-- EVILMANA.COM PSP LUA CODEBASE
-- www.evilmana.com/tutorials/codebase
-- Diagonal Background Scrolling
-- SUBMITTED BY: Madcupid

background1A = Image.load("area 51/background1A.png")
-- here you load the 4 images needed
background1B = Image.load("area 51/background1B.png")
-- remember that these 4 images will have
background1C = Image.load("area 51/background1C.png")
-- to be blitted all times at the same time
background1D = Image.load("area 51/background1D.png")



-- note that you only load the 4 images if they are
-- different from each other, or else you can load
-- only one and blit it several times in the loop!

-- here you define the starting position for each background image, its height and width

Background1 = {x = 0, y = 0}
Background2 = {x = 480, y = 0}
Background3 = {x = 0, y = -272}
Background4 = {x = 480, y = -272}

backgroundWidth = 480
backgroundHeight = 272

-- this function will make the 4 images scroll diagonally function backgroundMoving()

Background1.x = Background1.x - 4 -- here you define how fast you want it to scroll
Background1.y = Background1.y + 4 -- please note the in order for this to work flawlessly
Background2.x = Background2.x - 4 -- you have to set the speed to a multiple of 272(height of image)
Background2.y = Background2.y + 4 -- i'll give you the examples i used (.5, 1, 2, 4, 8, 16) but you can
Background3.x = Background3.x - 4 -- keep going to get a faster speed!!!
Background3.y = Background3.y + 4
Background4.x = Background4.x - 4
Background4.y = Background4.y + 4 -- just substitute all 4's with another multiple of 272!!!


if Background1.y >= 272 then
Background1.y = -272
Background1.x = Background3.x
end

if Background2.x + backgroundWidth <= 0 then
Background1.x = Background2.x + backgroundWidth
Background3.x = Background4.x + backgroundWidth
end

if Background2.y >= 272 then
Background2.y = -272
Background2.x = Background4.x
end

if Background2.x + backgroundWidth <= 0 then
Background2.x = Background1.x + backgroundWidth
Background4.x = Background3.x + backgroundWidth
end

if Background4.y >= 272 then
Background4.y = -272
Background4.x = Background2.x
end

if Background4.x + backgroundWidth <= 0 then
Background2.x = Background1.x + backgroundWidth
Background4.x = Background3.x + backgroundWidth
end

if Background3.y >= 272 then
Background3.y = -272
Background3.x = Background1.x
end

if Background3.x + backgroundWidth <= 0 then
Background1.x = Background2.x + backgroundWidth
Background3.x = Background4.x + backgroundWidth
end


end


while true do

backgroundMoving() -- here you call the function that makes that images scroll

screen:blit(Background1.x, Background1.y, background1A) -- here, obviously, you put the on the screen screen:blit(Background2.x, Background2.y, background1B) screen:blit(Background3.x, Background3.y, background1C) screen:blit(Background4.x, Background4.y, background1D)

screen.waitVblankStart()
screen.flip()
end


-------------------

--and that's it!!!