Image transforms
Rotate, scale, reflect, shear and translate images and SVG about their centre, as paint.
Image components support center-origin affine paint transforms, including rotation, nonuniform scaling, reflection, shear and translation:
image("Logo", source)
.size(160., 100.)
.with_transformation(Affine::rotation(0.5))For changing transforms, use image_signal and return
Arc::new(source.transformed(matrix)). The new value shares the original pixel
allocation and image identity. GPU uploads are reused, layout stays cached,
and damage includes both the previous and new painted bounds. a.then(b)
applies a first. Positive rotation is clockwise in screen coordinates.
Transforms do not change layout allocation. Fill/contain/scale-down transformed
images can paint outside that allocation; ancestor overflow_hidden still
clips them. Cover/none fitting retains its viewport crop. Hit testing uses the
inverse transform. Singular transforms paint nothing and receive no image hit;
nonfinite matrices supplied to ImageData::transformed normalize to identity.
This API applies to image/SVG views. Any view, container subtrees included, takes .scale, .rotate and .skew styles instead (see styling), composited as a cached layer. SVG is
decoded once with zgx_gpu::assets::decode_svg; the
runnable example changes its
transform without redecoding. Resolution remains the decoded resolution.
Regression coverage in affine_images tests covers rotations, reflection,
shear, singular matrices, clipped/overflowing and isolated content, and compares
incremental frames with fresh full frames in GPU and software renderers.
For SVG without application-owned raster management, use svg(label, source)
or svg_signal, with Arc<SvgData> source bytes. These default to a 24-pixel
square and accept ordinary .size styling, .svg_tint(color), and
.with_transformation(matrix). The renderer rasterizes at the allocated display
resolution and caches up to 32 MiB of SVG pixels. Size/tint changes rebuild that
image; affine-only changes reuse the upload. External resources and SVG text
remain restricted as described by the asset decoder. Invalid XML surfaces as a
render error. svg_rasterizations and svg_raster_bytes expose cache activity.