From 304a69b676239e6074d857c841b50435a42e51eb Mon Sep 17 00:00:00 2001
From: Lars Ivar Hatledal <larsivarhatledal@gmail.com>
Date: Sat, 16 Mar 2024 20:32:30 +0100
Subject: [PATCH] refactor task management

---
 src/CMakeLists.txt                |  1 +
 src/threepp/canvas/Canvas.cpp     | 26 ++++---------------
 src/threepp/utils/TaskManager.hpp | 43 +++++++++++++++++++++++++++++++
 3 files changed, 49 insertions(+), 21 deletions(-)
 create mode 100644 src/threepp/utils/TaskManager.hpp

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 05665a6f..e2a2ece4 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -233,6 +233,7 @@ set(privateHeaders
         "threepp/renderers/gl/UniformUtils.hpp"
 
         "threepp/utils/RegexUtil.hpp"
+        "threepp/utils/TaskManager.hpp"
 
 )
 
diff --git a/src/threepp/canvas/Canvas.cpp b/src/threepp/canvas/Canvas.cpp
index 53a9505c..3bbc7d36 100644
--- a/src/threepp/canvas/Canvas.cpp
+++ b/src/threepp/canvas/Canvas.cpp
@@ -4,6 +4,7 @@
 #include "threepp/favicon.hpp"
 #include "threepp/loaders/ImageLoader.hpp"
 #include "threepp/utils/StringUtils.hpp"
+#include "threepp/utils/TaskManager.hpp"
 
 #ifndef EMSCRIPTEN
 #include "threepp/utils/LoadGlad.hpp"
@@ -22,12 +23,6 @@ using namespace threepp;
 
 namespace {
 
-    typedef std::pair<std::function<void()>, float> Task;
-
-    struct CustomComparator {
-        bool operator()(const Task& l, const Task& r) const { return l.second > r.second; }
-    };
-
 #if EMSCRIPTEN
     struct FunctionWrapper {
         std::function<void()> loopFunction;
@@ -173,7 +168,8 @@ struct Canvas::Impl {
     bool close_{false};
     bool exitOnKeyEscape_;
 
-    std::priority_queue<Task, std::vector<Task>, CustomComparator> tasks_;
+    utils::TaskManager taskManager;
+
     std::optional<std::function<void(WindowSize)>> resizeListener;
 
     explicit Impl(Canvas& scope, const Canvas::Parameters& params)
@@ -248,25 +244,13 @@ struct Canvas::Impl {
         glfwSetWindowSize(window, size.width, size.height);
     }
 
-    inline void handleTasks() {
-        while (!tasks_.empty()) {
-            auto& task = tasks_.top();
-            if (task.second < glfwGetTime()) {
-                task.first();
-                tasks_.pop();
-            } else {
-                break;
-            }
-        }
-    }
-
     bool animateOnce(const std::function<void()>& f) {
 
         if (close_ || glfwWindowShouldClose(window)) {
             return false;
         }
 
-        handleTasks();
+        taskManager.handleTasks(static_cast<float>(glfwGetTime()));
 
         f();
 
@@ -290,7 +274,7 @@ struct Canvas::Impl {
     }
 
     void invokeLater(const std::function<void()>& f, float t) {
-        tasks_.emplace(f, static_cast<float>(glfwGetTime()) + t);
+        taskManager.invokeLater(f, static_cast<float>(glfwGetTime()) + t);
     }
 
     void close() {
diff --git a/src/threepp/utils/TaskManager.hpp b/src/threepp/utils/TaskManager.hpp
new file mode 100644
index 00000000..6dbdf595
--- /dev/null
+++ b/src/threepp/utils/TaskManager.hpp
@@ -0,0 +1,43 @@
+
+#ifndef THREEPP_TASKMANAGER_HPP
+#define THREEPP_TASKMANAGER_HPP
+
+#include <functional>
+#include <queue>
+#include <utility>
+
+namespace threepp::utils {
+
+    using Task = std::pair<std::function<void()>, float>;
+
+    class TaskManager {
+
+    public:
+        inline void handleTasks(float currentTime) {
+            while (!tasks_.empty()) {
+                auto& task = tasks_.top();
+                if (task.second < currentTime) {
+                    task.first();
+                    tasks_.pop();
+                } else {
+                    break;
+                }
+            }
+        }
+
+        void invokeLater(const std::function<void()>& f, float tNow, float tPassed = 0) {
+
+            tasks_.emplace(f, tNow + tPassed);
+        }
+
+    private:
+        struct CustomComparator {
+            bool operator()(const Task& l, const Task& r) const { return l.second > r.second; }
+        };
+
+        std::priority_queue<Task, std::vector<Task>, CustomComparator> tasks_;
+    };
+
+}// namespace threepp::utils
+
+#endif//THREEPP_TASKMANAGER_HPP