prevent the editor to load the same texture over and over again

- the editor uses a lot of built-in textures for internal needs (mostly icons) and they were loaded over and over again in some places (world viewer for instance) which caused redundant work and memory bloat (both RAM and VRAM)

editor/src/lib.rs

@@ -84,6 +84,7 @@ use crate::{
             color::Color,
             futures::executor::block_on,
             log::{Log, MessageKind},
+            parking_lot::Mutex,
             pool::Handle,
             task::TaskPool,
             uuid::Uuid,
@@ -150,8 +151,8 @@ use crate::{
     overlay::OverlayRenderPass,
     particle::ParticleSystemPreviewControlPanel,
     physics::ColliderControlPanel,
-    plugin::EditorPlugin,
-    plugins::collider::ColliderShapePlugin,
+    plugin::{EditorPlugin, EditorPluginsContainer},
+    plugins::{collider::ColliderShapePlugin, tilemap::TileMapEditorPlugin},
     scene::{
         commands::{
             make_delete_selection_command, ChangeSelectionCommand, GameSceneContext, PasteCommand,
@@ -172,6 +173,7 @@ use crate::{
     utils::{doc::DocWindow, path_fixer::PathFixer, ragdoll::RagdollWizard},
     world::{graph::menu::SceneNodeContextMenu, graph::EditorSceneWrapper, WorldViewer},
 };
+pub use message::Message;
 use std::{
     cell::RefCell,
     collections::VecDeque,
@@ -187,10 +189,6 @@ use std::{
     time::{Duration, Instant},
 };
 
-use crate::plugin::EditorPluginsContainer;
-use crate::plugins::tilemap::TileMapEditorPlugin;
-pub use message::Message;
-
 pub const FIXED_TIMESTEP: f32 = 1.0 / 60.0;
 pub const MSG_SYNC_FLAG: u64 = 1;
 
@@ -199,15 +197,34 @@ pub fn send_sync_message(ui: &UserInterface, mut msg: UiMessage) {
     ui.send_message(msg);
 }
 
+lazy_static! {
+    static ref EDITOR_TEXTURE_CACHE: Mutex<FxHashMap<usize, TextureResource>> = Default::default();
+}
+
 pub fn load_texture(data: &[u8]) -> Option<TextureResource> {
-    TextureResource::load_from_memory(
-        Default::default(),
-        data,
-        TextureImportOptions::default()
-            .with_compression(CompressionOptions::NoCompression)
-            .with_minification_filter(TextureMinificationFilter::Linear),
-    )
-    .ok()
+    let mut cache = EDITOR_TEXTURE_CACHE.lock();
+
+    // Editor use data that is embedded in the binary, so each such piece of data will have fixed
+    // location in memory. This fact allows us to cache the resources and skip redundant loading if
+    // they're already loaded.
+    let id = data.as_ptr() as usize;
+
+    if let Some(existing) = cache.get(&id) {
+        Some(existing.clone())
+    } else {
+        let texture = TextureResource::load_from_memory(
+            Default::default(),
+            data,
+            TextureImportOptions::default()
+                .with_compression(CompressionOptions::NoCompression)
+                .with_minification_filter(TextureMinificationFilter::Linear),
+        )
+        .ok()?;
+
+        cache.insert(id, texture.clone());
+
+        Some(texture)
+    }
 }
 
 pub fn load_image(data: &[u8]) -> Option<UntypedResource> {