LibWeb: Draw dashed and dotted lines in Skia painter

Use the `SkDashPathEffect` path effect, to implement dashed and dotted
line styles.
This commit is contained in:
BenJilks 2024-07-12 13:52:21 +01:00 committed by Alexander Kalenik
parent 24bed027b2
commit a8c1bb0461
Notes: sideshowbarker 2024-07-17 11:30:05 +09:00

View file

@ -13,8 +13,10 @@
#include <core/SkMaskFilter.h>
#include <core/SkPath.h>
#include <core/SkPathBuilder.h>
#include <core/SkPathEffect.h>
#include <core/SkRRect.h>
#include <core/SkSurface.h>
#include <effects/SkDashPathEffect.h>
#include <effects/SkGradientShader.h>
#include <effects/SkImageFilters.h>
#include <gpu/GrDirectContext.h>
@ -923,9 +925,44 @@ CommandResult DisplayListPlayerSkia::draw_line(DrawLine const& command)
auto from = to_skia_point(command.from);
auto to = to_skia_point(command.to);
auto& canvas = surface().canvas();
SkPaint paint;
paint.setStrokeWidth(command.thickness);
paint.setColor(to_skia_color(command.color));
switch (command.style) {
case Gfx::LineStyle::Solid:
break;
case Gfx::LineStyle::Dotted: {
auto length = command.to.distance_from(command.from);
auto dot_count = floor(length / (static_cast<float>(command.thickness) * 2));
auto interval = length / dot_count;
SkScalar intervals[] = { 0, interval };
paint.setPathEffect(SkDashPathEffect::Make(intervals, 2, 0));
paint.setStrokeCap(SkPaint::Cap::kRound_Cap);
// NOTE: As Skia doesn't render a dot exactly at the end of a line, we need
// to extend it by less then an interval.
auto direction = to - from;
direction.normalize();
to += direction * (interval / 2.0f);
break;
}
case Gfx::LineStyle::Dashed: {
auto length = command.to.distance_from(command.from) + command.thickness;
auto dash_count = floor(length / static_cast<float>(command.thickness) / 4) * 2 + 1;
auto interval = length / dash_count;
SkScalar intervals[] = { interval, interval };
paint.setPathEffect(SkDashPathEffect::Make(intervals, 2, 0));
auto direction = to - from;
direction.normalize();
from -= direction * (command.thickness / 2.0f);
to += direction * (command.thickness / 2.0f);
break;
}
}
canvas.drawLine(from, to, paint);
return CommandResult::Continue;
}