Refactored gltf imported and mesh management

1 files changed, 45 insertions, 0 deletions

diff --git a/src/mesh.cpp b/src/mesh.cpp
new file mode 100644
index 0000000..c9b5358
--- /dev/null
+++ b/src/mesh.cpp
@@ -0,0 +1,45 @@
+#include "mesh.hpp"
+
+static std::vector<Mesh> meshes {};
+
+void Mesh::add_submesh(const submesh& submesh) {
+    auto position_components = attribute_components(ATTRIBUTE_TYPE::POSITION);
+    submeshes.emplace_back(submesh_info {
+        (uint32_t)attributes[ATTRIBUTE_TYPE::POSITION].size() / position_components,
+        (uint32_t)indices.size(),
+        submesh.index_count,
+        0
+    });
+
+    {
+        auto indices_off = indices.size();
+        indices.resize(indices_off + submesh.index_count);
+        std::memcpy(&indices[indices_off], submesh.indices.data, submesh.indices.length);
+    }
+
+    for (uint32_t attribute_index { ATTRIBUTE_TYPE::POSITION }; attribute_index < ATTRIBUTE_TYPE::MAX_ATTRIBUTE; attribute_index++) {
+        const auto& submesh_attribute = submesh.attributes[attribute_index];
+        if (submesh_attribute.data == nullptr) continue;
+
+        auto& mesh_attribute = attributes[attribute_index];
+        auto attribute_off = mesh_attribute.size();
+        auto element_components = attribute_components(static_cast<ATTRIBUTE_TYPE>(attribute_index));
+        auto elements_count = submesh.vertex_count * element_components;
+
+        mesh_attribute.resize(attribute_off + elements_count);
+        std::memcpy(&mesh_attribute[attribute_off], submesh_attribute.data, submesh_attribute.length);
+    }
+
+    vertex_count += submesh.vertex_count;
+    index_count += submesh.index_count;
+}
+
+[[nodiscard]] Mesh::mesh_instance Mesh::instantiate () const {
+    return {
+        *this
+    };
+}
+
+void Mesh::register_mesh(const Mesh& mesh) {
+    meshes.emplace_back(mesh);
+}