Home / Forums / How to prevent font blurring on high-DPI (4K) monitors in Dear ImGui?

UnreliableCode Community

Developer Research, Reverse Engineering & Coding Community

Subforums Leaderboard Log In to Post
Question

How to prevent font blurring on high-DPI (4K) monitors in Dear ImGui?

NoRecoilDev
Input & Recoil Math
MEMBER
Rep: 130
Join Date: Nov 2024
Posts: 20
Thanks: 32
6y ago · Jul 1, 2020 1:42 PM
#1
My Dear ImGui menu text looks blurry on high-resolution displays. What is the proper way to handle DPI scaling and sharp font rendering?
NoRecoilDev | Smoothing Algorithms & Input Events
The following users thanked NoRecoilDev for this post:
DirectXRay
DirectX 12 / Vulkan Dev
MEMBER
Rep: 240
Join Date: Feb 2023
Posts: 31
Thanks: 60
6y ago · Jul 1, 2020 4:23 PM
#2
When loading your font via ImGui::GetIO().Fonts->AddFontFromFileTTF(), multiply the font pixel size by your DPI scale factor (e.g. 16.0f * dpiScale). Then set ImFontConfig::OversampleH = 2 and ImFontConfig::OversampleV = 1. In your render loop, scale ImGui::GetStyle().ScaleAllSizes(dpiScale)!
DirectXRay · DirectX 12 & Vulkan Command Lists
SecurityAudit
AppSec & Code Auditor
MEMBER
Rep: 135
Join Date: Jan 2025
Posts: 28
Thanks: 29
6y ago · Jul 1, 2020 8:23 PM
#3
Never scale the rendered ImDrawList texture with GPU sampling—always rebuild the font atlas with larger native glyph point sizes!
SecurityAudit | Secure C++ Architecture & Boundary Auditing