13 files changed, 481 insertions, 327 deletions
diff --git a/game/shared/world/chunk.cc b/game/shared/world/chunk.cc
index e59b68d..b1b19a6 100644
--- a/game/shared/world/chunk.cc
+++ b/game/shared/world/chunk.cc
@@ -2,6 +2,8 @@
 
 #include "shared/world/chunk.hh"
 
+#include "shared/world/voxel_registry.hh"
+
 #include "shared/coord.hh"
 
 world::Chunk::Chunk(entt::entity entity, Dimension* dimension)
@@ -12,30 +14,35 @@ world::Chunk::Chunk(entt::entity entity, Dimension* dimension)
     m_biome = BIOME_VOID;
 }
 
-voxel_id world::Chunk::get_voxel(const local_pos& lpos) const
+const world::Voxel* world::Chunk::get_voxel(const local_pos& lpos) const
 {
     return get_voxel(coord::to_index(lpos));
 }
 
-voxel_id world::Chunk::get_voxel(const std::size_t index) const
+const world::Voxel* world::Chunk::get_voxel(const std::size_t index) const
 {
     if(index >= CHUNK_VOLUME) {
-        return NULL_VOXEL_ID;
-    }
-    else {
-        return m_voxels[index];
+        return nullptr;
     }
+
+    return voxel_registry::find(m_voxels[index]);
 }
 
-void world::Chunk::set_voxel(voxel_id voxel, const local_pos& lpos)
+void world::Chunk::set_voxel(const Voxel* voxel, const local_pos& lpos)
 {
     set_voxel(voxel, coord::to_index(lpos));
 }
 
-void world::Chunk::set_voxel(voxel_id voxel, const std::size_t index)
+void world::Chunk::set_voxel(const Voxel* voxel, const std::size_t index)
 {
     if(index < CHUNK_VOLUME) {
-        m_voxels[index] = voxel;
+        if(voxel == nullptr) {
+            m_voxels[index] = NULL_VOXEL_ID;
+            return;
+        }
+
+        m_voxels[index] = voxel->get_id();
+        return;
     }
 }
 
diff --git a/game/shared/world/chunk.hh b/game/shared/world/chunk.hh
index c5bba12..4a1e557 100644
--- a/game/shared/world/chunk.hh
+++ b/game/shared/world/chunk.hh
@@ -9,6 +9,7 @@ constexpr static unsigned int BIOME_VOID = 0U;
 namespace world
 {
 class Dimension;
+class Voxel;
 } // namespace world
 
 namespace world
@@ -18,11 +19,11 @@ public:
     explicit Chunk(entt::entity entity, Dimension* dimension);
     virtual ~Chunk(void) = default;
 
-    voxel_id get_voxel(const local_pos& lpos) const;
-    voxel_id get_voxel(const std::size_t index) const;
+    const Voxel* get_voxel(const local_pos& lpos) const;
+    const Voxel* get_voxel(const std::size_t index) const;
 
-    void set_voxel(voxel_id voxel, const local_pos& lpos);
-    void set_voxel(voxel_id voxel, const std::size_t index);
+    void set_voxel(const Voxel* voxel, const local_pos& lpos);
+    void set_voxel(const Voxel* voxel, const std::size_t index);
 
     const VoxelStorage& get_voxels(void) const;
     void set_voxels(const VoxelStorage& voxels);
diff --git a/game/shared/world/dimension.cc b/game/shared/world/dimension.cc
index dd28449..31a19af 100644
--- a/game/shared/world/dimension.cc
+++ b/game/shared/world/dimension.cc
@@ -3,6 +3,7 @@
 #include "shared/world/dimension.hh"
 
 #include "shared/world/chunk.hh"
+#include "shared/world/voxel_registry.hh"
 
 #include "shared/coord.hh"
 #include "shared/globals.hh"
@@ -107,7 +108,7 @@ void world::Dimension::remove_chunk(Chunk* chunk)
     }
 }
 
-voxel_id world::Dimension::get_voxel(const voxel_pos& vpos) const
+const world::Voxel* world::Dimension::get_voxel(const voxel_pos& vpos) const
 {
     auto cpos = coord::to_chunk(vpos);
     auto lpos = coord::to_local(vpos);
@@ -115,12 +116,11 @@ voxel_id world::Dimension::get_voxel(const voxel_pos& vpos) const
     if(auto chunk = find_chunk(cpos)) {
         return chunk->get_voxel(lpos);
     }
-    else {
-        return NULL_VOXEL_ID;
-    }
+
+    return nullptr;
 }
 
-voxel_id world::Dimension::get_voxel(const chunk_pos& cpos, const local_pos& lpos) const
+const world::Voxel* world::Dimension::get_voxel(const chunk_pos& cpos, const local_pos& lpos) const
 {
     // This allows accessing get_voxel with negative
     // local coordinates that usually would result in an
@@ -128,19 +128,33 @@ voxel_id world::Dimension::get_voxel(const chunk_pos& cpos, const local_pos& lpo
     return get_voxel(coord::to_voxel(cpos, lpos));
 }
 
