Fix flickering

The fix should lower GPU pressure too.
alexzk1 · Jul 21, 2024 · ed271ab · ed271ab
1 parent 44016f8
commit ed271ab
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Showing 2 changed files with 83 additions and 6 deletions.
diff --git a/cpp/drawables.h b/cpp/drawables.h
@@ -7,6 +7,7 @@
 #include <string>
 #include <optional>
 #include <map>
+#include <tuple>
 
 #include "json.hpp"
 
@@ -52,6 +53,8 @@ namespace draw_task
         std::string command;
 
         drawmode_t  drawmode{drawmode_t::idk};
+        //Anti-flickering field,
+        bool already_rendered{false};
 
         // common
         int x{0};
@@ -64,6 +67,15 @@ namespace draw_task
             std::string text;
             std::string size;
             std::optional<int> fontSize{std::nullopt};
+            bool operator==(const drawtext_t& other) const
+            {
+                static const auto tie = [](const drawtext_t& val)
+                {
+                    return std::tie(val.text, val.size, val.fontSize);
+                };
+
+                return tie(*this) == tie(other);
+            }
         } text;
 
         struct drawshape_t
@@ -74,8 +86,27 @@ namespace draw_task
             int w{0};
             int h{0};
             json vect;
+
+            bool operator==(const drawshape_t& other) const
+            {
+                static const auto tie = [](const drawshape_t& val)
+                {
+                    return std::tie(val.shape, val.fill, val.w, val.h, val.vect);
+                };
+
+                return tie(*this) == tie(other);
+            }
         } shape;
 
+        bool IsEqualStoredData(const drawitem_t& other) const
+        {
+            static const auto tie = [](const drawitem_t& item)
+            {
+                return std::tie(item.id, item.drawmode, item.color, item.text, item.shape);
+            };
+            return tie(*this) == tie(other);
+        }
+
         bool isExpired() const
         {
             return ttl.isExpired();
@@ -85,6 +116,11 @@ namespace draw_task
         {
             return !command.empty();
         }
+
+        void SetAlreadyRendered()
+        {
+            already_rendered = true;
+        }
     };
 
     using draw_items_t = std::map<std::string, drawitem_t>;

diff --git a/cpp/main.cpp b/cpp/main.cpp
@@ -6,6 +6,11 @@
 #include <csignal>
 #include <mutex>
 #include <map>
+#include <memory>
+#include <thread>
+#include <functional>
+#include <string>
+#include <stdexcept>
 
 #include "socket.hh"
 #include "json_message.hh"
@@ -125,7 +130,24 @@ int main(int argc, char* argv[])
                         if ((!(*should_close_ptr)))
                         {
                             incoming_draws.merge(allDraws);
-                            allDraws.clear();
+
+                            //Anti-flickering support.
+                            if (!allDraws.empty())
+                            {
+                                for (const auto& old : allDraws)
+                                {
+                                    const auto it = incoming_draws.find(old.first);
+                                    if (it != incoming_draws.end())
+                                    {
+                                        if (it->second.IsEqualStoredData(old.second))
+                                        {
+                                            it->second.SetAlreadyRendered();
+                                        }
+                                    }
+                                }
+                                allDraws.clear();
+                            }
+
                             std::swap(allDraws, incoming_draws);
                         }
                     }
@@ -173,6 +195,7 @@ int main(int argc, char* argv[])
             },
         };
 
+        bool window_was_hidden = false;
         while (serverThread)
         {
             std::this_thread::sleep_for(100ms);
@@ -182,10 +205,9 @@ int main(int argc, char* argv[])
                 targetAppActive = programName.empty()
                                   || utility::strcontains(drawer.getFocusedWindowBinaryPath(), programName);
             }
-
-            drawer.cleanFrame();
             {
                 std::lock_guard grd(*mut);
+                bool skip_render = true;
                 for(auto iter = allDraws.begin(); iter != allDraws.end(); )
                 {
                     const bool isCommand = iter->second.isCommand();
@@ -197,13 +219,17 @@ int main(int argc, char* argv[])
                         {
                             if (cmd_iter->second())
                             {
+                                skip_render = false;
                                 break;
                             }
                         }
                     }
 
+                    skip_render = skip_render && iter->second.already_rendered;
+
                     if (isCommand || iter->second.isExpired())
                     {
+                        skip_render = false;
                         iter = allDraws.erase(iter);
                     }
                     else
@@ -214,13 +240,28 @@ int main(int argc, char* argv[])
 
                 if (targetAppActive && !commandHideLayer)
                 {
-                    for (const auto& drawitem : allDraws)
+                    if (!skip_render || window_was_hidden)
+                    {
+                        drawer.cleanFrame();
+                        for (auto& drawitem : allDraws)
+                        {
+                            drawer.draw(drawitem.second);
+                            drawitem.second.SetAlreadyRendered();
+                        }
+                        drawer.flushFrame();
+                    }
+                    window_was_hidden = false;
+                }
+                else
+                {
+                    if (!window_was_hidden)
                     {
-                        drawer.draw(drawitem.second);
+                        drawer.cleanFrame();
+                        drawer.flushFrame();
                     }
+                    window_was_hidden = true;
                 }
             }
-            drawer.flushFrame();
         }
     }
     catch(...)