From a7cedddcef1531465a6f1a0a42395e26cdf0134b Mon Sep 17 00:00:00 2001
From: Bartosz Taudul <wolf.pld@gmail.com>
Date: Tue, 24 Mar 2020 18:10:56 +0100
Subject: [PATCH] Use clipper to render source view.

---
 server/TracySourceView.cpp | 26 ++++++++++++++++++++------
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/server/TracySourceView.cpp b/server/TracySourceView.cpp
index 9f1b8df4..90dd22c5 100644
--- a/server/TracySourceView.cpp
+++ b/server/TracySourceView.cpp
@@ -74,15 +74,29 @@ void SourceView::Render()
     ImGui::BeginChild( "##sourceView", ImVec2( 0, 0 ), true );
     if( m_font ) ImGui::PushFont( m_font );
     const auto nw = ImGui::CalcTextSize( "123,345" ).x;
-    int lineNum = 1;
-    for( auto& line : m_lines )
+    if( m_targetLine != 0 )
     {
-        if( m_targetLine == lineNum )
+        int lineNum = 1;
+        for( auto& line : m_lines )
         {
-            m_targetLine = 0;
-            ImGui::SetScrollHereY();
+            if( m_targetLine == lineNum )
+            {
+                m_targetLine = 0;
+                ImGui::SetScrollHereY();
+            }
+            RenderLine( line, lineNum++ );
+        }
+    }
+    else
+    {
+        ImGuiListClipper clipper( m_lines.size() );
+        while( clipper.Step() )
+        {
+            for( auto i=clipper.DisplayStart; i<clipper.DisplayEnd; i++ )
+            {
+                RenderLine( m_lines[i], i+1 );
+            }
         }
-        RenderLine( line, lineNum++ );
     }
     if( m_font ) ImGui::PopFont();
     ImGui::EndChild();