-bool world::Dimension::set_voxel(voxel_id voxel, const voxel_pos& vpos)
+bool world::Dimension::set_voxel(const Voxel* voxel, const voxel_pos& vpos)
 {
     auto cpos = coord::to_chunk(vpos);
     auto lpos = coord::to_local(vpos);
 
     if(auto chunk = find_chunk(cpos)) {
+        if(auto old_voxel = chunk->get_voxel(lpos)) {
+            if(old_voxel != voxel) {
+                // Notify the old voxel that it is
+                // being replaced with a different voxel
+                old_voxel->on_remove(this, vpos);
+            }
+        }
+
         chunk->set_voxel(voxel, lpos);
 
+        if(voxel) {
+            // If we're not placing air, notify the
+            // new voxel that it has been placed
+            voxel->on_place(this, vpos);
+        }
+
         VoxelSetEvent event;
         event.dimension = this;
+        event.voxel = voxel;
         event.cpos = cpos;
         event.lpos = lpos;
-        event.voxel = voxel;
         event.chunk = chunk;
 
         globals::dispatcher.trigger(event);
@@ -151,7 +165,7 @@ bool world::Dimension::set_voxel(voxel_id voxel, const voxel_pos& vpos)
     return false;
 }
 
-bool world::Dimension::set_voxel(voxel_id voxel, const chunk_pos& cpos, const local_pos& lpos)
+bool world::Dimension::set_voxel(const Voxel* voxel, const chunk_pos& cpos, const local_pos& lpos)
 {
     // This allows accessing set_voxel with negative
     // local coordinates that usually would result in an
diff --git a/game/shared/world/dimension.hh b/game/shared/world/dimension.hh
index bf9bfe1..58e0765 100644
--- a/game/shared/world/dimension.hh
+++ b/game/shared/world/dimension.hh
@@ -11,6 +11,7 @@ class ConfigMap;
 namespace world
 {
 class Chunk;
+class Voxel;
 class VoxelStorage;
 } // namespace world
 
@@ -40,11 +41,11 @@ public:
     void remove_chunk(Chunk* chunk);
 
 public:
-    voxel_id get_voxel(const voxel_pos& vpos) const;
-    voxel_id get_voxel(const chunk_pos& cpos, const local_pos& lpos) const;
+    const Voxel* get_voxel(const voxel_pos& vpos) const;
+    const Voxel* get_voxel(const chunk_pos& cpos, const local_pos& lpos) const;
 
-    bool set_voxel(voxel_id voxel, const voxel_pos& vpos);
-    bool set_voxel(voxel_id voxel, const chunk_pos& cpos, const local_pos& lpos);
+    bool set_voxel(const Voxel* voxel, const voxel_pos& vpos);
+    bool set_voxel(const Voxel* voxel, const chunk_pos& cpos, const local_pos& lpos);
 
 public:
     virtual void init(io::ConfigMap& config);
@@ -92,9 +93,9 @@ struct ChunkUpdateEvent final {
 
 struct VoxelSetEvent final {
     Dimension* dimension;
+    const Voxel* voxel;
     chunk_pos cpos;
     local_pos lpos;
-    voxel_id voxel;
     Chunk* chunk;
 };
 } // namespace world
diff --git a/game/shared/world/feature.cc b/game/shared/world/feature.cc
index 4212043..cbf660e 100644
--- a/game/shared/world/feature.cc
+++ b/game/shared/world/feature.cc
@@ -4,7 +4,6 @@
 
 #include "shared/world/chunk.hh"
 #include "shared/world/dimension.hh"
-#include "shared/world/voxel_storage.hh"
 
 #include "shared/coord.hh"
 
@@ -30,7 +29,7 @@ void world::Feature::place(const voxel_pos& vpos, Dimension* dimension) const
     }
 }
 
-void world::Feature::place(const voxel_pos& vpos, const chunk_pos& cpos, VoxelStorage& voxels) const
+void world::Feature::place(const voxel_pos& vpos, const chunk_pos& cpos, Chunk& chunk) const
 {
     for(const auto [rpos, voxel, overwrite] : (*this)) {
         auto it_vpos = vpos + rpos;
@@ -40,14 +39,14 @@ void world::Feature::place(const voxel_pos& vpos, const chunk_pos& cpos, VoxelSt
             auto it_lpos = coord::to_local(it_vpos);
             auto it_index = coord::to_index(it_lpos);
 
-            if(voxels[it_index] && !overwrite) {
+            if(chunk.get_voxel(it_index) && !overwrite) {
                 // There is something in the way
                 // and the called intentionally requested
                 // we do not force feature to overwrite voxels
                 continue;
             }
 
