--information:プレースホルダーを出せるカスタムオブジェクト
--track@box_width:幅,1,7680,640,1
--track@box_height:高さ,1,4320,360,1

--group:背景,true
--check@show_background:背景を表示,true
--color@background_color:背景色,0x808080
--track@background_transparency:背景の透明度,0,100,50,1
--group

--group:対角線・枠線,true
--check@show_diagonal:対角線を表示,true
--check@show_border:枠線を表示,true
--track@line_width:線の太さ,0.1,100,1.5,0.1
--color@line_color:線の色,0x666666
--track@line_transparency:線の透明度,0,100,0,1
--group



-- 四角形の座標を計算
local w = math.max(1, math.floor(box_width + 0.5))
local h = math.max(1, math.floor(box_height + 0.5))
local lw = math.max(0.1, line_width)

local left = -w * 0.5
local right = w * 0.5
local top = -h * 0.5
local bottom = h * 0.5

-- 色および透明度を、RGBA値に変換
local function color_components(color, opacity_percent)
    local a = math.max(0, math.min(1, opacity_percent / 100))
    local r = math.floor(color / 0x10000) % 0x100 / 255
    local g = math.floor(color / 0x100) % 0x100 / 255
    local b = color % 0x100 / 255
    return r * a, g * a, b * a, a
end

-- 四隅の頂点
local function vertex(x, y, r, g, b, a)
    return {x, y, 0, r, g, b, a}
end

local function append_quad(list, x0, y0, x1, y1, x2, y2, x3, y3, r, g, b, a)
    table.insert(list, vertex(x0, y0, r, g, b, a))
    table.insert(list, vertex(x1, y1, r, g, b, a))
    table.insert(list, vertex(x2, y2, r, g, b, a))
    table.insert(list, vertex(x3, y3, r, g, b, a))
end


-- 線を描画
local function append_line_quad(list, x0, y0, x1, y1, thickness, r, g, b, a)

    -- 長さベクトルに伸ばす
    local dx = x1 - x0
    local dy = y1 - y0
    local length = math.sqrt(dx * dx + dy * dy)
    if length <= 0 then return end

    -- 90度回転ベクトル（太さ方向）に伸ばす    
    local nx = -dy / length * thickness * 0.5
    local ny = dx / length * thickness * 0.5

    -- 1辺ずつの線
    append_quad(list,
        x0 - nx, y0 - ny,
        x1 - nx, y1 - ny,
        x1 + nx, y1 + ny,
        x0 + nx, y0 + ny,
        r, g, b, a)
end


-- tempbufferで描画。描画領域の設定
obj.setoption("drawtarget", "tempbuffer", w, h)


-- 描画（背景）
if show_background and background_transparency < 100 then
    local r, g, b, a = color_components(background_color, 100 - background_transparency)
    local quads = {}
    append_quad(quads, left, top, right, top, right, bottom, left, bottom, r, g, b, a)
    obj.drawpoly(quads, 4)
end

-- 描画（対角線）
if show_diagonal and line_transparency < 100 then
    local r, g, b, a = color_components(line_color, 100 - line_transparency)
    local quads = {}
    append_line_quad(quads, left, top, right, bottom, lw, r, g, b, a)
    append_line_quad(quads, right, top, left, bottom, lw, r, g, b, a)
    obj.drawpoly(quads, 4)
end


-- 描画（枠線）
if show_border and line_transparency < 100 then
    local r, g, b, a = color_components(line_color, 100 - line_transparency)
    local quads = {}

    -- 太すぎる場合はオブジェクトの半分までに制限
    local bw = math.min(lw, math.min(w, h) * 0.5)

    append_quad(quads, left, top, right, top,
        right, top + bw, left, top + bw, r, g, b, a)
    append_quad(quads, left, bottom - bw, right, bottom - bw,
        right, bottom, left, bottom, r, g, b, a)
    append_quad(quads, left, top + bw, left + bw, top + bw,
        left + bw, bottom - bw, left, bottom - bw, r, g, b, a)
    append_quad(quads, right - bw, top + bw, right, top + bw,
        right, bottom - bw, right - bw, bottom - bw, r, g, b, a)
    obj.drawpoly(quads, 4)
end


-- tempbufferで描画したものをobject化
-- 描画先をframebufferへ戻す
obj.copybuffer("object", "tempbuffer")
obj.setoption("drawtarget", "framebuffer")

-- プレビュー画面のリサイズを禁止
obj.setoption("focus_mode", "no_resize")