From 570ab663b7f5b974438a7d6f5fbeb07b91339043 Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Mon, 30 Mar 2020 14:57:14 +0400
Subject: [PATCH] Use cache for remembered last dice frames.

---
 .../history/view/media/history_view_sticker.cpp    | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/Telegram/SourceFiles/history/view/media/history_view_sticker.cpp b/Telegram/SourceFiles/history/view/media/history_view_sticker.cpp
index 434359764..800de02f7 100644
--- a/Telegram/SourceFiles/history/view/media/history_view_sticker.cpp
+++ b/Telegram/SourceFiles/history/view/media/history_view_sticker.cpp
@@ -31,12 +31,22 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 namespace HistoryView {
 namespace {
 
-double GetEmojiStickerZoom(not_null<Main::Session*> session) {
+[[nodiscard]] double GetEmojiStickerZoom(not_null<Main::Session*> session) {
 	return session->account().appConfig().get<double>(
 		"emojies_animated_zoom",
 		0.625);
 }
 
+[[nodiscard]] QImage CacheDiceImage(int index, const QImage &image) {
+	static auto Cache = base::flat_map<int, QImage>();
+	const auto i = Cache.find(index);
+	if (i != end(Cache) && i->second.size() == image.size()) {
+		return i->second;
+	}
+	Cache[index] = image;
+	return image;
+}
+
 } // namespace
 
 Sticker::Sticker(
@@ -116,7 +126,7 @@ void Sticker::paintLottie(Painter &p, const QRect &r, bool selected) {
 		: Lottie::Animation::FrameInfo();
 	if (_nextLastDiceFrame) {
 		_nextLastDiceFrame = false;
-		_lastDiceFrame = frame.image;
+		_lastDiceFrame = CacheDiceImage(_diceIndex, frame.image);
 	}
 	const auto &image = _lastDiceFrame.isNull()
 		? frame.image