When building GPU vertices from paths, we call stroke.SplitCubic once
per OpCubic. Before this change, each call to stroke.SplitCubic would
allocate a slice, which we would only use to iterate over.
This allocation can be easily avoided by reusing the slice. We can
conveniently store it in gpu.quadSplitter.
In a real application that renders hundreds of paths with tens of
rounded rectangles per path, this saved roughly 4500 allocations (or 1
MB worth) per frame.
Signed-off-by: Dominik Honnef <dominik@honnef.co>
There are no public API that uses f32.Rectangle anymore. Move Rectangle
to an internal package for internal use.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Complex strokes are not yet supported in either of the current renderers,
so they are converted to filled outlines in package gpu.
We're about to move that complexity up to the op/clip package, so we're
going to need the converter available from outside package gpu. This
change extracts the conversion code and related types to the separate,
internal package stroke.
No functional changes; a follow-up moves the stroke conversion.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
We're about to let clip.Path use more of the compute renderer features
(lines, cubic béziers). This change prepares the gpu package for reading
one of several commands types, not just the quadratic béziers of before.
The old Quad type is still the basis for the stroking algorithms, but
this change moves it into package gpu which is the only user.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
This is a first step towards supporting affine drawing transforms.
The rendering algorithm relies on quadratic curves that do not cross
x = 0 more than once, thus curves must be split after any rotation/shear
transforms. Move this logic and the generation of vertices to package gpu.
Also close all curves and draw zero-width edges as preparation for
transform since the will no longer implicitly be vertical with no
effect.
This commit will severely affect performance since vertexes are now
transformed also for cached items, using cpu resources.
Signed-off-by: Viktor <viktor.ogeman@gmail.com>