make the embossing effect configurable

README.md

@@ -46,7 +46,10 @@ The *Unified Hammers API* can be used by calling the `uniham.register_hammer` fu
 ```lua
 uniham.register_hammer('my_cool_id', {
     name = 'My Cool Hammer',
-    head = 'mymod_my_cool_head_base_texture.png',
+    head = {
+        texture = 'mymod_my_cool_head_base_texture.png',
+        opacity = 51.2
+    }
     --- Alternative to `head`, see description below
     -- texture = 'mymod_my_cool_hammer_texture.png',
     craft = 'mymod:my_cool_item',
@@ -54,7 +57,7 @@ uniham.register_hammer('my_cool_id', {
 })
 ```
 
-This registers a hammer with the name “My Cool Hammer” that has the ID `mymod:my_cool_id`. The head base texture is `mymod_my_cool_texture.png` and the texture is automatically masked to form a hammer head.
+This registers a hammer with the name “My Cool Hammer” that has the ID `mymod:my_cool_id`. The head base texture is `mymod_my_cool_texture.png` with the embossing effect being 20% visible (51.2) and the texture is automatically masked to form a hammer head.
 
 If instead of `head` the value `texture` is provided then the automatic texture generation is disabled and the hammer will get the texture defined by the `texture` value. If both values are added then the `texture` value is given precedence.
 

registry/default.lua

@@ -5,56 +5,74 @@ local S = uniham.translator
 
 register_hammer('hammer_bronze', {
     name = S('Bronze Hammer'),
-    head = 'default_bronze_block.png',
+    head = {
+        texture = 'default_bronze_block.png',
+    },
     craft = 'default:bronze_ingot',
     uses = 150
 })
 
 register_hammer('hammer_diamond', {
     name = S('Diamond Hammer'),
-    head = 'default_diamond_block.png',
+    head = {
+        texture = 'default_diamond_block.png',
+        opacity = 120
+    },
     craft = 'default:diamond',
     uses = 300
 })
 
 register_hammer('hammer_gold', {
     name = S('Golden Hammer'),
-    head = 'default_gold_block.png',
+    head = {
+        texture = 'default_gold_block.png',
+    },
     craft = 'default:gold_ingot',
     uses = 100
 })
 
 register_hammer('hammer_mese', {
     name = S('Mese Hammer'),
-    head = 'default_mese_block.png',
+    head = {
+        texture = 'default_mese_block.png',
+    },
     craft = 'default:mese_crystal',
     uses = 350
 })
 
 register_hammer('hammer_obsidian', {
     name = S('Obsidian Hammer'),
-    head = 'default_obsidian_block.png',
+    head = {
+        texture = 'default_obsidian_block.png',
+        opacity = 25
+    },
     craft = 'default:obsidian_shard',
     uses = 400
 })
 
 register_hammer('hammer_steel', {
     name = S('Steel Hammer'),
-    head = 'default_steel_block.png',
+    head = {
+        texture = 'default_steel_block.png',
+    },
     craft = 'default:steel_ingot',
     uses = 200
 })
 
 register_hammer('hammer_stone', {
     name = S('Stone Hammer'),
-    head = 'default_stone.png',
+    head = {
+        texture = 'default_stone.png',
+    },
     craft = 'default:cobble',
     uses = 70
 })
 
 register_hammer('hammer_wood', {
     name = S('Wooden Hammer'),
-    head = 'default_wood.png',
+    head = {
+        texture = 'default_wood.png',
+    },
     craft = 'default:wood',
     uses = 30
 })

registry/moreores.lua

@@ -5,14 +5,18 @@ local S = uniham.translator
 
 register_hammer('hammer_mithril', {
     name = S('Mithril Hammer'),
-    head = 'moreores_mithril_block.png',
+    head = {
+        texture = 'moreores_mithril_block.png',
+    },
     craft = 'moreores:mithril_ingot',
     uses = 450
 })
 
 register_hammer('hammer_silver', {
     name = S('Silver Hammer'),
-    head = 'moreores_silver_block.png',
+    head = {
+        texture = 'moreores_silver_block.png',
+    },
     craft = 'moreores:silver_ingot',
     uses = 250
 })

system/register_hammer.lua

@@ -6,7 +6,10 @@ local crush_nodes = uniham.crush_nodes
 --
 -- definition = {
 --   name = 'Name of the hammer',
---   head = 'head_material_texture.png',
+--   head = {
+--       texture = 'head_material_texture.png',
+--       opacity = 20
+--   },
 --   texture = 'hammer_texture.png',
 --   craft = 'crafting:material',
 --   on_use = on_use_function,
@@ -16,9 +19,16 @@ local crush_nodes = uniham.crush_nodes
 -- The `name` will be shown as tooltip on hovering the item in the inventory
 -- and will be used as it is.
 --
--- `head` is a texture that is used as base for the hammer head texture mask.
+-- `head` is a texture table containing two entries. The `texture` entry
+-- defines the texture that is used as base for the hammer head texture mask.
+-- The `opacity` entry is the opacity value between 0 (fully transparent) and
+-- 255 (fully visible) of the embossing effect. When omitting the opacity
+-- value, 51.2 will be used.
+--
 -- To change the mask textture packs need to add `uniham_head_mask.png` with
--- another file. All black pixels will become transparent.
+-- another file. All black pixels will become transparent. To change the
+-- embossing effect add `uniham_emboss.png` with transparent backgground. The
+-- embossing texture is simply overlayed over the generated head texture.
 --
 -- Instead of `head` the entry `texture` can be used. This does not auto-create
 -- The hammer texture but uses the given texture file as hammer texture. If
@@ -54,17 +64,20 @@ local crush_nodes = uniham.crush_nodes
 -- @return void
 uniham.register_hammer = function (short_id, definition)
     local on_use = definition.on_use or crush_nodes
-    local autotexture = '([combine:16x16:-1,1=+s)^((+h^+m)^[makealpha:0,0,0)'
+    local autotexture = '(([combine:16x16:-1,1=+s)^((+h^+m)^[makealpha:0,0,0))'
     local hammer_id = minetest.get_current_modname()..':'..short_id
     local texture = ''
+    local opacity = ''
 
     if definition.head and not definition.texture then
         texture = autotexture:gsub('+.', {
             ['+s'] = 'default_stick.png',
-            ['+h'] = definition.head,
+            ['+h'] = definition.head.texture,
             ['+m'] = 'uniham_head_mask.png'
         })
-        texture = '(('..texture..')^(uniham_emboss.png^[opacity:51.2))'
+
+        opacity = definition.head.opacity or 51.2
+        texture = '('..texture..'^(uniham_emboss.png^[opacity:'..opacity..'))'
     end
 
     if definition.texture then