Node texture animation

16 files changed, 421 insertions, 82 deletions

diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index 4dec9b394..6f2d0e033 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -1124,17 +1124,29 @@ Item definition (register_node, register_craftitem, register_tool)
     ^ The default functions handle regular use cases.
 }
 
+Tile definition:
+- "image.png"
+- {name="image.png", animation={Tile Animation definition}}
+- {name="image.png", backface_culling=bool}
+  ^ backface culling only supported in special tiles
+- deprecated still supported field names:
+  - image -> name
+
+Tile animation definition:
+- {type="vertical_frames", aspect_w=16, aspect_h=16, length=3.0}
+
 Node definition (register_node)
 {
     <all fields allowed in item definitions>,
 
     drawtype = "normal",
     visual_scale = 1.0,
-    tile_images = {"default_unknown_block.png"},
-    special_materials = {
-        {image="", backface_culling=true},
-        {image="", backface_culling=true},
-    },
+    tiles = {tile definition 1, def2, def3, def4, def5, def6},
+    ^ List can be shortened to needed length
+    ^ Old field name: tile_images
+    special_tiles = {tile definition 1, Tile definition 2},
+    ^ List can be shortened to needed length
+    ^ Old field name: special_materials
     alpha = 255,
     post_effect_color = {a=0, r=0, g=0, b=0},
     paramtype = "none",
diff --git a/games/minimal/mods/default/init.lua b/games/minimal/mods/default/init.lua
index 1ffe24837..03a54794c 100644
--- a/games/minimal/mods/default/init.lua
+++ b/games/minimal/mods/default/init.lua
@@ -1040,8 +1040,16 @@ minetest.register_node("default:lava_flowing", {
 	damage_per_second = 4*2,
 	post_effect_color = {a=192, r=255, g=64, b=0},
 	special_materials = {
-		{image="default_lava.png", backface_culling=false},
-		{image="default_lava.png", backface_culling=true},
+		{
+			image="default_lava_flowing_animated.png",
+			backface_culling=false,
+			animation={type="vertical_frames", aspect_w=16, aspect_h=16, length=3.3}
+		},
+		{
+			image="default_lava_flowing_animated.png",
+			backface_culling=true,
+			animation={type="vertical_frames", aspect_w=16, aspect_h=16, length=3.3}
+		},
 	},
 	groups = {lava=3, liquid=2, hot=3},
 })
@@ -1050,7 +1058,10 @@ minetest.register_node("default:lava_source", {
 	description = "Lava",
 	inventory_image = minetest.inventorycube("default_lava.png"),
 	drawtype = "liquid",
-	tile_images = {"default_lava.png"},
+	--tile_images = {"default_lava.png"},
+	tile_images = {
+		{name="default_lava_source_animated.png", animation={type="vertical_frames", aspect_w=16, aspect_h=16, length=3.0}}
+	},
 	paramtype = "light",
 	light_source = LIGHT_MAX - 1,
 	walkable = false,
diff --git a/games/minimal/mods/default/textures/default_lava_flowing_animated.png b/games/minimal/mods/default/textures/default_lava_flowing_animated.png
new file mode 100644
index 000000000..cef8e3611
--- /dev/null
+++ b/games/minimal/mods/default/textures/default_lava_flowing_animated.png
diff --git a/games/minimal/mods/default/textures/default_lava_source_animated.png b/games/minimal/mods/default/textures/default_lava_source_animated.png
new file mode 100644
index 000000000..9339a684e
--- /dev/null
+++ b/games/minimal/mods/default/textures/default_lava_source_animated.png
diff --git a/src/clientserver.h b/src/clientserver.h
index 7b8fe8e39..86e929f61 100644
--- a/src/clientserver.h
+++ b/src/clientserver.h
@@ -54,6 +54,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 	PROTOCOL_VERSION 10:
 		TOCLIENT_PRIVILEGES
 		Version raised to force 'fly' and 'fast' privileges into effect.
+		Node metadata change (came in later; somewhat incompatible)
+		TileDef in ContentFeatures (non-TileDef deserialization is supported)
 */
 
 #define PROTOCOL_VERSION 10
diff --git a/src/content_mapblock.cpp b/src/content_mapblock.cpp
index 7585abb69..9d95e1758 100644
--- a/src/content_mapblock.cpp
+++ b/src/content_mapblock.cpp
@@ -471,7 +471,9 @@ void mapblock_mesh_generate_special(MeshMakeData *data,
 							pa_liquid.x0(), pa_liquid.y0()),
 				};
 				
