Remove all bump mapping and parallax occlusion related code.

doc/lua_api.txt

@@ -401,35 +401,6 @@ stripping out the file extension:
 * e.g. `foomod_foothing`
 
 
-Normalmap Textures
-------------------
-
-If shaders and bumpmapping or parallax occlusion is enabled, Minetest tries
-to load normalmaps.
-Those image files have to end with `_normal.png` and start with the same name
-as their corresponding texture.
-For example a normalmap for `foomod_foothing.png` has to be called
-`foomod_foothing_normal.png`.
-
-The sRGB R, G and B colour values of a normalmap pixel are each directly
-mapped from `{0, ..., 255}` to `[-1, 1]` and, taken together,
-define the normal vector.
-The alpha channel defines the heightmap for parallax occlusion.
-To be safe, the alpha values should always be bigger than zero
-because the colour values, which define the normal vector,
-may be undefined for image formats where colour is discarded in fully
-transparent pixels.
-
-Bumpmapping and parallax occlusion are currently experimental features:
-
-* Bumpmapping in Minetest happens in an obscure way; there are no light sources
-  defined in the shaders except the sunlight direction.
-* Parallax occlusion with relief-mapping mode does not yet work correctly
-  together with Minetest's Fastfaces.
-* The normalmap files must end with `.png`, so other image files are not
-  supported.
-
-
 Texture modifiers
 -----------------
 
@@ -834,7 +805,7 @@ Example (colored grass block):
         -- Overlay tiles: define them in the same style
         -- The top and bottom tile does not have overlay
         overlay_tiles = {"", "",
-            {name = "default_grass_side.png", tileable_vertical = false}},
+            {name = "default_grass_side.png"}},
         -- Global color, used in inventory
         color = "green",
         -- Palette in the world
@@ -1204,7 +1175,7 @@ Look for examples in `games/devtest` or `games/minetest_game`.
       base cube without affecting them.
     * The base cube texture tiles are defined as normal, the `plantlike`
       extension uses the defined special tile, for example:
-      `special_tiles = {{name = "default_papyrus.png", tileable_vertical = true}},`
+      `special_tiles = {{name = "default_papyrus.png"}},`
 
 `*_optional` drawtypes need less rendering time if deactivated
 (always client-side).
@@ -7043,13 +7014,8 @@ Tile definition
 
 * `"image.png"`
 * `{name="image.png", animation={Tile Animation definition}}`
-* `{name="image.png", backface_culling=bool, tileable_vertical=bool,
-  tileable_horizontal=bool, align_style="node"/"world"/"user", scale=int}`
+* `{name="image.png", backface_culling=bool, align_style="node"/"world"/"user", scale=int}`
     * backface culling enabled by default for most nodes
-    * tileable flags are info for shaders, how they should treat texture
-      when displacement mapping is used.
-      Directions are from the point of view of the tile texture,
-      not the node it's on.
     * align style determines whether the texture will be rotated with the node
       or kept aligned with its surroundings. "user" means that client
       setting will be used, similar to `glasslike_framed_optional`.