[Cyberistic]

Plan is to have GPUIx expose MotionStyle scale/translate.
Adds ElementTransform to GPUI: Style::transform with translate, scale.

div()
    .transform(
        ElementTransform::default()
            .origin(point(0.5, 0.5))
            .translate(point(px(pan_x), px(pan_y)))
            .scale(size(zoom, zoom)),
    )

ported from zed-industries/zed#53306
as a feature-request discussion in April, implemented it on
feature/53306-07-text-raster-subpixel-regressions

slop below:

Layout is untouched — Taffy still lays out in base coordinates, and the matrix
is applied after layout, so children do not multiply their own positions or font
sizes. This is what makes a camera pan/zoom a single property on a container
instead of arithmetic on every node.
]

This commit is that branch, re-resolved against this fork's newer GPUI (the
branch is based on 2026-05-20; gpuix is 2565b8a → f77e5cf). Conflict
resolution was mechanical: import unions, ViewElement's cache key replacing
the branch's AnyViewState, GPUix's element.take() in deferred prepaint,
paint_quad's transparent-border strip split, Hitbox.identity, and
Shadow.element_bounds now transformed alongside bounds. The author field is
his; the merge and the formatting are mine.

crates/gpui is Apache-2.0, so carrying it in this fork is a licence-compatible
use; the fork already publishes gpui and this adds no dependency.

• No rotation. The public API omits it; quads and shadows only have bounds
  transformed, so a rotation would paint an axis-aligned box under rotated text.
• Scale transforms bounds, not decoration geometry — fixed in 951ff5f: a
  quad, shadow and underline now scale their corner radii, border widths and
  blur with the element. A rotated or anisotropic matrix still leaves the
  decorations alone, because a rounded corner cannot become an ellipse.
• Only div (and text, which builds a div) honour it today.
• Anchored layers position in layout space, so do not nest an overlay inside a
  transformed subtree.
• Fractional scale drops text to grayscale AA at the endpoint (subpixel is only
  used for unit or integer scales); raster scale is clamped at 4×.

[Copilot]

🟡 Changes recommended

Transformed controls retain incorrect accessibility and click bounds that can activate the wrong control, while rendering, text hit-testing, and deferred clipping also handle transforms inconsistently.

6 open issues

• Accessibility bounds ignore element and ancestor transforms · New
• Deferred masks apply the transform twice · New
• Inset shadows ignore the active transform · New
• Glyph origins are quantized at the wrong scale · New
• GPU surfaces ignore the active transform · New
• InteractiveText hit testing ignores layout transforms · New

What changed in this PR

Adds post-layout pan and zoom to GPUI through ElementTransform, providing a foundation for GPUIx scale and translation styling without changing child layout coordinates.

Changes:

• Adds transform styling and applies it throughout div subtree rendering, clipping and hit testing.
• Makes view caching and text rendering transform-aware, including zoom-dependent glyph rasterization.
• Adds regression tests and documents coordinate conversion for custom elements.

File	Description
crates/​gpui/​src/​window.rs	Tracks transforms across drawing, clipping, hitboxes and deferred rendering; adjusts glyph rasterization.
crates/​gpui/​src/​view.rs	Includes transforms in view cache keys.
crates/​gpui/​src/​text_system/​line.rs	Uses transformed glyph bounds for clipping checks.
crates/​gpui/​src/​styled.rs	Adds the fluent .transform() styling method.
crates/​gpui/​src/​style.rs	Defines ElementTransform and resolves scale, translation and origin.
crates/​gpui/​src/​scene.rs	Transforms primitives and adds matrix inversion and bounds helpers.
crates/​gpui/​src/​elements/​div.rs	Applies style transforms during subtree prepaint and paint.
crates/​gpui/​README.md	Documents pan and zoom, coordinate conversion and limitations.

_{Review effort: Balanced}