consolidate single color sprites into one master file

CLAUDE.md

@@ -51,10 +51,10 @@ The player is not one entity — it is **up to three simultaneous colored copies
 
 ## Art pipeline
 
-Sprites are authored in full color, then split into per-channel `_r`/`_g`/`_b` PNGs so each color copy draws its own layer. The `art/*.sh` scripts drive this with ImageMagick `convert`:
-- `reduce_colors.sh <file>` — remap to `art/palette`/`palette.png`.
-- `extract.sh <file>` — split one image into R/G/B channel PNGs.
-- `reduce_and_extract.sh` — both steps over every PNG in the cwd (run from inside an `art/` subfolder).
+**One full-color master PNG per sprite.** The RGB channels are split at *load time*, not stored as separate files: `getAllAssets` (`level_editor/object_attributes.lua`) points all three of `sprites.{red,green,blue}` at the same master, and `Entity:draw(channel)` tints it through `gColor[channel]` — so `master × (1,0,0)` renders the red gun, and the additive `"screen"` blend recombines overlapping copies into the original color. Per-channel collision shapes come from `getChannelCells` (`_helpers.lua`), which inspects each channel of the master's ImageData. Adding a sprite (or a new sprite *state*) is now one file, not three.
+- `getAllAssets` treats every master PNG in a non-`_`-prefixed content folder as a placeable color asset, except the names in its `NON_ASSET_SPRITES` set (the palette swatch and sprites owned by dedicated classes like `player_*`, `door_unlocked`, `switch_pressed`).
+- The `_r`/`_g`/`_b` channel-splitting step is gone (older revisions had an `extract.sh`; the pre-split channel PNGs live in git history if ever needed).
+- `reduce_colors.sh <file>` / `reduce_and_extract.sh` — optional palette remap to `art/palette.png` (authoring step only; produces a master, no split).
 
 ## Bundled libraries (`libs/`, do not edit)
 

_helpers.lua

@@ -160,11 +160,12 @@ function cellShapeFromBox(box)
 	return cells
 end
 
--- Which 16x16 cells of an image are non-empty, for multi-cell collision
--- shapes. LÖVE 11 no longer exposes Image:getData(), so inspect ImageData
--- directly instead of creating a GPU Image first.
-function getCellsFromSprite(spritePath)
-	local img = love.image.newImageData(spritePath)
+-- Which 16x16 cells of an ImageData are non-empty, for multi-cell collision
+-- shapes. `channel` ("red"/"green"/"blue") restricts the test to one colour
+-- gun: a single full-colour master now feeds all three copies, so each copy's
+-- collision shape comes from its own channel of the master (a cell with only
+-- red pixels blocks the red copy but not blue). nil = "any channel lit".
+local function cellsFromImageData(img, channel)
 	local w, h = img:getWidth(), img:getHeight()
 	local box = {w = w / 16, h = h / 16}
 	local boxCells = cellShapeFromBox(box)
@@ -182,7 +183,12 @@ function getCellsFromSprite(spritePath)
 		for i = startPixel.x, endPixel.x do
 			for j = startPixel.y, endPixel.y do
 				local r, g, b, a = img:getPixel(i, j)
-				if a > 0 and (r > 0 or g > 0 or b > 0) then
+				local lit
+				if channel == "red" then lit = r > 0
+				elseif channel == "green" then lit = g > 0
+				elseif channel == "blue" then lit = b > 0
+				else lit = r > 0 or g > 0 or b > 0 end
+				if a > 0 and lit then
 					empty = false
 				end
 			end
@@ -204,3 +210,20 @@ function getCellsFromSprite(spritePath)
 
 	return boxCells
 end
+
+-- LÖVE 11 no longer exposes Image:getData(), so inspect ImageData directly
+-- instead of creating a GPU Image first.
+function getCellsFromSprite(spritePath, channel)
+	return cellsFromImageData(love.image.newImageData(spritePath), channel)
+end
+
+-- Per-channel collision cell shapes for one full-colour master, loaded once.
+-- Returns { red = cells, green = cells, blue = cells }.
+function getChannelCells(spritePath)
+	local img = love.image.newImageData(spritePath)
+	return {
+		red   = cellsFromImageData(img, "red"),
+		green = cellsFromImageData(img, "green"),
+		blue  = cellsFromImageData(img, "blue"),
+	}
+end

door.lua

@@ -9,7 +9,7 @@ function Door:initialize(x, y, color)
 		y = y,
 		color = color,
 		collision = "unmoveable",
-		sprite = loadSprite("art/game/door_" .. color:sub(1, 1) .. ".png"),
+		sprite = loadSprite("art/game/door.png"),
 	})
 	self.isDoor = true
 	self.locked = true
@@ -21,7 +21,7 @@ end
 function Door:refreshSprites()
 	local sprite
 	if self.locked then
-		sprite = loadSprite("art/game/door_" .. self.doorColor:sub(1, 1) .. ".png")
+		sprite = loadSprite("art/game/door.png")
 	else
 		sprite = loadSprite("art/game/door_unlocked.png")
 	end

level_editor/object_attributes.lua

@@ -3,6 +3,20 @@ require "libs/TSerial"
 local targetFolder = "art"
 local reanalyzeCells = true
 
