From 114be0e62b549383b0764972a0c975f38a582bb5 Mon Sep 17 00:00:00 2001
From: Matt <m.moninger.h@gmail.com>
Date: Thu, 31 Dec 2020 20:36:17 +0200
Subject: [PATCH] Avoid unnecessary calculations when the passed DPI is the
 active DPI

---
 .../drawing/engines/opengl/OpenGLDrawingEngine.cpp          | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/openrct2-ui/drawing/engines/opengl/OpenGLDrawingEngine.cpp b/src/openrct2-ui/drawing/engines/opengl/OpenGLDrawingEngine.cpp
index c917a90e5b..ffb3905adb 100644
--- a/src/openrct2-ui/drawing/engines/opengl/OpenGLDrawingEngine.cpp
+++ b/src/openrct2-ui/drawing/engines/opengl/OpenGLDrawingEngine.cpp
@@ -1010,6 +1010,12 @@ void OpenGLDrawingContext::HandleTransparency()
 
 void OpenGLDrawingContext::SetDPI(rct_drawpixelinfo* dpi)
 {
+    if (dpi == _dpi)
+    {
+        // Don't need to recalculate anything if identical.
+        return;
+    }
+
     auto screenDPI = _engine->GetDPI();
     auto bytesPerRow = screenDPI->GetBytesPerRow();
     auto bitsOffset = static_cast<size_t>(dpi->bits - screenDPI->bits);