-				// This fixes a strange bug
+				// To get backface culling right, the vertices need to go
+				// clockwise around the front of the face. And we happened to
+				// calculate corner levels in exact reverse order.
 				s32 corner_resolve[4] = {3,2,1,0};
 
 				for(s32 i=0; i<4; i++)
@@ -482,6 +484,52 @@ void mapblock_mesh_generate_special(MeshMakeData *data,
 					vertices[i].Pos.Y += corner_levels[j];
 					vertices[i].Pos += intToFloat(p, BS);
 				}
+				
+				// Default downwards-flowing texture animation goes from 
+				// -Z towards +Z, thus the direction is +Z.
+				// Rotate texture to make animation go in flow direction
+				// Positive if liquid moves towards +Z
+				int dz = (corner_levels[side_corners[2][0]] +
+						corner_levels[side_corners[2][1]] <
+						corner_levels[side_corners[3][0]] +
+						corner_levels[side_corners[3][1]]);
+				// Positive if liquid moves towards +X
+				int dx = (corner_levels[side_corners[0][0]] +
+						corner_levels[side_corners[0][1]] <
+						corner_levels[side_corners[1][0]] +
+						corner_levels[side_corners[1][1]]);
+				// -X
+				if(-dx >= abs(dz))
+				{
+					v2f t = vertices[0].TCoords;
+					vertices[0].TCoords = vertices[1].TCoords;
+					vertices[1].TCoords = vertices[2].TCoords;
+					vertices[2].TCoords = vertices[3].TCoords;
+					vertices[3].TCoords = t;
+				}
+				// +X
+				if(dx >= abs(dz))
+				{
+					v2f t = vertices[0].TCoords;
+					vertices[0].TCoords = vertices[3].TCoords;
+					vertices[3].TCoords = vertices[2].TCoords;
+					vertices[2].TCoords = vertices[1].TCoords;
+					vertices[1].TCoords = t;
+				}
+				// -Z
+				if(-dz >= abs(dx))
+				{
+					v2f t = vertices[0].TCoords;
+					vertices[0].TCoords = vertices[3].TCoords;
+					vertices[3].TCoords = vertices[2].TCoords;
+					vertices[2].TCoords = vertices[1].TCoords;
+					vertices[1].TCoords = t;
+					t = vertices[0].TCoords;
+					vertices[0].TCoords = vertices[3].TCoords;
+					vertices[3].TCoords = vertices[2].TCoords;
+					vertices[2].TCoords = vertices[1].TCoords;
+					vertices[1].TCoords = t;
+				}
 
 				u16 indices[] = {0,1,2,2,3,0};
 				// Add to mesh collector
diff --git a/src/game.cpp b/src/game.cpp
index 6ccf02677..ac6d13af1 100644
--- a/src/game.cpp
+++ b/src/game.cpp
@@ -2206,7 +2206,7 @@ void the_game(
 				infotext = narrow_to_wide(meta->getString("infotext"));
 			} else {
 				MapNode n = map.getNode(nodepos);
-				if(nodedef->get(n).tname_tiles[0] == "unknown_block.png"){
+				if(nodedef->get(n).tiledef[0].name == "unknown_block.png"){
 					infotext = L"Unknown node: ";
 					infotext += narrow_to_wide(nodedef->get(n).name);
 				}
diff --git a/src/itemdef.cpp b/src/itemdef.cpp
index e8de06387..c8771c30c 100644
--- a/src/itemdef.cpp
+++ b/src/itemdef.cpp
@@ -451,7 +451,7 @@ public:
 					if(def->inventory_texture == NULL)
 					{
 						def->inventory_texture =
-							tsrc->getTextureRaw(f.tname_tiles[0]);
+							tsrc->getTextureRaw(f.tiledef[0].name);
 					}
 				}
 
diff --git a/src/mapblock_mesh.cpp b/src/mapblock_mesh.cpp
index 5584216ba..fd5937bbe 100644
--- a/src/mapblock_mesh.cpp
+++ b/src/mapblock_mesh.cpp
@@ -27,6 +27,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "gamedef.h"
 #include "mesh.h"
 #include "content_mapblock.h"
+#include "noise.h"
 
 /*
 	MeshMakeData
@@ -559,6 +560,11 @@ TileSpec getNodeTileN(MapNode mn, v3s16 p, u8 tileindex, MeshMakeData *data)
 		spec.material_flags |= MATERIAL_FLAG_CRACK;
 		spec.texture = data->m_gamedef->tsrc()->getTextureRawAP(spec.texture);
 	}
+	// If animated, replace tile texture with one without texture atlas
+	if(spec.material_flags & MATERIAL_FLAG_ANIMATION_VERTICAL_FRAMES)
+	{
+		spec.texture = data->m_gamedef->tsrc()->getTextureRawAP(spec.texture);
+	}
 	return spec;
 }
 
