-- YataiDONNantoka game -> result transition: taikonantoka's Play/Load/bg_end.png wipe.
-- The engine's ResultTransition calls new / start / update / draw / is_finished and, when
-- draw exists, skips its own shutter. taikonantoka starts the wipe when the song audio
-- stops (play-loop state 9): Scripts/background/background.lua starts it then and stores
-- the start in the shared global NK_PLAY_WIPE_MS; if the engine's transition comes first
-- (end_time + 8533 ms), the wipe starts here. y = 480 - 0.96 d, -480 from d = 1000 ms
-- (asm 0x41C229); taikonantoka switches scene at 1000 ms, the engine after its move
-- animation (983 ms) and the result_transition voice -- the wipe's bottom half covers the
-- whole screen from d = 500 ms, and the result screen opens on Result/Load/bg_start at y 0.

ResultTransition = {}
ResultTransition.__index = ResultTransition

-- Resolution independence: 640x480 px distances times K = screen width / 640 (integer 1 at
-- 640 wide, so the native skin keeps the same arithmetic).
local K = tex.get_screen_width() / 640
K = math.tointeger(K) or K
local SH, SPEED = 480 * K, 0.96 * K   -- screen height, wipe speed (px per ms)

function ResultTransition.new(player_num)
    local self = setmetatable({}, ResultTransition)
    tex.load_folder("background", "nk_load")
    self.id   = tex.get_texture("background/nk_load/bg_end")
    self.now  = nil
    self.started = false
    NK_PLAY_WIPE_MS = nil     -- a new play screen: forget the previous song's wipe
    return self
end

function ResultTransition:start()
    self.started = true
end

function ResultTransition:update(current_ms)
    self.now = current_ms
    if self.started and not self.t0 then self.t0 = current_ms end
end

-- The wipe starts with the engine's transition (not when the BGM stops): only this layer is
-- drawn above the engine's song title, and the user wants no title on the transition.
function ResultTransition:draw()
    if not (self.id and self.now and self.t0) then return end
    local d = self.now - self.t0
    tex.draw_texture(self.id, { x = 0, y = (d < 1000) and (SH - d * SPEED) or -SH })
end

function ResultTransition:is_finished()
    return false              -- the engine's move animation and voice decide
end