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omar edited this page Feb 18, 2021 · 17 revisions

If you are working on Dear ImGui codebase:

Metrics

The Metrics window exposes lots of information about the library state.

Item Picker

The Item Picker will allow you to pick an item with the mouse and have Dear ImGui break within the call-stack of that item. This is useful if you have large UI / codebase and you would to easily find out where some UI item is emitted. You can find it in Metrics>Tools>Item Picker. Also see #2673.

Item Picker

Visual debugging

You can use drawlist primitives on the foreground drawlist, e.g. GetForegroundDrawList()->AddRectFilled(...) to bypass clipping of the current window's drawlist.

Logging

You can use the IMGUI_DEBUG_LOG macro (declared in imgui_internal.h) to easily print text to the console while including the current frame counter, which is very often useful in log.

Using breakpoints

Using debugger breakpoints can be tedious in an interactive application dealing with lots of data. Even more so as the state of the application may be so reliant on mouse and keyboard inputs. One convenient trick is filter breakpoint based on custom conditions, e.g checking for the Alt key modifier to be pressed:

if (ImGui::GetIO().KeyAlt)
    printf(""); // Set a debugger breakpoint here!

So you can setup your UI state for debugging (open windows, mouse position, active action etc.) and then only when you press ALT your breakpoint will trigger.

Continuous integration

Branches pushed publicly will have build actions run on them.

Automation and regression testing system

We are using a large suite of automated tests (still unpublished, see #435), recurrent contributors can get access to it.

Using Natvis file for Visual Studio debugging

The misc/natvis/imgui.natvis file may be included in your project to provide support for dear imgui types in the debugger (e.g. expanding of ImVector<> arrays).

Using static analysis with PVS-Studio:

I am using PVS-Studio (Viva64 had kindly provided a licence to use with free software products) for static code analysis and it's been extremely helpful in reducing the amount of errors or confusing code.

run_pvs_studio.bat:

@echo off
set PVS_DIR=C:\Program Files (x86)\PVS-Studio
set WORK_DIR=C:\Work\imgui_dev\pvs_studio
set PROJ_DIR=C:\Work\imgui\examples\example_win32_directx11
set PROJ_NAME=example_win32_directx11
"%PVS_DIR%\PVS-Studio_Cmd.exe" -r -t "%PROJ_DIR%\%PROJ_NAME%.vcxproj"
mkdir "%WORK_DIR%\output"
"%PVS_DIR%\PlogConverter.exe" -a GA:1,2;OP:1 -t Html,FullHtml,Txt,Totals "%PROJ_DIR%\%PROJ_NAME%.plog" -o "%WORK_DIR%\output"
del "%PROJ_DIR%\%PROJ_NAME%.plog"
echo ---- Totals:
type "%WORK_DIR%\output\%PROJ_NAME%.plog_totals.txt"
start "" "%WORK_DIR%\output\fullhtml\index.html"
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