@@ -983,6 +989,23 @@ MapBlockMesh::MapBlockMesh(MeshMakeData *data):
 				crack_basename += "^[crack";
 			m_crack_materials.insert(std::make_pair(i, crack_basename));
 		}
+		// - Texture animation
+		if(p.tile.material_flags & MATERIAL_FLAG_ANIMATION_VERTICAL_FRAMES)
+		{
+			ITextureSource *tsrc = data->m_gamedef->tsrc();
+			// Add to MapBlockMesh in order to animate these tiles
+			m_animation_tiles[i] = p.tile;
+			m_animation_frames[i] = 0;
+			// Get starting position from noise
+			m_animation_frame_offsets[i] = 100000 * (2.0 + noise3d(
+					data->m_blockpos.X, data->m_blockpos.Y,
+					data->m_blockpos.Z, 0));
+			// Replace tile texture with the first animation frame
+			std::ostringstream os(std::ios::binary);
+			os<<tsrc->getTextureName(p.tile.texture.id);
+			os<<"^[verticalframe:"<<(int)p.tile.animation_frame_count<<":0";
+			p.tile.texture = tsrc->getTexture(os.str());
+		}
 		// - Lighting
 		for(u32 j = 0; j < p.vertices.size(); j++)
 		{
@@ -1055,7 +1078,8 @@ MapBlockMesh::MapBlockMesh(MeshMakeData *data):
 	// Check if animation is required for this mesh
 	m_has_animation =
 		!m_crack_materials.empty() ||
-		!m_daynight_diffs.empty();
+		!m_daynight_diffs.empty() ||
+		!m_animation_tiles.empty();
 }
 
 MapBlockMesh::~MapBlockMesh()
@@ -1094,6 +1118,34 @@ bool MapBlockMesh::animate(bool faraway, float time, int crack, u32 daynight_rat
 
 		m_last_crack = crack;
 	}
+	
+	// Texture animation
+	for(std::map<u32, TileSpec>::iterator
+			i = m_animation_tiles.begin();
+			i != m_animation_tiles.end(); i++)
+	{
+		const TileSpec &tile = i->second;
+		// Figure out current frame
+		int frameoffset = m_animation_frame_offsets[i->first];
+		int frame = (int)(time * 1000 / tile.animation_frame_length_ms
+				+ frameoffset) % tile.animation_frame_count;
+		// If frame doesn't change, skip
+		if(frame == m_animation_frames[i->first])
+			continue;
+
+		m_animation_frames[i->first] = frame;
+
+		scene::IMeshBuffer *buf = m_mesh->getMeshBuffer(i->first);
+		ITextureSource *tsrc = m_gamedef->getTextureSource();
+
+		// Create new texture name from original
+		std::ostringstream os(std::ios::binary);
+		os<<tsrc->getTextureName(tile.texture.id);
+		os<<"^[verticalframe:"<<(int)tile.animation_frame_count<<":"<<frame;
+		// Set the texture
+		AtlasPointer ap = tsrc->getTexture(os.str());
+		buf->getMaterial().setTexture(0, ap.atlas);
+	}
 
 	// Day-night transition
 	if(daynight_ratio != m_last_daynight_ratio)
diff --git a/src/mapblock_mesh.h b/src/mapblock_mesh.h
index 0877677bc..d5733120b 100644
--- a/src/mapblock_mesh.h
+++ b/src/mapblock_mesh.h
@@ -122,6 +122,12 @@ private:
 	// Maps mesh buffer (i.e. material) indices to base texture names
 	std::map<u32, std::string> m_crack_materials;
 
+	// Animation info: texture animationi
+	// Maps meshbuffers to TileSpecs
+	std::map<u32, TileSpec> m_animation_tiles;
+	std::map<u32, int> m_animation_frames; // last animation frame
+	std::map<u32, int> m_animation_frame_offsets;
+	
 	// Animation info: day/night transitions
 	// Last daynight_ratio value passed to animate()
 	u32 m_last_daynight_ratio;
diff --git a/src/nodedef.cpp b/src/nodedef.cpp
index 72f1ea2ea..d0ce3c19d 100644
--- a/src/nodedef.cpp
+++ b/src/nodedef.cpp
@@ -63,19 +63,29 @@ void NodeBox::deSerialize(std::istream &is)
 }
 
 /*
-	MaterialSpec
+	TileDef
 */
-
-void MaterialSpec::serialize(std::ostream &os) const
+	
+void TileDef::serialize(std::ostream &os) const
 {
-	os<<serializeString(tname);
-	writeU8(os, backface_culling);
+	writeU8(os, 0); // version
+	os<<serializeString(name);
+	writeU8(os, animation.type);
+	writeU16(os, animation.aspect_w);
+	writeU16(os, animation.aspect_h);
+	writeF1000(os, animation.length);
 }
 
