From 1e4d8ae943004689a9d2b7310853e10470b66ce3 Mon Sep 17 00:00:00 2001
From: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
Date: Tue, 25 Jan 2022 01:08:10 +0100
Subject: [PATCH] Remove warm-up of demo app

Since https://github.com/emilk/egui/pull/1149 we only update the
region of the font atlas that has changes, so loading new glyphs is much
cheaper. This means warm-up is much less needed.

There is now a small delay when opening the font book,
but not when opening anything else.
---
 egui_demo_lib/src/wrap_app.rs |  5 -----
 epi/src/lib.rs                | 23 ++++++++++++-----------
 2 files changed, 12 insertions(+), 16 deletions(-)

diff --git a/egui_demo_lib/src/wrap_app.rs b/egui_demo_lib/src/wrap_app.rs
index e277e58c..d07bc072 100644
--- a/egui_demo_lib/src/wrap_app.rs
+++ b/egui_demo_lib/src/wrap_app.rs
@@ -67,11 +67,6 @@ impl epi::App for WrapApp {
         egui::Rgba::TRANSPARENT // we set a `CentralPanel` fill color in `demo_windows.rs`
     }
 
-    fn warm_up_enabled(&self) -> bool {
-        // The example windows use a lot of emojis. Pre-cache them by running one frame where everything is open
-        cfg!(not(debug_assertions))
-    }
-
     fn update(&mut self, ctx: &egui::Context, frame: &epi::Frame) {
         if let Some(web_info) = frame.info().web_info.as_ref() {
             if let Some(anchor) = web_info.web_location_hash.strip_prefix('#') {
diff --git a/epi/src/lib.rs b/epi/src/lib.rs
index a7a15b49..bc1b5ea1 100644
--- a/epi/src/lib.rs
+++ b/epi/src/lib.rs
@@ -120,17 +120,6 @@ pub trait App {
     /// Also allows you to restore state, if there is a storage (required the "persistence" feature).
     fn setup(&mut self, _ctx: &egui::Context, _frame: &Frame, _storage: Option<&dyn Storage>) {}
 
-    /// If `true` a warm-up call to [`Self::update`] will be issued where
-    /// `ctx.memory().everything_is_visible()` will be set to `true`.
-    ///
-    /// This will help pre-caching all text, preventing stutter when
-    /// opening a window containing new glyphs.
-    ///
-    /// In this warm-up call, all painted shapes will be ignored.
-    fn warm_up_enabled(&self) -> bool {
-        false
-    }
-
     /// Called on shutdown, and perhaps at regular intervals. Allows you to save state.
     ///
     /// Only called when the "persistence" feature is enabled.
@@ -203,6 +192,18 @@ pub trait App {
     fn persist_egui_memory(&self) -> bool {
         true
     }
+
+    /// If `true` a warm-up call to [`Self::update`] will be issued where
+    /// `ctx.memory().everything_is_visible()` will be set to `true`.
+    ///
+    /// This can help pre-caching resources loaded by different parts of the UI, preventing stutter later on.
+    ///
+    /// In this warm-up call, all painted shapes will be ignored.
+    ///
+    /// The default is `false`, and it is unlikely you will want to change this.
+    fn warm_up_enabled(&self) -> bool {
+        false
+    }
 }
 
 /// Options controlling the behavior of a native window.