From fa10a03a53367ae9e112ec7cb3b62f0360514455 Mon Sep 17 00:00:00 2001
From: epezent <epezent@rice.edu>
Date: Thu, 3 Dec 2020 23:27:38 -0600
Subject: [PATCH] add ImPlotStyleVar_FitPadding

---
 implot.cpp | 10 ++++++++++
 implot.h   |  2 ++
 2 files changed, 12 insertions(+)

diff --git a/implot.cpp b/implot.cpp
index fce72b3..c38bc5e 100644
--- a/implot.cpp
+++ b/implot.cpp
@@ -121,6 +121,7 @@ ImPlotStyle::ImPlotStyle() {
     LegendSpacing      = ImVec2(0,0);
     MousePosPadding    = ImVec2(10,10);
     AnnotationPadding  = ImVec2(2,2);
+    FitPadding         = ImVec2(0,0);
     PlotDefaultSize    = ImVec2(400,300);
     PlotMinSize        = ImVec2(300,225);
 
@@ -263,6 +264,7 @@ static const ImPlotStyleVarInfo GPlotStyleVarInfo[] =
 
     { ImGuiDataType_Float, 2, (ImU32)IM_OFFSETOF(ImPlotStyle, MousePosPadding)    }, // ImPlotStyleVar_MousePosPadding
     { ImGuiDataType_Float, 2, (ImU32)IM_OFFSETOF(ImPlotStyle, AnnotationPadding)  }, // ImPlotStyleVar_AnnotationPadding
+    { ImGuiDataType_Float, 2, (ImU32)IM_OFFSETOF(ImPlotStyle, FitPadding)         }, // ImPlotStyleVar_FitPadding
     { ImGuiDataType_Float, 2, (ImU32)IM_OFFSETOF(ImPlotStyle, PlotDefaultSize)    }, // ImPlotStyleVar_PlotDefaultSize
     { ImGuiDataType_Float, 2, (ImU32)IM_OFFSETOF(ImPlotStyle, PlotMinSize)        }  // ImPlotStyleVar_PlotMinSize
 };
@@ -2383,6 +2385,9 @@ void EndPlot() {
     const bool axis_equal = ImHasFlag(plot.Flags, ImPlotFlags_Equal);
     if (gp.FitThisFrame && (gp.VisibleItemCount > 0 || plot.Queried)) {
         if (gp.FitX) {
+            const double ext_size = gp.ExtentsX.Size() * 0.5;
+            gp.ExtentsX.Min -= ext_size * gp.Style.FitPadding.x;
+            gp.ExtentsX.Max += ext_size * gp.Style.FitPadding.x;
             if (!ImHasFlag(plot.XAxis.Flags, ImPlotAxisFlags_LockMin) && !ImNanOrInf(gp.ExtentsX.Min))
                 plot.XAxis.Range.Min = (gp.ExtentsX.Min);
             if (!ImHasFlag(plot.XAxis.Flags, ImPlotAxisFlags_LockMax) && !ImNanOrInf(gp.ExtentsX.Max))
@@ -2397,6 +2402,9 @@ void EndPlot() {
         }
         for (int i = 0; i < IMPLOT_Y_AXES; i++) {
             if (gp.FitY[i]) {
+                const double ext_size = gp.ExtentsY[i].Size() * 0.5;
+                gp.ExtentsY[i].Min -= ext_size * gp.Style.FitPadding.y;
+                gp.ExtentsY[i].Max += ext_size * gp.Style.FitPadding.y;
                 if (!ImHasFlag(plot.YAxis[i].Flags, ImPlotAxisFlags_LockMin) && !ImNanOrInf(gp.ExtentsY[i].Min))
                     plot.YAxis[i].Range.Min = (gp.ExtentsY[i].Min);
                 if (!ImHasFlag(plot.YAxis[i].Flags, ImPlotAxisFlags_LockMax) && !ImNanOrInf(gp.ExtentsY[i].Max))
@@ -3489,6 +3497,8 @@ void ShowStyleEditor(ImPlotStyle* ref) {
             ImGui::SliderFloat2("LegendSpacing", (float*)&style.LegendSpacing, 0.0f, 5.0f, "%.0f");
             ImGui::SliderFloat2("MousePosPadding", (float*)&style.MousePosPadding, 0.0f, 20.0f, "%.0f");
             ImGui::SliderFloat2("AnnotationPadding", (float*)&style.AnnotationPadding, 0.0f, 5.0f, "%.0f");
+            ImGui::SliderFloat2("FitPadding", (float*)&style.FitPadding, 0, 0.2f, "%.2f");
+
             ImGui::EndTabItem();
         }
         if (ImGui::BeginTabItem("Colors")) {
diff --git a/implot.h b/implot.h
index 6efd30b..9d4def6 100644
--- a/implot.h
+++ b/implot.h
@@ -155,6 +155,7 @@ enum ImPlotStyleVar_ {
     ImPlotStyleVar_LegendSpacing,      // ImVec2, spacing between legend entries
     ImPlotStyleVar_MousePosPadding,    // ImVec2, padding between plot edge and interior info text
     ImPlotStyleVar_AnnotationPadding,  // ImVec2, text padding around annotation labels
+    ImPlotStyleVar_FitPadding,         // ImVec2, additional fit padding as a percentage of the fit extents (e.g. ImVec2(0.1f,0.1f) adds 10% to the fit extents of X and Y)
     ImPlotStyleVar_PlotDefaultSize,    // ImVec2, default size used when ImVec2(0,0) is passed to BeginPlot
     ImPlotStyleVar_PlotMinSize,        // ImVec2, minimum size plot frame can be when shrunk
     ImPlotStyleVar_COUNT
@@ -276,6 +277,7 @@ struct ImPlotStyle {
     ImVec2  LegendSpacing;           // = 0,0     spacing between legend entries
     ImVec2  MousePosPadding;         // = 10,10   padding between plot edge and interior mouse location text
     ImVec2  AnnotationPadding;       // = 2,2     text padding around annotation labels
+    ImVec2  FitPadding;              // = 0,0     additional fit padding as a percentage of the fit extents (e.g. ImVec2(0.1f,0.1f) adds 10% to the fit extents of X and Y)
     ImVec2  PlotDefaultSize;         // = 400,300 default size used when ImVec2(0,0) is passed to BeginPlot
     ImVec2  PlotMinSize;             // = 300,225 minimum size plot frame can be when shrunk
     // colors