Icons.lua

-- The two generated sheets and the drawing that reads them.
--
-- Both images load on first draw rather than at registration: the loader's
-- assets:image asserts on a graphics context (src/mods/Loader.lua:733), and
-- a headless load has none.  Deferring keeps `modkit validate` green.

local Icons = {}
Icons.__index = Icons

local ICON = 16
-- 4px of ink plus a 1px gutter.  The gutter is why the advance is 5 and
-- not 4: at a 4px advance adjacent glyphs touch and a caption is a blob.
-- Four glyphs at 5px is 20px, which fits the 21px cell -- that bounds how
-- much this font can draw legibly in one, not what Items.decorate actually
-- clips foreign captions to, which is that module's own constant.
local GLYPH_ADV, GLYPH_H = 5, 6
local GLYPH_ORDER = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789.- :é"

-- the face is white on the sheet so it can be tinted; this is the
-- default ink for anything drawn on the phone's pale surfaces
local INK = { 0.14, 0.18, 0.18 }

Icons.INDEX = {
  dex = 1, pkmn = 2, bag = 3, id = 4, optn = 5,
  save = 6, map = 7, link = 8, mods = 9,
  radio = 10, phone = 11, quit = 12, generic = 13,
  -- offered in the icon-customize picker in place of "generic"
  star = 14, heart = 15, flag = 16, bolt = 17,
  shield = 18, moon = 19, gem = 20, leaf = 21,
}

-- The icons a player may pick for a mod's own row, in picker order.
-- "generic" is first: it is the way back to the fallback "?", not just
-- another option.  Nine in total, which is deliberate: IconPicker.lua lays
-- these out on the same 3-wide grid the phone itself uses, and nine is a
-- full 3x3 with no ragged last row to wrap awkwardly out of.
Icons.CUSTOM_ORDER = { "generic", "star", "heart", "flag", "bolt",
                        "shield", "moon", "gem", "leaf" }

-- character to 0-based column in label_font.png
local GLYPH_AT = {}
-- Walk UTF-8 sequences, never bytes.  The face carries e-acute for the
-- POKeGEAR nameplate, and a byte-wise loop splits that one glyph into two
-- unknown bytes, each of which falls back to a blank.  The column index has
-- to match the generator's character index, and the generator counts
-- characters, so this must too.
local function chars(s)
  local i, n = 1, #s
  return function()
    if i > n then return nil end
    local b = s:byte(i)
    local len = 1
    if b >= 0xF0 then len = 4
    elseif b >= 0xE0 then len = 3
    elseif b >= 0xC0 then len = 2 end
    local ch = s:sub(i, i + len - 1)
    i = i + len
    return ch
  end
end

do
  local col = 0
  for ch in chars(GLYPH_ORDER) do
    GLYPH_AT[ch] = col
    col = col + 1
  end
end

function Icons.new(mod)
  return setmetatable({ mod = mod, failed = false }, Icons)
end

-- Load once, remember a failure so a missing sheet warns a single time
-- rather than once per frame.
function Icons:_sheets()
  if self.failed then return nil end
  if self.iconSheet and self.fontSheet then
    return self.iconSheet, self.fontSheet
  end
  local ok, iconSheet, fontSheet = pcall(function()
    return self.mod.assets:image("assets/icons.png"),
           self.mod.assets:image("assets/label_font.png")
  end)
  if not ok or not iconSheet or not fontSheet then
    self.failed = true
    self.mod.log:warn("could not load assets/icons.png or "
      .. "assets/label_font.png -- reinstall the mod; the phone draws "
      .. "without art this session")
    return nil
  end
  self.iconSheet, self.fontSheet = iconSheet, fontSheet
  self.iconQuads = {}
  for _, col in pairs(Icons.INDEX) do
    self.iconQuads[col] = love.graphics.newQuad(
      (col - 1) * ICON, 0, ICON, ICON,
      iconSheet:getWidth(), iconSheet:getHeight())
  end
  self.glyphQuads = {}
  for ch, col in pairs(GLYPH_AT) do
    self.glyphQuads[ch] = love.graphics.newQuad(
      col * GLYPH_ADV, 0, GLYPH_ADV, GLYPH_H,
      fontSheet:getWidth(), fontSheet:getHeight())
  end
  return self.iconSheet, self.fontSheet
end

function Icons:drawIcon(key, x, y, dim)
  local sheet = self:_sheets()
  if not sheet then return end
  local col = Icons.INDEX[key] or Icons.INDEX.generic
  local quad = self.iconQuads[col]
  if not quad then return end
  local r, g, b, a = love.graphics.getColor()
  love.graphics.setColor(1, 1, 1, dim and 0.4 or 1)
  love.graphics.draw(sheet, quad, x, y)
  love.graphics.setColor(r, g, b, a)
end

function Icons:labelWidth(text)
  local n = 0
  for _ in chars(tostring(text or "")) do n = n + 1 end
  return n * GLYPH_ADV
end

-- colour is optional and defaults to the dark ink.  The status bar
-- passes a light colour because it draws onto black; nothing else
-- needs to.
function Icons:drawLabel(text, x, y, dim, colour)
  local _, font = self:_sheets()
  if not font then return end
  local r, g, b, a = love.graphics.getColor()
  local c = colour or INK
  love.graphics.setColor(c[1], c[2], c[3], dim and 0.4 or 1)
  -- upper() is byte-wise, which leaves a multibyte glyph untouched: the
  -- bytes of e-acute are not ASCII letters, so they pass through unchanged.
  local upper = tostring(text or ""):upper()
  local i = 0
  for ch in chars(upper) do
    local quad = self.glyphQuads[ch] or self.glyphQuads[" "]
    if quad then
      love.graphics.draw(font, quad, x + i * GLYPH_ADV, y)
    end
    i = i + 1
  end
  love.graphics.setColor(r, g, b, a)
end

return Icons