陀螺争锋：转速先尽者倒

fx-topspin

local TopClash = {}

function Top.Step(t, dt)
    t.ang = t.ang + dt * (4 + t.spin / 18)      -- 转得越快转得越花
    t.x = t.x + t.vx * dt
    t.y = t.y + t.vy * dt
    -- 盘边反弹
    if t.x < 60 or t.x > SL:GetValue("width") - 60 then
        t.vx = -t.vx
        t.x = math.max(60, math.min(SL:GetValue("width") - 60, t.x))
    end
    if t.y < 70 or t.y > SL:GetValue("height") - 60 then
        t.vy = -t.vy
        t.y = math.max(70, math.min(SL:GetValue("height") - 60, t.y))
    end
    -- 自然损耗
    t.spin = math.max(0, t.spin - dt * 4)
end

function Top.Clash(me, foe)
    local dx, dy = foe.x - me.x, foe.y - me.y
    local d = math.sqrt(dx * dx + dy * dy)
    if d >= 52 or d == 0 then return end
    local nx, ny = dx / d, dy / d
    local rel = (me.vx - foe.vx) * nx + (me.vy - foe.vy) * ny
    if rel > 0 then
        -- 动量交换: 撞人者保留更多, 被撞者多吃
        me.vx = me.vx - 1.6 * rel * nx
        me.vy = me.vy - 1.6 * rel * ny
        foe.vx = foe.vx + 1.6 * rel * nx
        foe.vy = foe.vy + 1.6 * rel * ny
        me.spin = math.max(0, me.spin - 6)
        foe.spin = math.max(0, foe.spin - 8)
        SL:PlayFxAt("clash_spark", (me.x + foe.x) / 2, (me.y + foe.y) / 2)
        SL:PlaySfx("clash")
        if foe.spin == 0 then SL:SendEvent("top_fallen", "foe") end
        if me.spin == 0 then SL:SendEvent("top_fallen", "me") end
    end
end

function Whip.Me()
    me.spin = math.min(100, me.spin + 18)       -- 抽鞭续转, 上限截断
    SL:PlayBurst(me.x, me.y, "whip_spark", 5)
    SL:PlaySfx("whip")
end

return TopClash