Both Path.Arc and the internal stroke package needs to support arcs;
this change isolates the approximation computation into a function we
can move to internal/stroke in a follow-up.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The fill mode is now controlled by a SetFillMode command, not by flags
on each path segment and fill command.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Border can be expressed in-terms of clip.Stroke:
clip.Stroke{
Path: clip.UniformRRect(r, rr).Ops(ops),
Style: clip.StrokeStyle{Width: width},
}.Add(ops)
Signed-off-by: Egon Elbre <egonelbre@gmail.com>
Floating point error may accumulate and the round rect may not
necessarily close up entirely. Add an additional "Close" to ensure
it's properly closed.
Signed-off-by: Egon Elbre <egonelbre@gmail.com>
There's an argument that rounded caps and joins are the simplest stroke,
in that it can be defined to cover all pixels within lineWidth distance
from the supporting path.
However, the more important reason is that the compute renderer natively
supports this stroke style (without dashes), and users that don't care
(much) about the particular stroke style should get the efficient
implementation. A good example is op/clip.Border that strokes a closed
path, where the StrokeCap is irrelevant.
This is a (subtle) API change. If you have code that relies on the
default values of clip.StrokeStyle you may want to set Cap and Join
explicitly. See the test changes for examples. On the other hand, you
will get much better performance from the default Cap and Join values
once the compute renderer becomes the default.
Disablethe TestPaintClippedBorder test; dashes round-capped,
round-joined strokes doesn't seem to work correctly.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Since clip.Path now encodes paths in the format expected by
elements.comp, use that data directly instead of a roundtrip through
drawOps.buildVerts.
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>
The check for path segments in gpu is redundant; clip.Op.Add doesn't add
the Path op if there were no segments.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Outline represents a clipping operations that clips all drawing outside
a closed path. Before this change, paths not closed we're patched up by
adding an implicit line from the endpoint to the beginning.
These fixups are inefficient for a rare case, but acceptable because the
old renderer post-processes all paths anyway. However, the new compute
renderer don't need post-processing in most cases, making fixups too
expensive.
Given that clipping to an open path is fundamentally undefined and that
implicit fixup with a closing line segment is merely a way to force the
clip to be well-defined, this change adds a panic to Outline for Paths
that are not closed.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
It turns out restoring all operation state from the moment Defer
is executed is too much; for example, a right-click pop-up needs
the transformation, but not the current clip.
Change Defer to only restore the transformation, and reset all
other state.
Other combinations may be needed in future; we'll deal with them then,
possibly by exposing the load state mask.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The semantics were relaxed in a previous commit; this change renames
to operations accordingly.
API change. Use gofmt to adjust your code accordingly:
gofmt -r 'op.Push(a).Pop() -> op.Save(a).Load()'
gofmt -r 'op.Push(a) -> op.Save(a)'
gofmt -r 'v.Pop() -> v.Load()'
gofmt -r 'op.StackOp -> op.StateOp'
Signed-off-by: Elias Naur <mail@eliasnaur.com>
A previous change implemented save/restore semantics where a saved
state can be restored anywhere, not just in a stack-like manner.
This change similarly relaxes the exported Push/Pop operations; the next
change will rename them accordingly.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Push/Pop only allows saving and restoring operation state in a
stack-like manner. We're going to need restoring arbitrary state
for implementing deferred operations.
Generalize state save/restore and implement Push and Pop on top of
that.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
This CL introduces 2 new path builders:
- Outline which takes a PathSpec to be outlined
- Stroke which takes a PathSpec and a stroke style, to stroke a path.
typically, code like this:
var p clip.Path
...
p.Outline().Add(o)
should be replaced with:
var p clip.Path
...
clip.Outline{Path: p.End()}.Op().Add(o)
similarly, stroking should be modified from:
var p clip.Path
...
p.Stroke(width, clip.StrokeStyle{...}).Add(o)
to:
var p clip.Path
...
clip.Stroke{Path: p.End(), Style: clip.StrokeStyle{Width:...}}.Op().Add(o)
here are tentative 'rf' scripts (see rsc.io/rf for more details):
```
ex {
import "gioui.org/op";
import "gioui.org/op/clip";
var p clip.Path;
var o *op.Ops;
p.Outline().Add(o) -> clip.Outline{Path:p.End()}.Op().Add(o);
}
ex {
import "gioui.org/op";
import "gioui.org/op/clip";
var o *op.Ops;
var p clip.Path;
var sty clip.StrokeStyle;
var width float32;
p.Stroke(width, sty).Add(o) -> \
clip.Stroke{ \
Path:p.End(), \
Style: clip.StrokeStyle{ \
Width: width, \
}}.Op().Add(o);
}
```
Signed-off-by: Sebastien Binet <s@sbinet.org>
Currently this comes up with RRect/Border that has zero corners. It
improves them from ~250ns to ~170ns. While it's possible to check this
in RRect implementation, however it'll slow down calls with non-zero
corners.
Signed-off-by: Egon Elbre <egonelbre@gmail.com>
...interface{} requires constructing a slice, which is slow.
This cuts about 100ns from RRect and Border benchmark.
Signed-off-by: Egon Elbre <egonelbre@gmail.com>
Using delta position with Line and Quad can drift over successive calls.
Also, in some cases it's much more convenient to use absolute
coordinates rather than relative.
Signed-off-by: Egon Elbre <egonelbre@gmail.com>
color.RGBA has two problems with regards to using it.
First the color values need to be premultiplied, whereas most APIs
have non-premultiplied values. This is mainly to preserve color components
with low alpha values.
Second there are two ways to premultiply with sRGB. One is to premultiply
after sRGB conversion, the other is before. This makes using the API more
confusing.
Using color.NRGBA in sRGB makes it align with CSS.e
Signed-off-by: Egon Elbre <egonelbre@gmail.com>
Flat and Square caps are implemented.
Bevel joins are implemented.
Round caps, Round joins and Miter joins are left for another PR.
Signed-off-by: Sebastien Binet <s@sbinet.org>
PaintOp.Rect is the wrong abstraction; it implies a clip operation
better handled by package clip, and not all paints need it (colors).
Furthermore, it's awkward to specify a PaintOp that fills up the
current clip area, regardless of its size.
Redefine PathOp to mean "fill current clip area".
API change. Replace uses of PaintOp.Rect with a TransformOp applied
before the PaintOp.
Leave a TODO for the PathOp infinity area.
Fixes gio#167
Signed-off-by: Elias Naur <mail@eliasnaur.com>
We're about to remove PaintOp.Rect. Replacing PaintOps with Fill or
FillShape where possible will ease the transition.
Using Fill in tests exposed a problem with the infinity in paint.Fill.
Adjust it for now; it will be removed later.
Updates gio#167
Signed-off-by: Elias Naur <mail@eliasnaur.com>
This is effectively a revert of commit gioui.org/commit/69dfd2e3a5541.
ImageOp.Rect is the wrong abstraction; it implies a clipping operation that is
better handled by package clip.
API change. Uses of ImageOp.Rect should apply a clip.Rect before the PaintOp,
or use image.RGBA.SubImage (or similar).
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Elias Naur