Profiler threading support, flame graph

Changed the profiler into a node based system for better data access, more overhead than the simple struct+depth info but can hold more detail and less post processing of data Profiler now also profiles threads Added some test profile tags The profiler window now also has a FlameGraph
2024-10-20 23:17:41 +02:00
parent 2c84e650d6
commit 567714a52d
4 changed files with 371 additions and 101 deletions
@@ -0,0 +1,156 @@
+using ImGuiNET;
+using System.Numerics;
+
+namespace Nerfed.Runtime;
+
+public static class ProfilerVisualizer
+{
+    private const float barHeight = 20f;
+    private const float barPadding = 2f;
+
+    // Render the flame graph across multiple threads
+    public static void RenderFlameGraph(Profiler.Frame frame)
+    {
+        if (frame == null) return;
+        if (frame.RootNodes == null) return;
+
+        // Calculate the total timeline duration (max end time across all nodes)
+        double totalDuration = frame.EndTime - frame.StartTime;
+        double startTime = frame.StartTime;
+
+        // Precompute the maximum depth for each thread's call stack
+        Dictionary<int, int> threadMaxDepths = new Dictionary<int, int>();
+        foreach (IGrouping<int, Profiler.ScopeNode> threadGroup in frame.RootNodes.GroupBy(node => node.ManagedThreadId))
+        {
+            int maxDepth = 0;
+            foreach (Profiler.ScopeNode rootNode in threadGroup)
+            {
+                maxDepth = Math.Max(maxDepth, GetMaxDepth(rootNode, 0));
+            }
+            threadMaxDepths[threadGroup.Key] = maxDepth;
+        }
+
+        // Start a child window to support scrolling
+        ImGui.BeginChild("FlameGraph", new Vector2(0, 64), ImGuiChildFlags.Border | ImGuiChildFlags.ResizeY, ImGuiWindowFlags.HorizontalScrollbar | ImGuiWindowFlags.AlwaysVerticalScrollbar);
+
+        ImDrawListPtr drawList = ImGui.GetWindowDrawList();
+        Vector2 windowPos = ImGui.GetCursorScreenPos();
+
+        // Sort nodes by ThreadID, ensuring main thread (Thread ID 1) is on top
+        IOrderedEnumerable<IGrouping<int, Profiler.ScopeNode>> threadGroups = frame.RootNodes.GroupBy(node => node.ManagedThreadId).OrderBy(g => g.Key);
+
+        // Initial Y position for drawing
+        float baseY = windowPos.Y;
+        bool alternate = false;
+        float contentWidth = ImGui.GetContentRegionAvail().X;
+
+        // Draw each thread's flame graph row by row
+        foreach (IGrouping<int, Profiler.ScopeNode> threadGroup in threadGroups)
+        {
+            int threadId = threadGroup.Key;
+
+            // Compute the base Y position for this thread
+            float threadBaseY = baseY;
+
+            // Calculate the maximum height for this thread's flame graph
+            float threadHeight = (threadMaxDepths[threadId] + 1) * (barHeight + barPadding);
+
+            // Draw the alternating background for each thread row
+            uint backgroundColor = ImGui.ColorConvertFloat4ToU32(alternate ? new Vector4(0.2f, 0.2f, 0.2f, 1f) : new Vector4(0.1f, 0.1f, 0.1f, 1f));
+            drawList.AddRectFilled(new Vector2(windowPos.X, threadBaseY), new Vector2(windowPos.X + contentWidth, threadBaseY + threadHeight), backgroundColor);
+
+            alternate = !alternate;
+
+            // Draw each root node in the group (one per thread)
+            foreach (Profiler.ScopeNode rootNode in threadGroup)
+            {
+                RenderNode(drawList, rootNode, startTime, totalDuration, windowPos.X, threadBaseY, 0, contentWidth, false);
+            }
+
+            // Move to the next thread's row (max depth * height per level)
+            baseY += (threadMaxDepths[threadId] + 1) * (barHeight + barPadding);
+        }
+
+        // Ensure that ImGui knows the size of the content.
+        ImGui.Dummy(new Vector2(contentWidth, baseY));
+
+        ImGui.EndChild();
+    }
+
+    private static void RenderNode(ImDrawListPtr drawList, Profiler.ScopeNode node, double startTime, double totalDuration, float startX, float baseY, int depth, float contentWidth, bool alternate)
+    {
+        if (node == null) return;
+
+        double nodeStartTime = node.StartTime - startTime;
+        double nodeEndTime = node.EndTime - startTime;
+        double nodeDuration = nodeEndTime - nodeStartTime;
+
+        // Calculate the position and width of the bar based on time
+        float xPos = (float)(startX + (nodeStartTime / totalDuration) * contentWidth);
+        float width = (float)((nodeDuration / totalDuration) * contentWidth);
+
+        // Calculate the Y position based on depth
+        float yPos = baseY + (depth * (barHeight + barPadding)) + (barPadding * 0.5f);
+
+        // Define the rectangle bounds for the node
+        Vector2 min = new Vector2(xPos, yPos);
+        Vector2 max = new Vector2(xPos + width, yPos + barHeight);
+
+        // Define color.
+        Vector4 barColor = alternate ? new Vector4(0.4f, 0.6f, 0.9f, 1f) : new Vector4(0.4f, 0.5f, 0.8f, 1f);
+        Vector4 textColor = new Vector4(1f, 1f, 1f, 1f);
+
+        if (depth != 0)
+        {
+            // Draw the bar for the node (colored based on thread depth)
+            drawList.AddRectFilled(min, max, ImGui.ColorConvertFloat4ToU32(barColor));
+
+            // Draw the label if it fits inside the bar
+            string label = $"{node.Label} ({node.ElapsedMilliseconds():0.000} ms)";
+            if (width > ImGui.CalcTextSize(label).X)
+            {
+                drawList.AddText(new Vector2(xPos + barPadding, yPos + barPadding), ImGui.ColorConvertFloat4ToU32(textColor), label);
+            }
+
+            // Add tooltip on hover
+            if (ImGui.IsMouseHoveringRect(min, max))
+            {
+                // Show tooltip when hovering over the node
+                ImGui.BeginTooltip();
+                ImGui.Text($"{node.Label}");
+                ImGui.Text($"{node.ElapsedMilliseconds():0.000} ms");
+                ImGui.Text($"{node.ManagedThreadId}");
+                ImGui.EndTooltip();
+            }
+        }
+        else
+        {
+            // Aka root node.
+            string label = $"{node.Label}";
+            drawList.AddText(new Vector2(startX + barPadding, yPos + barPadding), ImGui.ColorConvertFloat4ToU32(textColor), label);
+        }
+
+        // Draw each child node under this node
+        foreach (Profiler.ScopeNode child in node.Children)
+        {
+            alternate = !alternate;
+            RenderNode(drawList, child, startTime, totalDuration, startX, baseY, depth + 1, contentWidth, alternate);
+        }
+    }
+
+    // Recursive function to calculate the maximum depth of the node tree
+    private static int GetMaxDepth(Profiler.ScopeNode node, int currentDepth)
+    {
+        if (node.Children == null || node.Children.Count == 0)
+        {
+            return currentDepth;
+        }
+
+        int maxDepth = currentDepth;
+        foreach (Profiler.ScopeNode child in node.Children)
+        {
+            maxDepth = Math.Max(maxDepth, GetMaxDepth(child, currentDepth + 1));
+        }
+        return maxDepth;
+    }
+}