-void MaterialSpec::deSerialize(std::istream &is)
+void TileDef::deSerialize(std::istream &is)
 {
-	tname = deSerializeString(is);
-	backface_culling = readU8(is);
+	int version = readU8(is);
+	if(version != 0)
+		throw SerializationError("unsupported TileDef version");
+	name = deSerializeString(is);
+	animation.type = (TileAnimationType)readU8(is);
+	animation.aspect_w = readU16(is);
+	animation.aspect_h = readU16(is);
+	animation.length = readF1000(is);
 }
 
 /*
@@ -133,9 +143,9 @@ void ContentFeatures::reset()
 	drawtype = NDT_NORMAL;
 	visual_scale = 1.0;
 	for(u32 i=0; i<6; i++)
-		tname_tiles[i] = "";
+		tiledef[i] = TileDef();
 	for(u16 j=0; j<CF_SPECIAL_COUNT; j++)
-		mspec_special[j] = MaterialSpec();
+		tiledef_special[j] = TileDef();
 	alpha = 255;
 	post_effect_color = video::SColor(0, 0, 0, 0);
 	param_type = CPT_NONE;
@@ -164,7 +174,7 @@ void ContentFeatures::reset()
 
 void ContentFeatures::serialize(std::ostream &os)
 {
-	writeU8(os, 3); // version
+	writeU8(os, 4); // version
 	os<<serializeString(name);
 	writeU16(os, groups.size());
 	for(ItemGroupList::const_iterator
@@ -176,10 +186,10 @@ void ContentFeatures::serialize(std::ostream &os)
 	writeF1000(os, visual_scale);
 	writeU8(os, 6);
 	for(u32 i=0; i<6; i++)
-		os<<serializeString(tname_tiles[i]);
+		tiledef[i].serialize(os);
 	writeU8(os, CF_SPECIAL_COUNT);
 	for(u32 i=0; i<CF_SPECIAL_COUNT; i++){
-		mspec_special[i].serialize(os);
+		tiledef_special[i].serialize(os);
 	}
 	writeU8(os, alpha);
 	writeU8(os, post_effect_color.getAlpha());
@@ -214,7 +224,7 @@ void ContentFeatures::serialize(std::ostream &os)
 void ContentFeatures::deSerialize(std::istream &is)
 {
 	int version = readU8(is);
-	if(version != 3)
+	if(version != 4 && version != 3)
 		throw SerializationError("unsupported ContentFeatures version");
 	name = deSerializeString(is);
 	groups.clear();
@@ -228,12 +238,21 @@ void ContentFeatures::deSerialize(std::istream &is)
 	visual_scale = readF1000(is);
 	if(readU8(is) != 6)
 		throw SerializationError("unsupported tile count");
-	for(u32 i=0; i<6; i++)
-		tname_tiles[i] = deSerializeString(is);
+	for(u32 i=0; i<6; i++){
+		if(version == 4)
+			tiledef[i].deSerialize(is);
+		else if(version == 3) // Allow connecting to older servers
+			tiledef[i].name = deSerializeString(is);
+	}
 	if(readU8(is) != CF_SPECIAL_COUNT)
 		throw SerializationError("unsupported CF_SPECIAL_COUNT");
 	for(u32 i=0; i<CF_SPECIAL_COUNT; i++){
-		mspec_special[i].deSerialize(is);
+		if(version == 4){
+			tiledef_special[i].deSerialize(is);
+		} else if(version == 3){ // Allow connecting to older servers
+			tiledef_special[i].name = deSerializeString(is);
+			tiledef_special[i].backface_culling = readU8(is);
+		}
 	}
 	alpha = readU8(is);
 	post_effect_color.setAlpha(readU8(is));
@@ -260,12 +279,12 @@ void ContentFeatures::deSerialize(std::istream &is)
 	selection_box.deSerialize(is);
 	legacy_facedir_simple = readU8(is);
 	legacy_wallmounted = readU8(is);
+	deSerializeSimpleSoundSpec(sound_footstep, is);
+	deSerializeSimpleSoundSpec(sound_dig, is);
+	deSerializeSimpleSoundSpec(sound_dug, is);
 	// If you add anything here, insert it primarily inside the try-catch
 	// block to not need to increase the version.
 	try{
-		deSerializeSimpleSoundSpec(sound_footstep, is);
-		deSerializeSimpleSoundSpec(sound_dig, is);
-		deSerializeSimpleSoundSpec(sound_dug, is);
 	}catch(SerializationError &e) {};
 }
 
