From dcb59e1a3fa5b3bcfa9057db34c49ba3fd3055b3 Mon Sep 17 00:00:00 2001
From: "Zed A. Shaw" <zed.shaw@gmail.com>
Date: Fri, 8 May 2026 22:45:38 -0400
Subject: [PATCH] Stop rendering all the time, render to the texture only when
 changing.

---
 src/slides_ui.cpp | 12 +++++++++---
 src/slides_ui.hpp |  1 +
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/slides_ui.cpp b/src/slides_ui.cpp
index 8889f5d..3a5dbe3 100644
--- a/src/slides_ui.cpp
+++ b/src/slides_ui.cpp
@@ -215,14 +215,20 @@ void SlidesUI::show_slide() {
   auto& cell = $gui.cell_for("slide");
 
   slide.init(cell, layout);
+
+  $needs_render = true;
 }
 
 void SlidesUI::render(sf::RenderTarget& window) {
   window.clear();
-  $gui.render($view_texture);
   auto& slide = $deck->current_slide();
-  slide.render($view_texture);
-  $view_texture.display();
+
+  if($needs_render) {
+    $gui.render($view_texture);
+    slide.render($view_texture);
+    $view_texture.display();
+    $needs_render = false;
+  }
 
   if(slide.$shader) {
     slide.$shader->setUniform("u_time", $clock.getElapsedTime().asSeconds());
diff --git a/src/slides_ui.hpp b/src/slides_ui.hpp
index 80cb40e..02a1d70 100644
--- a/src/slides_ui.hpp
+++ b/src/slides_ui.hpp
@@ -50,6 +50,7 @@ struct SlidesUI {
   sf::RenderTexture $view_texture;
   sf::Sprite $view_sprite;
   sf::Clock $clock;
+  bool $needs_render = true;
 
   SlidesUI(std::shared_ptr<SlideDeck> deck, sf::Vector2u size);
   void init();