Display performance

Settings > Display > Vertical sync (VSync) controls whether q0editor waits for display refresh when presenting frames. The preference is saved independently of the project and takes effect after restarting q0editor. Existing installations keep synchronization enabled by default.

Use the switch to investigate uneven frame presentation when rendering is fast. The performance snapshot records the active window's mode as presentation_vsync=on/off, even if a different preference is pending restart. Closing the editor and launching q0editor --no-vsync also disables synchronization for that launch only, without changing preferences. A second launch while the editor is already open does not change the existing window's presentation mode.

F4 copies a snapshot with several distinct measurements:

• frame.total: editor update time.
• frame.backend-cpu: the same frame's editor update, tessellation, texture uploads and GL submission. Display-refresh waiting and context switching are excluded by eframe's timer.
• frame.interval-including-idle: wall-clock time between updates, including intentional idle waits.
• frame.active-interval: intervals following an immediate repaint request while the window is focused and visible. These can reveal display/event-loop waits, but do not isolate a particular driver or scheduling cause.

The latest 32 update/backend peaks at least 33ms or active intervals at least 50ms remain in the report beyond the rolling 180-frame window. Their age and repaint causes are included. First-frame initialization costs should be evaluated separately from later pauses.