@@ -494,14 +513,15 @@ public:
 		for(u16 i=0; i<=MAX_CONTENT; i++)
 		{
 			ContentFeatures *f = &m_content_features[i];
-
-			std::string tname_tiles[6];
+			
+			// Figure out the actual tiles to use
+			TileDef tiledef[6];
 			for(u32 j=0; j<6; j++)
 			{
-				tname_tiles[j] = f->tname_tiles[j];
-				if(tname_tiles[j] == "")
-					tname_tiles[j] = "unknown_block.png";
-                        }
+				tiledef[j] = f->tiledef[j];
+				if(tiledef[j].name == "")
+					tiledef[j].name = "unknown_block.png";
+			}
 
 			switch(f->drawtype){
 			default:
@@ -547,7 +567,7 @@ public:
 					f->drawtype = NDT_NORMAL;
 					f->solidness = 2;
 					for(u32 i=0; i<6; i++){
-						tname_tiles[i] += std::string("^[noalpha");
+						tiledef[i].name += std::string("^[noalpha");
 					}
 				}
 				break;
@@ -560,29 +580,92 @@ public:
 				break;
 			}
 
-			// Tile textures
+			// Tiles (fill in f->tiles[])
 			for(u16 j=0; j<6; j++){
-				f->tiles[j].texture = tsrc->getTexture(tname_tiles[j]);
+				// Texture
+				f->tiles[j].texture = tsrc->getTexture(tiledef[j].name);
+				// Alpha
 				f->tiles[j].alpha = f->alpha;
 				if(f->alpha == 255)
 					f->tiles[j].material_type = MATERIAL_ALPHA_SIMPLE;
 				else
 					f->tiles[j].material_type = MATERIAL_ALPHA_VERTEX;
+				// Material flags
 				f->tiles[j].material_flags = 0;
 				if(f->backface_culling)
 					f->tiles[j].material_flags |= MATERIAL_FLAG_BACKFACE_CULLING;
+				if(tiledef[j].animation.type == TAT_VERTICAL_FRAMES)
+					f->tiles[j].material_flags |= MATERIAL_FLAG_ANIMATION_VERTICAL_FRAMES;
+				// Animation parameters
+				if(f->tiles[j].material_flags &
+						MATERIAL_FLAG_ANIMATION_VERTICAL_FRAMES)
+				{
+					// Get raw texture size to determine frame count by
+					// aspect ratio
+					video::ITexture *t = tsrc->getTextureRaw(tiledef[j].name);
+					v2u32 size = t->getOriginalSize();
+					int frame_height = (float)size.X /
+							(float)tiledef[j].animation.aspect_w *
+							(float)tiledef[j].animation.aspect_h;
+					int frame_count = size.Y / frame_height;
+					int frame_length_ms = 1000.0 *
+							tiledef[j].animation.length / frame_count;
+					f->tiles[j].animation_frame_count = frame_count;
+					f->tiles[j].animation_frame_length_ms = frame_length_ms;
+
+					// If there are no frames for an animation, switch
+					// animation off (so that having specified an animation
+					// for something but not using it in the texture pack
+					// gives no overhead)
+					if(frame_count == 1){
+						f->tiles[j].material_flags &=
+								~MATERIAL_FLAG_ANIMATION_VERTICAL_FRAMES;
+					}
+				}
 			}
-			// Special tiles
+			// Special tiles (fill in f->special_tiles[])
 			for(u16 j=0; j<CF_SPECIAL_COUNT; j++){
-				f->special_tiles[j].texture = tsrc->getTexture(f->mspec_special[j].tname);
+				// Texture
+				f->special_tiles[j].texture =
+						tsrc->getTexture(f->tiledef_special[j].name);
+				// Alpha
 				f->special_tiles[j].alpha = f->alpha;
 				if(f->alpha == 255)
 					f->special_tiles[j].material_type = MATERIAL_ALPHA_SIMPLE;
 				else
 					f->special_tiles[j].material_type = MATERIAL_ALPHA_VERTEX;
+				// Material flags
 				f->special_tiles[j].material_flags = 0;
-				if(f->mspec_special[j].backface_culling)
+				if(f->tiledef_special[j].backface_culling)
 					f->special_tiles[j].material_flags |= MATERIAL_FLAG_BACKFACE_CULLING;
+				if(f->tiledef_special[j].animation.type == TAT_VERTICAL_FRAMES)
+					f->special_tiles[j].material_flags |= MATERIAL_FLAG_ANIMATION_VERTICAL_FRAMES;
+				// Animation parameters
+				if(f->special_tiles[j].material_flags &
+						MATERIAL_FLAG_ANIMATION_VERTICAL_FRAMES)
+				{
+					// Get raw texture size to determine frame count by
+					// aspect ratio
+					video::ITexture *t = tsrc->getTextureRaw(f->tiledef_special[j].name);
+					v2u32 size = t->getOriginalSize();
+					int frame_height = (float)size.X /
+							(float)f->tiledef_special[j].animation.aspect_w *
+							(float)f->tiledef_special[j].animation.aspect_h;
+					int frame_count = size.Y / frame_height;
+					int frame_length_ms = 1000.0 *
+							f->tiledef_special[j].animation.length / frame_count;
+					f->special_tiles[j].animation_frame_count = frame_count;
+					f->special_tiles[j].animation_frame_length_ms = frame_length_ms;
+
+					// If there are no frames for an animation, switch
+					// animation off (so that having specified an animation
+					// for something but not using it in the texture pack
+					// gives no overhead)
+					if(frame_count == 1){
+						f->special_tiles[j].material_flags &=
+								~MATERIAL_FLAG_ANIMATION_VERTICAL_FRAMES;
+					}
+				}
 			}
 		}
 #endif
diff --git a/src/nodedef.h b/src/nodedef.h
index 04f375043..a376da30a 100644
--- a/src/nodedef.h
+++ b/src/nodedef.h
@@ -95,15 +95,33 @@ struct NodeBox
 struct MapNode;
 class NodeMetadata;
 