+-- Sprites loaded directly by dedicated entity classes or used as reference art
+-- (the palette swatch), not placeable RGB assets. Every other master PNG in a
+-- content folder is a colour asset. Keeping this list preserves the exact
+-- palette set from when assets were identified by their _r/_g/_b channel files.
+local NON_ASSET_SPRITES = {
+	palette = true,
+	color_changing_wall = true,
+	door_locked_w = true,
+	door_unlocked = true,
+	player_sad = true,
+	player_w = true,
+	switch_pressed = true,
+}
+
 function getAllAssets()
 	local objectnames = {}
 	local topFolder = "art"
@@ -12,24 +26,29 @@ function getAllAssets()
 			-- we ignore directories which are prepended w/ an underscore
 			if not string.find(folder, "%.") then
 				objectnames[folder] = {}
-				-- love.filesystem.createDirectory("art/" .. folder)
 				-- this is a folder, probably
 				local newFiles = love.filesystem.getDirectoryItems(topFolder .. "/" .. folder)
 				for _, fileToAnalyze in pairs(newFiles) do
-					if fileToAnalyze:find("_r.png") or fileToAnalyze:find("_g.png") or fileToAnalyze:find("_b.png")then
-						local color
-						if fileToAnalyze:find("_r.png") then color = "red"
-						elseif fileToAnalyze:find("_g.png") then color = "green"
-						elseif fileToAnalyze:find("_b.png") then color = "blue" end
+					-- One full-colour master PNG per asset. The draw path tints it
+					-- per gun (see Entity:draw), so red/green/blue copies are just
+					-- the same master drawn through gColor[channel]; the channels are
+					-- split at load time, not stored as separate files.
+					if fileToAnalyze:find("%.png$") then
+						local name = fileToAnalyze:sub(1, fileToAnalyze:len() - 4)
 
-						local name = fileToAnalyze:sub(1, fileToAnalyze:len() - 6)
+						-- first folder to define a name wins; skip engine/reference art
+						if not NON_ASSET_SPRITES[name]
+							and not (globalAssetProperties[name] and globalAssetProperties[name].directory ~= folder) then
+
+							local sprite = topFolder .. "/" .. folder .. "/" .. fileToAnalyze
 
 							if not globalAssetProperties[name] then
 								globalAssetProperties[name] = {}
-							globalAssetProperties[name].directory = folder
-							globalAssetProperties[name].sprites = {}
 								globalAssetProperties[name].preload = false
 							end
+							globalAssetProperties[name].directory = folder
+							-- all three channels point at the same master image
+							globalAssetProperties[name].sprites = { red = sprite, green = sprite, blue = sprite }
 
 							-- class comes from a <name>.meta sitting next to the art
 							-- (authoritative); default to immoveable if none exists
@@ -40,16 +59,13 @@ function getAllAssets()
 								globalAssetProperties[name].class = "immoveable"
 							end
 
-						local sprite = topFolder .. "/" .. folder .. "/" .. fileToAnalyze
-						globalAssetProperties[name].sprites[color] = sprite
-
-						-- Precompute the occupied-cell shape once per asset/colour and
-						-- cache it here; entities share this table by reference so
-						-- collision never rescans pixels at runtime. Keyed per colour
-						-- (each channel leaves its own gaps) rather than reset per file.
-						globalAssetProperties[name].cells = globalAssetProperties[name].cells or {}
-						if not globalAssetProperties[name].cells[color] or reanalyzeCells then
-							globalAssetProperties[name].cells[color] = getCellsFromSprite(sprite)
+							-- Precompute per-channel occupied-cell shapes once and cache
+							-- here; entities share this table by reference so collision
+							-- never rescans pixels at runtime. Keyed per colour because
+							-- each channel of the master leaves its own gaps.
+							if reanalyzeCells or not globalAssetProperties[name].cells then
+								globalAssetProperties[name].cells = getChannelCells(sprite)
+							end
 						end
 					end
 				end

npc.lua

@@ -224,11 +224,10 @@ function Sign:initialize(x, y)
 		x = x, y = y,
 		color = "red",            -- representative only; sprites are per-channel
 		collision = "unmoveable",
-		sprites = {
-			red   = loadSprite("art/npc/start_sign_r.png"),
-			green = loadSprite("art/npc/start_sign_g.png"),
-			blue  = loadSprite("art/npc/start_sign_b.png"),
-		},
+		sprites = (function()
+			local m = loadSprite("art/npc/start_sign.png")   -- one master, tinted per gun at draw time
+			return { red = m, green = m, blue = m }
+		end)(),
 	})
 	self:initWalker()
 end
@@ -244,11 +243,10 @@ function Jorge:initialize(x, y)
 		x = x, y = y,
 		color = "red",
 		collision = "unmoveable",
-		sprites = {
-			red   = loadSprite("art/npc/jorge_r.png"),
-			green = loadSprite("art/npc/jorge_g.png"),
-			blue  = loadSprite("art/npc/jorge_b.png"),
-		},
+		sprites = (function()
+			local m = loadSprite("art/npc/jorge.png")   -- one master, tinted per gun at draw time
+			return { red = m, green = m, blue = m }
+		end)(),
 	})
 	self:initWalker()
 end

switch.lua

@@ -9,7 +9,7 @@ function Switch:initialize(x, y, color)
 		color = color,
 		collision = "none", --switches are floor elements that can't be pushed or bloc movement!!
 		cellShape = {{x = 1, y = 1}},
-		sprite = loadSprite("art/game/switch_" .. color:sub(1, 1) .. ".png")
+		sprite = loadSprite("art/game/switch.png")
 	})
 
 	self.activated = false