Dye: Simplify recipes.

Create a simple triplet table (src1, src2, dst) for all the dye
recipes and group them logically, with a bit of explanation where
they actually come from.

This prunes a lot of recipes from the list, but the old list had a
ton of combinations that did not make any sense, as well as recipes
that were just gross approximations and duplicates, mixing the same
color with itself just to get the same color back, which just wastes
packets at logon.

The list has been checked to allow all colors created from the basic
dyes (flowers+coal) so that all colors can be crafted.

mods/dye/init.lua

@@ -74,36 +74,40 @@ minetest.register_craft({
 })
 
 -- Mix recipes
--- Just mix everything to everything somehow sanely
-
-local mixbases = {"pink", "magenta", "red", "orange", "brown", "yellow", "green", "dark_green", "cyan", "blue", "violet", "black", "dark_grey", "grey", "white"}
-
-local mixes = {
-	--             pink,     magenta,  red,      orange,      brown,       yellow,      green,       dark_green,  cyan,   blue,    violet,  black,      dark_grey,  grey,  white
-	white      = {"pink",   "pink",   "pink",   "orange",    "orange",    "yellow",    "green",     "green",     "grey", "cyan",  "violet","grey",     "grey",     "grey","white"},
-	grey       = {"pink",   "pink",   "pink",   "orange",    "orange",    "yellow",    "green",     "green",     "grey", "cyan",  "violet","dark_grey","grey",     "grey"},
-	dark_grey  = {"brown",  "brown",  "brown",  "brown",     "brown",     "brown",     "dark_green","dark_green","blue", "blue",  "violet","black",    "dark_grey"},
-	black      = {"black",  "black",  "black",  "black",     "black",     "black",     "black",     "black",     "black","black", "black", "black"},
-	violet     = {"magenta","magenta","magenta","red",       "brown",     "red",       "cyan",      "brown",     "blue", "violet","violet"},
-	blue       = {"violet", "violet", "magenta","brown",     "brown",     "dark_green","cyan",      "cyan",      "cyan", "blue"},
-	cyan       = {"brown",  "blue",   "brown",  "dark_green","dark_grey", "green",     "cyan",      "dark_green","cyan"},
-	dark_green = {"brown",  "brown",  "brown",  "brown",     "brown",     "green",     "green",     "dark_green"},
-	green      = {"yellow", "brown",  "yellow", "yellow",    "dark_green","green",     "green"},
-	yellow     = {"orange", "red",    "orange", "yellow",    "orange",    "yellow"},
-	brown      = {"brown",  "brown",  "brown",  "orange",    "brown"},
-	orange     = {"orange", "red",    "orange", "orange"},
-	red        = {"pink",   "magenta","red"},
-	magenta    = {"magenta","magenta"},
-	pink       = {"pink"},
+local dye_recipes = {
+	-- src1, src2, dst
+	-- RYB mixes
+	{"red", "blue", "violet"}, -- "purple"
+	{"yellow", "red", "orange"},
+	{"yellow", "blue", "green"},
+	-- RYB complementary mixes
+	{"red", "green", "dark_grey"},
+	{"yellow", "violet", "dark_grey"},
+	{"blue", "orange", "dark_grey"},
+	-- CMY mixes - approximation
+	{"cyan", "yellow", "green"},
+	{"cyan", "magenta", "blue"},
+	{"yellow", "magenta", "red"},
+	-- other mixes that result in a color we have
+	{"red", "green", "brown"},
+	{"magenta", "blue", "violet"},
+	{"green", "blue", "cyan"},
+	{"pink", "violet", "magenta"},
+	-- mixes with black
+	{"white", "black", "grey"},
+	{"grey", "black", "dark_grey"},
+	{"green", "black", "dark_green"},
+	{"orange", "black", "brown"},
+	-- mixes with white
+	{"white", "red", "pink"},
+	{"white", "dark_grey", "grey"},
+	{"white", "dark_green", "green"},
 }
 
-for one, results in pairs(mixes) do
-	for i, result in ipairs(results) do
-		local another = mixbases[i]
-		minetest.register_craft({
-			type = "shapeless",
-			output = 'dye:' .. result .. ' 2',
-			recipe = {'dye:' .. one, 'dye:' .. another},
-		})
-	end
+for _, mix in pairs(dye_recipes) do
+	minetest.register_craft({
+		type = "shapeless",
+		output = 'dye:' .. mix[3] .. ' 2',
+		recipe = {'dye:' .. mix[1], 'dye:' .. mix[2]},
+	})
 end