ladybird/Userland/Libraries/LibGfx/PathClipper.cpp
MacDue 6c26ff567e LibGfx+LibWeb: Move HTML::CanvasPathClipper to Gfx::PathClipper
This does not depend on anything outside of LibGfx, and seems like it
may be useful elsewhere.

No behaviour change.
2024-03-17 09:30:53 +01:00

47 lines
1.7 KiB
C++

/*
* Copyright (c) 2023, MacDue <macdue@dueutil.tech>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibGfx/AntiAliasingPainter.h>
#include <LibGfx/PathClipper.h>
namespace Gfx {
// FIXME: This pretty naive, we should be able to cut down the allocations here
// (especially for the paint style which is a bit sad).
ErrorOr<PathClipper> PathClipper::create(Painter& painter, ClipPath const& clip_path)
{
auto bounding_box = enclosing_int_rect(clip_path.path.bounding_box());
IntRect actual_save_rect {};
auto maybe_bitmap = painter.get_region_bitmap(bounding_box, BitmapFormat::BGRA8888, actual_save_rect);
RefPtr<Bitmap> saved_clip_region;
if (!maybe_bitmap.is_error()) {
saved_clip_region = maybe_bitmap.release_value();
} else if (actual_save_rect.is_empty()) {
// This is okay, no need to report an error.
} else {
return maybe_bitmap.release_error();
}
painter.save();
painter.add_clip_rect(bounding_box);
return PathClipper(move(saved_clip_region), bounding_box, clip_path);
}
ErrorOr<void> PathClipper::apply_clip(Painter& painter)
{
painter.restore();
if (!m_saved_clip_region)
return {};
IntRect actual_save_rect {};
auto clip_area = TRY(painter.get_region_bitmap(m_bounding_box, BitmapFormat::BGRA8888, actual_save_rect));
painter.blit(actual_save_rect.location(), *m_saved_clip_region, m_saved_clip_region->rect(), 1.0f, false);
AntiAliasingPainter aa_painter { painter };
auto fill_offset = m_bounding_box.location() - actual_save_rect.location();
aa_painter.fill_path(m_clip_path.path, TRY(BitmapPaintStyle::create(clip_area, fill_offset)), 1.0f, m_clip_path.winding_rule);
return {};
}
}