-struct MaterialSpec
+/*
+	Stand-alone definition of a TileSpec (basically a server-side TileSpec)
+*/
+enum TileAnimationType{
+	TAT_NONE=0,
+	TAT_VERTICAL_FRAMES=1,
+};
+struct TileDef
 {
-	std::string tname;
-	bool backface_culling;
-	
-	MaterialSpec(const std::string &tname_="", bool backface_culling_=true):
-		tname(tname_),
-		backface_culling(backface_culling_)
-	{}
+	std::string name;
+	bool backface_culling; // Takes effect only in special cases
+	struct{
+		enum TileAnimationType type;
+		int aspect_w; // width for aspect ratio
+		int aspect_h; // height for aspect ratio
+		float length; // seconds
+	} animation;
+
+	TileDef()
+	{
+		name = "";
+		backface_culling = true;
+		animation.type = TAT_NONE;
+		animation.aspect_w = 1;
+		animation.aspect_h = 1;
+		animation.length = 1.0;
+	}
 
 	void serialize(std::ostream &os) const;
 	void deSerialize(std::istream &is);
@@ -159,8 +177,8 @@ struct ContentFeatures
 	// Visual definition
 	enum NodeDrawType drawtype;
 	float visual_scale; // Misc. scale parameter
-	std::string tname_tiles[6];
-	MaterialSpec mspec_special[CF_SPECIAL_COUNT]; // Use setter methods
+	TileDef tiledef[6];
+	TileDef tiledef_special[CF_SPECIAL_COUNT]; // eg. flowing liquid
 	u8 alpha;
 
 	// Post effect color, drawn when the camera is inside the node.
diff --git a/src/scriptapi.cpp b/src/scriptapi.cpp
index afd8546d9..3868d1035 100644
--- a/src/scriptapi.cpp
+++ b/src/scriptapi.cpp
@@ -426,6 +426,13 @@ struct EnumString es_CraftMethod[] =
 	{0, NULL},
 };
 
+struct EnumString es_TileAnimationType[] =
+{
+	{TAT_NONE, "none"},
+	{TAT_VERTICAL_FRAMES, "vertical_frames"},
+	{0, NULL},
+};
+
 /*
 	C struct <-> Lua table converter functions
 */
@@ -992,6 +999,50 @@ static ItemDefinition read_item_definition(lua_State *L, int index,
 }
 
 /*
+	TileDef
+*/
+
+static TileDef read_tiledef(lua_State *L, int index)
+{
+	if(index < 0)
+		index = lua_gettop(L) + 1 + index;
+	
+	TileDef tiledef;
+
+	// key at index -2 and value at index
+	if(lua_isstring(L, index)){
+		// "default_lava.png"
+		tiledef.name = lua_tostring(L, index);
+	}
+	else if(lua_istable(L, index))
+	{
+		// {name="default_lava.png", animation={}}
+		tiledef.name = "";
+		getstringfield(L, index, "name", tiledef.name);
+		getstringfield(L, index, "image", tiledef.name); // MaterialSpec compat.
+		tiledef.backface_culling = getboolfield_default(
+					L, index, "backface_culling", true);
+		// animation = {}
+		lua_getfield(L, index, "animation");
+		if(lua_istable(L, -1)){
+			// {type="vertical_frames", aspect_w=16, aspect_h=16, length=2.0}
+			tiledef.animation.type = (TileAnimationType)
+					getenumfield(L, -1, "type", es_TileAnimationType,
+					TAT_NONE);
+			tiledef.animation.aspect_w =
+					getintfield_default(L, -1, "aspect_w", 16);
+			tiledef.animation.aspect_h =
+					getintfield_default(L, -1, "aspect_h", 16);
+			tiledef.animation.length =
+					getfloatfield_default(L, -1, "length", 1.0);
+		}
+		lua_pop(L, 1);
+	}
+
+	return tiledef;
+}
+
+/*
 	ContentFeatures
 */
 
