How to make sprites appear randomly on the screen and disappear

General
1

Hey guys, I have this idea for a simple game. Basically a sprite appears in some random space on the screen, you have to tap it within a certain time or you lose. But I don’t know how to make a sprite disappear. The circles will just keep being made randomly in different spots

P.s.
This is off topic, but is there a way to search discussion on this forum? I find looking for answers difficult because I have go from page to page reading titles of question and seeing if they are the same question as me

2

See the Google custom search textbox at upper right of the screen, above “Start a new discussion”?. Try that.

3

Thanks, anyway how do I make my circles disappear in the game I’m trying to make?

4

Use the touched function to detect finger touches, and test if they are within the circles. If so, stop drawing them.

I think this question has been asked a few times in the past, because touching things to make them disappear is a fairly obvious idea for a touch device, but I’m not sure where to find those threads.

I suggest you do a little research on the touched function (there is a demo app about it) to get started.

5

Try this


function setup()
    sprites={}
    delay=2
    timer=0
end

function draw()
    timer = timer + DeltaTime
    if timer>=delay then
        delay = delay * 0.95
        timer=0
        newSprite()
    end
    background(0)
    spriteMode(RADIUS)
    for i=#sprites,1,-1 do
        local sp=sprites[i]
        sp.timer = sp.timer + DeltaTime
        if sp.timer>=sp.delay then table.remove(sprites,i)return end
        fill(sp.col)
        ellipse(sp.pos.x,sp.pos.y,sp.rad)
    end
end

function touched(t)
    local tpos=vec2(t.x,t.y)
    for i=#sprites,1,-1 do
        local sp=sprites[i]
        if tpos:dist(sp.pos)<sp.rad then--i have tapped the sprite
            print("hit")
            table.remove(sprites,i)
        end
    end
end

function newSprite()
    table.insert(sprites,     
{pos=vec2(math.random(0,WIDTH),math.random(0,HEIGHT)),timer=0,rad=math.random(20,50),
    delay=math.random(1,4),col=color(math.random(255),math.random(255),math.random(255))})
end
6

Whack a mole for iPad? I haven’t seen anyone do a good one, go for it! Learn about touches in codea along with lua tables, these are the things you’ll be learning mostly.

7

@Progrmr235 Here’s something I wrote back in Nov 2012.

http://codea.io/talk/discussion/1874/hows-your-reflexes-#Item_12