Adds full support for COLRv1 radial gradients based on the two-point conical gradient algorithm at https://skia.org/docs/dev/design/conical/
Also adds robustness to degenerate cases in gradient encoding:
* Radial where p0 == p1 && r0 == r1 renders transparent solid
* Empty stops render as transparent solid
* Single stop renders as solid
This patch implements the pad, repeat and reflect extend modes for gradient brushes. Adds a new example demonstrating the functionality.
Also fixes a few bugs:
* Clamps alpha in blend.wgsl for the `blend_compose` function. The `Plus` mode was generating `alpha > 1.0` leading to incorrect rendering.
* Small change to radial gradients in fine.wgsl to reject pixels outside the cone when the circles don't nest. This requires further work to properly extend the cone when one of the radii is not 0.
The examples logged the total processing time for an SVG including both
parse and GPU buffer encoding times. Times for these two operations are
now logged separately.
This change moves the vello encoding logic to a new crate under
crates/encoding. Combined with the `vello_shaders` crate, this enables
lightweight integration of the Vello pipelines into renderers that don't
depend on wgpu (or perhaps written in languages other than Rust).
The Scene/Fragment API currently remain the vello crate.
Using vector graphics for the image doesn't make a huge amount of sense. The flower photo is by Raph and happily licensed to anyone who wants to use it.
* Add comment about naughty ptr2int cast
* Change Option to anyhow::Result in test scene ImageCache
* Replace magic constant with pixel stride from selected format
The test scenes can now supply their own optional base (background)
color. In the with_winit example, we also allow the user to provide a
base color as a CLI option. The precedence is as follows:
1. Use the color from the CLI options, if any.
2. Otherwise use the scene provided base color, if any.
3. Otherwise default to black.
* make SimpleText::add_run accept glyph_transform and style parameters so it doesn't unconditionally do oblique strokes
* replace fill/stroke methods on DrawGlyphs with a single draw method that accepts either fill or stroke styles
* update peniko rev to access the new style types used above
* for now, change glyph cache to only cache non-zero fills. Prior to this, style was ignored in the key which could lead to incorrect rendering.
Added two scenes that demonstrate conflation artifacts as described in
https://github.com/linebender/vello/issues/49. The first scene
demonstrates adjacent triangles and rects that belong to the same path
and use opposite winding.
The second scene demonstrates strokes with overlapping square caps
(these strokes are currently expressed as rects painted with the NonZero
fill rule).