The acrylic effect blits its backdrop from the default framebuffer using
the logical viewport size as the source rectangle. On a HiDPI display
the framebuffer is larger than the logical size, so the blur sampled
only the lower-left corner of the screen and the glass showed the wrong
region stretched across each panel.
- The capture blit source now uses the real framebuffer pixel size
(logical size times ImGui's DisplayFramebufferScale, truncated the
same way the GL backend does), while the capture and blur targets stay
at logical size. The framebuffer size is tracked separately from the
viewport size so quality or buffer-lifetime resets cannot lose it, and
moving the window between a Retina and a non-Retina display redoes the
capture. DX11 is unaffected; its scale is one.
- The debug screenshot sweep captures at framebuffer size too, so HiDPI
captures are no longer cropped.
Tests: the framebuffer-extent helper matches the GL backend's
truncation and falls back to the logical size when the scale is unknown.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>