Snake PSP alpha1

--------------xerpi - (c)   2011   -----------------


math.randomseed(os.time()/math.pi*os.clock()/os.time())

os.cpu(111)

tile={w=20,h=20,vertical=10,horizontal=10}
timers={move=0}
map ={map={},image={}}
    --Coordinates
        map.w = tile.horizontal*tile.w
        map.h = tile.vertical*tile.h
        map.x = 240-map.w/2
        map.y = 136-map.h/2
    --Images
        map.image.border = image.create(tile.w,tile.h,color.new(128,0,0))
        map.image.interior = image.create(tile.w,tile.h,color.new(34,139,34))

direction_list = {"up","down","right","left"}

snake = {body = {{}}, direction = "down", color ={}, image ={},velocity=2,steps=0,score=0}
    --Colors
        snake.color.head = color.new(255,0,0)
        snake.color.body = color.new(255,255,0)
        snake.color.tail = color.new(0,255,0)
    --Images
        snake.image.head = image.create(tile.w,tile.h,color.new(255,0,0))
        snake.image.body = image.create(tile.w,tile.h,color.new(255,255,0))
        snake.image.tail = image.create(tile.w,tile.h,color.new(0,255,0))

food = {{}}
    food.image = image.create(tile.w,tile.h,color.new(0,0,255))

--Snake
        function snake.random_head_position()
            snake.body[1].x = math.random(2,tile.horizontal-1)
            snake.body[1].y = 1--math.random(2,tile.vertical-1)
        end

        function snake.check_tile(x,y)
            for i = 1, #snake.body do
                if snake.body[i].x == x and snake.body[i].y == y then
                    return true
                end
            end
            return false
        end

        function snake.check_food(x,y)
            for i = 1, #food do
                if food[i].x == snake.body[1].x and food[i].y == snake.body[1].y then
                    snake.score = snake.score+10
                    food.change_randomly(i)
                    table.insert(snake.body,{x = snake.lastx,y = snake.lasty})
                end
            end

        end

        function snake.draw()
            for i = 1, #snake.body do
                if i == 1 then
                    snake.image.head:blit(map.x + (snake.body[1].x-1)*tile.w, map.y + (snake.body[1].y-1)*tile.h)
                elseif i == #snake.body then
                    snake.image.tail:blit(map.x + (snake.body[i].x-1)*tile.w, map.y + (snake.body[i].y-1)*tile.h)
                else
                    snake.image.body:blit(map.x + (snake.body[i].x-1)*tile.w, map.y + (snake.body[i].y-1)*tile.h)
                end
            end
        end

        function snake.die() --Poor snake :'(
            os.message("has perdido")
            errore()
        end

        function snake.self_colision(n)
            local maxn = #snake.body
            if maxn>1 then
                for i = 2, maxn do
                    if snake.body[1].x == snake.body[i].x and snake.body[1].y == snake.body[i].y then
                        return true
                    end
                end
            end
            return false
        end

        function snake.colision(n)
            if snake.body[1].x < 0 or snake.body[1].x > tile.horizontal or snake.body[1].y < 0 or
                snake.body[1].y > tile.vertical or snake.self_colision(n) then
                    snake.die()
            end
        end

        function snake.move()
            local maxn = #snake.body
            snake.steps = snake.steps+1
            if snake.steps >= 75/snake.velocity then
                snake.lastx = snake.body[#snake.body].x
                snake.lasty = snake.body[#snake.body].y
                --Move the rest of the body
                    for i = maxn, 2,-1 do
                        snake.body[i].y = snake.body[i-1].y
                        snake.body[i].x = snake.body[i-1].x
                    end
                --Move the head
                    if snake.direction == "down" then
                        snake.body[1].y = snake.body[1].y+1
                    elseif snake.direction == "up" then
                        snake.body[1].y = snake.body[1].y-1
                    elseif snake.direction == "right" then
                        snake.body[1].x = snake.body[1].x+1
                    elseif snake.direction == "left" then
                        snake.body[1].x = snake.body[1].x-1
                    end
                snake.steps = 0
                snake.velocity = snake.velocity+0.05
            end
            --Check self colision
                snake.colision(maxn)
        end

        function snake.change_direction()
            if controls.press("right") and snake.direction != "left" then
                snake.direction = "right"
            elseif controls.press("left") and snake.direction != "right" then
                snake.direction = "left"
            elseif controls.press("up") and snake.direction != "down" then
                snake.direction = "up"
            elseif controls.press("down") and snake.direction != "up"then
                snake.direction = "down"
            end
        end
--Food
        function food.insert_randomly()
            local x = math.random(1,tile.horizontal)
            local y = math.random(1,tile.vertical)
            while snake.check_tile(x,y) do
                x = math.random(1,tile.horizontal)
                y = math.random(1,tile.vertical)
            end
            food[1].x = x
            food[1].y = y
        end

        function food.change_randomly(i)
            local x = math.random(1,tile.horizontal)
            local y = math.random(1,tile.vertical)
            while snake.check_tile(x,y) do
                x = math.random(1,tile.horizontal)
                y = math.random(1,tile.vertical)
            end
            food[i].x = x
            food[i].y = y
        end

        function food.draw()
            for i = 1, #food do
                    food.image:blit(map.x + (food[1].x-1)*tile.w, map.y + (food[1].y-1)*tile.h)
            end
        end

    food.insert_randomly()

--Map

        function map.draw()
            for y = 0, tile.vertical+1 do
                for x = 0, tile.horizontal+1 do
                    if y==0 or y == tile.vertical+1 or x==0 or x == tile.horizontal+1 then
                        map.image.border:blit(map.x + (x-1)*tile.w, map.y + (y-1)*tile.h)
                    else
                        map.image.interior:blit(map.x + (x-1)*tile.w, map.y + (y-1)*tile.h)
                    end
                end
            end
        end

snake.random_head_position()

while true do
controls.read()



map.draw()
food.draw()
snake.change_direction()

snake.move()
snake.check_food(x,y)

if controls.press("r") then
    table.insert(snake.body,{x = snake.lastx,y = snake.lasty})
end


snake.draw()



screen.print(5,5,snake.direction)
screen.print(185,3,"Score: "..snake.score)
screen.print(5,25,snake.steps)
screen.print(5,45,snake.velocity)
screen.print(430,3,"@"..screen.fps())
screen.print(5,65,#snake.body)

if controls.select() then a() end
screen.flip()
end