Implement override.txt support for special tiles (#10140)

Add override targets for all special_tiles entries in node definitions, allowing texture packs to replace these textures. This makes overrides work properly with a variety of drawtypes.

The targets are named special1 through special6, covering the the current length of the special_tiles array.

6 files changed, 84 insertions, 16 deletions

diff --git a/doc/texture_packs.txt b/doc/texture_packs.txt
index 79d65a339..8af2cbad6 100644
--- a/doc/texture_packs.txt
+++ b/doc/texture_packs.txt
@@ -195,11 +195,27 @@ Here are targets you can choose from:
 | bottom        | y- face                                           |
 | sides         | x-, x+, z-, z+ faces                              |
 | all           | All faces. You can also use '*' instead of 'all'. |
+| special1      | The first entry in the special_tiles list         |
+| special2      | The second entry in the special_tiles list        |
+| special3      | The third entry in the special_tiles list         |
+| special4      | The fourth entry in the special_tiles list        |
+| special5      | The fifth entry in the special_tiles list         |
+| special6      | The sixth entry in the special_tiles list         |
 | inventory     | The inventory texture                             |
 | wield         | The texture used when held by the player          |
 
 Nodes support all targets, but other items only support 'inventory'
-and 'wield'
+and 'wield'.
+
+### Using the special targets
+
+The special* targets only apply to specific drawtypes:
+
+* `flowingliquid`: special1 sets the top texture, special2 sets the side texture
+* `allfaces_optional`: special1 is used by simple mode, see below
+* `glasslike_framed`: When containing a liquid, special1 sets the liquid texture
+* `glasslike_framed_optional`: Same as `glasslike_framed`
+* `plantlike_rooted`: special1 sets the plant's texture
 
 Designing leaves textures for the leaves rendering options
 ----------------------------------------------------------
diff --git a/src/nodedef.cpp b/src/nodedef.cpp
index e5cd2c2a7..82c4581fa 100644
--- a/src/nodedef.cpp
+++ b/src/nodedef.cpp
@@ -1337,6 +1337,7 @@ void NodeDefManager::applyTextureOverrides(const std::vector<TextureOverride> &o
 
 		ContentFeatures &nodedef = m_content_features[id];
 
+		// Override tiles
 		if (texture_override.hasTarget(OverrideTarget::TOP))
 			nodedef.tiledef[0].name = texture_override.texture;
 
@@ -1354,6 +1355,26 @@ void NodeDefManager::applyTextureOverrides(const std::vector<TextureOverride> &o
 
 		if (texture_override.hasTarget(OverrideTarget::FRONT))
 			nodedef.tiledef[5].name = texture_override.texture;
+
+
+		// Override special tiles, if applicable
+		if (texture_override.hasTarget(OverrideTarget::SPECIAL_1))
+			nodedef.tiledef_special[0].name = texture_override.texture;
+
+		if (texture_override.hasTarget(OverrideTarget::SPECIAL_2))
+			nodedef.tiledef_special[1].name = texture_override.texture;
+
+		if (texture_override.hasTarget(OverrideTarget::SPECIAL_3))
+			nodedef.tiledef_special[2].name = texture_override.texture;
+
+		if (texture_override.hasTarget(OverrideTarget::SPECIAL_4))
+			nodedef.tiledef_special[3].name = texture_override.texture;
+
+		if (texture_override.hasTarget(OverrideTarget::SPECIAL_5))
+			nodedef.tiledef_special[4].name = texture_override.texture;
+
+		if (texture_override.hasTarget(OverrideTarget::SPECIAL_6))
+			nodedef.tiledef_special[5].name = texture_override.texture;
 	}
 }
 
diff --git a/src/nodedef.h b/src/nodedef.h
index ff52f976f..d0da367ee 100644
--- a/src/nodedef.h
+++ b/src/nodedef.h
@@ -261,6 +261,11 @@ struct TileDef
 		NodeDrawType drawtype);
 };
 
+// Defines the number of special tiles per nodedef
+//
+// NOTE: When changing this value, the enum entries of OverrideTarget and
+//       parser in TextureOverrideSource must be updated so that all special
+//       tiles can be overridden.
 #define CF_SPECIAL_COUNT 6
 
 struct ContentFeatures
diff --git a/src/texture_override.cpp b/src/texture_override.cpp
index 10d129b87..effdb0efd 100644
--- a/src/texture_override.cpp
+++ b/src/texture_override.cpp
@@ -24,6 +24,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include <algorithm>
 #include <fstream>
 