-            voxels[it_index] = voxel;
+            chunk.set_voxel(voxel, it_index);
         }
     }
 }
diff --git a/game/shared/world/feature.hh b/game/shared/world/feature.hh
index 20a809b..09b913e 100644
--- a/game/shared/world/feature.hh
+++ b/game/shared/world/feature.hh
@@ -4,19 +4,20 @@
 
 namespace world
 {
+class Chunk;
 class Dimension;
-class VoxelStorage;
+class Voxel;
 } // namespace world
 
 namespace world
 {
-class Feature final : public std::vector<std::tuple<voxel_pos, voxel_id, bool>> {
+class Feature final : public std::vector<std::tuple<voxel_pos, const Voxel*, bool>> {
 public:
     Feature(void) = default;
     virtual ~Feature(void) = default;
 
 public:
     void place(const voxel_pos& vpos, Dimension* dimension) const;
-    void place(const voxel_pos& vpos, const chunk_pos& cpos, VoxelStorage& voxels) const;
+    void place(const voxel_pos& vpos, const chunk_pos& cpos, Chunk& chunk) const;
 };
 } // namespace world
diff --git a/game/shared/world/ray_dda.cc b/game/shared/world/ray_dda.cc
index b337e9d..7bb1068 100644
--- a/game/shared/world/ray_dda.cc
+++ b/game/shared/world/ray_dda.cc
@@ -71,7 +71,7 @@ void world::RayDDA::reset(const world::Dimension& dimension, const chunk_pos& st
     reset(&dimension, start_chunk, start_fpos, direction);
 }
 
-voxel_id world::RayDDA::step(void)
+const world::Voxel* world::RayDDA::step(void)
 {
     if(side_dist.x < side_dist.z) {
         if(side_dist.x < side_dist.y) {
diff --git a/game/shared/world/ray_dda.hh b/game/shared/world/ray_dda.hh
index 54bd48a..3071be2 100644
--- a/game/shared/world/ray_dda.hh
+++ b/game/shared/world/ray_dda.hh
@@ -7,6 +7,7 @@
 namespace world
 {
 class Dimension;
+class Voxel;
 } // namespace world
 
 namespace world
@@ -20,7 +21,7 @@ public:
     void reset(const Dimension* dimension, const chunk_pos& start_chunk, const glm::fvec3& start_fpos, const glm::fvec3& direction);
     void reset(const Dimension& dimension, const chunk_pos& start_chunk, const glm::fvec3& start_fpos, const glm::fvec3& direction);
 
-    voxel_id step(void);
+    const Voxel* step(void);
 
