feat(engine): add UpdateMesh renderer command

1 files changed, 42 insertions, 0 deletions

diff --git a/engine/src/renderer/opengl/graphics_mesh.rs b/engine/src/renderer/opengl/graphics_mesh.rs
index 3cf9181..c5ff0c6 100644
--- a/engine/src/renderer/opengl/graphics_mesh.rs
+++ b/engine/src/renderer/opengl/graphics_mesh.rs
@@ -143,6 +143,48 @@ impl GraphicsMesh
         })
     }
 
+    pub fn update(
+        &mut self,
+        current_context: &GlCurrentContextWithFns<'_>,
+        mesh: &Mesh,
+        mesh_usage: MeshUsage,
+    ) -> Result<(), Error>
+    {
+        let buffer_usage = mesh_usage_to_gl_buffer_usage(mesh_usage);
+
+        self.vertex_buffer
+            .store(current_context, mesh.vertex_buf().as_bytes(), buffer_usage)
+            .map_err(Error::StoreVerticesFailed)?;
+
+        if let Some(indices) = mesh.indices() {
+            let index_buffer = self
+                .index_buffer
+                .get_or_insert_with(|| GlBuffer::new(current_context));
+
+            index_buffer
+                .store(current_context, indices, buffer_usage)
+                .map_err(Error::StoreIndicesFailed)?;
+
+            self.vertex_arr
+                .bind_element_buffer(current_context, &index_buffer);
+
+            self.element_cnt = indices
+                .len()
+                .try_into()
+                .expect("Mesh index count does not fit into a 32-bit unsigned int");
+
+            return Ok(());
+        }
+
+        self.element_cnt = mesh
+            .vertex_buf()
+            .len()
+            .try_into()
+            .expect("Mesh vertex count does not fit into a 32-bit unsigned int");
+
+        Ok(())
+    }
+
     pub fn destroy(&mut self, curr_gl_ctx: &GlCurrentContextWithFns<'_>)
     {
         self.vertex_arr.delete(curr_gl_ctx);