holomerge

local f = fs.open("holo.conf", "r")
local conf = textutils.unserialise(f.readAll())
f.close()

local function find_by_partial_ID(id)
    return peripheral.find("hologram", function(name)
        return name:find(id) ~= nil
    end)
end

local real_holos = {}
for id, pos in pairs(conf.projectors) do
    local p = find_by_partial_ID(id)
    if not p then error(id .. " not found!") end
    table.insert(real_holos, { peripheral = p, position = pos})
end

local function on_all(fn, ...)
    for _, h in pairs(real_holos) do
        h.peripheral[fn](...)
    end
end

local h = {}
h.translation = {0, 0, 0}
h.scale = 1

function h.getTranslation()
    return unpack(h.translation)
end

function h.update_translation()
    local x, y, z = unpack(h.translation)
    for _, r in pairs(real_holos) do
        local hx, hy, hz = unpack(r.position)
        local tx, ty, tz = hx * h.scale * 3, hy * h.scale * 2, hz * h.scale * 3
        r.peripheral.setTranslation(x - tx, y - ty, z - tz)
    end
end

function h.setTranslation(x, y, z)
    h.translation = {x, y, z}
    h.update_translation()
end

function h.setScale(s)
    on_all("setScale", s)
    h.update_translation()
    h.scale = s
end

function h.getScale()
    return h.scale
end

function h.maxDepth()
    return 3 -- no idea what else to put - dynamically calculating it is probably fiddly
end

local function proxy(method)
    return function(...)
        on_all(method, ...)
    end
end

h.clear = proxy "clear"
h.copy = proxy "copy"

local function color_index(col)
    if col == 0 then return 1, 0 end
    local projector = math.ceil(col / 3)
    local index = (col % 3) + 1
    return projector, index
end

function h.set(x, y, z, c)
    on_all("set", x, y, z, 0) -- clear it on other projectors
    local p, i = color_index(c)
    real_holos[p].peripheral.set(x, y, z, i)
end

function h.get(x, y, z)
    error "Unavailable"
end

function h.fill(x, z, minY, maxY, c)
    on_all("fill", x, z, minY, maxY, 0) -- clear it on other projectors
    local p, i = color_index(c)
    real_holos[p].peripheral.fill(x, z, minY, maxY, i)
end

function h.getPaletteColor(c)
    local p, i = color_index(c)
    return real_holos[p].peripheral.getPaletteColor(i)
end

function h.setPaletteColor(c, rgb)
    local p, i = color_index(c)
    return real_holos[p].peripheral.setPaletteColor(i, rgb)
end

h.setScale(1)
h.clear()
h.setTranslation(0, 0, 0)

return h