Rocks

gistfile1.txt

--# Rock
-- Basic rock game

--[[
The game

A rock is falling down the screen. 

It is created 50 pixels above the top of the screen, and with a random x value.  

It falls at 100 pixels per second, and when it falls off the screen, a new rock appears at the top.

You have to avoid the rock hitting you, by touching the left or right of the screen to move out of the way.

You can use any of the images built into Codea.
--]]

function setup()
    speed = 100 / 60 --falling speed per "draw" (Codea draws 60 times per second)  
    pos=vec2(WIDTH/2,100) --our x position
    posChange=3 --how much our x position changes when we touch the screen
    personImg=readImage("Planet Cute:Character Boy")  --the image for us
    personSize=75 --the size of our image on the screen
    rockImg=readImage("Tyrian Remastered:Rock 4") --the image for the rock
    rockSize=75 --the size we want to draw the rock
    addRock() --add the rock
end

function draw()
    background(0)
    rockPos.y=rockPos.y-speed
    if rockPos.y<0 then --time for another rock!
        addRock()
    end
    --draw the rock, and us
    sprite(rockImg,rockPos.x,rockPos.y,rockSize)
    sprite(personImg,pos.x,pos.y,personSize)
    CheckCollision()
end

function touched(t)
    --move left or right, but don't go off the screen
    if t.x<WIDTH/2 then pos.x=math.max(50,pos.x-posChange) else pos.x=math.min(WIDTH-50,pos.x+posChange) end 
end

function addRock()
    --choose random x position, but not too close to the edge
    rockPos=vec2(math.random(50,WIDTH-50),HEIGHT+50)
end

function CheckCollision()
    --calculate the distance between us and the rock
    --if less than the radius of the rock, we are toast
    if pos:dist(rockPos)<rockSize/2 then
        sound(SOUND_EXPLODE, 26907)
        --put code here to change the score, end the game, start again, whatever
    end
end


--# MoreRocks
-- Multiple rock game

--[[
The game

Several rocks are falling down the screen. A new one falls, every second.

Each rock is created 50 pixels above the top of the screen, and with a random x value.  

Each rock falls at 100 pixels per second.

You have to avoid any of the rocks hitting you, by touching the left or right of the screen to move out of the way.

You can use any of the images built into Codea.
--]]

function setup()
    speed = 100 / 60 --falling speed per "draw" (Codea draws 60 times per second)  
    pos=vec2(WIDTH/2,100) --our x position
    posChange=3 --how much our x position changes when we touch the screen
    personImg=readImage("Planet Cute:Character Boy")  --the image for us
    personSize=75 --the size of our image on the screen
    rockImg=readImage("Tyrian Remastered:Rock 4") --the image for the rock
    rockSize=75 --the size we want to draw the rock
    --** new code below
    rockPos={} --**** a list of rocks
    timeBetweenRocks=1 --*** how often we add rocks (in seconds)
    timeOfLastRock=0 --*** time when we added the last rock
end

function draw()
    background(0)
    --***adjust position for all rocks
    for i=#rockPos,1,-1 do --*** loop through all rocks  $$$$ YOU NEED TO EXPLAIN WHY LOOP IS BACKWARDS $$$$
        rockPos[i].y=rockPos[i].y-speed
        if rockPos[i].y<0 then  --*** remove rock if it falls off screen
            table.remove(rockPos,i)
        else --draw the rock and check for collisions
            sprite(rockImg,rockPos[i].x,rockPos[i].y,rockSize)
            CheckCollision(rockPos[i]) --*** pass through the rock we are comparing
        end
    end
    if ElapsedTime>timeOfLastRock+timeBetweenRocks then --*** time for another rock!
        addRock()
        timeOfLastRock=ElapsedTime
    end
    sprite(personImg,pos.x,pos.y,personSize)
end

function touched(t)
    --move left or right, but don't go off the screen
    if t.x<WIDTH/2 then pos.x=math.max(50,pos.x-posChange) else pos.x=math.min(WIDTH-50,pos.x+posChange) end 
end

function addRock()
    --*** add a new rock to the table
    --choose random x position, but not too close to the edge
    table.insert(rockPos,vec2(math.random(50,WIDTH-50),HEIGHT+50))
end

function CheckCollision(r) --*** we pass through the rock position we are comparing
    --calculate the distance between us and the rock
    --if less than the radius of the rock, we are toast
    if pos:dist(r)<rockSize/2 then
        sound(SOUND_EXPLODE, 26907)
        --put code here to change the score, end the game, start again, whatever
    end
end


--# BetterRocks
-- More interesting rock game

--[[
The game

These rules are the same as before -
Several rocks are falling down the screen. A new one falls, every second.
Each rock is created 50 pixels above the top of the screen, and with a random x value.  
Each rock falls at 100 pixels per second.
You have to avoid any of the rocks hitting you, by touching the left or right of the screen to move out of the way.
You can use any of the images built into Codea.