 public:
     const Dimension* dimension;
diff --git a/game/shared/world/voxel.cc b/game/shared/world/voxel.cc
new file mode 100644
index 0000000..d51b5a1
--- /dev/null
+++ b/game/shared/world/voxel.cc
@@ -0,0 +1,120 @@
+#include "shared/pch.hh"
+
+#include "shared/world/voxel.hh"
+
+#include "core/math/crc64.hh"
+
+#include "shared/world/dimension.hh"
+
+void world::Voxel::on_place(Dimension* dimension, const voxel_pos& vpos) const
+{
+    // empty
+}
+
+void world::Voxel::on_remove(Dimension* dimension, const voxel_pos& vpos) const
+{
+    // empty
+}
+
+void world::Voxel::on_tick(Dimension* dimension, const voxel_pos& vpos) const
+{
+    // empty
+}
+
+void world::Voxel::set_id(voxel_id id) noexcept
+{
+    m_id = id;
+}
+
+std::size_t world::Voxel::get_random_texture_index(VoxelFace face, const voxel_pos& vpos) const
+{
+    const auto& textures = get_face_textures(face);
+
+    assert(textures.size());
+
+    std::uint64_t hash = 0U;
+    hash = math::crc64(&vpos.x, sizeof(vpos.x), hash);
+    hash = math::crc64(&vpos.y, sizeof(vpos.y), hash);
+    hash = math::crc64(&vpos.z, sizeof(vpos.z), hash);
+
+    return static_cast<std::size_t>(hash % textures.size());
+}
+
+void world::Voxel::set_face_cache(VoxelFace face, std::size_t offset, std::size_t plane)
+{
+    assert(face < m_cached_face_offsets.size());
+    assert(face < m_cached_face_planes.size());
+
+    m_cached_face_offsets[face] = offset;
+    m_cached_face_planes[face] = plane;
+}
+
+std::uint64_t world::Voxel::calculate_checksum(std::uint64_t combine) const
+{
+    combine = math::crc64(m_name.data(), m_name.size(), combine);
+    combine += static_cast<std::uint64_t>(m_shape);
+    combine += static_cast<std::uint64_t>(m_render_mode);
+    return combine;
+}
+
+std::shared_ptr<world::Voxel> world::Voxel::clone(void) const
+{
+    return std::make_shared<Voxel>(*this);
+}
+
+void world::Voxel::set_name(std::string_view name) noexcept
+{
+    assert(name.size());
+
+    m_name = name;
+}
+
+void world::Voxel::set_render_mode(VoxelRender mode) noexcept
+{
+    m_render_mode = mode;
+}
+
+void world::Voxel::set_shape(VoxelShape shape) noexcept
+{
+    m_shape = shape;
+}
+
+void world::Voxel::set_animated(bool animated) noexcept
+{
+    m_animated = animated;
+}
+
+void world::Voxel::set_touch_type(VoxelTouch type) noexcept
+{
+    m_touch_type = type;
+}
+
+void world::Voxel::set_touch_values(const glm::fvec3& values) noexcept
+{
+    m_touch_values = values;
+}
+
+void world::Voxel::set_surface_material(VoxelMaterial material) noexcept
+{
+    m_surface_material = material;
+}
+
+void world::Voxel::set_collision(const math::AABBf& box) noexcept
+{
+    m_collision = box;
+}
+
+void world::Voxel::add_default_texture(std::string_view path)
+{
+    assert(path.size());
+
+    m_default_textures.emplace_back(path);
+}
+
+void world::Voxel::add_face_texture(VoxelFace face, std::string_view path)
+{
+    assert(face < m_face_textures.size());
+    assert(path.size());
+
+    m_face_textures[face].emplace_back(path);
+}
diff --git a/game/shared/world/voxel.hh b/game/shared/world/voxel.hh
new file mode 100644
index 0000000..0bd83b7
--- /dev/null
+++ b/game/shared/world/voxel.hh
@@ -0,0 +1,236 @@
+#pragma once
+
+#include "core/math/aabb.hh"
+
+#include "shared/types.hh"
+
+namespace world
+{
+class Dimension;
+} // namespace world
+
+namespace world
+{
+enum VoxelRender : unsigned short {
+    VRENDER_NONE = 0U, ///< The voxel is not rendered at all
+    VRENDER_OPAQUE,    ///< The voxel is fully opaque
+    VRENDER_BLEND,     ///< The voxel is blended (e.g. water, glass)
+};
+
+enum VoxelShape : unsigned short {
+    VSHAPE_CUBE = 0U, ///< Full cube shape
+    VSHAPE_CROSS,     ///< TODO: Cross shape
+    VSHAPE_MODEL,     ///< TODO: Custom model shape
+};
+
+enum VoxelFace : unsigned short {
+    VFACE_NORTH = 0U, ///< Positive Z face
+    VFACE_SOUTH,      ///< Negative Z face
+    VFACE_EAST,       ///< Positive X face
+    VFACE_WEST,       ///< Negative X face
+    VFACE_TOP,        ///< Positive Y face
+    VFACE_BOTTOM,     ///< Negative Y face
+    VFACE_CROSS_NWSE, ///< Diagonal cross face northwest-southeast
+    VFACE_CROSS_NESW, ///< Diagonal cross face northeast-southwest
+    VFACE_COUNT
+};
+
+enum VoxelTouch : unsigned short {
+    VTOUCH_NONE = 0xFFFFU,
+    VTOUCH_SOLID = 0U, ///< The entity is stopped in its tracks
+    VTOUCH_BOUNCE,     ///< The entity bounces back with some energy loss
+    VTOUCH_SINK,       ///< The entity phases/sinks through the voxel
+};
+
+enum VoxelMaterial : unsigned short {
+    VMAT_DEFAULT = 0U,
+    VMAT_STONE,
+    VMAT_DIRT,
+    VMAT_GLASS,
+    VMAT_GRASS,
+    VMAT_GRAVEL,
+    VMAT_METAL,
+    VMAT_SAND,
+    VMAT_WOOD,
+    VMAT_SLOSH,
+    VMAT_COUNT
+};
+
+enum VoxelVisBits : unsigned short {
+    VVIS_NORTH = 1U << VFACE_NORTH, ///< Positive Z
+    VVIS_SOUTH = 1U << VFACE_SOUTH, ///< Negative Z
+    VVIS_EAST = 1U << VFACE_EAST,   ///< Positive X
+    VVIS_WEST = 1U << VFACE_WEST,   ///< Negative X
+    VVIS_UP = 1U << VFACE_TOP,      ///< Positive Y
+    VVIS_DOWN = 1U << VFACE_BOTTOM, ///< Negative Y
+};
+} // namespace world
+
+namespace world
+{
+class Voxel {
+public:
+    /// Called when the voxel is placed in the world
+    /// @param dimension The dimension the voxel is placed in
+    /// @param vpos The absolute voxel position where the voxel is placed
+    virtual void on_place(Dimension* dimension, const voxel_pos& vpos) const;
+
+    /// Called when the voxel is removed from the world
+    /// @param dimension The dimension the voxel is removed from
+    /// @param vpos The absolute voxel position where the voxel is removed
+    virtual void on_remove(Dimension* dimension, const voxel_pos& vpos) const;
+
