Falling sand game start-off

Examples
1

Here’s I suppose what you could call the foundation to starting a falling sand game, not too hard for beginners either:


-- cells

-- Use this function to perform your initial setup
function setup()
    displayMode(FULLSCREEN)
    p = {}
    filled = {}
    tn = 30
    time = 0
    m = {}
    rect = {}
    for x = 1,tn do
        p[x] = {}
        rect[x] = {}
        m[x] = {}
        filled[x] = {}
        for y = 1,tn do
            m[x][y] = mesh()
            filled[x][y] = 0
            p[x][y] = vec2(-(WIDTH/tn)/2+(WIDTH/tn)*x,-(HEIGHT/tn)/2+(HEIGHT/tn)*y)
            rect[x][y] = m[x][y]:addRect(p[x][y].x,p[x][y].y,WIDTH/tn,HEIGHT/tn)
        end
    end
end

function touched(t)
    if t.state == BEGAN then time = 5 else time = time + 1 end
    tpos = vec2(t.x,t.y)
    for x = 1,tn do
        for y = 1,tn do
            if t.x < x*WIDTH/tn and t.y < y*HEIGHT/tn and t.x > x*WIDTH/tn - WIDTH/tn and t.y > y*HEIGHT/tn - HEIGHT/tn then
                if vec2(t.deltaX,t.deltaY):len() > 1.5 and filled[x][y] == 0 then
                    filled[x][y] = 1
                elseif t.state == BEGAN and filled[x][y] == 1 then
                    filled[x][y] = 0
                end
            end
        end
    end
end
-- This function gets called once every frame
function draw()
    -- This sets a dark background color 
    background(40, 40, 50)

    -- This sets the line thickness
    strokeWidth(0)
    -- Do your drawing here
    for x = 1,tn do
        for y = 1,tn do
            if filled[x][y] == 0 then
                m[x][y]:setColors(100,100,100,255)
            elseif filled[x][y] == 1 then
                if filled[x][y-1] == 0 and y > 1 then
                    filled[x][y] = 0
                    filled[x][y-1] = 1
                end
                m[x][y]:setColors(200,200,200,255)
            end
            m[x][y]:draw()
        end
    end
end
2

Added water and eraser:

-- cells

-- Use this function to perform your initial setup
function setup()
    displayMode(FULLSCREEN)
    p = {}
    filled = {}
    tn = 30
    time = 0
    typ = {}
    brush = 1
    m = {}
    Orect = rect
    rect = {}
    for x = 1,tn do
        p[x] = {}
        typ[x] = {}
        rect[x] = {}
        m[x] = {}
        filled[x] = {}
        for y = 1,tn do
            m[x][y] = mesh()
            filled[x][y] = 0
            p[x][y] = vec2(-(WIDTH/tn)/2+(WIDTH/tn)*x,-(HEIGHT/tn)/2+(HEIGHT/tn)*y)
            rect[x][y] = m[x][y]:addRect(p[x][y].x,p[x][y].y,WIDTH/tn,HEIGHT/tn)
            typ[x][y] = 0
        end
    end
end

function touched(t)
    tpos = vec2(t.x,t.y)
    if t.state == BEGAN and tpos:dist(vec2(100,HEIGHT-100)) < 75 then
        brush = 1
    elseif t.state == BEGAN and tpos:dist(vec2(200,HEIGHT-100)) < 75 then
        brush = 2
    elseif t.state == BEGAN and tpos:dist(vec2(300,HEIGHT-100)) < 75 then
        brush = 3
    elseif tpos:dist(vec2(150,HEIGHT-100)) > 125 then
        for x = 1,tn do
            for y = 1,tn do
                if t.x < x*WIDTH/tn and t.y < y*HEIGHT/tn and t.x > x*WIDTH/tn - WIDTH/tn and t.y > y*HEIGHT/tn - HEIGHT/tn then
                    if vec2(t.deltaX,t.deltaY):len() > 1.5 and filled[x][y] == 0 then
                        typ[x][y] = brush
                        filled[x][y] = 1
                    end
                    if brush == 3 then
                        filled[x][y] = 0
                    end
                end
            end
        end
    end
end
-- This function gets called once every frame
function draw()
    -- This sets a dark background color 
    background(40, 40, 50)
    
    -- This sets the line thickness
    strokeWidth(0)
    -- Do your drawing here
    for x = 1,tn do
        for y = 1,tn do
            if filled[x][y] == 0 then
                m[x][y]:setColors(100,100,100,255)
            elseif filled[x][y] == 1 then
                local dir = math.random(-1,1)
                if x+dir == 0 then dir = 1 elseif x+dir == 31 then dir = -1 end
                if typ[x][y] == 2 and filled[x+dir][y] == 0 and filled[x][y-1] == 1 then 
                    filled[x][y] = 0
                    typ[x][y] = 0
                    filled[x+dir][y] = 1
                    typ[x+dir][y] = 2
                end
                if filled[x][y-1] == 0 and y > 1 then
                    filled[x][y] = 0
                    filled[x][y-1] = 1
                    typ[x][y-1] = typ[x][y]
                    --typ[x][y+1] = 0
                end
                if typ[x][y] == 1 then
                    m[x][y]:setColors(200,200,200,255)
                elseif typ[x][y] == 2 then
                    m[x][y]:setColors(0,0,200,255)
                end
            end
            m[x][y]:draw()
        end
    end
    
    fill(200,200,200,200)
    ellipse(100,HEIGHT-100,70)
    fill(255, 255, 255, 255)
    text("Stone",100,HEIGHT-50)
    
    fill(0,0,200,200)
    ellipse(200,HEIGHT-100,70)
    fill(255, 255, 255, 255)
    text("Water",200,HEIGHT-50)
    
    fill(255,255,255,200)
    ellipse(300,HEIGHT-100,70)
    fill(255,255,255,255)
    text("Eraser",300,HEIGHT-50)
end
3

Very cool, thanks for posting that up. I like how the water moves.