Text and the SVG button images are mixed on screen, so they now share
UIDropShadowParams (3 UI units of blur, 0.66 intensity, no offset, the
atlas's existing look) instead of the text having its own.
draw_text.cpp included <windows.h> directly, whose min/max macros broke
the std::max calls added here. Include CommonWindows.h instead.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
CompositeDropShadow in Common/Render/DropShadow.cpp blurs a premultiplied
RGBA image's alpha (with an optional offset) and composites the image
over it. The atlas's AddDropShadow and TextDrawer::AddDropShadow are now
thin wrappers that pick the parameters.
The blur scatters only the non-transparent texels, which makes atlas
shadows 3-7x faster than the old gather-with-clamping version. Atlas
output is unchanged apart from rounding (alpha differs by at most 1).
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