+    /// Called when the voxel is ticked by something
+    /// @param dimension The dimension the voxel is ticked in
+    /// @param vpos The absolute voxel position where the voxel is ticked
+    virtual void on_tick(Dimension* dimension, const voxel_pos& vpos) const;
+
+    constexpr std::string_view get_name(void) const noexcept;
+    constexpr voxel_id get_id(void) const noexcept;
+    void set_id(voxel_id id) noexcept;
+
+    constexpr VoxelRender get_render_mode(void) const noexcept;
+    constexpr VoxelShape get_shape(void) const noexcept;
+    constexpr bool is_animated(void) const noexcept;
+
+    constexpr VoxelTouch get_touch_type(void) const noexcept;
+    constexpr const glm::fvec3& get_touch_values(void) const noexcept;
+    constexpr VoxelMaterial get_surface_material(void) const noexcept;
+
+    constexpr const math::AABBf& get_collision(void) const noexcept;
+
+    constexpr const std::vector<std::string>& get_default_textures(void) const noexcept;
+    constexpr const std::vector<std::string>& get_face_textures(VoxelFace face) const noexcept;
+    constexpr std::size_t get_cached_face_offset(VoxelFace face) const noexcept;
+    constexpr std::size_t get_cached_face_plane(VoxelFace face) const noexcept;
+
+    /// Non-model voxel shapes support texture variation based on the
+    /// voxel position on the world; this method handles the math behind this
+    /// @param face The face of the voxel to get the texture index for
+    /// @param vpos The absolute voxel position to get the texture index for
+    /// @return The index of the texture to use for the given face at the given position
+    /// @remarks On client-side: plane[get_cached_face_plane][get_cached_face_offset + thisFunctionResult]
+    std::size_t get_random_texture_index(VoxelFace face, const voxel_pos& vpos) const;
+
+    /// Assign cached plane index and plane offset for a given face
+    /// @param face The face to assign the cache for
+    /// @param offset The offset to assign to the face
+    /// @param plane The plane index to assign to the face
+    void set_face_cache(VoxelFace face, std::size_t offset, std::size_t plane);
+
+    /// Calculate a checksum for the voxel's properties
+    /// @param combine An optional initial checksum to combine with
+    /// @return The calculated checksum
+    std::uint64_t calculate_checksum(std::uint64_t combine = 0U) const;
+
+    /// Produce a copy of itself as a shared pointer; the voxel registry
+    /// does not change the owner of a voxel instance it registers
+    virtual std::shared_ptr<Voxel> clone(void) const;
+
+protected:
+    void set_name(std::string_view name) noexcept;
+
+    void set_render_mode(VoxelRender mode) noexcept;
+    void set_shape(VoxelShape shape) noexcept;
+    void set_animated(bool animated) noexcept;
+
+    void set_touch_type(VoxelTouch type) noexcept;
+    void set_touch_values(const glm::fvec3& values) noexcept;
+    void set_surface_material(VoxelMaterial material) noexcept;
+
+    void set_collision(const math::AABBf& box) noexcept;
+
+    void add_default_texture(std::string_view path);
+    void add_face_texture(VoxelFace face, std::string_view path);
+
+private:
+    std::string m_name;
+    voxel_id m_id { NULL_VOXEL_ID };
+
+    VoxelRender m_render_mode { VRENDER_OPAQUE };
+    VoxelShape m_shape { VSHAPE_CUBE };
+    bool m_animated { false };
+
+    VoxelTouch m_touch_type { VTOUCH_SOLID };
+    glm::fvec3 m_touch_values { 0.0f };
+    VoxelMaterial m_surface_material { VMAT_DEFAULT };
+
+    math::AABBf m_collision { { 0.0f, 0.0f, 0.0f }, { 1.0f, 1.0f, 1.0f } };
+
+    std::vector<std::string> m_default_textures;
+    std::array<std::vector<std::string>, VFACE_COUNT> m_face_textures;
+    std::array<std::size_t, VFACE_COUNT> m_cached_face_offsets;
+    std::array<std::size_t, VFACE_COUNT> m_cached_face_planes;
+};
+} // namespace world
+
+constexpr std::string_view world::Voxel::get_name(void) const noexcept
+{
+    return m_name;
+}
+
+constexpr voxel_id world::Voxel::get_id(void) const noexcept
+{
+    return m_id;
+}
+
+constexpr world::VoxelRender world::Voxel::get_render_mode(void) const noexcept
+{
+    return m_render_mode;
+}
+
+constexpr world::VoxelShape world::Voxel::get_shape(void) const noexcept
+{
+    return m_shape;
+}
+
+constexpr bool world::Voxel::is_animated(void) const noexcept
+{
+    return m_animated;
+}
+
+constexpr world::VoxelTouch world::Voxel::get_touch_type(void) const noexcept
+{
+    return m_touch_type;
+}
+
+constexpr const glm::fvec3& world::Voxel::get_touch_values(void) const noexcept
+{
+    return m_touch_values;
+}
+
+constexpr world::VoxelMaterial world::Voxel::get_surface_material(void) const noexcept
+{
+    return m_surface_material;
+}
+
+constexpr const math::AABBf& world::Voxel::get_collision(void) const noexcept
+{
+    return m_collision;
+}
+
+constexpr const std::vector<std::string>& world::Voxel::get_default_textures(void) const noexcept
+{
+    return m_default_textures;
+}
+
+constexpr const std::vector<std::string>& world::Voxel::get_face_textures(VoxelFace face) const noexcept
+{
+    assert(face <= m_face_textures.size());
+
+    return m_face_textures[face];
+}
+
+constexpr std::size_t world::Voxel::get_cached_face_offset(VoxelFace face) const noexcept
+{
+    assert(face <= m_cached_face_offsets.size());
+
+    return m_cached_face_offsets[face];
+}
+
+constexpr std::size_t world::Voxel::get_cached_face_plane(VoxelFace face) const noexcept
+{
+    assert(face <= m_cached_face_planes.size());
+
+    return m_cached_face_planes[face];
+}
diff --git a/game/shared/world/voxel_registry.cc b/game/shared/world/voxel_registry.cc
index b44845e..4c2f360 100644
--- a/game/shared/world/voxel_registry.cc
+++ b/game/shared/world/voxel_registry.cc
@@ -2,195 +2,65 @@
 
