Adding log-scale option for displaying plot data.

profiler/src/profiler/TracyPlotMapping.hpp

@@ -0,0 +1,45 @@
+#ifndef __TRACYPLOTMAPPING_HPP__
+#define __TRACYPLOTMAPPING_HPP__
+
+#include <math.h>
+#include <stdint.h>
+
+namespace tracy
+{
+
+// To add a mapping: append an enum value (before Count), then extend PlotMappingName() and MapPlotValue().
+// Mappings must be strictly monotonic increasing and defined for all finite doubles.
+enum class PlotMapping : uint8_t
+{
+    Linear,
+    SymLog,
+    Count
+};
+
+static inline const char* PlotMappingName( PlotMapping mapping )
+{
+    switch( mapping )
+    {
+    case PlotMapping::Linear: return "Linear";
+    case PlotMapping::SymLog: return "Logarithmic";
+    default: return "";
+    }
+}
+
+static inline double MapPlotValue( PlotMapping mapping, double v )
+{
+    switch( mapping )
+    {
+    case PlotMapping::SymLog:
+        // sign(v) * log10( 1 + |v| ), computed via log1p to stay accurate for tiny |v|
+        // TODO(slomp): nearly linear for sub-1 floating-point data; consider scaling by a data-derived constant
+        return copysign( log1p( fabs( v ) ) * 0.43429448190325176, v );
+    case PlotMapping::Linear:
+    default:
+        return v;
+    }
+}
+
+}
+
+#endif

profiler/src/profiler/TracyTimelineItemPlot.cpp

@@ -120,6 +120,20 @@ void TimelineItemPlot::DrawFinished()
     m_draw.clear();
 }
 
+void TimelineItemPlot::DrawExtraPopupItems()
+{
+    if( ImGui::BeginMenu( "Y-axis scale" ) )
+    {
+        auto& current = m_view.GetPlotMapping( m_plot );
+        for( uint8_t i=0; i<(uint8_t)PlotMapping::Count; i++ )
+        {
+            const auto mapping = (PlotMapping)i;
+            if( ImGui::MenuItem( PlotMappingName( mapping ), nullptr, current == mapping ) ) current = mapping;
+        }
+        ImGui::EndMenu();
+    }
+}
+
 void TimelineItemPlot::Preprocess( const TimelineContext& ctx, TaskDispatch& td, bool visible, int yPos )
 {
     assert( m_draw.empty() );

profiler/src/profiler/TracyTimelineItemPlot.hpp

@@ -27,6 +27,7 @@ protected:
     void HeaderTooltip( const char* label ) const override;
     void HeaderExtraContents( const TimelineContext& ctx, int offset, float labelWidth ) override;
     void HeaderZoomed() override;
+    void DrawExtraPopupItems() override;
 
     bool DrawContents( const TimelineContext& ctx, int& offset ) override;
     void DrawFinished() override;

profiler/src/profiler/TracyView.hpp

@@ -20,6 +20,7 @@
 #include "TracyDecayValue.hpp"
 #include "TracyManualWindow.hpp"
 #include "TracyMarkdown.hpp"
+#include "TracyPlotMapping.hpp"
 #include "TracySourceContents.hpp"
 #include "TracyTimelineController.hpp"
 #include "TracyTimelineDraw.hpp"
@@ -205,6 +206,7 @@ public:
     void HighlightThread( uint64_t thread );
     void SelectThread( uint64_t thread );
     uint64_t GetSelectThread() const { return m_selectedThread; }
+    PlotMapping& GetPlotMapping( const PlotData* plot ) { return m_plotMapping[plot]; }
     void ZoomToRange( int64_t start, int64_t end, bool pause = true );
     bool DrawPlot( const TimelineContext& ctx, PlotData& plot, const std::vector<uint32_t>& plotDraw, int& offset, bool rightEnd );
     void DrawThread( const TimelineContext& ctx, const ThreadData& thread, const std::vector<TimelineDraw>& draw, const std::vector<ContextSwitchDraw>& ctxDraw, const std::vector<SamplesDraw>& samplesDraw, const std::vector<std::unique_ptr<LockDraw>>& lockDraw, int& offset, int depth, bool hasCtxSwitches, bool hasSamples );
@@ -496,6 +498,7 @@ private:
     unordered_flat_map<uint64_t, bool> m_flameGraphThread;
     unordered_flat_map<const void*, int> m_gpuDrift;
     unordered_flat_map<const PlotData*, PlotView> m_plotView;
+    unordered_flat_map<const PlotData*, PlotMapping> m_plotMapping;
     Vector<const ThreadData*> m_threadOrder;
     Vector<const ThreadData*> m_threadReinsert;
     Vector<float> m_threadDnd;

