ParticleLib alpha1 [xerpi]

--------------xerpi - (c)   2011   -----------------
math.randomseed(os.time()/math.pi*os.clock()/os.time())

function draw.circle(x,y,r,color)
  local x0, y0 = r, 0
  for i=0,90,9 do
     local x1,y1 = r*math.cos( math.rad( i )), r*math.sin(math.rad( i ));
     draw.line(x+x1,y+y1,x+x0,y+y0,color);
     draw.line(x+x0,y-y0,x+x1,y-y1,color);
     draw.line(x-x0,y+y0,x-x1,y+y1,color);
     draw.line(x-x0,y-y0,x-x1,y-y1,color);
     x0, y0 = x1, y1;
  end
end


particles = {}
os.cpu(333)

function random_color()
    return color.new(math.random(50,255),math.random(50,255),math.random(50,255))
end


function particles.create(n,max_rad)
    local tab ={initx=ix,inity=iy,status="stop",particles={},rad=max_rad}
    for i = 1, n do
        table.insert(tab.particles,{status="alive",x=0,y=0,vel = math.random(15000,50000)/10000,ang = math.rad(math.random(0,360))})
        tab.particles[i].img = image.create(math.random(500,1000)/100,math.random(200,500)/100,random_color())
        --tab.particles[i].img:clear(color.new(255,0,0))
        tab.particles[i].img:center()
        tab.particles[i].img:rotate(math.deg(tab.particles[i].ang))
    end
    return tab
end

function particles.blit(cx,cy,part,rad)
    if part.status != "stop" then
        for i =1, #part.particles do
            if part.particles[i].status != "alive" then continue end
            if part.status == "run" then
                part.particles[i].x = part.particles[i].x + math.cos(part.particles[i].ang)*part.particles[i].vel
                part.particles[i].y = part.particles[i].y + math.sin(part.particles[i].ang)*part.particles[i].vel
                local x = (part.particles[i].x+cx)
                local y = (part.particles[i].y+cy)
                if x >= 480 or x <= 0 or y >= 272 or y <= 0 or math.sqrt(part.particles[i].x*part.particles[i].x+part.particles[i].y*part.particles[i].y) >= rad then
                    part.particles[i].status = "dead"
                end
            end
            part.particles[i].img:blit(cx+part.particles[i].x,cy+part.particles[i].y)
        end
    end
end


function particles.init(part)
    part.status = "run"
end
function particles.pause(part)
    part.status = "pause"
end
function particles.stop(part)
    part.status = "stop"
end
function particles.reset(part)
    for i =1, #part.particles do
        part.particles[i].status = "alive"
        part.particles[i].x = 0
        part.particles[i].y = 0
    end
end

my_part = particles.create(90,100)

lol=  {x=240,y=136,rad=50}


while true do
controls.read()

if math.abs(controls.analogx())>=50 then lol.x=lol.x+controls.analogx()/50 end
if math.abs(controls.analogy())>=50 then lol.y=lol.y+controls.analogy()/50 end
if lol.x>=480 then lol.x = 479 end
if lol.y>=272 then lol.y = 271 end
if lol.x<=0 then lol.x = 0 end
if lol.y<=0 then lol.y = 0 end

draw.circle(lol.x,lol.y,lol.rad,color.new(0,255,0))
draw.line(lol.x-5,lol.y,lol.x+5,lol.y,color.new(0,255,0))
draw.line(lol.x,lol.y-5,lol.x,lol.y+5,color.new(0,255,0))

if controls.press("cross") then
    particles.reset(my_part)
    particles.init(my_part)
end
if controls.press("square") then
    particles.pause(my_part)
end
if controls.r() then lol.rad=lol.rad+1 end
if controls.l() then lol.rad=lol.rad-1 end

particles.blit(lol.x,lol.y,my_part,lol.rad)

screen.print(430,3,"@"..screen.fps())
if controls.select() then a() end
screen.flip()
end