 #include "shared/world/voxel_registry.hh"
 
-#include "core/math/crc64.hh"
+static std::uint64_t registry_checksum = 0U;
+emhash8::HashMap<std::string, voxel_id> world::voxel_registry::names;
+std::vector<std::shared_ptr<world::Voxel>> world::voxel_registry::voxels;
 
-std::unordered_map<std::string, world::VoxelInfoBuilder> world::voxel_registry::builders = {};
-std::unordered_map<std::string, voxel_id> world::voxel_registry::names = {};
-std::vector<std::shared_ptr<world::VoxelInfo>> world::voxel_registry::voxels = {};
-
-world::VoxelInfoBuilder::VoxelInfoBuilder(std::string_view name, voxel_type type, bool animated, bool blending)
-{
-    prototype.name = name;
-    prototype.type = type;
-    prototype.animated = animated;
-    prototype.blending = blending;
-
-    switch(type) {
-        case voxel_type::CUBE:
-            prototype.textures.resize(static_cast<std::size_t>(voxel_face::CUBE__NR));
-            break;
-        case voxel_type::CROSS:
-            prototype.textures.resize(static_cast<std::size_t>(voxel_face::CROSS__NR));
-            break;
-        case voxel_type::MODEL:
-            // Custom models should use a different texture
-            // resource management that is not a voxel atlas
-            // TODO: actually implement custom models lol
-            prototype.textures.resize(0);
-            break;
-        default:
-            // Something really bad should happen if we end up here.
-            // The outside code would static_cast an int to VoxelType
-            // and possibly fuck a lot of things up to cause this
-            spdlog::critical("voxel_registry: {}: unknown voxel type {}", name, static_cast<int>(type));
-            std::terminate();
-    }
-
-    // Physics properties
-    prototype.touch_type = voxel_touch::SOLID;
-    prototype.touch_values = glm::fvec3(0.0f, 0.0f, 0.0f);
-    prototype.surface = voxel_surface::DEFAULT;
-
-    // Things set in future by item_def
-    prototype.item_pick = NULL_ITEM_ID;
-}
-
-world::VoxelInfoBuilder& world::VoxelInfoBuilder::add_texture_default(std::string_view texture)
+static void recalculate_checksum(void)
 {
-    default_texture.paths.push_back(std::string(texture));
-    return *this;
-}
+    registry_checksum = 0U;
 
-world::VoxelInfoBuilder& world::VoxelInfoBuilder::add_texture(voxel_face face, std::string_view texture)
-{
-    const auto index = static_cast<std::size_t>(face);
-    prototype.textures[index].paths.push_back(std::string(texture));
-    return *this;
-}
-
-world::VoxelInfoBuilder& world::VoxelInfoBuilder::set_touch(voxel_touch type, const glm::fvec3& values)
-{
-    prototype.touch_type = type;
-    prototype.touch_values = values;
-    return *this;
+    for(const auto& voxel : world::voxel_registry::voxels) {
+        registry_checksum = voxel->calculate_checksum(registry_checksum);
+    }
 }
 
-world::VoxelInfoBuilder& world::VoxelInfoBuilder::set_surface(voxel_surface surface)
+world::Voxel* world::voxel_registry::register_voxel(const Voxel& voxel_template)
 {
-    prototype.surface = surface;
-    return *this;
-}
+    assert(voxel_template.get_name().size());
+    assert(nullptr == find(voxel_template.get_name()));
 
-voxel_id world::VoxelInfoBuilder::build(void) const
-{
-    const auto it = world::voxel_registry::names.find(prototype.name);
+    const auto id = static_cast<voxel_id>(voxels.size());
 
-    if(it != world::voxel_registry::names.cend()) {
-        spdlog::warn("voxel_registry: cannot build {}: name already present", prototype.name);
-        return it->second;
-    }
+    auto voxel = voxel_template.clone();
+    voxel->set_id(id);
 
-    std::size_t state_count;
-
-    switch(prototype.type) {
-        case voxel_type::CUBE:
-        case voxel_type::CROSS:
-        case voxel_type::MODEL:
-            state_count = 1;
-            break;
-        default:
-            // Something really bad should happen if we end up here.
-            // The outside code would static_cast an int to VoxelType
-            // and possibly fuck a lot of things up to cause this
-            spdlog::critical("voxel_registry: {}: unknown voxel type {}", prototype.name, static_cast<int>(prototype.type));
-            std::terminate();
-    }
+    names.emplace(std::string(voxel_template.get_name()), id);
+    voxels.push_back(std::move(voxel));
 
-    if((world::voxel_registry::voxels.size() + state_count) >= MAX_VOXEL_ID) {
-        spdlog::critical("voxel_registry: voxel registry overflow");
-        std::terminate();
-    }
+    recalculate_checksum();
 