+#define override_cast static_cast<override_t>
+
 TextureOverrideSource::TextureOverrideSource(std::string filepath)
 {
 	std::ifstream infile(filepath.c_str());
@@ -56,25 +58,37 @@ TextureOverrideSource::TextureOverrideSource(std::string filepath)
 		std::vector<std::string> targets = str_split(splitted[1], ',');
 		for (const std::string &target : targets) {
 			if (target == "top")
-				texture_override.target |= static_cast<u8>(OverrideTarget::TOP);
+				texture_override.target |= override_cast(OverrideTarget::TOP);
 			else if (target == "bottom")
-				texture_override.target |= static_cast<u8>(OverrideTarget::BOTTOM);
+				texture_override.target |= override_cast(OverrideTarget::BOTTOM);
 			else if (target == "left")
-				texture_override.target |= static_cast<u8>(OverrideTarget::LEFT);
+				texture_override.target |= override_cast(OverrideTarget::LEFT);
 			else if (target == "right")
-				texture_override.target |= static_cast<u8>(OverrideTarget::RIGHT);
+				texture_override.target |= override_cast(OverrideTarget::RIGHT);
 			else if (target == "front")
-				texture_override.target |= static_cast<u8>(OverrideTarget::FRONT);
+				texture_override.target |= override_cast(OverrideTarget::FRONT);
 			else if (target == "back")
-				texture_override.target |= static_cast<u8>(OverrideTarget::BACK);
+				texture_override.target |= override_cast(OverrideTarget::BACK);
 			else if (target == "inventory")
-				texture_override.target |= static_cast<u8>(OverrideTarget::INVENTORY);
+				texture_override.target |= override_cast(OverrideTarget::INVENTORY);
 			else if (target == "wield")
-				texture_override.target |= static_cast<u8>(OverrideTarget::WIELD);
+				texture_override.target |= override_cast(OverrideTarget::WIELD);
+			else if (target == "special1")
+				texture_override.target |= override_cast(OverrideTarget::SPECIAL_1);
+			else if (target == "special2")
+				texture_override.target |= override_cast(OverrideTarget::SPECIAL_2);
+			else if (target == "special3")
+				texture_override.target |= override_cast(OverrideTarget::SPECIAL_3);
+			else if (target == "special4")
+				texture_override.target |= override_cast(OverrideTarget::SPECIAL_4);
+			else if (target == "special5")
+				texture_override.target |= override_cast(OverrideTarget::SPECIAL_5);
+			else if (target == "special6")
+				texture_override.target |= override_cast(OverrideTarget::SPECIAL_6);
 			else if (target == "sides")
-				texture_override.target |= static_cast<u8>(OverrideTarget::SIDES);
+				texture_override.target |= override_cast(OverrideTarget::SIDES);
 			else if (target == "all" || target == "*")
-				texture_override.target |= static_cast<u8>(OverrideTarget::ALL_FACES);
+				texture_override.target |= override_cast(OverrideTarget::ALL_FACES);
 			else {
 				// Report invalid target
 				warningstream << filepath << ":" << line_index
@@ -85,7 +99,7 @@ TextureOverrideSource::TextureOverrideSource(std::string filepath)
 		}
 
 		// If there are no valid targets, skip adding this override
-		if (texture_override.target == static_cast<u8>(OverrideTarget::INVALID)) {
+		if (texture_override.target == override_cast(OverrideTarget::INVALID)) {
 			continue;
 		}
 
@@ -112,7 +126,7 @@ std::vector<TextureOverride> TextureOverrideSource::getNodeTileOverrides()
 	std::vector<TextureOverride> found_overrides;
 
 	for (const TextureOverride &texture_override : m_overrides) {
-		if (texture_override.hasTarget(OverrideTarget::ALL_FACES))
+		if (texture_override.hasTarget(OverrideTarget::NODE_TARGETS))
 			found_overrides.push_back(texture_override);
 	}
 
diff --git a/src/texture_override.h b/src/texture_override.h
index db03bd014..bdc95e732 100644
--- a/src/texture_override.h
+++ b/src/texture_override.h
@@ -23,8 +23,10 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include <string>
 #include <vector>
 
+typedef u16 override_t;
+
 //! Bitmask enum specifying what a texture override should apply to
-enum class OverrideTarget : u8
+enum class OverrideTarget : override_t
 {
 	INVALID = 0,
 	TOP = 1 << 0,
@@ -35,23 +37,33 @@ enum class OverrideTarget : u8
 	BACK = 1 << 5,
 	INVENTORY = 1 << 6,
 	WIELD = 1 << 7,
+	SPECIAL_1 = 1 << 8,
+	SPECIAL_2 = 1 << 9,
+	SPECIAL_3 = 1 << 10,
+	SPECIAL_4 = 1 << 11,
+	SPECIAL_5 = 1 << 12,
+	SPECIAL_6 = 1 << 13,
 
+	// clang-format off
 	SIDES = LEFT | RIGHT | FRONT | BACK,
 	ALL_FACES = TOP | BOTTOM | SIDES,
+	ALL_SPECIAL = SPECIAL_1 | SPECIAL_2 | SPECIAL_3 | SPECIAL_4 | SPECIAL_5 | SPECIAL_6,
+	NODE_TARGETS = ALL_FACES | ALL_SPECIAL,
 	ITEM_TARGETS = INVENTORY | WIELD,
+	// clang-format on
 };
 
 struct TextureOverride
 {
 	std::string id;
 	std::string texture;
-	u8 target;
+	override_t target;
 
 	// Helper function for checking if an OverrideTarget is found in
 	// a TextureOverride without casting
 	inline bool hasTarget(OverrideTarget overrideTarget) const
 	{
-		return (target & static_cast<u8>(overrideTarget)) != 0;
+		return (target & static_cast<override_t>(overrideTarget)) != 0;
 	}
 };
 
diff --git a/util/ci/lint.sh b/util/ci/lint.sh
index 395445ca7..395445ca7 100644..100755
--- a/util/ci/lint.sh
+++ b/util/ci/lint.sh