紫禁城 (FC) HUD script for Mesen

hud.lua

--[[
紫禁城 (FC) HUD script for Mesen
--]]

local function warn(msg)
    emu.log(msg)
end

local function mem_read(addr)
    return emu.read(addr, emu.memType.cpu)
end

local function color_rgba(r, g, b, a)
    local a_inv = 0xFF - a

    return (a_inv << 24) | (r << 16) | (g << 8) | b
end

local function color_rgb(r, g, b)
    return color_rgba(r, g, b, 0xFF)
end

local BOARD_W = 14
local BOARD_H = 8
local BOARD_LEN = BOARD_W * BOARD_H

local PAI_COUNT_MAX = 85

local PIT_COUNT_MAX = 60

local function unpack_pai_value(value)
    local id = value & 0x7F
    local fixed = (value & 0x80) ~= 0

    return id, fixed
end

local function get_pai(idx)
    local addr = 0x0620 + 3 * idx

    local state = mem_read(addr)
    local pos = mem_read(addr + 1)
    local value = mem_read(addr + 2)

    -- 無効な牌なら nil を返す。一応バグ面にも対応可能にしておく。
    if state == 0 or pos == 0 or pos > BOARD_LEN then
        return nil
    end

    local hidden = nil
    if state >= 2 then
        local id, fixed = unpack_pai_value(state - 2)
        hidden = {
            pos = pos,
            id = id,
            fixed = fixed,
        }
    end

    local id, fixed = unpack_pai_value(value)

    return {
        pos = pos,
        id = id,
        fixed = fixed,
        hidden = hidden,
    }
end

local function get_pai_board()
    local board = {}

    for _pos = 1, BOARD_LEN do
        table.insert(board, {})
    end

    for i = 1, PAI_COUNT_MAX do
        local pai = get_pai(i - 1)
        if pai ~= nil then
            table.insert(board[pai.pos], pai)
        end
    end

    return board
end

local function get_pit(idx)
    local addr = 0x079F + idx

    local pos = mem_read(addr)

    -- 落とし穴の位置が無効なら nil を返す。一応バグ面にも対応可能にしておく。
    if pos == 0 or pos > BOARD_LEN then
        return nil
    end

    return pos
end

local function get_pit_board()
    local board = {}

    for _pos = 1, BOARD_LEN do
        table.insert(board, false)
    end

    for i = 1, PIT_COUNT_MAX do
        local pos = get_pit(i - 1)
        if pos ~= nil then
            board[pos] = true
        end
    end

    return board
end

local function get_history_count()
    return mem_read(0x07DE)
end

local COLOR_TEXT = color_rgb(0xFF, 0xFF, 0xFF)

local COLOR_PAI_NORMAL = color_rgb(0, 0xFF, 0xFF)
local COLOR_PAI_FIXED = color_rgb(0xFF, 0, 0)
local COLOR_PAI_HIDDEN = color_rgb(0, 0xFF, 0)
local COLOR_PAI_HIDDEN_FIXED = color_rgb(0xFF, 0x80, 0)
local COLOR_PIT = color_rgb(0xFF, 0, 0xFF)

local COLOR_BG = color_rgba(0, 0, 0, 0xC0)

local function base36_char(x)
    if x <= 9 then
        return string.char(0x30 + x)
    elseif x <= 35 then
        return string.char(0x41 + x - 10)
    else
        return "?"
    end
end

local function pos_to_screen_coord(pos)
    local col = (pos - 1) % 14
    local row = (pos - 1) // 14

    local x = 16 + 16 * col
    local y = 16 + 24 * row

    return x, y
end

local function color_pai_shown(pai)
    if pai.fixed then
        return COLOR_PAI_FIXED
    else
        return COLOR_PAI_NORMAL
    end
end

local function color_pai_hidden(pai)
    if pai.fixed then
        return COLOR_PAI_HIDDEN_FIXED
    else
        return COLOR_PAI_HIDDEN
    end
end

local function draw()
    local pai_board = get_pai_board()
    local pit_board = get_pit_board()
    local history_count = get_history_count()

    for pos = 1, BOARD_LEN do
        local x_base, y_base = pos_to_screen_coord(pos)

        -- 牌または落とし穴があるならマスを枠で囲む。
        if #pai_board[pos] ~= 0 or pit_board[pos] then
            emu.drawRectangle(x_base, y_base, 16, 24, color_rgb(0xC0, 0x40, 0))
        end

        -- 牌たちを表示。
        for i, pai in ipairs(pai_board[pos]) do
            local x = x_base
            local y = y_base + 8 * (i - 1)
            emu.drawString(x, y, base36_char(pai.id), color_pai_shown(pai), COLOR_BG)
            if pai.hidden ~= nil then
                emu.drawString(x + 8, y, base36_char(pai.hidden.id), color_pai_hidden(pai.hidden), COLOR_BG)
            end
        end

        -- 落とし穴を表示。
        if pit_board[pos] then
            local x = x_base + 8
            local y = y_base + 16
            emu.drawString(x, y, "*", COLOR_PIT, COLOR_BG)
        end
    end

    emu.drawString(224, 232, string.format("HIST:%d", history_count), COLOR_TEXT, COLOR_BG)
end

local function main()
    emu.addEventCallback(draw, emu.eventType.endFrame)
end

main()