-    auto new_info = std::make_shared<VoxelInfo>();
-    new_info->name = prototype.name;
-    new_info->type = prototype.type;
-    new_info->animated = prototype.animated;
-    new_info->blending = prototype.blending;
-
-    new_info->textures.resize(prototype.textures.size());
-
-    for(std::size_t i = 0; i < prototype.textures.size(); ++i) {
-        if(prototype.textures[i].paths.empty()) {
-            new_info->textures[i].paths = default_texture.paths;
-            new_info->textures[i].cached_offset = SIZE_MAX;
-            new_info->textures[i].cached_plane = SIZE_MAX;
-        }
-        else {
-            new_info->textures[i].paths = prototype.textures[i].paths;
-            new_info->textures[i].cached_offset = SIZE_MAX;
-            new_info->textures[i].cached_plane = SIZE_MAX;
-        }
-    }
-
-    // Physics properties
-    new_info->touch_type = prototype.touch_type;
-    new_info->touch_values = prototype.touch_values;
-    new_info->surface = prototype.surface;
-
-    // Things set in future by item_def
-    new_info->item_pick = prototype.item_pick;
-
-    // Base voxel identifier offset
-    new_info->base_voxel = world::voxel_registry::voxels.size() + 1;
-
-    for(std::size_t i = 0; i < state_count; ++i)
-        world::voxel_registry::voxels.push_back(new_info);
-    world::voxel_registry::names.insert_or_assign(new_info->name, new_info->base_voxel);
-
-    return new_info->base_voxel;
-}
-
-world::VoxelInfoBuilder& world::voxel_registry::construct(std::string_view name, voxel_type type, bool animated, bool blending)
-{
-    const auto it = world::voxel_registry::builders.find(std::string(name));
-
-    if(it != world::voxel_registry::builders.cend()) {
-        return it->second;
-    }
-    else {
-        return world::voxel_registry::builders.emplace(std::string(name), VoxelInfoBuilder(name, type, animated, blending)).first->second;
-    }
+    return voxels.back().get();
 }
 
-world::VoxelInfo* world::voxel_registry::find(std::string_view name)
+world::Voxel* world::voxel_registry::find(std::string_view name)
 {
-    const auto it = world::voxel_registry::names.find(std::string(name));
+    const auto it = names.find(name);
 
-    if(it != world::voxel_registry::names.cend()) {
-        return world::voxel_registry::find(it->second);
-    }
-    else {
+    if(it == names.end()) {
         return nullptr;
     }
+
+    return voxels[it->second].get();
 }
 
-world::VoxelInfo* world::voxel_registry::find(const voxel_id voxel)
+world::Voxel* world::voxel_registry::find(voxel_id id)
 {
-    if((voxel != NULL_VOXEL_ID) && (voxel <= world::voxel_registry::voxels.size())) {
-        return world::voxel_registry::voxels[voxel - 1].get();
-    }
-    else {
+    if(id >= voxels.size()) {
         return nullptr;
     }
+
+    return voxels[id].get();
 }
 
 void world::voxel_registry::purge(void)
 {
-    world::voxel_registry::builders.clear();
-    world::voxel_registry::names.clear();
-    world::voxel_registry::voxels.clear();
+    registry_checksum = 0U;
+    voxels.clear();
+    names.clear();
 }
 
-std::uint64_t world::voxel_registry::calculate_checksum(void)
+std::uint64_t world::voxel_registry::get_checksum(void)
 {
-    std::uint64_t result = 0;
-
-    for(const std::shared_ptr<VoxelInfo>& info : world::voxel_registry::voxels) {
-        result = math::crc64(info->name, result);
-        result += static_cast<std::uint64_t>(info->type);
-        result += static_cast<std::uint64_t>(info->base_voxel);
-        result += info->blending ? 256 : 1;
-    }
-
-    return result;
+    return registry_checksum;
 }
diff --git a/game/shared/world/voxel_registry.hh b/game/shared/world/voxel_registry.hh
index a75f59f..b9d9a34 100644
--- a/game/shared/world/voxel_registry.hh
+++ b/game/shared/world/voxel_registry.hh
@@ -1,141 +1,18 @@
 #pragma once
 