*** These are new rules to make the game more interesting
The rocks should be different images and sizes, rotate at different speeds, and fall at different speeds, 
and maybe even do different damage

--]]

function setup()
    pos=vec2(WIDTH/2,100) --our x position
    posChange=3 --how much our x position changes when we touch the screen
    personImg=readImage("Planet Cute:Character Boy")  --the image for us
    personSize=75 --the size of our image on the screen
    rockImg=readImage("Tyrian Remastered:Rock 4") --the image for the rock
    rockSize=75 --the size we want to draw the rock
    LoadRocks() --*** set up the rocks, do this in another function to avoid making a mess
    timeBetweenRocks=1 -- how often we add rocks (in seconds)
    timeOfLastRock=0 -- time when we added the last rock
end

function LoadRocks() --*** new function to set up a list of rocks
    rocks={} --*** an empty list of rocks (name has changed from rockPos because we are not just storing position)
    
    --*** now read in a set of images to choose from
    rockImages={} --we'll put them in a list
    --start with the 7 rock images in Codea, we can use a loop for that
    for i=1,7 do
        table.insert(rockImages,readImage("Tyrian Remastered:Rock "..i))
    end
    --now add some more, for fun
    table.insert(rockImages,readImage("Tyrian Remastered:Mine Spiked Huge"))
    table.insert(rockImages,readImage("Tyrian Remastered:Flame Wave"))
    table.insert(rockImages,readImage("Tyrian Remastered:Fire Rock"))
end

function draw()
    background(0)
    --adjust position for all rocks
    for i=#rocks,1,-1 do --loop through all rocks
        local r = rocks[i] --*** this is just to make the code below easier to read
        r.pos.y=r.pos.y-r.speed/60 --*** now we use the vaues for each rock
        r.angle=r.angle+r.rotateSpeed
        if r.pos.y<0 then  --remove rock if it falls off screen
            table.remove(rocks,i)
        else --draw the rock and check for collisions
            pushMatrix() --** we need to translate and then rotate
            translate(r.pos.x,r.pos.y)
            rotate(r.angle)
            sprite(r.image,0,0,r.size)
            popMatrix()
            CheckCollision(r) --pass through the rock we are comparing
        end
    end
    if ElapsedTime>timeOfLastRock+timeBetweenRocks then --time for another rock!
        addRock()
        timeOfLastRock=ElapsedTime
    end
    sprite(personImg,pos.x,pos.y,personSize)
end

function touched(t)
    --move left or right, but don't go off the screen
    if t.x<WIDTH/2 then pos.x=math.max(50,pos.x-posChange) else pos.x=math.min(WIDTH-50,pos.x+posChange) end 
end

function addRock() --*** big changes here!
    --we need to store a list of items for each rock, and each rock is part of a list
    --this is how we can do it
    local t={} --make a new list for this rock's items
    --*** we'll give the items names to make them easier to use when we draw
    t.pos=vec2(math.random(50,WIDTH-50),HEIGHT+50) --choose random x position, but not too close to the edge
    t.speed=math.random(80,120) -- falling speed
    t.image=rockImages[math.random(1,#rockImages)]-- image to use
    t.size=math.random(20,50)-- size
    t.angle=math.random(-360,360)-- rotation angle
    t.rotateSpeed=math.random()-0.5-- rotation speed
    t.damage=t.size*t.speed -- damage caused if it hits us
    
    --now add our list of items to the list of rocks 
    table.insert(rocks,t)
end

function CheckCollision(r) --we pass through the rock position we are comparing
    --calculate the distance between us and the rock
    --if less than the radius of the rock, we are toast
    if pos:dist(r.pos)<rockSize/2 then
        sound(SOUND_EXPLODE, 26907)
        --put code here to change the score, end the game, start again, whatever
    end
end


--# Main
-- MultiStep

function setup()
    demos = listProjectTabs()
    for i=#demos,1,-1 do
        if demos[i]=="Notes" or demos[i]=="Utility" then table.remove(demos,i) end 
    end
    table.remove(demos) --remove the last tab
    startDemo()
    global = "select a step"
end

function showList()
    output.clear()
    for i=1,#demos do print(i,demos[i]) end
end

function startDemo()
    resetMatrix()
    if cleanup then cleanup() end
    setup,draw,touched,collide,PrintExplanation=nil,nil,nil,nil,nil
    lastDemo=Demo or  readProjectData("lastDemo") or 1
    lastDemo=math.min(lastDemo,#demos)
    saveProjectData("lastDemo",lastDemo) 
    parameter.clear()
    parameter.integer("Demo", 1, #demos, lastDemo,showList)
    parameter.action("Run", startDemo)
    loadstring(readProjectTab(demos[Demo]))()
    if PrintExplanation then PrintExplanation() end
    setup()
end