--[[ fog generator
generates fog
    posX, posY, posZ - position in space
    size - size of billboard
    brightness - [0,1] fog brightness
--]]
function generateFog(posX, posY, posZ, size, brightness)
    print("<Billboard ")
        print("position = \"")
            print(posX) print(",")
            print(posY) print(",")
            print(posZ) print("\" ")
        print("colour=\"")
            print(brightness) print(",")
            print(brightness) print(",")
            print(brightness) print("\" ")
        print("material=\"Smoke/Smoke\" scale=")
        print(size)
    print(" />")
end

--[[ asteroid field generator
generates asteroid field
    posX, posY, posZ - position in space
    minSize, maxSize - size boundaries of each asteroid
    radius - size of the cube around position in space
    count - number of asteroids
    fog - enable fog 0/1
--]]
function asteroidField(posX, posY, posZ, minSize, maxSize, radius, count, fog)
    for i = 1, count, 1 do
        size = (math.random() * (maxSize - minSize)) + minSize
        pX = (2 * math.random() * radius) - radius + posX
        pY = (2 * math.random() * radius) - radius + posY
        pZ = (2 * math.random() * radius) - radius + posZ
        print("<StaticEntity ")

        print("position = \"")
        print(pX) print(",")
        print(pY) print(",")
        print(pZ) print("\" ")

        print("scale = \"") print(size) print("\" ")

        print("collisionType = static linearDamping = 0.8 angularDamping = 1 ")
        print("collisiondamage = 1000 enablecollisiondamage = true>")

        print("<attached>")
            print("<Model mass=\"") print(size * 10) print("\" ")
            print("mesh=\"ast") print(math.mod(i,6) + 1) print(".mesh\" />")
        print("</attached>")

        print("<collisionShapes> ")
            print("<SphereCollisionShape radius=\"")
            print(size * 2.5) print("\" />")
        print("</collisionShapes>")

        print("</StaticEntity>")

        if fog == 1 and i % 5 == 0 then
            generateFog(pX, pY, pZ, radius*0.04, 0.2)
        end
    end
end


--[[ asteroid belt generator
generates asteroid belt
    posX, posY, posZ - position in space
    yaw, pitch - rotation
    minSize, maxSize - size boundaries of each asteroid
    radius0, radius1 - inner/outer radius
    count - number of asteroids
    fog - enable fog 0/1
--]]
function asteroidBelt(centerX, centerY, centerZ, yaw, pitch, segments, minSize, maxSize, radius0, radius1, count, fog)
    dPhi = (2 * math.pi) / segments
    width = math.abs(radius1 - radius0)
    radius = (radius1 + radius0) / 2
    segmentCount = count / segments

    print("<StaticEntity collisionType=static yaw=") print(yaw)
    print(" pitch=") print(pitch)

    print(" position = \"")
        print(centerX) print(",")
        print(centerY) print(",")
        print(centerZ) print("\"")
    print(">")

    print("<attached>")

    for i = 0, segments - 1, 1 do
        asteroidField((radius * math.cos(i * dPhi)),
                    (radius * math.sin(i * dPhi)),
                    0, minSize, maxSize, width, segmentCount, fog)
    end

    print("</attached>")
    print("</StaticEntity>")
end