    end
    if love.keyboard.isDown("down") then
        playery = playery + (speed * dt)
    elseif love.keyboard.isDown("up") then
        playery = playery - (speed * dt)
    end
    if love.keyboard.isDown(" ") then
    	if shotwait == 0 then
	    	shotwait = 50
	    	for i=0,10,1 do
				if false==shot[i].getshot() then
					if 1==player then shot[i].moveto(playerx+fish.getw()/2+10,playery) end
					if 2==player then shot[i].moveto(playerx+seal.getw()/2+10,playery) end
					if 3==player then shot[i].moveto(playerx+dog.getw()/2+10,playery) end
					if 4==player then shot[i].moveto(playerx+man.getw()/2+10,playery) end
					shot[i].setshot(true)
					break
				end
			end
		end
	end
	if shotwait > 0 then shotwait=shotwait-1 end

	if playerx<0   then playerx=800-5 end
	if playerx>800 then playerx=5 end
	if playery<0   then playery=600-5 end
	if playery>600 then playery=5 end
end

function funny_background()
	for i=0,30,1 do
		love.graphics.setColor(100+i*5,100+i*5,255)
		love.graphics.rectangle( "fill", 0, i*10, 800, 20 )
	end
	for i=60,30,-1 do
		love.graphics.setColor(100+i*5,255,100+i*5) -- hier ist irgendwas komisch -> wenn ich i verändere, ändert sich ansch. auch die Höhe der rectangles !?!
		love.graphics.rectangle( "fill", 0, i*10, 800, 20 )
	end
end

function love.draw()
	love.graphics.setCaption("evoLUTION alpha")

	love.graphics.setBackgroundColor( 255,255,255 )
	funny_background()

	love.graphics.setColor(255,255,255) -- reset previous color changes !?!
    if player==1 then fish.moveto(playerx,playery) else fish.move() end
    if player==2 then seal.moveto(playerx,playery) else seal.move() end
    if player==3 then dog.moveto(playerx,playery)  else dog.move() end
    if player==4 then man.moveto(playerx,playery)  else man.move() end

   	for i=0,10,1 do
		if true==shot[i].getshot() then
			shot[i].move()
			shot[i].draw()
--		    love.graphics.print("shot "..tostring(shot[i].getshot()), 10, i*10)
		end
	    if fish.collide(shot[i].getx(),shot[i].gety()) then player=1 shot[i].moveto(0,0) shot[i].setshot(false) playerx=fish.getx() playery=fish.gety() else fish.draw() end
	    if seal.collide(shot[i].getx(),shot[i].gety()) then player=2 shot[i].moveto(0,0) shot[i].setshot(false) playerx=seal.getx() playery=seal.gety() else seal.draw() end
	    if dog.collide(shot[i].getx(),shot[i].gety()) then player=3 shot[i].moveto(0,0) shot[i].setshot(false) playerx=dog.getx() playery=dog.gety() else dog.draw() end
	    if man.collide(shot[i].getx(),shot[i].gety()) then player=4 shot[i].moveto(0,0) shot[i].setshot(false) playerx=man.getx() playery=man.gety() else man.draw() end
	end

	love.graphics.setColor(0,0,0)
    love.graphics.print("FPS: "..tostring(love.timer.getFPS()), 730, 314)
    love.graphics.print("BBOX on", 730, 334)
    love.graphics.print("Press SPACE | arrow keys", 300, 580)
end