切水果：一刀下去满屏果汁

fx-slice

local FruitSlice = {}
local KEY = { HALF_V = 70, GRAVITY = 380 }

function FS.Slice(x, y)
    -- 刀光: 以点击点为中心的斜向刀痕
    SL:PlayFxAt("blade_line", x - 60, y + 40, x + 60, y - 40)
    SL:PlaySfx("slice")
    for i = #fruits, 1, -1 do
        local f = fruits[i]
        if not f.sliced
           and math.abs(f.x - x) < 34
           and math.abs(f.y - y) < 34 then
            table.remove(fruits, i)
            -- 两半分飞: 顺着刀光方向的法线分开
            local nx, ny = 1, -0.6
            local len = math.sqrt(nx * nx + ny * ny)
            nx, ny = nx / len, ny / len
            halves[#halves + 1] = {
                x = f.x - nx * 4, y = f.y - ny * 4,
                vx = f.vx - nx * KEY.HALF_V,
                vy = f.vy * 0.5 - ny * 30,
                rot = f.rot - 0.6, side = -1, def = f.def
            }
            halves[#halves + 1] = {
                x = f.x + nx * 4, y = f.y + ny * 4,
                vx = f.vx + nx * KEY.HALF_V,
                vy = f.vy * 0.5 + ny * 30,
                rot = f.rot + 0.6, side = 1, def = f.def
            }
            SL:SetValue("score", SL:GetValue("score") + 10)
            SL:SetValue("combo", SL:GetValue("combo") + 1)
            SL:PlayBurst(f.x, f.y, "juice", 8)
        end
    end
end

function FS.Tick(dt)
    for i = #halves, 1, -1 do
        local h = halves[i]
        h.vy = h.vy + KEY.GRAVITY * dt
        h.x = h.x + h.vx * dt
        h.y = h.y + h.vy * dt
        h.rot = h.rot + h.side * dt * 3
        if h.y > SL:GetValue("height") + 40 then
            table.remove(halves, i)
        end
    end
end

return FS