@@ -1026,18 +1077,23 @@ static ContentFeatures read_content_features(lua_State *L, int index)
 	f.drawtype = (NodeDrawType)getenumfield(L, index, "drawtype", es_DrawType,
 			NDT_NORMAL);
 	getfloatfield(L, index, "visual_scale", f.visual_scale);
-
-	lua_getfield(L, index, "tile_images");
+	
+	// tiles = {}
+	lua_getfield(L, index, "tiles");
+	// If nil, try the deprecated name "tile_images" instead
+	if(lua_isnil(L, -1)){
+		lua_pop(L, 1);
+		warn_if_field_exists(L, index, "tile_images",
+				"Deprecated; new name is \"tiles\".");
+		lua_getfield(L, index, "tile_images");
+	}
 	if(lua_istable(L, -1)){
 		int table = lua_gettop(L);
 		lua_pushnil(L);
 		int i = 0;
 		while(lua_next(L, table) != 0){
-			// key at index -2 and value at index -1
-			if(lua_isstring(L, -1))
-				f.tname_tiles[i] = lua_tostring(L, -1);
-			else
-				f.tname_tiles[i] = "";
+			// Read tiledef from value
+			f.tiledef[i] = read_tiledef(L, -1);
 			// removes value, keeps key for next iteration
 			lua_pop(L, 1);
 			i++;
@@ -1048,29 +1104,31 @@ static ContentFeatures read_content_features(lua_State *L, int index)
 		}
 		// Copy last value to all remaining textures
 		if(i >= 1){
-			std::string lastname = f.tname_tiles[i-1];
+			TileDef lasttile = f.tiledef[i-1];
 			while(i < 6){
-				f.tname_tiles[i] = lastname;
+				f.tiledef[i] = lasttile;
 				i++;
 			}
 		}
 	}
 	lua_pop(L, 1);
-
-	lua_getfield(L, index, "special_materials");
+	
+	// special_tiles = {}
+	lua_getfield(L, index, "special_tiles");
+	// If nil, try the deprecated name "special_materials" instead
+	if(lua_isnil(L, -1)){
+		lua_pop(L, 1);
+		warn_if_field_exists(L, index, "special_materials",
+				"Deprecated; new name is \"special_tiles\".");
+		lua_getfield(L, index, "special_materials");
+	}
 	if(lua_istable(L, -1)){
 		int table = lua_gettop(L);
 		lua_pushnil(L);
 		int i = 0;
 		while(lua_next(L, table) != 0){
-			// key at index -2 and value at index -1
-			int smtable = lua_gettop(L);
-			std::string tname = getstringfield_default(
-					L, smtable, "image", "");
-			bool backface_culling = getboolfield_default(
-					L, smtable, "backface_culling", true);
-			MaterialSpec mspec(tname, backface_culling);
-			f.mspec_special[i] = mspec;
+			// Read tiledef from value
+			f.tiledef_special[i] = read_tiledef(L, -1);
 			// removes value, keeps key for next iteration
 			lua_pop(L, 1);
 			i++;
diff --git a/src/test.cpp b/src/test.cpp
index 5b969017f..448ba23ce 100644
--- a/src/test.cpp
+++ b/src/test.cpp
@@ -80,7 +80,7 @@ void define_some_nodes(IWritableItemDefManager *idef, IWritableNodeDefManager *n
 	f = ContentFeatures();
 	f.name = itemdef.name;
 	for(int i = 0; i < 6; i++)
-		f.tname_tiles[i] = "default_stone.png";
+		f.tiledef[i].name = "default_stone.png";
 	f.is_ground_content = true;
 	idef->registerItem(itemdef);
 	ndef->set(i, f);
@@ -100,10 +100,10 @@ void define_some_nodes(IWritableItemDefManager *idef, IWritableNodeDefManager *n
 		"{default_dirt.png&default_grass_side.png";
 	f = ContentFeatures();
 	f.name = itemdef.name;
-	f.tname_tiles[0] = "default_grass.png";
-	f.tname_tiles[1] = "default_dirt.png";
+	f.tiledef[0].name = "default_grass.png";
+	f.tiledef[1].name = "default_dirt.png";
 	for(int i = 2; i < 6; i++)
-		f.tname_tiles[i] = "default_dirt.png^default_grass_side.png";
+		f.tiledef[i].name = "default_dirt.png^default_grass_side.png";
