ImPlot

ImPlot is an immediate mode plotting widget for Dear ImGui. It aims to provide a first-class API that will make ImGui users feel right at home.

Features

mutliple plot types: line, scatter, virtical/horizontal bars, stem, error bars
mix/match multiple plot items on a single plot
zooming, panning, and box selection controls
several plot styling options: 10 marker types, adjustable marker sizes, line weights, outline colors, fill colors, etc.
optional plot titles, axis labels, and grid labels
optional legend with toggle buttons to show/hide items
reversible and lockable axes
logarithmic axis scaling
size-aware grid with smart labels that are always power-of-ten multiples of 1, 2, and 5
default styling based on current ImGui theme, but most elements can be customized independently
mouse cursor location display and optional crosshairs cursor
customizable data getters and data striding (just like ImGui:PlotLines)
relatively good performance for high density plots

Controls

scroll wheel zoom (both axes if plot area hovered, individual axes if axis labels hovered)
panning/dragging (both axes if plot area dragged, individual axes if axis labels dragged)
auto fit data (double-left-click plot area)
selection box (right-drag in plot area)
context menu (double-right-click plot area)

Usage

The API is used just like any other ImGui Begin/End function. First, start a plotting context with BeginPlot(). Next, plot as many items as you want with the provided API functions (e.g. Plot(), PlotBar(), PlotErrorBars(), etc). Finally, wrap things up with a call to EndPlot(). That's it!

if (ImGui::BeginPlot("My Plot") {
    ImGui::Plot("My Line Plot", xs ys, 1000);
    ImGui::PlotBar("My Bar Plot", values, 20);
    ...
    ImGui::EndPlot();
}

Consult implot_demo.cpp for a full run down of features.

Special Notes

By default, no anti-aliasing is done on line plots for performance reasons. My apps use 4X MSAA, so I didn't see any reason to waste cycles on software AA. However, you can enable AA with the ImPlotFlags_AntiAliased flag.
If you plan to render several thousands lines or points, then you should consider enabling 32-bit indices by uncommenting #define ImDrawIdx unsigned int in your imconfig.h file, OR handling the ImGuiBackendFlags_RendererHasVtxOffset flag in your renderer (the official OpenGL3 renderer supports this). If you fail to do this, then you may at some point hit the maximum number of indices that can be rendered.

Known Issues (Fix Me!)

Mouse scroll zooming on a plot that is in scrollable ImGui region will both zoom and scroll the window since there is no built in scroll capture for ImGui. The current workaround is to CTRL+Scroll the plot (this disables window scrolling).
Zooming to a range beyond the limits of FLT_MAX and FLT_MIN causes axes labels to disappear.

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