-#include "shared/types.hh"
-
-namespace world
-{
-enum class voxel_face : unsigned short {
-    CUBE_NORTH = 0x0000,
-    CUBE_SOUTH = 0x0001,
-    CUBE_EAST = 0x0002,
-    CUBE_WEST = 0x0003,
-    CUBE_TOP = 0x0004,
-    CUBE_BOTTOM = 0x0005,
-    CUBE__NR = 0x0006,
-
-    CROSS_NESW = 0x0000,
-    CROSS_NWSE = 0x0001,
-    CROSS__NR = 0x0002,
-};
-
-enum class voxel_type : unsigned short {
-    CUBE = 0x0000,
-    CROSS = 0x0001, // TODO
-    MODEL = 0x0002, // TODO
-};
-
-enum class voxel_facing : unsigned short {
-    NORTH = 0x0000,
-    SOUTH = 0x0001,
-    EAST = 0x0002,
-    WEST = 0x0003,
-    UP = 0x0004,
-    DOWN = 0x0005,
-    NESW = 0x0006,
-    NWSE = 0x0007,
-};
-
-enum class voxel_touch : unsigned short {
-    SOLID = 0x0000,  // The entity is stopped in its tracks
-    BOUNCE = 0x0001, // The entity bounces back with some energy loss
-    SINK = 0x0002,   // The entity phases/sinks through the voxel
-    NOTHING = 0xFFFF,
-};
-
-enum class voxel_surface : unsigned short {
-    DEFAULT = 0x0000,
-    STONE = 0x0001,
-    DIRT = 0x0002,
-    GLASS = 0x0003,
-    GRASS = 0x0004,
-    GRAVEL = 0x0005,
-    METAL = 0x0006,
-    SAND = 0x0007,
-    WOOD = 0x0008,
-    SLOSH = 0x0009,
-    COUNT = 0x000A,
-    UNKNOWN = 0xFFFF,
-};
-
-using voxel_vis = unsigned short;
-constexpr static voxel_vis VIS_NORTH = 1 << static_cast<unsigned int>(voxel_facing::NORTH);
-constexpr static voxel_vis VIS_SOUTH = 1 << static_cast<unsigned int>(voxel_facing::SOUTH);
-constexpr static voxel_vis VIS_EAST = 1 << static_cast<unsigned int>(voxel_facing::EAST);
-constexpr static voxel_vis VIS_WEST = 1 << static_cast<unsigned int>(voxel_facing::WEST);
-constexpr static voxel_vis VIS_UP = 1 << static_cast<unsigned int>(voxel_facing::UP);
-constexpr static voxel_vis VIS_DOWN = 1 << static_cast<unsigned int>(voxel_facing::DOWN);
-} // namespace world
-
-namespace world
-{
-struct VoxelTexture final {
-    std::vector<std::string> paths;
-    std::size_t cached_offset; // client-side only
-    std::size_t cached_plane;  // client-side only
-};
-
-struct VoxelInfo final {
-    std::string name;
-    voxel_type type;
-    bool animated;
-    bool blending;
-
-    std::vector<VoxelTexture> textures;
-
-    // Physics properties go here
-    // TODO: player_move friction modifiers
-    // that would make the voxel very sticky or
-    // very slippery to walk on
-    voxel_touch touch_type;
-    glm::fvec3 touch_values;
-    voxel_surface surface;
-
-    // Some voxel types might occupy multiple voxel_id
-    // values that reference to the exact same VoxelInfo
-    // structure; the actual numeric state is figured out by
-    // subtracting base_voxel from the checking voxel_id
-    voxel_id base_voxel;
-
-    // These will be set by item_registry
-    // and by default set to NULL_ITEM_ID
-    item_id item_pick;
-};
-} // namespace world
-
-namespace world
-{
-class VoxelInfoBuilder final {
-public:
-    explicit VoxelInfoBuilder(std::string_view name, voxel_type type, bool animated, bool blending);
-    virtual ~VoxelInfoBuilder(void) = default;
-
-public:
-    VoxelInfoBuilder& add_texture_default(std::string_view texture);
-    VoxelInfoBuilder& add_texture(voxel_face face, std::string_view texture);
-    VoxelInfoBuilder& set_touch(voxel_touch type, const glm::fvec3& values);
-    VoxelInfoBuilder& set_surface(voxel_surface surface);
-
-public:
-    voxel_id build(void) const;
-
-private:
-    VoxelTexture default_texture;
-    VoxelInfo prototype;
-};
-} // namespace world
+#include "shared/world/voxel.hh"
 
 namespace world::voxel_registry
 {
-extern std::unordered_map<std::string, VoxelInfoBuilder> builders;
-extern std::unordered_map<std::string, voxel_id> names;
-extern std::vector<std::shared_ptr<VoxelInfo>> voxels;
+extern emhash8::HashMap<std::string, voxel_id> names;
+extern std::vector<std::shared_ptr<Voxel>> voxels;
 } // namespace world::voxel_registry
 
 namespace world::voxel_registry
 {
-VoxelInfoBuilder& construct(std::string_view name, voxel_type type, bool animated, bool blending);
-VoxelInfo* find(std::string_view name);
-VoxelInfo* find(const voxel_id voxel);
+Voxel* register_voxel(const Voxel& voxel_template);
+Voxel* find(std::string_view name);
+Voxel* find(voxel_id id);
 } // namespace world::voxel_registry
 
 namespace world::voxel_registry
@@ -145,5 +22,5 @@ void purge(void);
 
 namespace world::voxel_registry
 {
-std::uint64_t calculate_checksum(void);
+std::uint64_t get_checksum(void);
 } // namespace world::voxel_registry
diff --git a/game/shared/world/voxels/generic.hh b/game/shared/world/voxels/generic.hh
new file mode 100644
index 0000000..a661792
--- /dev/null
+++ b/game/shared/world/voxels/generic.hh
@@ -0,0 +1,27 @@
+#pragma once
+
+#include "shared/world/voxel.hh"
+
+namespace world::voxels
+{
+class GenericCube final : public Voxel {
+public:
+    template<typename... TexturesT>
+    requires(std::is_convertible_v<TexturesT, std::string_view> && ...)
+    explicit GenericCube(std::string_view name, VoxelRender render_mode, bool animated, VoxelMaterial surface_material, VoxelTouch touch,
+        const glm::fvec3& touch_values, TexturesT&&... textures) noexcept
+    {
+        set_name(name);
+
+        set_shape(VoxelShape::CUBE);
+        set_render_mode(render_mode);
+        set_animated(animated);
+
+        set_surface_material(surface_material);
+        set_touch_values(touch_values);
+        set_touch_type(touch);
+
+        add_texture_default(std::forward<TexturesT>(textures)...);
+    }
+};
+} // namespace world::voxels