 	f.is_ground_content = true;
 	idef->registerItem(itemdef);
 	ndef->set(i, f);
diff --git a/src/tile.cpp b/src/tile.cpp
index d2a61b931..92c56c277 100644
--- a/src/tile.cpp
+++ b/src/tile.cpp
@@ -858,7 +858,7 @@ void TextureSource::buildMainAtlas(class IGameDef *gamedef)
 		const ContentFeatures &f = ndef->get(j);
 		for(u32 i=0; i<6; i++)
 		{
-			std::string name = f.tname_tiles[i];
+			std::string name = f.tiledef[i].name;
 			sourcelist[name] = true;
 		}
 	}
@@ -988,7 +988,7 @@ void TextureSource::buildMainAtlas(class IGameDef *gamedef)
 				src_x = pos_in_atlas.X;
 			}
 			s32 y = y0 + pos_in_atlas.Y;
-			s32 src_y = MYMAX(pos_in_atlas.Y, MYMIN(pos_in_atlas.Y + dim.Height - 1, y));
+			s32 src_y = MYMAX((int)pos_in_atlas.Y, MYMIN((int)pos_in_atlas.Y + (int)dim.Height - 1, y));
 			s32 dst_y = y;
 			video::SColor c = atlas_img->getPixel(src_x, src_y);
 			atlas_img->setPixel(dst_x,dst_y,c);
@@ -1638,6 +1638,48 @@ bool generate_image(std::string part_of_name, video::IImage *& baseimg,
 				img2->drop();
 			}
 		}
+		/*
+			[verticalframe:N:I
+			Crops a frame of a vertical animation.
+			N = frame count, I = frame index
+		*/
+		else if(part_of_name.substr(0,15) == "[verticalframe:")
+		{
+			Strfnd sf(part_of_name);
+			sf.next(":");
+			u32 frame_count = stoi(sf.next(":"));
+			u32 frame_index = stoi(sf.next(":"));
+
+			if(baseimg == NULL){
+				errorstream<<"generate_image(): baseimg!=NULL "
+						<<"for part_of_name=\""<<part_of_name
+						<<"\", cancelling."<<std::endl;
+				return false;
+			}
+			
+			v2u32 frame_size = baseimg->getDimension();
+			frame_size.Y /= frame_count;
+
+			video::IImage *img = driver->createImage(video::ECF_A8R8G8B8,
+					frame_size);
+			if(!img){
+				errorstream<<"generate_image(): Could not create image "
+						<<"for part_of_name=\""<<part_of_name
+						<<"\", cancelling."<<std::endl;
+				return false;
+			}
+
+			core::dimension2d<u32> dim = frame_size;
+			core::position2d<s32> pos_dst(0, 0);
+			core::position2d<s32> pos_src(0, frame_index * frame_size.Y);
+			baseimg->copyToWithAlpha(img, pos_dst,
+					core::rect<s32>(pos_src, dim),
+					video::SColor(255,255,255,255),
+					NULL);
+			// Replace baseimg
+			baseimg->drop();
+			baseimg = img;
+		}
 		else
 		{
 			errorstream<<"generate_image(): Invalid "
diff --git a/src/tile.h b/src/tile.h
index 1211569bc..8b19b4c32 100644
--- a/src/tile.h
+++ b/src/tile.h
@@ -162,6 +162,9 @@ enum MaterialType{
 // Should the crack be drawn on transparent pixels (unset) or not (set)?
 // Ignored if MATERIAL_FLAG_CRACK is not set.
 #define MATERIAL_FLAG_CRACK_OVERLAY 0x04
+// Animation made up by splitting the texture to vertical frames, as
+// defined by extra parameters
+#define MATERIAL_FLAG_ANIMATION_VERTICAL_FRAMES 0x08
 
 /*
 	This fully defines the looks of a tile.
@@ -178,7 +181,9 @@ struct TileSpec
 		material_flags(
 			//0 // <- DEBUG, Use the one below
 			MATERIAL_FLAG_BACKFACE_CULLING
-		)
+		),
+		animation_frame_count(1),
+		animation_frame_length_ms(0)
 	{
 	}
 
@@ -227,10 +232,12 @@ struct TileSpec
 	AtlasPointer texture;
 	// Vertex alpha
 	u8 alpha;
-	// Material type
+	// Material parameters
 	u8 material_type;
-	// Material flags
 	u8 material_flags;
+	// Animation parameters
+	u8 animation_frame_count;
+	u16 animation_frame_length_ms;
 };
 
 #endif