profiler/src/profiler/TracyView_Plots.cpp

@@ -54,6 +54,10 @@ bool View::DrawPlot( const TimelineContext& ctx, PlotData& plot, const std::vect
             max = pv.max;
         }
 
+        const auto mapping = GetPlotMapping( &plot );
+        min = MapPlotValue( mapping, min );
+        max = MapPlotValue( mapping, max );
+
         const auto color = GetPlotColor( plot, m_worker );
         const auto bg = 0x22000000 | ( DarkenColorMore( color ) & 0xFFFFFF );
         const auto fill = 0x22000000 | ( DarkenColor( color ) & 0xFFFFFF );
@@ -73,7 +77,7 @@ bool View::DrawPlot( const TimelineContext& ctx, PlotData& plot, const std::vect
             const auto i0 = *it++;
             const auto& v0 = vec[i0];
             double x = ( v0.time.Val() - m_vd.zvStart ) * pxns;
-            double y = PlotHeight - ( v0.val - min ) * revrange * PlotHeight;
+            double y = PlotHeight - ( MapPlotValue( mapping, v0.val ) - min ) * revrange * PlotHeight;
 
             if( first )
             {
@@ -119,13 +123,13 @@ bool View::DrawPlot( const TimelineContext& ctx, PlotData& plot, const std::vect
                 const auto i1 = i0 + cnt - 1;
                 const auto& v1 = vec[i1];
                 px = x;
-                py = PlotHeight - ( v1.val - min ) * revrange * PlotHeight;
+                py = PlotHeight - ( MapPlotValue( mapping, v1.val ) - min ) * revrange * PlotHeight;
                 const auto imin = *it++;
                 const auto imax = *it++;
                 const auto vmin = vec[imin].val;
                 const auto vmax = vec[imax].val;
-                const auto ymin = offset + PlotHeight - ( vmin - min ) * revrange * PlotHeight;
-                const auto ymax = offset + PlotHeight - ( vmax - min ) * revrange * PlotHeight;
+                const auto ymin = offset + PlotHeight - ( MapPlotValue( mapping, vmin ) - min ) * revrange * PlotHeight;
+                const auto ymax = offset + PlotHeight - ( MapPlotValue( mapping, vmax ) - min ) * revrange * PlotHeight;
                 if( cnt < MaxShow )
                 {
                     DrawLine( draw, dpos + ImVec2( x, ymin ), dpos + ImVec2( x, ymax ), color );
@@ -134,7 +138,7 @@ bool View::DrawPlot( const TimelineContext& ctx, PlotData& plot, const std::vect
                     {
                         const auto is = i0 + i;
                         const auto& vs = vec[is];
-                        auto ys = PlotHeight - ( vs.val - min ) * revrange * PlotHeight;
+                        auto ys = PlotHeight - ( MapPlotValue( mapping, vs.val ) - min ) * revrange * PlotHeight;
                         DrawPlotPoint( wpos, x, ys, offset, color, hover, vs.val, plot.format, PlotHeight );
                     }
                 }
@@ -190,7 +194,7 @@ bool View::DrawPlot( const TimelineContext& ctx, PlotData& plot, const std::vect
                 else
                 {
                     x0 = ( plot.data.back().time.Val() - m_vd.zvStart ) * pxns;
-                    y = PlotHeight - ( plot.data.back().val - min ) * revrange * PlotHeight;
+                    y = PlotHeight - ( MapPlotValue( mapping, plot.data.back().val ) - min ) * revrange * PlotHeight;
                     DrawLine( draw, dpos + ImVec2( x0, offset + y ), dpos + ImVec2( x1, offset + y ), color );
                 }