Merge pull request #1835 from campavao/rfc-0019-level-visible

engine: pokemon.level_visible, a level a mode can take off the screen (RFC 0019)

src/battle/BattleState.lua

@@ -16,6 +16,7 @@ local Damage = require("src.battle.Damage")
 local EffectRegistry = require("src.battle.EffectRegistry")
 local Experience = require("src.battle.Experience")
 local Font = require("src.render.Font")
+local LevelDisplay = require("src.ui.LevelDisplay")
 local Logger = require("src.core.Logger")
 local MoveEffects = require("src.battle.MoveEffects")
 local Party = require("src.pokemon.Party")
@@ -6337,7 +6338,7 @@ function BattleState:drawHUDs(slide)
     end
     if self.enemy.shownStatus then
       Font.draw(self:statusLabel({ status = self.enemy.shownStatus }), 40, 8)
-    else
+    elseif LevelDisplay.visible(self.enemy.mon, "battle.enemy", self.game) then
       hudTile(0x6E, 32, 8) -- <LV>
       Font.draw(tostring(self.enemy.mon.level), 40, 8)
     end
@@ -6421,7 +6422,7 @@ function BattleState:drawHUDs(slide)
     Font.draw(self.player.name, nameX(10, self.player.name), 56)
     if self.player.shownStatus then
       Font.draw(self:statusLabel({ status = self.player.shownStatus }), 120, 64)
-    else
+    elseif LevelDisplay.visible(self.player.mon, "battle.player", self.game) then
       hudTile(0x6E, 112, 64) -- <LV>
       Font.draw(tostring(self.player.mon.level), 120, 64)
     end

src/ui/LevelDisplay.lua

@@ -0,0 +1,33 @@
+-- Whether a Pokémon's level is printed on a screen that would normally
+-- print it (RFC 0019).
+--
+-- Every Gen 1 screen that shows a level does it with the same pokered rule
+-- -- home/pokemon.asm:335-345 PrintLevel: the <LV> tile, then the digits
+-- left-aligned after it, with a level of 100 writing its third digit back
+-- over the tile -- and each screen hand-rolls that rule against its own
+-- coordinates. This module does not touch any of that. It answers one
+-- question, in one place, so that a mode which wants the number off does
+-- not have to know four call sites and a glyph code.
+--
+-- Default is true, and `Runtime.wantsHook` is checked first, so a build
+-- with no mod wrapping the hook prints exactly what it always did and pays
+-- nothing for the seam on a per-frame draw path.
+--
+-- `where` names the surface rather than the widget, because the number
+-- means different things on different screens: on the battle HUD an
+-- opponent's level is information about them, on the party and status
+-- screens your own level is information about you. A mode can hide one and
+-- keep the other.
+
+local Runtime = require("src.mods.Runtime")
+
+local LevelDisplay = {}
+
+-- where: "battle.enemy" | "battle.player" | "party" | "summary"
+function LevelDisplay.visible(mon, where, game)
+  if not Runtime.wantsHook("pokemon.level_visible") then return true end
+  return Runtime.call("pokemon.level_visible", function() return true end,
+                      mon, { where = where, game = game }) ~= false
+end
+
+return LevelDisplay

src/ui/PartyMenu.lua

@@ -11,6 +11,7 @@
 
 local Assets = require("src.render.Assets")
 local Font = require("src.render.Font")
+local LevelDisplay = require("src.ui.LevelDisplay")
 local Logger = require("src.core.Logger")
 local Runtime = require("src.mods.Runtime")
 local Screens = require("src.ui.Screens")
@@ -794,7 +795,11 @@ function PartyMenu:draw()
     -- level at column 13 (<LV> tile + digits, PrintLevel) AND the
     -- status/FNT text at column 17 (PrintStatusCondition), like the
     -- original rows -- statused mons keep their level display
-    if mon.level < 100 then
+    if not LevelDisplay.visible(mon, "party", self.game) then -- RFC 0019
+      -- the level column is simply empty; the status/FNT column at 17 is a
+      -- separate field and still prints, exactly as it does for a mon whose
+      -- level is on screen
+    elseif mon.level < 100 then
       HudTiles.tile(0x6E, 104, y) -- <LV>
       Font.draw(tostring(mon.level), 112, y)
     else

src/ui/SummaryMenu.lua

@@ -12,6 +12,7 @@ local Font = require("src.render.Font")
 -- TypeChart.displayName maps it back to "PSYCHIC", like HallOfFame and the
 -- battle move-type box already do (#214).
 local TypeChart = require("src.battle.TypeChart")
+local LevelDisplay = require("src.ui.LevelDisplay")
 local Strings = require("src.core.Strings")
 local Stats = require("src.pokemon.Stats")
 local Status = require("src.battle.Status")
@@ -137,7 +138,9 @@ function SummaryMenu:draw()
   if self.page == 1 then
     -- level is page 1 only: StatusScreen2 opens with ClearScreenArea over
     -- (9,2) 5x10 (status_screen.asm:303-305). #280
-    printLevel(14, 2, mon.level)
+    if LevelDisplay.visible(mon, "summary", self.game) then -- RFC 0019
+      printLevel(14, 2, mon.level)
+    end
     drawLineBox(19, 1, 6, 10)
     -- engine/pokemon/status_screen.asm:120-125
     local PaletteFX = require("src.render.PaletteFX")
@@ -196,8 +199,12 @@ function SummaryMenu:draw()
     local nextExp = mon.level < 100
       and (Growth.expForLevel(def.growthRate, mon.level + 1) - mon.exp) or 0
     Font.draw(("%7d"):format(math.max(0, nextExp)), 56, 48)
-    HudTiles.statusTile(0x70, 112, 48) -- '<to>' at (14,6), was missing (#280)
-    printLevel(16, 6, math.min(100, mon.level + 1))
+    if LevelDisplay.visible(mon, "summary", self.game) then -- RFC 0019
+      -- the '<to>' arrow is half a sentence without the level it points at,
+      -- so the pair is hidden together
+      HudTiles.statusTile(0x70, 112, 48) -- '<to>' at (14,6), was missing (#280)
+      printLevel(16, 6, math.min(100, mon.level + 1))
+    end
     Font.drawBox(0, 8, 20, 10)
     for i = 1, 4 do
       local mv = mon.moves[i]